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Cooperi State Research Service Agriculture Handbook No. 616 UNIVERSITY OF ILLINOIS aORICULTURe LIBRARIfi >pruce Budworms iandbook Spruce Budworm Parasites in Maine: A Reference Manual for Collection and Identification of Common Species ftSRICmiURE lib/,',,,. , APR J 2 1989 ‘""•“Hf.'ilTV "*■ " 1 ' In 1977, the United States Department of Agriculture and the Canada Department of the Environment agreed to cooperate in an expanded and accelerated research and development effort, the Canada/United States Spruce Budworms Program (C ANUS A), aimed at the spruce budworm in the East and the western spruce budworm in the West. The objective of CANUSA was to design and evaluate strategies for controlling the spruce budworms and managing budworm-susceptible forests, to help forest managers attain their objectives in an economically and environmentally acceptable manner. The work reported in this publication was wholly or partially funded by the Program. This manual is one in a series on the spruce budworm. canu/a Canada United States Spruce Budworms Program n Contents lif,PlCUl-TURt Introduction. 5 Methods for Sampling and Collecting Parasites. 6 When To Sample . 6 Design of Sampling Methods. 6 Collecting Techniques . 7 Handling of Collected Insects . 7 Dissection Techniques for Spruce Budworm Larvae . 8 Rearing Spruce Budworm Parasites. 8 Key to the Adult Stages of Common Parasites of the Spruce Budworm in Maine . 10 Key to Puparia of Common Dipteran Parasites of the Spruce Budworm in Maine . 15 Damage to Spruce Budworm Pupal Cases Caused by Emergence of Some Common Parasite Groups . 17 Morphological Comparisons Between Three Hymenopterous Larvae Found in Association with Early-Instar Spruce Budworm in Maine . 18 Notes on Abundance, Biology, and Comparison of Spruce Budworm Parasites in Maine . 20 Egg Parasites. 20 Larval Parasites. 20 Pupal Parasites . 24 Acknowledgments. 28 Literature Cited . 28 Appendixes . 30 General External Morphology of a Parasitic Wasp, Glypta fumiferanae (Viereck). 30 Glossary . 31 Table 1 Host Stage Preference and Relative Abundance of Spruce Budworm in Maine . 33 Table 2 Parasites Recorded Parasitizing Spruce Budworms (C. fumiferana and C. occidentalis) in North America . 34 Digitized by the Internet Archive in 2018 with funding from University of Illinois Urbana-Champaign Alternates https://archive.org/details/lepidopteraassoc6166stev Spruce Budworm Parasites in Maine: A Reference Manual for Collection and Identification of Common Species by David A. Tilles and Norman E. Woodley* Introduction The spruce budworm, Choristoneura fumiferana (Clemens), is one of the most destructive forest insects in North America. This pest causes serious damage to spruce-fir forests throughout New England and the Lake States in the United States, and the Canadian Provinces of Ontario, Quebec, Nova Scotia, and Newfoundland (Baker 1972). Major outbreaks occurring in Eastern North America eventually subside, probably as a result of climatic factors and the limited availability of food. Natural control agents (e.g., predators, parasites, disease) have shown little effectiveness in regulating budworm populations during outbreaks. However, between outbreaks, natural controls are important to maintain endemic budworm populations at low levels (Dearborn 1980). Spruce budworm parasites include various species of wasps (Hymenoptera), and flies (Diptera). Adult parasites place their eggs (or larvae in some cases) on, in, or near the immature stage of their host. Either the egg, larva, or pupa of the budworm may be attacked, depending upon the species of parasite. The immature parasite feeds upon the internal tissues and body fluids of its host, killing the host before it reaches maturity. Entomologists are often interested in determining the effects of parasites on specific budworm populations. In some cases, estimates of parasite numbers are needed to determine the effect that a particular pesticide may have on various natural enemies. Dearborn (1980) has suggested that parasitism might be used as one indicator of budworm population quality. 'During the preparation of this manual, David Tilles was a lecturer in entomology at the University of Massachusetts, Amherst. He is presently a visiting scientist at the Swedish University of Agriculture Sciences, Uppsala, Sweden. Norman Woodley was in the Graduate School of Arts and Sciences of Harvard University, Cambridge, Mass., and is now with the USDA Insect Identification and Beneficial Insect Introduction Institute at the U.S. National Museum in Washington, D.C. Prior to this publication, information pertaining to the collection, rearing, and identification of the more common budworm parasites was scattered throughout the scientific literature. Three keys to budworm parasites have been prepared; one addresses parasitic Hymenoptera in the Lake States (Wilson and Bean 1964), and the others deal with puparia (Ross 1952) and adults (Coppel 1960) of parasitic Diptera. We have attempted to condense the present literature and supplement it with our own observations in order to prepare a manual that should facilitate identification of budworm parasites and estimation of parasitism levels. Most of the parasites treated in this manual are also found in other areas of the Northeast, and some range as far west as British Columbia. However, it should be emphasized that the keys in this manual may not be applicable to areas other than Maine. In addition to the sections covering eollection, identification, and life histories of common parasite species, an illustration of general external morphology of a parasitic wasp (fig. 43), a glossary, and two reference tables are presented in the appendix. Appendix Table 1 is a summary of the host stages attacked and the relative abundance of 18 of the common budworm parasites in Maine. Appendix Table 2 is a compilation of all 82 species reported to parasitize spruce budworm in North America. The species names in this manual follow those given in Amaud (1978) and Krombein et al. (1979). 5 Methods for Sampling and Collecting Parasites The design and implementation of a parasite sampling project will depend upon study objectives, as well as numerous other biological (e.g., budworm population level, forest stand composition) and economic (e.g., manpower) constraints. In this section, we suggest guidelines for sampling parasites and provide examples of methods used by other workers. When To Sample Each parasite species is specialized to attack at a particular developmental stage of the budworm. Thus, to detect all species of parasites, collections must be undertaken at several stages in the host’s life cycle. Suggested collection times are peak of the fourth instar, peak of the sixth instar (50-percent pupation), peak of the pupal stage (50-percent emergence), and peak of new (green) egg-mass deposition. If collections are made too early in a sampling period, hosts may not yet have been parasitized; late sampling carries the risk that parasites may have already emerged from their hosts. F. A. Titus“ suggests using degree-day measurements to time the parasite collections. If 5.6°C is accepted as the temperature threshold, early-larval parasites should be collected at 222 degree-days, which will occur during the fourth instar. Late-larval parasites should be collected at 472 degree-days, which will coincide with sixth-instar development; and pupal parasites should be collected at 611 degree-days. If the degree-day method is not used to time budworm collections, another, but more difficult, alternative would be to sample budworm populations systematically at frequent intervals. Two references helpful for this procedure are McGugan (1954), for techniques to differentiate between different budworm instars, and Sanders (1980), for a review of techniques used in sampling budworm populations. Houseweart et al. (1982) reported that budworm egg-mass deposition spans about 27 days and peaks in early to mid-July. We suggest that egg parasites be sampled during the deposition period because egg parasites cause eggs to turn black, allowing all parasitism to be recorded. Specific information about budworm development in Maine may also be obtained from the Maine Forest Service Entomology Laboratory in Augusta. ’Unpublished internal report. Field and laboratory procedures for the study of spruce budworm parasitism. Maritimes Forest Research Centre, Fredericton, N.B., Canada. 1979. Degree-days are accumulated every day (starting in late winter) that the average daily temperature is higher than the threshold temperature at which development starts. For example, if the daily temperature was 10 °C for the first 3 days, and the temperature threshold was 5 °C, then a total of 15 degree-days would have been accumulated during those 3 days. Design of Sampling Methods Sample plots should be located in forest stands that contain a high proportion of balsam fir, Abies balsamea (L.) Mill., because parasite samples are most commonly collected from budworms on this tree species. Additionally, the chances are better that large numbers of budworm larvae can be located in stands containing a high proportion of balsam fir than in stands consisting mainly of spruce and/or hardwoods (Baker 1972). The most commonly used sampling unit in the United States is a branch tip 18 inches (45.7 cm) long. If all sample branches are the same size, then the number of budworms or budworm parasites per branch tip can be converted into a useful standardized estimate of insect density. For example, Simmons (1973) presented a conversion factor to change budworm density estimates from branch tip to area of host foliage. The abundance of different budworm parasites has been observed to vary, depending upon the relative size of the host populations. For example, the degree of parasitism by Meteorus trachynotus (Viereck) has been known to increase greatly during periods of sharply declining budworm populations (Miller 1963), whereas other parasites show density-dependent relationships with their budworm hosts (Miller 1963). It is, therefore, necessary to estimate budworm population levels concurrently with parasitism levels, if one is to obtain accurate estimates of actual parasitism. In Weseloh’s (1976) review of forest insect parasite behavior, he stressed that parasites in a forest stand are often unequally distributed between different plant species and microhabitats. Thus, variability between samples can be minimized by collecting from trees of the same species that are similar in such respects as height, percentage of live crown, and exposure to light. In addition, branches should be removed from the same aspects (e.g., NE, SW) and crown levels. In the Northeast, generally accepted methods are to sample for larval and pupal parasites at midcrown levels of balsam fir, as suggested by Kemp and Simmons (1976). Houseweart et al. (1982) sampled for egg parasites in the upper crowns of balsam fir because the largest proportion of budworm eggs are usually deposited in this region. 6 The number of budworm larvae sampled must be large if parasitism rates are to be accurately determined.^ Sampling must be more intensive in areas with low budworm populations than in areas with high populations. Because sampling intensity (i.e., the number of branches sampled before obtaining a predetermined number of budworms required by the sampling plan) is inversely proportional to budworm numbers, formulae can be developed that use sampling intensity to compute budworm density. In this way Kemp and Simmons (1976) have standardized parasite sampling procedures so that budworm densities may be estimated with little extra effort. Sometimes, trees are spaced so closely that it is not possible to sample branches from more than one or two aspects of any single tree in the group. In such cases, the cluster of trees can be treated as a single tree for sampling purposes. When budworm populations are low, clusters of trees offer an additional advantage over single trees because more branches may be available for intensive sampling. To reduce sampling error due to intertree variability, it is advisable to sample branches from the same trees or clusters of trees during each collection period. This may extend to also sampling the same sites during the following year, since some parasites (e.g., Glypta and Apanteles fumiferanae) attack during one season and emerge during the next (Brown 1946a, b). Then, it may be necessary to relate the number of emerging parasites to budworm populations from the previous year. Simmons and Chen (1974) have described a method of estimating the proportion of parasitism caused by Apanteles and Glypta spp. that involves sampling foliage for parasite cocoons. The advantage of this method is that no rearing or dissection is needed. However, a rather involved mathematical formula or a computer program (available from the authors'*) must be used. Collecting Techniques Branches can be removed from trees with a sectional pole pruner. To prevent loss of larvae during branch removal, a basket can be attached to the pruner. However, baskets are cumbersome and are not necessary for collecting pupae or ^For example, Bradbury (1978) collected a minimum of 100 larvae or pupae per plot at each of the sampling stages; Kemp and Simmons (1976), 200 per plot. ■‘Dr. Gary Simmons, Dept, of Entomology, Michigan State University, East Lansing, MI 48824. egg masses. Stein (1969) describes a modified pole pruner with a holding clip that firmly grasps the branch as it is being lowered from the tree. It can be used for sampling pupae, larvae, or eggs. If they are to be counted in the field, small budworm larvae may be removed from branches by gently tapping the branch over a white drop cloth. Care should be taken to ensure that those larvae held tightly in by their webbing are also dislodged. Large larvae and pupae are easier to locate and can be hand-picked to avoid unneccessary damage. All larvae should be handled only with featherweight forceps or a fine-tipped paintbrush. If larvae are to be counted in the laboratory rather than in the field, they can be transported directly on fresh balsam fir foliage in containers with adequate ventilation. Bradbury (1978) placed sample branches with larvae in plastic bags which were then transported to the laboratory for processing. Pupae are delicate and during transport must be placed in sturdy containers (e.g., petri dishes) or sandwiched between two layers of cotton. Empty pupal cases should also be collected, since they may represent successful emergence of unparasitized budworms. (See section on damage to the pupal case caused by emerging budworm adults and their parasites.) All collected insects should be kept shaded and cool (preferably at less than 40 °F) in the field and en route to the laboratory. This is especially critical if they are in plastic bags. Handling of Collected Insects —Two different strategies are employed to recover budworm parasites. Parasites of early-stage larvae can be collected by dissecting fourth- instar budworms, or larvae can be reared in the laboratory until their parasites emerge. Dissection has the advantage that data can be acquired promptly, without prolonged rearing procedures. However, some of the rarer parasites of fourth- and fifth-instar budworm (e.g., Enytus or Synetaeris), are extremely difficult to identify unless they are allowed to develop to the adult stage. Late-larval, pupal, and egg parasites should always be allowed to emerge from their hosts. For egg and pupal parasites, this is relatively easy, as eggs and pupae require little care other than regulation of temperature and humidity. However, larger larvae must be provided with a continuous supply of food, and their excrement may require periodic removal. 7 During periods when budworm populations are low and parasite populations are high, multiparasitism may occur among several parasite species (e.g., M. trachynotus, Actia interrupta Curran, Omotoma fiimiferanae Tothill). Although more than one parasite may have attacked the host, usually, only one species emerges. Consequently, parasitism estimates based solely on larval rearings may underestimate the actual attack rate. Dissection Techniques for Spruce Budworm Larvae— Kemp and Simmons (1976) described a method of dissecting budworm larvae that allows recovery of early larval parasites. They recommend refrigerating the larvae at 7 to 10 °C after collection, if they are not to be dissected immediately. Although larvae can be stored for several days in this manner, it is still preferable to process larvae within a day after collection. The cooled larvae are also less agile and are easier to handle than those stored at room temperature. Each larva to be dissected is placed under a dissecting microscope and held down with a probe. The sharp edge of a syringe needle is then used to make an incision just behind the head capsule. The blunt side of the needle can be used to force the body contents out through the cut. This must be done carefully because the delicate parasites are easily damaged. Nearly mature parasite larvae, when present, may be found within these body contents. Another effective dissection method is to make a longitudinal cut along the entire dorsal midline of the larva with the sharp edge of a syringe needle. The cuticle may then be separated to expose the body contents. Titus^ preferred using a black background as the dissection surface, to contrast with the lighter colored parasites. He also recommended dissecting small larvae in 60-percent ethanol. In contrast, Bradbury (1978) found that 70-percent ethanol formed a cloudy solution and killed the parasites, making them more difficult to locate. He preferred dissecting fourth-instar budworms in water and tearing the host larva apart by pulling on each end of it with a dissecting needle. Parasites then “popped” out into the water. Immature parasites should be preserved in 70-percent ethanol if they are to be retained for identification later, but it is preferable to identify them as soon as possible because they lose their natural colors during storage. Parasite larvae most likely to be recovered during the dissections include Apanteles fumiferanae Viereck, Glypta fumiferanae (Viereck), and the less common Synetaeris tenuifemur Walley. Rearing Spruce Budworm Parasites —Stehr (1954) suggested that budworm larvae be reared under an 18 h light/16 h dark regime at 21.5 ± 1° C and 68-, to 75- percent relative humidity. Again, budworm larvae should not be handled directly, but should be manipulated with a soft, fine-tipped paintbrush. Larvae can be reared on a synthetic diet. Since its preparation is time consuming and usually requires that the raw materials be acquired in bulk (McMorran 1965), commercially prepared diet should be used for small rearing operations. Synthetic diet and 1 oz plastic creamer cups and lids can be acquired from a biological supply house.^ A minimum of 20 1 must be purchased at approximately $5.00/1. Between 500 and 600 larvae can be reared on 1 1 of diet. Grisdale (1970) described rearing techniques with synthetic diet. Ten ml of diet was poured into each creamer cup. After it cooled, an antifungal solution (1.5 g sorbic acid -I- 0.6 g methyl-p-hydroxybenzoate in 100 ml ethyl alcohol) was sprayed on the surface of the diet and the inner surfaces of the cup with an atomizer. Larvae were placed into each cup; the cups were then fitted with cardboard (unwaxed) lids and inverted. According to Dearborn,^ cannibalism is likely if more than one larva is reared in each cup. However, Grisdale (1970) had problems with cannibalism only with six or more larvae per cup. If insufficient diet remains in the cup or if the diet becomes dry, larvae should be carefully transferred to a new cup with fresh diet. Titus^ recommends checking for parasites, dead larvae, pupae, and mold every 2 days. Balsam fir foliage is the least expensive type of budworm diet, but frequent foliage collection can be demanding, and care must be taken to avoid adding to the sample other budworms that may already be on the foliage. Newly opened balsam fir buds are the best source of food. If they are unavailable, fresh balsam fir foliage tips will suffice. Bradbury (1978) reared sixth-instar budworms individually in inverted 25 x 95 mm shell vials, plugged with absorbent cotton to reduce fungus development. Fir tips were replaced and excrement removed twice before the ^Bioserve, Inc., P.O. Box B.S., Frenchtown, NJ 08825. The use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the U.S. Department of Agriculture or the Forest Service of any product to the exclusion of others that may be suitable. ^Personal communication from R. G. Dearborn, Maine Forest Service, Entomology Laboratory, Augusta, ME 04473. 8 budworms pupated. Stehr (1954) reared four to six larvae together in each 16 X 100 mm petri dish, using balsam fir buds as food. Note: If several larvae are held together, newly developed pupae should be transferred to a separate container, to eliminate any confusion regarding the origin of a resulting parasite. Titus^ and Bradbury (1978) placed individual budworm pupae into 9 X 42 mm shell vials plugged with cotton. They had problems with parasites (especially tachinids) escaping from loosely plugged vials. Kemp and Simmons (1976) reared as many as 10 pupae together in petri dishes 100 mm in diameter and cautioned that emerging moths should be removed from the dishes because their wing scales can asphyxiate the remaining budworm pupae and parasites. Budworm pupae from which neither moths nor parasites emerge should be dissected and their contents identified, if possible. If dipterous puparia are to be reared to the adult stage, they may need to undergo a cold period before they can complete development. Titus^ ended this dormant state by placing the puparia in a rodent-proof covered tray with moistened peat moss and leaving the tray outdoors over the winter. Adult flies then emerged within a few weeks after their return to room temperature. To locate budworm egg masses in the laboratory, branches should be examined according to procedures outlined by Dixon et al. (1978). Needles with egg masses can be placed in shell vials and tightly corked to prevent emerging parasites from escaping. After 2 weeks’ time, egg parasites can be collected and the percentage of black (parasitized) eggs determined (Houseweart et al. 1982). All collected adult parasites should be preserved in 70- percent ethanol or mounted on an insect pin. Parasite larvae and puparia should be preserved in 70-percent alcohol. Oman (1952) presented a comprehensive review of insect collecting and preservation techniques. 9 Key to the Adult Stages of Common Parasites of the Spruce Budworm in Maine (Adapted from Wilson and Bean 1964, Coppel 1960) Parasites from Budworm Larvae 1. Parasite emerged from spruce budworm egg mass; minute insects; length about 1 mm or less.Hymenoptera; Trichogramma sp. (p.20) Parasite emerged from spruce budworm larva .2 Parasite emerged from spruce budworm pupa .11 2. With four membranous wings; body not bristled (Hymenoptera) .3 With two membranous wings, the hind pair reduced to small, knoblike structures; body with many long bristles (Diptera) .8 Hymenoptera Figure 1 —Front wing of a braconid wasp, rv = recurrent vein. 3. Front wing with one recurrent vein (rv) (fig. 1) (Braconidae) .4 Figure 2 —Front wing of an ichneumonid wasp, rv = recurrent vein. Front wing with two recurrent veins (rv) (fig. 2) (Ichneumonidae) .... 6 Figure 3 —Front wing of an Apanteles sp. wasp. 4. Forewing with four closed cells (fig. 3); eyes with dense hairs present over entire surface; thorax and abdomen black . . Apanteles fumiferanae Viereck (p.22) Front wing with five or six closed cells; eyes bare or at most with sparse hairs on surface; thorax and abdomen with some yellow coloration ... 5 Figure 4 —Front wing of Meteorus trachynotus Viereck. 5. Forewing with five closed cells; cell IR, (= Cell 5) somewhat square (fig. 4); eyes with short, sparse hairs . . Meteorus trachynotus (Viereck) (p.23) 10 Figure 5 —Front wing of a Macrocentrus sp. wasp. Diptera Figure 6—Wing of Actia interrupta Curran. Figure 7—Wing of Lypha setifacies (West). Figure 8 —Wing of Aplomya caesar (Aldrich). Forewing with six closed cells; cell IR^ (= Cell 5) elongate (fig. 5); eyes completely bare . Macrocentrus sp. (p.23) 6 . Petiole or first segment of abdomen (gaster) broad, when viewed from above appearing nearly as broad as other segments; tergites 2-A with deep impressions shaped like an inverted “V”; ovipositor very long, about as long as gaster. Glypta fumiferanae (Viereck)(p. 24) Petiole narrow, when viewed from above; appearing much narrower than remainder of gaster, especially toward base; tergites of gaster smooth, without deep impressions; ovipositor much shorter than gaster .7 7. Legs mostly yelow-orange, including entire hind femur . . Enytus montanus (Ashmead) (p.23) Legs mostly brown to black, with hind femur especially dark. . Synetaeris tenuifemur Walley (p.24) 8 . Eyes bare; wing veins R,, R 4+5 and CuA, with numerous setae (fig. 6 ) . Actia interrupta Curran (p.20 ) Eyes with dense hairs over entire surface; wings with setae only on base ofR445(fig. 7).9 9. Most of scutellum usually yellowish (always yellowish at least at apex), contrasting with coloration of rest of thorax. . Phryxe pecosensis (Townsend) (p.22) Scutellum dark colored, concolorous with rest of thorax .10 10. Palpi yellow; wing with four or five long setae on base of R 4+5 (fig. 7); body with distinctly bronze coloration .Lypha setifacies (West)(p.21) Palpi black; wing with one or two short bristles on R 4+5 (fig. 8 ); body with only faint bronze reflections . Aplomya caesar (Aldrich) (p. 20) 11 Parasites from Budworm Pupae 11. With four membranous wings; body not bristly (Hymenoptera) . 12 With two membranous wings, the hind pair reduced to small, knoblike structures; body with many long bristles (Diptera) . 16 12. Small insects, 3 mm or less in length; brilliant metallic green body; front wing without closed cells (fig. 9) (Pteromalidae) .13 Much larger insects, usually at least 8 mm long; not metallic green but most of body reddish or black; front wing with several closed cells (Ichneumonidae) .14 Figure 9 —Front wing of a Pteromalid wasp. ring segments 13. Antennae with three ring segments; middle of oral margin shallowly notched (fig. 10) . Mesopolobus verditer {'Hox{on){'p.Tl) Figure 10 —Anterior of head of Mesopolobus verditer (Norton). Figure II—Anterior view of head of Psychophagus tortricis (Brues). Figure 12 — Tip of ovipositor in Ephialtes Ontario (Cresson). Antennae with two ring sements; middle of oral margin sharply notched (fig. 11) . Psychophagus tortricis ip.ll) 14. Abdomen with basal half or more reddish; antenna dark with medial white band at segments 10, 11, and 12; ovipositor sheath short, scarcely protruding beyond end of abdomen . . Phaeogenes maculicornis hariolus (Cresson) (p. 26) Abdomen dark, sometimes with yellowish bands on apices of segments, but without basal red area; antenna entirely black, without contrasting white band near middle; ovipositor sheath protrudes well beyond end of abdomen.15 15. Face extensively yellow in male, at least along eye margins in female; middle tarsi black; hind tarsal segments white basally; ovipositor hooked downward at tip (fig. 12) ... .Ephialtes Ontario (Cresson) (p.25) 12 Face black; middle and hind tarsal segments strongly black and white banded; ovipositor sheath straight (fig. 13) . . Itoplectis conquisitor (Say)(p.26) Figure 13 —Tip of ovipositor in Itoplectis conquisitor (Say). 16. Eyes hairy; postscutellum (psc) bulging just below rim of scutellum (sc) (fig. 14) (Tachinidae).17 Figure 14 —Lateral view of a dipteran thorax with a well-developed postscutellum. sc = scutellum; psc = postscutellum. SC Figure 15 —Lateral view of a dipteran thorax with a poorly developed postscutellum. sc = scutellum; psc = postscutellum. Eyes bare; postscutellum not bulging Just below rim of scutellum (fig. 15) (Sarcophagidae). Agria housei Shewed (p-24) 17. Scutellum with at least some yellowish coloration which contrasts with coloration of rest of thorax.18 Scutellum wholly black, color similar to rest of thorax . . Aplomya caesar (Aldrich) (p. 20) 13 Figure 16 —Head of Phryxe pecosensis (Townsend), pfr = parafacial region (from Coppel 1960). Figure 17 —Head of Omotoma fumiferanae (Tothill). pfr = parafacial region (from Coppel 1960). 18. Palpi black; antennae black; parafacial region bare (fig. 16) . . Phryxe pecosensis (Townsend) (p. 22) Palpi yellow; antennae with some reddish-yellow coloration; parafacial region hairy (fig. 17) . Omotoma fumiferanae {Tothi\\){p. 25) 14 Key to Puparia of Common Dipteran Parasites of the Spruce Budworm in Maine (adapted from Ross 1952) Figure 18 —Cocoon of braconid. Ichneumonid cocoons are similar. The actual pupa is inside, and the adult emerges by cutting off the head end of the cocoon, which can be seen at the upper right. Note the fibrous nature of the cocoon, which is much different from the smooth puparium of Diptera. Figure 19 —Puparium of tachinid. The puparium is actually the hardened skin of the last larval instar. It is quite smooth and not composed of fibers. The adult fly emerges by popping off the head end. The posterior spiracles, important for identification of tachinid and sarcophagid species, are indicated by the arrow. Both cocoons of hymenopterous and puparia of dipterous parasites may be found after they have emerged from cultured budworm larvae. Hymenoptera cocoons (fig. 18, a braconid example) are distinctive, usually appearing fibrous as they are actually spun by the parasite larva. It is not possible to identify hymenopteran parasites simply from the cocoon because the cocoons are all similar in appearance. In contrast, puparia of Diptera (fig. 19) are quite distinctive, even between species. They are smooth, because they are formed from the skin of the last larval stage, and are not made of fibers. Spiracles are easily seen on both dipterous larvae and puparia; thus, the following key, based primarily on the appearance of the spiracles, may be used to identify both dipterous larvae and puparia. Figure 20 —Posterior spiracle from a Phryxe pecosensis (Townsend) puparium. 1. Emerged from spruce budworm larva .2 Emerged from spruce budworm pupa .5 2. Each posterior spiracle with four strongly sinuate slits (fig. 20) . Phyrxe pecosensis (Townsend) (p.22 ) Each posterior spiracle with three slits .3 3. Posterior spiracles borne on a distinct protuberance of the last segment; each spiracular slit rather short and nearly straight (fig. 21) . . Actia interrupta Curran (p. 20) Posterior spiracles not borne on a distinct protuberance; spiracular slits longer, but also more or less straight.4 Figure 21 —Posterior end of an Actia interrupta Curran puparium as seen from lateral view, sp = spiracle. 15 groove Figure 22 —Posterior spiracles and spiracular groove as seen in a Lypha setifacies (West) puparium from posterior view. 4. Posterior spiracles surrounded by a more or less well-defined groove; puparium rugose (fig. 22) . Lypha setifacies (West) (p. 21) Posterior spiracles without a groove surrounding them; puparium glossy . Aplomya caesar (Aldrich) (p. 20) 5. Posterior spiracles in a deep cavity on the posterior surface of the last abdominal segment and partly hidden from view . . Agria housei Shewell (p. 24) Posterior spiracles level with the posterior surface of the last abdominal segment .6 6 . Each posterior spiracle with four strongly sinuate slits (fig. 20) . . Phryxe pecosensis (Townsend) (p.22 ) Each posterior spiracle with three more or less straight slits .7 Figure 23 —Posterior end of an Omotoma fumiferanae (Tothill) puparium from lateral view, with posterior spiracle illustrated, p = protuberance. 7. A distinct, well-developed protuberance present, ventral to the posterior spiracles, noticeable in profile and projecting beyond the spiracles (fig. 23); middle spiracular slit usually distinctly bent near middle (fig. 23) . Omotoma fumiferanae (Tothill) (p. 25 ) no P Protuberance ventral to posterior spiracles very poorly developed, not noticeable in profile, and not projecting beyond the spiracles themselves; middle spiracular slit straight (fig. 24) . .Aplomya caesar (Aldrich)(p.20) Figure 24 —Posterior end of an Aplomya caesar (Aldrich) puparium from lateral view. 16 Damage to Spruce Budworm Pupal Cases Caused by Emergence of Some Common Parasite Groups Figure 25—Spruce budworm pupal skin after normal emergence of an adult moth (dorsal view). Note distinct split on dorsal area of thorax (arrow). Figure 26—Spruce budworm pupal skin after normal emergence of an adult moth (lateral view). Note the antennal cases which have become separated from the main body of the pupal skin (arrow). Figure 27 —Spruce budworm pupal skin showing damage caused by an emerging tachinid fly maggot Note that there is little noticeable damage and the antennal cases are still attached to the main body. Maggot emerged from space indicated by arrow. Figure 28 —Spruce budworm pupal skin showing damage caused by an emerging ichneumonid larva Note large emergence hole near head end of pupa (arrow). Figure 29—Spruce budworm pupal skin showing damage caused by emerging pteromalids. Note tiny, round emergence holes (arrows). Some general identifications can be made from empty pupal cases of the spruce budworm, from which either the budworm moth or various parasites have emerged. The following notes and accompanying photographs should prove useful for identifying empty pupal cases. • Normal budworm emergence. When the adult budworm emerges from its pupal skin, a well-defined split of the skin occurs in the head region, usually leaving the anterior end appearing somewhat frayed (fig. 25). The antennal sheaths are separated from the main body of the pupal skin during emergence (fig. 26). When various parasites emerge from a budworm pupa, the sheaths remain closely appressed to the pupal skin, and the anterodorsal splitting does not occur. • Dipteran emergence. When Diptera emerge from a budworm pupa, they do so as maggot larvae. Because the fly maggot is fairly soft, when it breaks through the pupal skin of the budworm, usually near the wing cases, it causes little damage to the pupal skin. The only evidence of dipteran emergence is a small crack near the wing cases, which leaves no frayed areas or distinct holes (fig. 27). • Ichneumonid emergence. While it is not possible to specifically identify ichneumonid species by characteristic damage which they cause to the budworm pupa, it is possible to determine that an ichneumonid in general has emerged. These wasps chew a large characteristic hole at the anterior end of the budworm pupa from which they escape (fig. 28). The hole does not have frayed margins, and may be dorsal, ventral, or in the anterior portion of the pupal skin. • Pteromalid emergence. Because several pteromalids usually emerge from a single budworm pupa, characteristic damage to the pupal skin results. These tiny wasps chew small, nearly round holes in the pupal skin, through which they escape. Holes are about 1 mm in diameter and may be anywhere on the pupal skin (fig. 29). Using the above criteria, a general evaluation of parasitism by major parasite groups can be determined by collecting empty budworm pupal skins. 17 Morphological Comparisons Between Three Hymenopterous Larvae Found in Association with Early-Instar Spruce Budworm in Maine T3 U, (J D 2 5 vSi. .2S S’ TD C ^ ca S2 c/5 Oij c O t- ^ -to C g o 3 -2 I c/> . c/5 o x: c/5 Ui fU > (U CJJ CO T3 C (D O. 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Figure 34 —Omotoma fumiferanae (Tothill), a representative of Tachinidae. Note the very bristly body. Egg Parasites Hymenoptera: IVichogrammatidae IVichogramma minutum Riley (fig. 33)—This minute wasp is the only parasite known to attack eggs of the spruce budworm. It is distributed widely throughout North America and attacks many hosts in six different insect orders (Anderson 1976). As yet, no relationship has been shown between the rate of parasite attack and budworm density. In general, T. minutum parasitizes up to 15 percent of the spruce budworm egg-mass population. However, Hewitt (1912) reported parasitism rates as high as 77 percent in Ontario and Quebec. Eggs are attacked beginning immediately after oviposition, and adult wasps emerge within about 2 weeks (Houseweart et al. 1982). T. minutum may be easily recognized by its extremely small size; wings with only one distinct vein and no closed cells; three-segmented tarsi; and its usually yellowish coloration. The only other small wasps that are parasites of the budworm are the metallic Pteromalidae, which emerge from budworm pupae, never from budworm eggs. Larval Parasites Diptera: Tachinidae (fig. 34) Actia interrupta Curran —This fly is a very rare parasite of budworm larvae in Maine, although Blais (1965) reported parasitism rates as high as 32 percent in Quebec. Both fifth- and sixth-instar budworms are attacked. The mature parasite maggot emerges from the sixth instar of the host and overwinters as a pupa in the soil. Adult —This is the smallest tachinid fly (length 5 mm) discussed in this handbook. It may easily be recognized by its bare eyes; all other tachinids that parasitize the spruce budworm have hairy eyes. Actia is also unique in having rows of bristle-like setae on the dorsal surfaces of wing veins Ri, R 4+5 and CuAj (fig. 6 ). The large third antennal segment in Actia is only slightly smaller than the eye when viewed in profile. Immature Stages —Maggots and puparia of A. interrupta have posterior spiracles which are borne on a well- developed, posteriorly projecting process of the last abdominal segment (fig. 21). No other species of parasitic Diptera in this manual have such a structure. 20 Aplomya caesar {Aldrich) —An uncommon parasite of the budworm in Maine, A. caesar rarely attacks more than 6 percent of the budworm population. However, Jaynes and Figure 35 —Lypha setifacies (West), Tachinidae. Another common fly parasite. Drooz (1952) have reported parasitism rates as high as 32 percent in New York State, while Blais (1965) has observed 27-percent parasitism in Quebec. Fifth- and sixth- instar budworms are attacked and the parasite emerges from either the sixth instar or the budworm pupa. The parasite overwinters as a pupa in the soil. Adult —Among the dipteran parasites that emerge from budworm larvae and pupae, the entirely black scutellum will separate Aplomya from other adult tachinids with hairy eyes. Actia interrupta has a yellowish scutellum but has bare eyes. Lypha setifacies also has at least some yellowish coloration on the scutellum but differs from Aplomya in having yellow palpi [Aplomya has black palpi). See the discussion under Lypha for other differences. Immature Stages—Aplomya puparia are similar to those of Lypha, which also emerge from budworm larvae; but Aplomya puparia have larger posterior spiracles and lack the spiracular groove found in Lypha (fig. 22). Aplomya may also emerge from the pupa of the budworm and is most similar to puparia of Omotoma, which also emerge from budworm pupae. However, Aplomya (fig. 24) lacks the ventral protuberance found in Omotoma (fig. 23) and has the middle spiracular slit straight, while it is at least slightly bent in Omotoma (fig. 24). Lypha setifacies (West) (fig. 35)^—This species is probably the most abundant tachinid parasite of spruce budworm in Maine. Jaynes and Drooz (1952) reported that parasitism by this fly increased in Maine from 3 percent in 1950 to 17 percent in 1951. The increase in 1951 was associated with a sudden drop in the budworm population. The life cycle is basically similar to that of A. interrupta. Adult —This tachinid has hairy eyes, a dark-colored scutellum and yellow palpi; a combination of characters not found in other Diptera emerging from budworm larvae. It is most similar to Aplomya, but Lypha has more and longer setae on the base of wing vein R 4+5 (fig. 7). In addition, the body of Lypha has an overall bronzy sheen, whereas Aplomya is black, with little metallic coloration. The third antennal segment is shorter in Lypha than in Aplomya, but this difference is difficult to appreciate without specimens of both for comparison. Immature Stages —Puparia of Lypha are quite similar to those of Aplomya, which may also emerge from budworm larvae. The posterior spiracles are much smaller in Lypha, although again this is difficult to ascertain unless the two can be directly compared. In addition, the spiracles of 21 Figure 36 —Apanteles sp., Braconidae. Note the overall black body coloration, and the relatively short ovipositor. Lypha are surrounded by a shallow but rather well-defined groove (fig. 22) that is absent in Aplomya. The surface of the puparium is rugose in Lypha but glossy in Aplomya. Phryxe pecosensis {Townsend )— P. pecosensis is distributed over a wide geographic area and parasitizes a wide variety of lepidopterous hosts. It is a frequent parasite of the western spruce budworm, Choristoneura occidentalis Freeman, but relatively uncommon in Maine populations of spruce budworm. Jaynes and Drooz (1952) reported that mortality due to this parasite reached 27 percent in New York State. Unlike that of L. setafacies, increases in P. pecosensis parasitism are not associated with decreases in the host population. This fly is active from May to October and produces several generations each year. Parasite larvae emerge from either the sixth instar or pupae of the budworm. Pupation occurs quickly, and a new generation of adults soon emerge to attack alternate hosts. Parasite maggots then overwinter in their alternate hosts. Adult—Phryxe can be distinguished from other Diptera that emerge from budworm larvae by the yellowish coloration of at least the apex of the scutellum. The only other dipterous parasite with a yellowish scutellum is Omotoma, which also has yellowish palpi and hairy parafacials (fig. 17). Omotoma emerges only from budworm pupae, while Phryxe can emerge from either budworm larvae or pupae. Actia has bare eyes and may easily be separated from Phryxe, which has hairy eyes. Immature Stages —The late-instar maggot and puparium of Phryxe are easily distinguished by the very distinctive posterior spiracles, which possess four strongly sinuate slits (fig. 20). All other fly parasites of the budworm have only three spiracular slits which are essentially straight. Hymenoptera: Braconidae Apanteles fumiferanae Viereck (fig. 36)—Five species of Apanteles (table 2) and one of Dolichogenidea^ attack budworm in Maine and throughout the Northeast. Mason (1974) has constructed a key to these species, but A. fumiferanae Viereck is by far the most common in Maine. Oviposition is believed to occur in first-instar budworms either before or after the budworm spins the hibemaculum. The parasite larva then overwinters in the second- instar budworm and emerges from the fourth-instar budworm, after which it spins a characteristic cocoon on the nearby foliage. ^Apanteles absona Meusebeck was recently reclassified as Dolichogenidea absona (Meusebeck). 22 Figure 37 —Meterous trachynotus (Viereck), Braconidae. Note pale body coloration and relatively long ovipositor. Macrocentrus is similar in general appearance. Adult—Apanteles spp. may be easily recognized by their distinctive forewings, which have only four closed cells (fig. 3). The other two common braconids that parasitize the spruce budworm in Maine have five or six closed cells in the forewing. The bodies of Apanteles spp. are dark, while both Meteorus and Macrocentrus have yellowish or light brown bodies. The densely hairy eyes of Apanteles are also distinctive. A. fumiferanae can be differentiated from other species of Apanteles attacking spruce budworm by its bright reddish hind femora and tibiae. Macrocentrus spp.—These are extremely rare parasites of spruce budworm in Maine, and little is known about the biology of this parasite. Adult —^This yellowish braconid is similar to Meteorus in general appearance but has completely bare eyes and six closed cells in the forewing (fig. 5). The two taxa are contrasted below in the following note on Meteorus. Meteorus trachynotus {Viereck) (fig. 37)—This is a common parasite of spruce budworm throughout the Northeast and is well known for its ability to increase in abundance during declining budworm outbreaks (Miller 1963). It attacks fifth- or sixth-instar budworm, emerges from the sixth instar, and pupates on nearby foliage. A new generation of adults appears in late July and early August. It is not clear whether the adults overwinter and attack budworm the following spring or require an alternate host in which to spend the winter. Indications are that this species does require an alternate host, which would limit its ability to increase its populations in response to increasing budworm populations. Miller (1963) reported parasitism rates as high as 80 percent on several plots in Ontario. Adult—Meteorus has five closed cells in the forewing (fig. 4), an overall yellowish or brownish coloration, and sparsely hairy eyes. It is superficially similar to Macrocentrus; however, the latter has six closed cells in the front wing (fig. 5) and bare eyes. In addition, the wing cell IRs is nearly square in Meteorus, but elongate in Macrocentrus. Ichneumonidae Enytus montanus (Ashmead) — E. montanus was previously named Horogenes patens (Townes). It is a rare parasite that is occasionally found when fourth-instar budworm larvae are dissected. Little is known of its biology. 23 Figure 38 —Glypta fumiferanae (Viereck), Ichneumonidae. Note long ovipositor (arrow). Adult —This wasp is most similar to Synetaeris tenuifemur, for both of them are smaller than any of the other more common Ichneumonidae that parasitize the spruce budworm in Maine. Enytus has conspicuously orange- yellow legs, while Synetaeris has dark legs. Glypta fumiferanae (Viereck) (fig. 38)—This is a common parasite of budworm larvae throughout the Northeast, with a life history very similar to that of A. fumiferanae. Miller (1963) postulated that parasitism in the boreal forest type will rarely exceed 20 percent and probably ranges between 10 and 15 percent, with the highest rates corresponding to the peaks in the budworm population. Adult —This is the largest ichneumonid known to emerge from budworm larvae in Maine. The impressions on tergites 2-A of the gaster are distinctive, and no other common ichneumonid parasite of the budworm has these impressions. The ovipositor, nearly as long as the gaster, is also distinctive. The other two ichneumonids that emerge from budworm larvae are noticeably smaller than Glypta, and both of these have a slender first segment of the gaster, while the first segment is broad in Glypta. Synetaeris tenuifemur Walley —A relatively rare parasite in Maine, this wasp has been reported to parasitize up to 60 percent of the budworms on experimental plots in New Brunswick (Miller 1963). S. tenuifemur overwinters in a cocoon attached to tree foliage. Adults emerge in early spring and attack second- and third-instar budworms. The host develops very slowly, doing little feeding but remaining alive until August, when the parasite larva emerges and spins its cocoon. Adult —This species is similar in size to Enytus and both species emerge from budworm larvae. Both are much smaller than Glypta, the only other ichneumonid commonly emerging from the budworm larva. In addition, both Enytus and Synetaeris have a slender first segment of the gaster. Synetaeris may be easily separated from Enytus, which has orange-yellow legs. The front legs in Synetaeris may be somewhat yellowish, but the middle and hind legs are always dark. Pupal Parasites Diptera: Sarcophagidae 24 Agria housei Shewell —This species is a well-known parasite of western spruce budworm and other Lepidoptera, Orthoptera, and Hymenoptera. A. housei was introduced Figure 39 —Ephialtes Ontario (Cresson), Ichneumonidae. Note that ovipositor is hooked near tip, middle tarsi are not banded (arrows). into eastern Canada in the 1950’s (Coppel et al. 1959). Although it may actually be native to Eastern North America, it is rarely found parasitizing Maine budworm pupae. The late-larval or pupal stage of the budworm is attacked, and the parasite maggot then emerges from the host pupa, forms a puparium, and overwinters in the soil. The taxonomic confusion concerning this species was summarized, and resolved, by Shewell (1971). Adult —The postscutellum, which is flat (fig. 15), will easily distinguish this species from the other flies, all of which are Tachinidae and have an expanded, bulging postscutellum (fig. 14). Also, A. housei is the only fly species emerging from budworm pupae that has bare eyes. Immature Stages —The maggots and puparia of A. housei are distinctive in that the posterior spiracles are recessed within a deep cavity on the posterior surface of the last abdominal segment, partly hidden from view. All other dipterous parasites of the spruce budworm have the spiracles on the surface of the last segment and easily visible. Tachinidae Omotoma fumiferanae (Tothill )—This species is well known as a parasite of both the western spruce budworm and the spruce budworm in Maine. It attacks and emerges from the budworm pupa. About 25 percent of the parasite pupae develop into adults the first year. Their fate is unknown. The other 75 percent overwinter in the soil (Coppel and Smith 1957). Adult —This is the largest parasitic fly that emerges from the spruce budworm in Maine, although some smaller individuals may overlap in size with other tachinid parasites. Omotoma has distinctive light brownish to yellowish coloration on the scutellum, and thus is similar only to Phryxe among the pupal parasites. It differs from Phryxe in having yellow palpi and hairy parafacials (fig. 17). Phryxe has dark palpi and bare parafacials (fig. 16). Immature Stages —The puparium of Omotoma is quite similar to that of Aplomya, which may also emerge from the budworm pupa. The protuberance below the posterior spiracles (fig. 23) and the bent middle spiracular slit (fig. 23) will usually serve to identify Omotoma. Poorly developed puparia may be difficult to distinguish because the protuberance may not be well formed. Hymenoptera: Ichneumonidae Ephialtes Ontario (Cresson) (fig. 39)—Jaynes and Drooz (1952) reported that this parasite was fairly common in 25 Figure 40 —Itoplectis conquisitor (Say), Ichneumonidae. Note that tip of ovipositor is straight, and middle tarsi are distinctly banded (arrows). Figure 41— Phaeogenes maculicornis hariolus (Cresson), Ichneumonidae. Note that ovipositor is very short, and antennae have a distinct white band near the middle (arrows). Maine during the years 1949-51. It appears to be most abundant during the early years of a spruce budworm outbreak. E. Ontario attacks and emerges from the budworm pupa. It overwinters as a larva in a variety of alternate hosts. Adult —This genus can be separated from other Ichneumonidae that emerge from spruce budworm pupae by the yellowish coloration on the face. In the male, the face is completely yellow; in the female, the face is yellowish only along the margins of the eyes. In Phaeogenes the areas lateral to the antennae may be pale brownish, but the markings are not as well developed as they are in Ephialtes. Ephialtes is quite similar in appearance to Itoplectis, but pale abdominal bands are reduced or lacking in Ephialtes, the tip of the ovipositor is hooked downward (fig. 12), and the middle tarsi are not banded as they are in Itoplectis. Itoplectis conquisitor (Say) (fig. 40)— I. conquisitor is a well-known parasite that attacks a wide range of moth species (Miller 1963). Although rare as a parasite of the budworm in Maine, I. conquisitor has been reported parasitizing 8 percent of the budworm in New York State (Jaynes and Drooz 1952). It attacks and emerges from budworm pupae and probably overwinters in an alternate host. Adult —This genus is quite similar in appearance to Ephialtes but differs from it in that the face of both sexes is entirely black, the end of the ovipositor straight (fig. 13), and the middle tarsi strongly and distinctly banded. In addition, the abdomen is conspicuously marked with narrow, transverse, light bands. Phaeogenes maculicornis hariolus (Cresson) (fig. 41)— This taxon was previously known as P. hariolus but was recently reduced to a subspecies of P. maculicornis. It is occasionally found parasitizing Maine budworm in moderately high numbers. It is particularly abundant during the later stages of budworm outbreak, unlike E. Ontario, which tends to be more common during the outbreak’s earlier stages. P. maculicornis overwinters as an adult and probably does not require an alternate host. Adult —This species can be distinguished from other ichneumonid parasites of budworm pupae by the reddish coloration on the base of the rather short, stout abdomen. It has very short ovipositor sheaths. The white band near the middle of the antenna is also quite distinctive. 26 Pteromalidae Figure 42 —Mesopolobus verditer (Norton), Pteromalidae. The two common pteromalids that parasitize the spruce budworm are similar in general appearance. Note the short, elbowed antennae and the wings which have only one distinct vein. Mesopolobus verditer (Norton) (fig. 42) and Psychophagus tortricis (Brues)—These strikingly colored wasps are rarely reared from budworm pupae in Maine. However, when they are present, as many as a dozen of this polyembryonic species may emerge from the same budworm pupa. Some taxonomists believe that these wasps are hyperparasitic on certain pupal parasites of the budworm, while others believe them to be primary parasites. Both views may be correct, since these wasps may behave differently in different situations. Adult Both species of Pteromalidae that emerge from spruce budworm pupae are small (less than 3 mm), and are bright, metallic green wasps. This coloration easily separates them from the other Hymenoptera (all ichneumonids) that emerge from budworm pupae. Ichneumonids are much larger and mostly black. M. verditer, with three ring segments on its antennae (fig. 10) is easily separated from P. tortricis, which has only two (fig. 11). 27 Acknowledgments Literature Cited At the outset of this project, I. W. Varty (Department of Forestry, University of New Brunswick, Fredericton), E. G. Kettela (Forest Protection Ltd., Fredericton, N.B.), and G. A. Simmons (Department of Entomology, Michigan State University, East Lansing) offered valuable suggestions as to the scope and content of this manual. We would like to thank W. P. Kemp, R. Bradbury, and R. G. Dearborn (Maine Forest Service Entomology Laboratory, Augusta), who provided information and lent us parasite specimens; and A. Menke (Systematic Entomology Laboratory [SEL], U.S. Department of Agriculture, Washington, D.C.) for lending us parasite specimens. We are indebted to Rune Axelsson and Karl-Frederick Berggren (Department of Plant and Forest Protection, Swedish University of Agricultural Science, Uppsala) for their photographic and illustration services. Mr. Axelsson reproduced published material for figures 16, 17, 30-32, and 43. Mr. Berggren prepared figures 14 and 15. M. W. Houseweart (College of Forest Resources, University of Maine, Orono) deserves special thanks for his help in preparing this manual. He provided information, lent us parasite specimens, and gave us especially helpful critical reviews of the manuscript. Entomologists at the SEL, USDA Insect Identification and Beneficial Insect Introduction Institute, Beltsville, Md., provided expert help in verifying the taxonomic names in this manual. These people included E. Eric Grissell, Arnold S. Menke, and Scott R. Shaw. Terry P. Nuhn, biological laboratory technician at SEL, verified the ichneumonid names. William L. Murphy coordinated the exercise and verified approximately half of the species names. Figures 16 and 17 were reproduced with permission from the Annals of the Entomological Society of America. Likewise, figures 30, 31, 32, and 43 were adapted from illustrations originally published in The Canadian Entomologist. We are indebted to D. C. Allen (SUNY College of Environmental Science and Forestry, Syracuse) for the photograph of T. minutum (fig. 33). Anderson, J. F. Egg parasitoids of forest defoliating Lepidoptera. In: Anderson, J. F; Kaya, H. K., eds. Perspectives in forest entomology. New York; Academic Press; 1976: 233-249. Arnaud, P. H., Jr. A host-parasite catalog of North American Tachinidae (Diptera). Misc. Publ. 1319. Washington, DC: United States Department of Agriculture; 1978. 860 p. Baker, W. L. Eastern forest insects. Misc. Publ. 1175. Washington, DC: U. S. Department of Agriculture, Forest Service; 1972. 642 p. Blais, J. R. Spruce budworm parasite investigations in the lower St. Lawrence and Gaspe regions of Quebec. Canadian Entomologist. 92; 384-396; 1960. Blais, J. R. Parasite studies in two residual spruce budworm {Choristoneura fumiferana [Clem.]) outbreaks in Quebec. Canadian Entomologist. 97; 129-136; 1965. Bradbury, R. Spruce budworm parasite survey in Maine. Tech. Rep. 7. Maine Forest Service, Entomology Division; 1978. 9 p. Brooks, A. R. New Canadian Diptera (Tachinidae). Canadian Entomologist. 77; 78-96; 1945. Brown, N. R. Studies on parasites of the spruce budworm, Archips fumiferanae (Clem). I. Life History of Apanteles fumiferanae Viereck (Hymenoptera: Braconidae). Canadian Entomologist. 78: 121-129; 1946a. Brown, N. R. Studies on parasites of the spruce budworm, Archips fumiferanae (Clem.) 11. Life history of Glypta fumiferanae Viereck (Hymenoptera: Ichneumonidae). Canadian Entomologist. 78: 138-146; 1946b. Coppel, H. C. Key to adults of dipterous parasites of spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae). Annals of the Entomological Society of America. 53; 94-97; 1960. Coppel, H. C.; Smith, B. C. Studies on dipterous parasites of the spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae). V. Omotoma fumiferanae (Tot.) (Diptera: Tachinidae). Canadian Journal of Zoology. 35; 581-592; 1957. Coppel, H. C.; House, H. L.; Maw, M. G. Studies on dipterous parasites of the spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae). VII. Agria affinis (Fall.) (Diptera: Sarcophagidae). Canadian Journal of Zoology. 37; 817-830; 1959. Dearborn, R. G. A look at parasitism in populations of the eastern spruce budworm in Maine. Maine Forest Review. 13: 34-48; 1980. Dixon, W. N.; Houseweart, M. W.; Jennings, D. T. How to examine branches for spruce budworm egg masses. Qrono, ME: University of Maine, Cooperative Forestry Research Unit, School of Forest Resources; 1978. 18 p. Grisdale, D. An improved method for rearing large numbers of spruce budworm, Choristoneura fumiferana (Lepidoptera, Tortricidae). Canadian Entomologist. 102: 1111-1117; 1970. Hanson, P. M. Parasitoids in endemic spruce budworm {Choristoneura fumiferana [Clem.]) populations in Vermont. Burlington, VT; University of Vermont; 1982. 40 p. Thesis. 28 Hewitt, E. G. Some of the work of the Division of Entomology in 1911. In: Entomological Society of Ontario; 42nd Annual Report; 1912. Houseweart, M. W.; Southard, S. G.; Jennings, D.T. Availability and acceptability of spruce bud worm eggs to parasitism by the egg parasitoid, Trichogramma minutum (Hymenoptera: Trichogrammatidae). Canadian Entomologist. 114(8): 657-666; 1982. Jaynes, H. A., Drooz, A. T. The importance of parasites in the spruce budworm infestations in New York and Maine. Journal of Economic Entomology. 45: 1057-1061; 1952. Kemp, W. P., Simmons, G. A. Field instructions for dissection and rearing of spruce budworm larvae and pupae for parasite identification and determination of parasitism rates. Life Sci. Agric. Exp. Stn. Misc. Rep. 180; Orono, ME: University of Maine; 1976. Kemp, W. P.; Simmons, G. A. The influence of stand factors on parasitism of spruce budworm eggs by Trichogramma minutum. Environmental Entomology. 7: 685-688; 1978. Krombein, K.V.; Hurd, P. D.; Smith, D. R.; Burks, B. D., eds. Catalog of Hymenoptera in America North of Mexico. Washington, DC: Smithsonian Institution Press; 1979. 2735 p. Leonard, D. E. Parasitism of the spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae) by Brachymeria intermedia (Hymenoptera: Chalcidae). New York Entomological Society. 83: 269; 1975. Lewis, F. B. Factors affecting assessment of parasitization by Apanteles fumiferanae Vier. and Glypta fumiferanae (Vier.) on spruce budworm larvae. Canadian Entomologist. 92: 882-891; 1960. Mason, W. R, M. The Apanteles species (Hymenoptera: Braconidae) attacking Lepidoptera in the micro-habitat of the spruce budworm (Lepidoptera: Tortricidae). Canadian Entomologist. 106: 1087-1102; 1974. Maw, M. G.; Coppel, H. C. Studies on dipterous parasites of the spruce budworm, Choristoneura fumiferana (Clem.). (Lepidoptera: Tortricidae). II. Phryxe pecosensis (WS) (Diptera: Tachinidae). Canadian Journal of Zoology. 31: 392-403; 1953. McMorran, A. R. A synthetic diet for spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae). Canadian Entomologist. 86: 423-428; 1965. McGugan, B. M. Needle mining habits and larval instars of the spruce budworm. Canadian Entomologist. 86: 439-454; 1954. Miller, C. A. I^asites and the spruce budworm. In: Morris, R. F., ed. Dynamics of epidemic spruce budworm populations. Memoirs of the Entomological Society of Canada. 31: 228-241; 1963. Miller, C. A.; Renault, T. R. Notes on the biology of Synetaeris tenuifemur Walley (Hymenoptera: Ichneumonidae). Canadian Entomologist. 95: 24-28; 1963. Oman, P. W. How to collect and preserve insects for study. In: Insects, the yearbook of agriculture. Washington, DC: U.S. Department of Agriculture; 1952: 65-78. Ross, D. A. Key to the puparia of the dipterous parasites of Choristoneura fumiferana (Clem.). Canadian Entomologist. 84: 108-112; 1952. Sanders, C. J. A summary of current techniques used for sampling spruce budworm populations and estimating defoliation in eastern Canada. Rep. O-X-30b. Sault Ste. Marie, ON: Canadian Forest Service; 1980. 33 p. -1- appendix. Shewell, G. E. On the type of Agria, with decription of a new Nearctic species (Diptera: Sarcophagidae). Canadian Entomologist. 103: 1179-1191; 1971. Simmons, G. A. Conversion table for spruce budworm sampling units. Life Sci. Agric. Exp. Stn. Misc. Rep. 151. Orono, ME: University of Maine; 1973. 4 p. Simmons, G. A.; Chen, C. W. Estimating a mortality proportion when it is impossible to count the house insect and the mortality factor at the same time. Annals of the Entomological Society of America. 67(6): 987-988; 1974. Stehr, G. A laboratory method for rearing the spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae). Canadian Entomologist. 86: 423-428; 1954. Stein, J. D. Modified tree pruner for twig sampling. Res. Note RM-130. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station; 1969. 2 p. Thomas, H. A. I^asitism by Trichogramma minutum (Hymenoptera: Trichogrammatidae) in the spruce budworm outbreak in Maine. Annals of the Entomological Society of America. 59: 723-725; 1966. Weseloh, R. M. Behavior of forest insect parasitoids. In: Anderson, J. E; Kaya, H. K., eds. Perspectives in forest entomology. New York, NY: Academic Press; 1976: 99-110. Wilson, L. F.; Bean, J. L. A field key to the adult hymenopterous parasites of the spruce budworm in Minnesota. Res. Note LS-53. Columbus, OH: U.S. Department of Agriculture, Forest Service, Lake States Forest Experiment Station; 1964. 4 p. 29 Appendixes General External Morphology of a Parasitic Wasp Figure 43. Figure 43 (from Brown 1946b) represents the external morphology of the parasitic wasp Glypta fumiferanae (Viereck). We include it as a refresher on the anatomical structures typical of such parasites and mentioned elsewhere in this manual. Key to abbreviations: ant = antenna, cl = cell, cmp = compound eye, fr = femur, fwg = forewing, gs = gaster, hd = head, hwg = hindwing, oc = ocelli, ovp = ovipositor, pip = palpi, tb = tibia, th = thorax, tr = trochanter, ts = tarsi, tss = tarsal segment, vn = vein. 30 Glossary Host the organism in or on which a parasite lives; and the plant on which an insect feeds. Abdomen the hindmost of an insect’s three main body divisions. Antennal ring segments —from one to three markedly compressed segments immediately following the second antennal segment in some Hymenoptera. Anterior— at or situated in front; foremost; opposed to posterior. Apex that part of any joint or segment opposite the base by which it is attached; that point of a wing farthest from the base or at the end of the costal area. Basal— at or pertaining to the base or point of attachment to or nearest the main body. Bilobed —divided into two lobes, the lobes often rounded. Caudal —of or pertaining to the tail or anal end of the insect body. Cell —a space in an insect wing partly or completely surrounded by veins. Density-dependent factor— a controlling factor that is governed by the density of the population controlled. Diapause —spontaneous state of dormancy during an insect’s developmental period. Dorsal —of or pertaining to the upper surface. Eclosion— emergence of the adult insect from the pupa; the act or process of hatching from the egg. Emarginate —notched; with an obtuse, rounded or quadrate section cut out from a margin. Endemic population —normal, low level of a population as opposed to epidemic or outbreak. Femur (pi., femora) —the leg segment between the trochanter and tibia. Gaster— the remaining part of the abdomen posterior to the constricted first abdominal segment in Hymenoptera. Hibernaculum —the small silken web in which second- instar spruce budworms spend the winter. Hyperparasite — parasite that parasitizes (attacks, kills) another parasite. Instar the period or stage between molts in the larva, numbered to designate the various periods (e.g., the second-instar larva is the stage between the first and second larval molts). Lateral— relating, pertaining, or attached to the side. Medial— referring to, or at the middle. Oral —pertaining to the mouth. Ovipositor —the egg-laying appendage. Palpus (pi., palpi) —small, antennalike appendages of an insect’s mouthparts. Parafacial region —in Diptera, the region between the face and the anterior margin of the eye on either side. Parasite —an animal that lives in or on the body of another animal, at least during part of its life cycle. Petiole —basal stalk of abdomen in Hymenoptera. Polyembryony —the case in which a single egg develops into more than one offspring. Posterior —at or situated behind; hindmost; opposed to anterior. Prepupa —a quiescent instar between the end of the larval period and the pupal period proper. Protuberance —any elevation above the surface; a swelling. Pupa (pi., pupae) —the resting, inactive instar in insects with complete metamorphosis; the intermediate stage between the larva and the adult stages of such an insect. Puparium (pi., puparia) —in higher Diptera, the thickened, hardened, barrellike larval skin within which the pupa is formed. 31 Rudiment —the beginning of any structure or part before it has developed. Rugose —wrinkled, marked with coarse elevations. Sclerite —a hardened body wall plate, usually bordered by sutures or membraneous areas. Scutellum —a dorsal, thoracic sclerite posterior to the mesonotum. Segment —a subdivision of the body or an appendage, between joints or articulations. Seta (pi., setae) —a rather short, stiff, pointed hair. Sinuate —wavy, specifically referring to edges or margins, or referring to wing veins. Spiracle —an external opening of the insect’s respiratory (tracheal) system. Tarsus (pi., tarsi) —the part of the leg beyond the tibia, usually consisting of two to five divisions. Tergite —a sclerite on the upper surface of an insect’s body. Thorax —the body region behind the head which bears the legs and wings. Tibia (pi., tibiae) —the leg segment between the femur and the tarsus. IVansverse— running across; intersecting the longitudinal axis at right angles. Ventral —pertaining to the under or lower surface. 32 Table 1-Host stage preference and relative abundance of spruce budworm parasites in Maine' Stage of host^ Relative abundance Classification Attack Emergence Rank^ Percent Comments Reference Hymenoptera Braconidae Meteorus trachynotus (Vier.) Apanteles fumiferanae Viereck Macrocentrus spp. Ls Le L, Lg L5 Lg U A R 0.4-35 15-28 0-1 4,5 Blais (1965) Brown (1946a) Lewis (1960) Ichneumonidae Ephialtes Ontario (Cress.) Itoplectis conquisitor (Say) Phaeogenes maculicornis hariolus P P P P P P C R U 1-20 0-3 1-15 Blais (1965) Blais (1960) (Cress.) Glypta fumiferanae (Vier.) L| L 2 Lg Lg U 2-11 5 Brown (1946a) Synetaeris tenuifemur Walley L, L 3 L4 R 0-1 4.5 Lewis (1960) Miller and Enytus montanus (Ashmead) U L5 Lg R 0-1 Renault (1963) Pteromalidae Psychophagus spp. P 6 Amblymerus spp. P 6 Trichogrammatidae Trichogramma minutum Riley E E A 2-34 Thomas (1966), Kemp and Simmons (1978), Houseweart et al. (1982) Diptera Tachinidae Lypha setifacies (West) Actia interrupta Curran Omotoma fumiferanae (Toth.) Aplomya caesar Aldr. C5 Le L5 Le L5 Lg C5 Lg Lg Lg P Lg, P U R U U 1- 17 0-1 0-3 2 - 6 4 4,5 4,5 Brooks (1945) Blais (1965) Coppel and Smith (1957) Phryxe pecosensis (Tnsd.) L5 Lg Lg, P u 1-12 5 Maw and Coppel (1953) Sareophagidae Agria housei Shewell C5 Lej P P u 1-5 Coppel et al. (1959) 'Adapted from Dearborn (1980). ^ egg; L' — first larval stage, U = second larval stage, etc.; P = pupa. JlVasite Po^lation survey data for Maine were averaged from data reported by Jaynes and Drooz (1952), Thomas (1966), and Bradbury (1978) K traref — U-2% parasitism rate U (uncommon) = 3—9% parasitism rate C (common) = 10-14% parasitism rate A (abundant) = 15% or greater parasitism rate ^Percent parasitism has been known to increase significantly in periods of declining budworm populations. t ough It IS uncommon or rare in Maine, this parasite has been shown to be abundant in other areas of the Northeast, ouspected of being hyperparasites. 33 Table 2 —Insect parasites reported parasitizing spruce budworms (C. fumiferana and C. occidentalis) in North America A. Diptera known to parasitize the spruce budworm* Taxon Muscidae Muscina stabulans (Fallen) Phoridae Megaselia spp. Sarcophagidae Agria housei Shewed Sarcophaga aldrichi Parker Sarcophaga cooleyi Parker Tachinidae^ Actia interrupta Curran Aplomya caesar (Aldrich) Ceromasia auricaudata Townsend Ceromasia aurifrons Townsend Compsilura concinnata (Meigen) Hemisturmia tortricis (Coquillett) Lypha setifacies (West) Madremyia saundersii (Williston) Nemorilla pyste (Walker) Omotoma fumiferanae (Tothill) “Phorocera” incrassata Smith 'Coppel (1960). ^Amaud (1978). ^Krombein et al. (1979). "Hanson (1982). ’Leonard (1975). Comments Europe, USSR, Alaska-Newfoundland, Southern Georgia, and Arizona Western; but introduced and may be established in Manitoba, Newfound¬ land, and New Brunswick Introduced and established Western; introduced and may be established in Ontario, New Bruns¬ wick, and New¬ foundland Phryxe pecosensis (Townsend) Phyrxe vulgaris (Fallen) Pseudoperichaeta erecta (Coquillett) Sturmia spp. Tachinomyia nigricans Webber Winthemia spp. Xanthophyto spp. Taxon Chalcidoidea Eulophidae Dicladocerus spp. Syntomosphyrum esurus (Riley) Elachertus aeneoniger Girault Chalcididae Brachymeria intermedia (Nees) Pteromalidae Habrocytus phycidis Ashmead Mesopolobus milleri (Crawford) Mesopolobus verditer (Norton) Psychophagus omnivorus (Walker) Psychophagus tortricis (Brues) Torymidae Monodontomerus minor (Ratzeburg) Recorded from New Brunswick, Quebec Recorded from British Columbia, New Brunswick (Comments Collected from endemic level budworm populations in Vermont Introduced in Maine, possibly established^ Western States only From Connecticut and New York, south; west to California; Europe B. Hymenopterous parasites of the spruce budworm^ 34 Ichneumonoidea Braconidae Agathis acrobasidis (Cushman) Agathis binominata Muesebeck Apanteles aristoteliae (Viereck) Apanteles fumiferanae Viereck Apanteles morrisi Mason Apanteles petrovae Walley Apanteles polychrosidis Viereck Bracon cushmani (Muesebeck) Bracon politiventris (Cushman) Charmon gracilis (Provancher) Clinocentrus fumiferanae Muesebeck Dolichogenidea absona (Muesebeck) Macrocentrus iridescens French Macrocentrus peroneae Muesebeck Meteor us ruficeps (Nees) Meteorus trachynotus Viereck Microgaster canadensis Muesebeck Oncophanes americanus (Weed) Orgilus lateralis (Cresson) Ichneumonidae Acropimpla alboricta (Cresson) Campoplex spp. Chorinaeus excessorius Davis Chorinaeus longicalcar Thomson Enytus montanus (Ashmead) New Jersey and North Dakota, south Pennsylvania, south New York, Minnesota Introduced; probably not established Collected from endemic level budworm populations in Vermont‘S Previously known as Horogenes patens Townes Ephialtes annulicornis (Cresson) Ephialtes Ontario (Cresson) Exeristes comstockii (Cresson) Exochus nigripalpis tectulum Townes Gelis spp. Glypta fumiferanae (Viereck) Ischnus inquisitorius atricollaris (Walsh) Ischnus minor Townes Itoplectis conquisitor (Say) Itoplectis evetriae Viereck Itoplectis quadricingulata (Provancher) Mastrus laplantei Mason Mesochorus sylvarum Curtis Parania geniculata (Holmgren) Phaeogenes maculicornis hariolus (Cresson) Phytodietus fumiferanae Rohwer Pimpla [Coccygomimus] tenuicornis Cresson Pterocormus gestuosus (Cresson) Scambus dec or us Walley Scambus hispae (Harris) Stictopisthus flaviceps (Provancher) Syspasis tauma (Heinrich) Theronia atalantae fulvescens (Cresson) Tranosema rostrale (Brischke) Trichogrammatidae Trichogramma minutum Riley Collected from endemic level budworm populations in Vermont"^ Collected from moderate and endemic level populations in Vermont Introduced in eastern Canada but apparently not established Reared from moderate level budworm populations in Vermont Reared from endemic level budworm populations in Vermont'^ 35 t X United States Department of Agriculture Forest Service Agriculture Handbook No. 617 National Forest Landscape Management UNIVERSITY OF ILLlNOfi AGRICm.TURE UBRAOT Ski Areas Volume 2, Chapter 7 Foreword Acknowledgments Volume 1 National Forest Landscape Management, Volume 1, is a train¬ ing document that was distributed throughout the National Forest System in April 1973. It is used as a basic text to illus¬ trate the concept, elements, and principles of our landscape management program. This program seeks to identify the visual characteristics of the landscape and analyze, in advance, the visual effects of resource management actions. Volume 1 was prepared by landscape architects, land management spe¬ cialists, and research scientists from throughout the Forest Service. Endorsed by the American Ski Federation This handbook, which deals with the application of visual resource management principles in planning, designing, and constructing winter sports developments, would not have been possible without the work of many individuals. The principal author is Hubertus J. Mittmann, Regional Land¬ scape Architect, Rocky Mountain Region. Much of the infor¬ mation contained in “Planning Considerations for Winter Sports Resort Development” (USDA FS 1973) is incorporated in the text. Volume 2 National Forest Landscape Management, Volume 2, consists of several chapters. Those already published are: The Visual Management System, Utilities, Range, Roads, Timber, and Fire. Additional chapters are expected in the future. The effort to produce each chapter has been spearheaded by one Forest Service Region, chosen for its experience and demonstrated expertise in the field, utilizing contributions from other Regions, research scientists, industry, and universities. We hope you find this chapter thought provoking and useful. Comments and suggestions are always welcome. R. Max Peterson Chief June 1984 Dr. James D. Mertes, Department of Park Administration and Landscape Architecture of Texas Tech University, and Thomas A. Musiak, Department of Landscape Architecture in the Col¬ lege of Architecture and Design at Kansas State University, worked on the Beaver Creek project, supplied considerable information and materials, and consulted on all phases of this publication. For their continuous cooperation, we would like to thank Vail Associates, especially Dean Kerkling, David Mott, and Jack Zehren. Beaver Creek photographs and daily reports on the project were provided by Larry Warren, the Forest Service liai¬ son person on the Beaver Creek project, and David Roden, a landscape architecture student at Texas Tech University. Erik Martin, the Forest landscape architect on the White River National Forest, contributed many ideas and photographs. Cover photo by H. Peter Wingle. All Beaver Creek sketches by Robert Armon. II For sale by the Siiperiiiteiideiit of Documents. U.S. Government Printing Office Washington, D.C. 20402 Contents Introduction I Chapter Objectives I A Historical Perspective j Ski Area Developments and the USDA Forest Service 2 Landscape Management Concepts for Ski Area Planning and Design ^ Visual Quality Objectives 4 Desired Character 5 Dominance Elements 5 Landscape Design Considerations and Techniques 7 A Planning Procedure 11 Identification and Approval of the Site II Issuance of a Study Permit jj Formulation and Issuance of the Prospectus 11 Development of the Master Plan H Preparation of the Environmental Assessment Report |2 Issuance of Special Use Permits H Preparation of Detailed Site Plans and Facility Designs by the Permittees I3 Approval of Plans by the Forest Service I 3 Developing the Master Plan 13 Visual Resource Management Planning Considerations 13 Visual Inventory and Analysis Procedure IS Mountain Capacity and Skiing Quality 17 Lifts 18 Structures 19 Transportation and Parking 19 Soils 20 Hydrology 22 Utilities 22 Skier Safety and Hazard Management 22 Vegetation Management 23 Air Quality 23 PERSPECTIVE PLOT Computer Graphics Program 24 Detailed Design and Construction 27 Common Areas of Concern 28 The Mountain 32 The Base Area 40 Monitoring 48 Literature Cited SI Other Publications in the Land Management Series 51 Appendix—Beaver Creek Design Regulations 53 Introduction Winter sports developments have a considerable impact on the land, especially from a visual standpoint. Chapter Objectives Ski area developments can have considerable and long-lasting impacts on large areas of land. Because these areas are used— and viewed—by thousands of visitors daily, it is important to use the techniques and procedures available for minimizing any adverse impacts associated with these resorts, while providing optimum recreation opportunities. The objectives of this chapter are to • Demonstrate how landscape management principles and techniques can be used in the planning, designing, and building processes to achieve and maintain desired visual quality. • Explain and illustrate the planning and design require¬ ments for constructing or expanding winter sports devel¬ opments. The first portion of this publication describes concepts relative to landscape management and a general planning procedure for developing or expanding winter sports complexes. This sec¬ tion is followed by a more indepth discussion of master plan¬ ning. The remaining text deals specifically with detailed design and construction processes and describes methods for main¬ taining the visual integrity of these important public places. The techniques and concepts presented in this publication are not intended to represent new policy or direction. Rather, they are suggested as a framework for stimulating new ideas and formulating better planning methods. They are presented here generally in the context of a m.ajor destination resort since such a facility best illustrates the need for coordinated planning. However, the principles apply equally well to small and/or day-use areas. A Historical Perspective Skis have been used for winter travel for thousands of years. Their earliest use was recorded in stone age cave drawings at Rodoy, Norway, near the Arctic Circle, and skis have been dis¬ covered that are more than 4,500 years old. In Scandinavia, their use during wartime became an important factor because they provided increased mobility. In the United States, the use of skis goes back to the first settlers. Their skis were long and 1 Ski Area Developments and the USDA Forest Service heavy, and their journeys across the country were difficult, especially in mountainous terrain. People began using skis for recreational purposes during fron¬ tier times. After the first rope tow was developed, skiing for recreation became more widespread. Although some ski runs and lifts were built during the 1920’s and 1930’s, the ski indus¬ try did not really develop until after World War II. Many members of the 10th Mountain Division, headquartered at Camp Hale in the Colorado mountains, took an active part in promoting skiing and developing ski areas. Skiing has become a major recreational activity, and participa¬ tion in this sport continues to increase. As a result, e.xisting winter sports areas will be expanded and new areas will be built to accommodate the growing demand. Most of the newer developments do not concentrate solely on winter sports, but combine facilities for summer and winter recreation activities in multimillion-dollar resort complexes featuring numerous conveniences. In the future, expansion and rehabilitation of existing areas will be much more prevalent than the creation of new areas, but consideration of protection and enhancement of the natu¬ ral scene will be an objective in all cases. On the National Forests, private sector concession-operated ski areas provide sophisticated winter recreation activities. In addi¬ tion to their intended use, these areas are expected to empha¬ size the forest setting and introduce the public to the more rus¬ tic, natural resource-based recreation opportunities that are provided nearby with public funds. Direction for providing and planning for these activities is based on the Multiple-Use Sustained Yield Act of I960, which authorizes and directs the Forest Service to manage the National Forests under principles of multiple use, and the National Environmental Policy Act of 1969 (NEPA), which requires a systematic, interdisciplinary approach to the plan¬ ning of projects associated with Federal lands. In concert, these two acts provide the direction necessary to ensure proper and prudent development or expansion of these areas. Most major ski areas in the United States depend on National Forest System lands for ski runs and lift sites. Also, appro¬ priate base facilities are sometimes located on these lands. As of July 1982, more than 55,500 acres, representing 167 sites, had been developed on National Forest System lands, provid¬ ing a total nationwide capacity for more than 455,000 skiers at one time. The need to provide sound, responsible planning for this ever-expanding recreational activity is a major Forest Ser¬ vice concern. Forest plans and environmental assessments consider not only the various uses for which the land is suited but also the feasi¬ bility of a site for a particular purpose. Numerous sites that are physically suitable for winter resort development may not be acceptable for this purpose because of conflicting social, resource, or other reasons. To determine a site’s feasibility, extensive studies of such factors as terrain, soil, climatic and snow conditions, visual characteristics, hydrology, access, eco¬ nomics, and environmental impacts must be conducted. Sites will not be approved for use by the USDA Forest Service unless all appropriate analyses are favorable or potential adverse effects can be mitigated. Reprinted by permission from Denver Public Library, Irwin (Gunnison County). Colo. Photo¬ graph by Mellan. March 1883, 2 Landscape Management Concepts for Ski Area Planning and Design Many associated social, medical, and business amenities result from the development of winter sports sites. In addition to the amenities they pro¬ vide, these resorts generally improve the overall economic climate of the community they serve. Because winter sports areas are developed for the public’s enjoyment, it is important to make these areas both attractive and useful, while retaining as much of the natural character and charm as possible. Accordingly, in planning for alterations of the land and introduction of structures, potential changes and effects on the character of the landscape must be identified and considered. This emphasis must be in place at the very beginning of the process and must remain a critical and guid¬ ing force throughout the planning, detailed design, and con¬ struction phases. Many of the winter resort areas are readily visible from major highways and other heavily used recreation areas. The amount of potential landscape modification will vary greatly with slope, aspect, vegetation color and texture, type of terrain, dis¬ tance from the viewer, and character of the structures intro¬ duced to the site. A variety of methods to lessen visual impacts should be consid¬ ered in planning. Runs can be shaped and natural openings The appearance of a winter sports area depends greatly on the consideration that was given to visual resource management during the planning, design¬ ing, and construction stages. Proper planning can result in an area with a very pleasant, natural appearance. 3 used to minimize straight-line effects. Feathering and scallop¬ ing of run edges, thinning or glading of timber, and creating natural-appearing openings are effective methods. Lift lines can be blended into ski runs, topography, and natural open¬ ings. Strict design regulations and guides can be developed for all structures. Roads can be minimized or designed and screened in a manner that will not detract from the site’s natu¬ ral character. Innovative construction methods, such as heli¬ copter chairlift construction and pumping concrete to tower sites, can also be used to lessen the overall visual changes. By establishing visual quality objectives—five categories of acceptable landscape alteration—for a proposed or existing area and then analyzing them from the perspective of what the desired character to be retained or created over time is going to be, the process of effectively dealing with the issue of visual quality can begin. Visual Quality Objectives Visual quality objectives are measured in terms of contrast with the surrounding, natural-appearing landscape. Natural¬ appearing landscapes are those in which historic cultural changes are accepted and which appear to have evolved to their present state through natural processes. The process for determining VQO’s and the way in which they are used is documented in Agriculture Handbook No. 462 (USDA FS 1974), which describes the visual management sys¬ tem in detail. The visual quality objectives are the following: • Preservation (P)—Only ecological changes permitted. • Retention (R)—Management activities are not visually evident. • Partial Retention (PR)—Management activities remain visually subordinate. • Modification (M)—Management activities in foreground and middleground are dominant, but appear natural. • Maximum Modification (MM)—Management activities are dominant, but appear natural when seen as back¬ ground. The objectives are based upon the physical characteristics of the land and the sensitivity of the landscape as viewed by peo¬ ple. In addition to the visual quality objectives, the Visual Management System also provides for two short-term man¬ agement alternatives—enhancement and rehabilitation—that may be employed to increase landscape variety and to rehabili¬ tate landscapes that have been excessively modified. The rugged mountains, the climatic condition, and the well-planned configuration of the ski runs gives this winter sports area a natural appearance. The road seems to be the only artificial intrusion. The straight lift line with associated plantings is the only indication that this is a ski area. The run design, with its natural vegetation edge, blends well with the surrounding landscape. Enhancement Enhancement is a short-term management alternative aimed at increasing positive visual variety where little variety exists. Enhancement may be achieved through addition, subtraction, or alteration of vegetation, water, rock, earthforms, or struc¬ tures to create additional variety of forms, edges, colors, tex¬ tures, patterns, or spaces. Rehabilitation Landscape rehabilitation is a short-term management alterna¬ tive used to restore landscapes containing undesirable visual impacts to a desired visual quality. Rehabilitation may not 4 All features on the mountain must be considered when determining ski site designs. A dominant straight lift line can ruin the effect of ski runs that have been carefully designed to appear natural. always bring about the prescribed visual quality objective immediately, but it should provide a more visually desirable landscape in the interim. Rehabilitation may be achieved through alteration, concealment, or removal of obtrusive elements. Desired Character The appearance of the landscape to be retained or created over time is termed its desired character. It is a combination of design attributes and opportunities, as well as biological opportunities and constraints. Once a parcel of land is allo¬ cated for winter sports use, the degree of alteration of the landscape varies considerably with the different types of activi¬ ties. The greatest impact will be generated by facilities that require considerable alteration of the landscape through vege¬ tation manipulation, soils manipulation, and the introduction of structures. Of all the winter sports facilities, downhill ski areas require the greatest landscape alteration because of the need for ski run clearings, road construction, and associated structures. Because of the time and financial commitment involved, the impact of ski areas must be considered to be permanent. For this reason, it is important to analyze what the land with its natural features has to offer and the extent of alterations needed for achieving the desired character through planning and design. Special attention must be given to long- range vegetation management because of the dynamic and con¬ stantly changing plant communities. Once an area is allocated to ski area development, planners must take advantage of the terrain to best satisfy the winter sports and summer use needs while, at the same time, main¬ taining the visual integrity of the area through appropriate design. Enhancement can be achieved in areas that lack visual variety by adding a variety of vegetation spe¬ cies, colors, or age classes. The desired character of an area, then, should be a blending of the constructed alterations into the natural, established land¬ scape in a way that achieves harmony during all seasons of the year. The design of the desired character for a new or expanding ski area must recognize that the site, regardless of size, is a dynamic and constantly changing community of plants, people, and structures. Dominance Elements To achieve the desired character for an area, it is important first to identify and analyze its landscape features in terms of the elements of form, line, color, and texture. These are impor¬ tant considerations during the planning and design phases— when significant decisions are made about the mountain regarding retention of the existing landscape character. Form Form is the mass of an object or of a combination of objects that appear unified. In ski area developments, the strongest form is usually the mountain. Other forms are structures or tree masses. The appearance of a natural form should be com¬ plemented by landscape alterations. 5 Although the landscape character is dominated by the natural form of the mountains, the desired character along the road can be controlled through proper visual resource management. Line Line is a point that has been extended; it is anything that is arranged in a row or sequence. Line can describe the silhouette of form or it can be considered separately. Line is also defined as the intersection of two planes: obvious examples are ridge¬ lines, timberlines, and powerlines. Line is also evident in tree trunks, avalanche paths, and vegetative boundaries. In winter sports developments, many manmade lines are intro¬ duced in the form of ski runs, vegetation edges, ski lifts, utili¬ ties, and roads. Color Color enables us to differentiate objects that may have identi¬ cal form, line, and texture. Color dominance often depends on the observer’s position. Colors viewed at a distance are usually muted by a bluish haze caused by dust and moisture. Fore¬ ground colors are stronger and more dominant. This is espe¬ cially important to consider when speaking of the same color from various viewing distances. How well ski area developments fit into the naturally estab¬ lished landscape will depend greatly on how the colors of the area’s components harmonize with the surrounding landscape. Texture Texture dominance varies with distance. When a tree is viewed at close range, the texture of the leaf patterns is dominant; when the tree is viewed from a few hundred feet, major boughs form the dominant texture; when the tree is viewed at a dis¬ tance of several miles, entire groups or stands of trees become the dominant texture. In addition to introducing new textures with constructed facili¬ ties, like lifts and buildings, winter sports developments also 6 The natural form of the mountain dominates this scene. Any winter sports development should coor¬ dinate the forms or shapes of the introduced struc¬ tures with the existing form configuration. Vegetation Modification Vegetation can be removed, modified, or added. The visual impact depends on the form and scale of this change in relation to the surrounding landscape. After the suitability of the ter¬ rain for skiing is determined, the ski runs, roads, and lift clear¬ ings have to be designed. The initial clearing should be the minimum acceptable for skiing, as well as for road and lift construction. Should it become necessary in the future to clear additional trees, it can be done easily and is less costly than adding trees or building snow fences. The tree edge of all clear¬ ings needs to be carefully designed for the best natural blending From this perspective, the lift line is immediately obvious in an otherwise natural-appearing area. Because of the contrast with natural surroundings, straight lift lines visually dominate the scene. Care¬ ful planning and designing can minimize this effect. can alter the natural texture of the landscape by removing vegetation for these sites and the ski runs. Careful planning and design should be used to achieve a visually acceptable blending. Landscape Design Considerations and Techniques For the most part, three kinds of activities that directly affect visual character can occur on a mountain during ski area development: vegetation modification, soils manipulation, and introduction of structures. By considering the basic design techniques of manipulating the edge, the shape, and the scale of these activities in the planning and design phases, it is quite possible to achieve an esthetically pleasing development. 7 During winter, landscape colors are primarily gray and green, contrasted against the white snow. Tex¬ ture provided by vegetation and open areas will help developments appear more natural. Straight lift line clearings like this should be avoided. with windfirm trees. Because a natural-appearing edge is per¬ ceived mainly in terms of texture, it should be located where a variety of tree sizes, age classes, and species can be incor¬ porated. The line of the edge should not be straight but, rather, flow with the topography and vegetation pattern. Soils Manipulation Any soils manipulation must ensure blending, erosion control. Because the colors and texture of vegetation in an area can vary considerably during spring, summer, and fall, their pattern should be used to the best advantage when designing ski areas. and revegetation. From the visual standpoint, improper soils manipulation can have a long-lasting, negative effect. Only roads that are absolutely necessary should be planned, because on steep ski mountains, cuts and fills can create a visual pat¬ tern that will not meet the visual quality objectives or allow a safe ski run pattern. Wherever soils manipulation is planned, soils properties, the hydrologic regime, and the possible visual impacts need to be known. The design should ensure a smooth blending with existing topography, allowing for a natural-appearing edge. All cut and fill slopes should be designed to prevent moisture load¬ ing and slippage. Roads crossing ski runs should have smooth transitions to allow for good skiability. Because of the quick runoff in spring, grading of shallow ditches into established natural drainage patterns is necessary, but should reflect the natural configuration of the land on the ski run. Introduction of Structures Structures are as important from the appearance standpoint as 8 Initially, ski trail clearing should be held to the min¬ imum acceptable for skiing. Additional clearing can be done later, if necessary. This slope grading project was blended well with the existing topography. vegetation and soils manipulation. Architectural style, building materials, size, and color can be used very effectively to reach the desired character and meet the adopted visual quality objectives. The colors should be neutral and dark on lift facilities. Build¬ ings should be designed to create a pleasant, relaxing atmos¬ phere within a developed and controlled architectural theme. Strong and bright colors should be used only as accents. Natural-appearing materials and colors can usually help estab¬ lish the desired character throughout an area. When the edge of a ski trail is located, windfirm trees should be carefully selected to avoid wind-damage. Before grading the slope, the topsoil should be removed and saved. Steep banks should be avoided, and proper blending with the existing topography should be achieved. 9 To avoid surface erosion and to insure good revege¬ tation. the topsoil should be mulched after seeding and fertilizing, and the mulch should be held in place by netting. Utility installments for water and gas require large ditching operations. The lines should be located in open or cleared areas or beneath the ski runs. As in grading operations, topsoil can be saved from these projects for rehabilitation. Many types of structures are used in winter sports areas. Architectural style, building materials, color, and siting must be considered for creating visually acceptable designs. These structures have been well designed using design elements of form, line, color, and texture. 10 A Planning Procedure The steps for developing a new or expanding an existing ski area on or associated with National Forest land can vary from one location to the next depending upon environmental, social, and financial considerations. In addition, it is feasible that two or more steps might occur simultaneously. Although not a formal agency process, the steps normally considered in the planning procedure generally are as follows: 1. Identification and approval of the site. 2. Issuance of a study permit. 3. Formulation and issuance of the prospectus. 4. Development of the master plan. 5. Preparation of the environmental assessment report. 6. Issuance of special use permits. 7. Preparation of detailed site plans and facility designs by the permittees. 8. Approval of plans by the Forest Service. Identification and Approval of the Site Potential sites are first identified and some eventually approved for possible development through the forest land management planning process. Selection and approval is based upon the suitability, capability, and the availability of sites. Intensive State and local government participation is impor¬ tant to ensure proper coordination with their own land man¬ agement objectives and resources. Issuance of a Study Permit If analysis work on a site involves removing trees or making other changes in the forest condition, a study permit will be required. Permission to collect data and perform studies does not guarantee that a development permit will eventually be issued, even if a particular project proves to be technically and economically feasible in an area. At this point, proponents will normally begin a close review of the various physical characteristics of the area to determine its real potential as a ski area. They will examine the slope, aspect,, and snow conditions and make preliminary estimates of skier capacity. In addition, they may review possible lift locations and begin considering potential locations for base facilities and mountain amenities. Formulation and Issuance of the Prospectus When studies show that it may be feasible to develop certain National Forest System lands for a winter ski resort, open competition for development rights through a prospectus may be required, regardless of who undertakes the initial studies. Bidders are required to prepare a conceptual development proposal and to present their financial and managerial capabili¬ ties. Once selected, the successful bidder will be asked to pre¬ pare a master development plan, which will be reviewed and approved by the Forest Service prior to issuing the special use permits. Development of the Master Plan Perhaps the most time-consuming and rigorous step in the ski area planning process is development of the comprehensive master plan. The Forest Service monitors planning progress during this effort to verify the data reported by a proponent Plans for resort areas should show the total devel¬ opment, including the proposed recreation areas and the transportation system. In this situation, two separate ski area permits were granted to meet the need for increased skier capac¬ ity; however, the topographic situation was not suitable for expanding the existing area. and plays an instrumental role in determining the optimum level of development to meet long-term public needs. A more detailed discussion of ski area master planning consid¬ erations is presented in the next section. In most cases, an interdisciplinary team helps formulate the master development scheme describing the ultimate plan for the site. Specialists in ecological sciences, skiing, soils, hydrol¬ ogy, community planning, forestry, and landscape architecture, for example, provide expertise to the team leaders, who, in turn, coordinate the inventory, analysis, and synthesis of information that culminates in a final master development plan. Preparation of the Environmental Assessment Report Proponents of new or expanded ski areas are responsible for preparing and/or providing information needed for the en¬ vironmental assessment report. The requirements may vary slightly from one Region to the next; however, all reports review the master plan and examine alternatives to the pro¬ posed development scheme. The report analyzes the environ- 12 Developing ihe Master Plan mental consequences of each alternative, surfaces areas of potential resource damage, and recommends mitigating measures. Issuance of Special Use Permits The Forest Service issues two types of special use permits: term permits and annual permits. These permits are the contract and operating agreements between the Forest Service and the per¬ mittee. The term permit, which is normally issued for 20 years with a statutory maximum of 30, can include an area of up to 80 acres and usually covers that part of the site where the major capital investments are located. A companion annual special use permit is issued for the additional area needed for ski runs and other needs such as avalanche control and access. The Forest Service may not terminate the special use permit except upon breach of the permit terms by the permittee. The permits may be reissued or amended to provide for additional development or to update the permit provisions, if agreeable to both parties. When a commitment is made by the permittee to provide improved or additional services and capital invest¬ ments, the term permit may be extended, but never beyond the maximum of 30 years. Normally, when permits are issued for new resort developments, a period of a few years may be neces¬ sary to allow for completion of development plans, financial arrangements, and other matters. However, if these require¬ ments cannot be met within a reasonable time, the permits may be subject to termination. Preparation of Detailed Site Plans and Facility Designs by the Permittees Once given final approval for development, based on an accepted comprehensive master development plan and en¬ vironmental assessment, the permittee is responsible for pre¬ paring all site plans and facility designs that will be used within the boundary of the winter sports site. These are reviewed by the agency to ensure compliance with the master plan and to ensure that all environmental concerns are being carefully considered. Approval of Plans by the Forest Service Following review and completion of any requested changes, plans are approved by the Forest Service and construction may begin. Often, several separate approvals are necessary at this stage, extending over a period of time, to provide for an orderly, sequential construction process. The winter resort industry has been the major catalyst for the accelerated growth of mountain resort communities during the past decade. Development plans can no longer be limited to such items as skiing facilities, lodges, and runs. While winter sports—especially downhill skiing may constitute the initial phase of development, support facilities and services from local government and the private sector must be considered in plan¬ ning. Land suitable for these purposes is limited; therefore, the optimum development of each site must be carefully analyzed and considered in the master planning stage. Plans must reflect the proposed master scheme for the entire area under consideration— both private and National Forest System lands—and should include a schedule for phase development. The actual approach and requirements for this level of plan¬ ning may vary from area to area, but the ultimate goal is always to form a responsible and feasible long-range frame¬ work for developing the ski area. The following discussions present some of the issues and concerns that normally should be addressed in the master planning process for major ski areas. Visual Resource Management Planning Considerations Of utmost concern in the contemporary planning for any mountain resort community is the visual linkage between the development components (such as buildings, lifts, roads, ski runs, and utilities) and the existing visual character of the area. In fact, recent use surveys have shown that the highest priority of the majority of skiers is experiencing outstanding scenic quality. To respond accordingly, master planning must develop a framework that allows for retaining or enhancing as much of the visual quality of the area as possible. Ski areas usually contribute to the expansion of existing communities or the formation of new communities. Long-range planning will ensure proper growth. 13 Providing good travel routes to winter sports areas is a primary planning consideration, particularly when ordinary use from nearby metropolitan areas is e.xpected to be considerable. The contrast created by ski runs is visible from a considerable distance. The configuration of the developments of the ski mountain will determine whether the impact is positive or negative. A vegetation pattern like this is conducive to the kind of vegetation manipulation necessary for developing ski areas. An inventory of the entire site is necessary to determine its existing visual condi¬ tion and its visual absorption capability. 14 Visual quality objectives should be established not only for the ski area itself but also for the land that can be seen from the ski area. By using basic visual management concepts and principles from the start, it is possible to provide information regarding the best locations for development components that will result in minimum disturbance of the visual quality. This is based on the physical attributes of the landscape, people’s sensitivity regarding change in the landscape, and the ability of the land¬ scape to accept alteration without losing its inherent visual character. Of course, during the master plan development process, other issues—like providing feasible access routes, adequate and varied skiing terrain that works well with a system of lifts, and other economic and social factors—must be considered and occasionally tradeoffs must be made. If, however, visual con¬ siderations are analyzed and surfaced early in the process and taken into account at each decision level, the resulting plan will reflect a sensitivity for retaining and maintaining the site’s scenic characteristics. Visual Inventory and Analysis Procedure By combining the visual quality objectives and the visual absorption capability of a site, it is possible to identify the total visual constraints of an area and thus what precautions must be taken into account in the planning, design, and construction phases. The following example graphically illustrates this technique. THE VISUAL MANAGEMENT SYSTEM PLANNING PROCESS alternatives A 0 C 0 E ADOPTED ^ VISUAL * QUALITY OBJECTIVES 15 Visual Quality Objectives (VQO’s) The VQO’s for the area were based on “The Visual Manage¬ ment System,” which is Volume 2, Chapter 1, of the National Forest Landscape Management series (USDA FS 1974). In the planning stage, the VQO’s were primarily determined as seen from the Interstate Highway and the road that was constructed into the area. It was recommended that new. more detailed VQO’s be established for the area as soon as new roads, trails, pedestrian circulation patterns, and other viewpoints were established that reflected new viewer sensitivity levels. At this time, it was recognized that the inventoried retention and par¬ tial retention VQO’s could not be met with the landscape alter¬ ation necessary to build this resort but that, through proper design, the alteration would blend well into the naturally estab¬ lished landscape. Visual Absorption Capability (VAC) The VAC of a landscape is based on physical factors inherent in that landscape. As there are different types of landscape alterations, the VAC will depend on different physical factors. The following matrix shows the VAC factors pertinent to this example. The VAC information is used to determine how the facilities planned for an area can best be located with the least impact on the landscape. This information also can be used in the preparation of cost estimates as they relate to the visual resource requirements of the area. For example, if facilities must be placed in an area with a low VAC, it will usually be more expensive to meet adopted visual quality objectives than in an area with a high VAC. All these factors were mapped separately on clear acetate combined in an overlay. The com¬ bination of different factors determined the score for the VAC and was then mapped for application in the planning and design process. The map clearly identifies the areas with a high, medium, or low VAC. Total Visual Constraints and Recommendations By combining the visual quality objective map with the visual absorption capability map, the relative total visual constraints for the area can be displayed graphically. Because the degree of visual impact of the area depends on, and is in direct proportion to, the amount of contrast with the natural character of the landscape, the map indicating the total visual constraints is essential for predicting visual impacts. Areas of low and moderately low ability to withstand modifi¬ cation from the visual standpoint are graphically shown on the map and serve as “red flag” areas to the land manager. The “red flag” areas shown on the map are not areas where modifi¬ cation should not take place; rather, they are areas where it would be more difficult and possibly more expensive to retain VISUAL QUALITY OBJECTIVES (AS PER NATIONAL FOREST LANDSCAPE MANAGEMENT. VOLUME 2. CHAPTER 1) R Retention PR Partial Retention fg foreground distance zone mg middleground distance zone I highest viewer sensitivity 8 variety class common to the character type I6 the natural character of the landscape. In the design phase of the proposed development, the designer must be aware of the locations of these visually sensitive areas and the reasons they are sensitive. By referring to the VAC and VQO maps, planners and designers can clearly see why some areas are more sensitive than others. Mountain Capacity and Skiing Quality The number of people that should be accommodated varies widely because of topography, snowfall, esthetic criteria, limita¬ tions of either the base or the mountain, and many other fac¬ tors. Whatever the optimum number of people, space must be reserved at the base to provide parking and the service facilities that ultimately will be needed. The acreage suitable for base facilities varies greatly among areas. To a large degree, the amount of available acreage determines if an area can be developed sufficiently to be a self- contained community or if the area’s success is dependent upon people living within commuting distance. The Forest Service recognizes the expense of developing a resort area and that land sales or leases are often needed to recover initial develop¬ ment costs within a reasonable period of time. There must be a balance between the development opportunities on the moun¬ tain and at the base area. VISUAL ABSORPTION CAPABILITY Score of 10 through 16 - Low Score of 17 through 23 ■ Medium Score of 24 through 30 - High ASPECT RELATIVE 800-100° 60°-80° Less than 60° TO VIEWER 100°-I20° More than 120° EXISTING 1 2 3 VEGETATIVE AND LANDFORM SLOPE 60X + 25-60% 0-25% SCREENING 2 3 ABILITY VEGETATIVE HEIGHT 0-6 ft. 6-30 ft. 30 ft. + 1 2 3 VEGETATIVE DENSITY 0-20Z 20-80% 80%-100% (Summer Months) 1 2 3 LANDSCAPE LANDFORM DIVERSITY Low Medium High DIVERSITY 1 2 3 SOIL PRODUCTIVITY Low Medium High VEGETATION REGENERATION 1 2 3 ASPECT 180°-270O 90-180° 0-90° POTENTIAL 270-360° 1 2 3 POTENTIAL SOIL White to Medium Brown to Black COLOR CONTRAST Yellow POTENTIAL MAGNITUDE 1 2 3 OF SOIL CONTRAST EROSION HAZARD High Medium Low RATINGS 1 2 3 SOIL STABILITY Low Medium High (Mass Movement) 1 2 3 Point Value Each 12 3 An area’s visual absorption capability should be inventoried carefully. Different tree species, color combinations, and a good revegetation potential contribute to a high-rated visual absorption capability. VISUAL ABSORPTION CAPABILITY (V.A.C.) (RELATIVE TO THIS STUDY AREA) 1 T High VA C. ^1^ Medium Low V.A.C. ■■ LOWV.A.C. 17 Planners must carefully consider skiing quality because skiers do not like crowding or congestion, poor snow conditions, or poorly designed runs. If the skiing difficulty of a run changes, it will hinder skiers who cannot easily negotiate the most diffi¬ cult sections. It may be necessary to manipulate run locations to create an ideal proportion of beginner, intermediate, and advanced or e.xpert runs. Such manipulation may lower the capacity of an area but increase its popularity and viability. Heavy skier use can wear out snow, particularly in congested areas. Snowmaking, dispersal of skiers, and distribution of lifts, runs, and other facilities can be used to increase an area’s capacity. Wind, unstable soil conditions, uncontrolled flowing water, esthetic quality, and existing or potential snow condi¬ tions, such as an avalanche, can reduce capacity if not consid¬ ered in the planning stages. Determining an area’s capacity involves many technical, eco¬ nomic, and social disciplines. It is both a subjective art and a quantitative science. Making this determination is time con¬ suming and expensive, but it is an essential element in area planning and should be disclosed in appropriate NEPA documents. I 0 Least able to withstand modification from the visual standpoint I 1 Low ability to withstand modificalion I 2 Moderately low ability to withstand modirication I 3 Moderalely able to withstand modificalion V.Q.O.-VA.C. MATRIX VISUAL AB SORPTION C APABILITY LOW MED. HIGH OBJECTIVE R 0 1 2 PR 1 2 3 L QUALITY M 2 3 4 3 > MM 2 3 4 When planning a winter resort area, the Forest Service is inter¬ ested primarily in obtaining optimum recreation development to serve the general public. Although private land values are affected by the location of resort areas, maximizing the value of individual tracts of private land must be a secondary consid¬ eration of the Forest Service. Development plans for an area must show the placement of skiing terrain in relationship to private lands and the base area. To determine this, approxi¬ mate locations and general specifications of lifts and runs are needed. A legal commitment to use certain private lands between the base areas and National Forest land for parking, ski runs, hiker access, and similar purposes will be needed. As year-round resort communities develop near ski areas, the ski slopes become important hiking and summer recreation areas. When an area is being developed, seasonally changing uses should be considered because the beauty of the mountain itself during the summer will affect the attractiveness of the area as a resort and is an important element in meeting the National Forest recreation goal. Lifts Lifts should be located to serve the best skiing terrain. Ski runs and slopes should be planned to provide the best skiing oppor¬ tunities without wasting terrain. Lifts should then be located to best serve these ski runs. Lifts are merely a means of access, and the type of lift may vary depending on the terrain that it must cross. Seldom should the type of lift dictate the location of ski runs. A lift intended to provide ski run access and scenic views for summer tourists is one exception to this principle. There are various means available for constructing lifts and they should not be located only where good upper and lower 18 This type of trail development with multiple bases ensures good dispersal with little congestion, and wear-out problems are minimized. terminal sites have been selected to minimize construction costs. Of course, costs are important concerns and must be considered equally with the issues of skiing quality, esthetics, and other environmental factors. Structures If there is only one major lift from the base area, lift lines will be long and trails near the base will be congested. Besides considering shops, restaurants, and accommodations for residents and visitors, the impact analysis for the resort complex needs to concern itself with water supply, interpretive services, medical facilities, sewage treatment, community ser¬ vices, service stations, fire protection, law enforcement, and public transportation. Transportation and Parking Planning for transportation is an integral part of the planning process and must reflect the future needs for goods and ser¬ vices from the area and its surroundings, as well as the demands created by the resort. The Forest Service will perform the transportation planning necessary for the multiple-use management of the extensive forest areas that include and sur¬ round a ski resort. In some cases, planning for development or management of resources adjacent to a ski resort may not be complete at the time a permittee wishes to develop a ski area. Development of road systems, inside or outside the permit area, may have to be deferred if a permittee wishes to acceler¬ ate the development. In such cases, alternative methods of facility construction that do not require roads may have to be used. Adjacent private lands that are required for adequate public service must be addressed in the master planning stage. Public service and maintenance buildings, ski runs, lift and terminal structure locations, parking lots, utility systems, and all other buildings should be designed to take advantage of the full potential of the area to minimize visual conflicts, to allow for grading and drainage needs, and to protect and enhance the area’s environmental resources. From a functional as well as a visual standpoint, the design criteria identified in the master plan should be sufficiently detailed to allow for evaluation of it as it relates to the mountain. A w'ell-planned road system is usually needed to ensure an effi¬ cient resort operation. Before construction is begun on any road, its long-range location and use in the overall develop¬ ment should be determined. Certain roads may be needed to provide for future area construction or for transporting sup¬ plies and personnel during the winter. Unneeded roads, on the other hand, may be a liability. Unneeded construction roads to tower locations can be backfilled and revegetated after they have fulfilled their purpose. However, serious consideration should be given to alternate methods of construction if roads will have no subsequent use. 19 The main road system should be located so it will not interfere with the long-term operation of the area. Roads should be located, designed, and constructed to serve the purpose for which they are needed and with consideration for their long¬ term maintenance. Roads can be narrow where they cross ski runs. Culverts can direct water away from ski runs and help control water runoff problems. Switchbacks can be located on flat benches where they will not damage skiing quality, or they can be confined to areas where ski runs will never be needed. The quality of skiing is what draws skiers to a particular area, and it is therefore essential that the slopes be well groomed. Ski runs should be designed so that snow maintenance equip¬ ment can operate efficiently without sacrificing skiing quality. Snowpacking equipment cannot maintain runs that have abrupt road crossings, nor can skiers cross them easily or safely. Runs of intermediate difficulty become more difficult to ski if they are crossed by roads at steep locations. Snowpack¬ ing machines should not cross ski runs at steep locations as they work their way up the hill because these routes become flat “benches” and downgrade skiing quality. Soils After the most appropriate alternatives have been selected for installing facilities and locating ski runs, roads, and other improvements, a detailed site analysis of the soils is usually needed. These studies provide detailed ihformation regarding specific sections of the construction site so that the design can overcome unavoidable limitations or hazards. The expertise of hydrologists, landscape architects, geologists, and engineers is needed to design a system for fragile soils and hazardous sites. Deep borings, laboratory tests, and detailed studies are often necessary. Specific prescriptions may also be necessary to ensure revegetation and stabilization of the site to prevent ero¬ sion or other soil problems during winter or spring. Before a site is approved for resort development, a preliminary soils report must be prepared as part of the environmental 20 While parking lots like this are easy to construct and the simple, uncomplicated design makes snow removal easy, the addition of surrounding vegeta¬ tion or islands of vegetation could have made this lot more attractive. Helicopters can be used for lift tower installation to obviate the need for e.xpensive road construction. Instead of building roads to each tower site for transporting concrete, concrete was pumped to the sites. analysis. It is through this analysis that the basic land use deci¬ sions are made. The preliminary soils report is general, and it estimates the suitability, hazards, and limitations of the area for various impacts. More comprehensive soil studies are needed during the concep¬ tual development planning process carried out by the interdis¬ ciplinary team. These studies are based on soil examinations of the upper 5 feet of the earth’s crust and identify areas where problems exist. Where deep soil situations are significant, or where mass land instability is involved, the services of engineer¬ ing geologists are required. Soil maps showing the extent and distribution of different soils in the area may be needed to show soil descriptions, which are the recorded information of the physical and chemical soil characteristics of each soil body. Soil interpretations are derived from soil characteristics and the environmental influ¬ ence of climate, geology, topography, and vegetation. 21 Soil properties must be carefully analyzed. When the loose topsoil on this steep slope was saturated with water, massive soil slippage resulted. If at all possible, ski runs should not be located over major drainage channels because they can cause severe melting problems in the fall or spring. Hydrology Ski runs in water courses may cause problems for a ski area operator if flowing water melts the snow. This is a common problem in areas where the effects of water runoff have not been considered before ski runs were planned. The problem can be especially critical early in winter when snow depth is minimal. Water should follow a natural course and be directed off the ski slopes. Culverts to carry water are expensive and must be designed to carry the peak load. Utilities Utilities are planned to serve the ultimate development. These plans should include power, potable water, waste water treat¬ ment and disposal, telephone, television, and gas. Onsite impacts should be minimized to protect the visual resources. Utilities should generally be underground. Domestic Water Water needs for new resort communities must be anticipated. Maintaining water quality is important not only to the com¬ munity but to the downstream user as well. Because of prior claims, sufficient water rights may not be available for new resort or community development. Rights must be acquired for both domestic use and snowmaking needs. Sewage Treatment Sewage treatment is closely scrutinized. Such agencies as the Federal Water Quality Administration, State and county health departments, and the USDA Forest Service must review and approve plans before construction of treatment facilities is authorized. This may be a time-consuming process, but it can¬ not be shortened at the expense of public health. Many areas suitable for future development of winter resort areas lie high in the headwaters of domestic watersheds. In such situations, wastewater must receive complete treatment before being released. Power Transmission and Telephones Power lines or telephone cables that are visible from the base or from areas served by lifts should be buried. Consequently, the locations of future lifts and runs must be known before any proposals are made to install lines to lifts and buildings. If the approximate location of all distribution lines can be deter¬ mined during the planning stage, future burying costs can be avoided. Utility companies may require considerable lead time to pro¬ vide new transmission line services to an area. Therefore, basic needs should be estimated several years in advance. Utility consultants often can save both time and money for develop¬ ers. Independent contractors, bidding on specifications pro¬ vided by the consultants, frequently can be very cost- competitive with utility company proposals. Skier Safety and Hazard Management Planners must identify hazard areas throughout the site and must design control procedures, especially for avalanche areas. The cost of effective snow-safety programs almost invariably is underestimated by area planners and developers, perhaps because of a misunderstanding of the problem. Consequently, many large, modern ski areas in the United States face continu¬ ing problems and annual expenses that greatly exceed the amount that the areas’ planners originally spent to evaluate the situation. Such an evaluation is an investment. If done care- 22 fully, it may pay for itself many times over in decreased costs and reduced danger to skiers and facilities. Small, inconspicuous slide paths are a major concern. The large paths are usually well identified. Another problem often results when skiers who are unaware of hazards look for powder snow in the trees adjacent to the cleared slope or when they ski out of bounds into hazardous areas. In addition, roads, parking lots, buildings, lift terminals, and towers are still being proposed by developers for construction in slide paths. Planners often spend insufficient time in the field immediately after storms, or during hazard conditions, to recognize these problems. Identifying them during the summer is often difficult, so historical data should be obtained. Ski area operations are often complicated or disrupted by ava¬ lanche problems. Where avalanche hazards exist, preliminary safety and operating plans, along with cost analyses, should be part of the development plan. The need for artillery or recoilless rifle control measures should be avoided because the equipment will not be available indefi¬ nitely and because ammunition and control crews are becom¬ ing a great expense to permittees. An area should be planned in such a way that control teams can get above the hazards using ski lifts. Teams should be able to ski down to control areas and control avalanches by protective skiing or by using hand charges. Maintaining avalanche weather forecasting instruments and collecting and analyzing data is time consuming, expensive, but essential in high-hazard areas. Permittees are expected to own, operate, and use this forecasting equipment. Major utilities that service winter sports areas do not necessarily have to make a negative visual impact; power lines can be blended into the landscape. In complex situations, a large number of snow' safety techni¬ cians are needed to ensure public safety. Area layout should be such that segments of the area can always be operated while control is being carried out in the more hazardous areas. Vegetation Management To ensure attainment and continuance of the identified desired character of the site, a long-range vegetation management plan should be prepared and implemented in close coordination with the visual management plan. The inventory for this plan should consist of species, age class, disease and insect infesta¬ tions and resistance, wind firmness, reproduction potential, and location of species. This should be done for trees, shrubs, and ground covers. If not managed properly, the forest area remaining between ski runs may deteriorate significantly over time. Exposing trees to wind and sun often accelerates problems. Over time, the viabil¬ ity of the ski resort, as well as scenic quality, may suffer. The timber values on an area may be high enough to warrant commercial sales, and the economic and social benefits of plac¬ ing this material on the market should not be overlooked. Timber management planning and area development planning should be performed concurrently because additional time may be needed for the sale and removal of merchantable timber. In addition, timber contractors have a responsibility to perform logging operations in a manner consistent w'ith the long-term use of the land. The practices necessary for integrated land use should be spelled out in contracts and permits. Air Quality Concern for the environment has led to regulations such as the procedures that were established to govern the burning of wood product waste and other materials in the State of Colo¬ rado. Alternatives to burning must be investigated and used where advisable before burning will be recommended. 23 The visual impact of different types of landscape alterations can be checked for all design alternatives through a true perspective representation viewed from any location. During the actual construction process, a Forest Service permit is required for burning slash. This is coordinated with favora¬ ble weather conditions and low onsite fire indexes. Planning for fireplaces in living units and commercial buildings is an important aspect of the overall master plan. Increases in numbers of wood burning fireplaces has resulted in many situations where local mountain communities have found it necessary to either severely restrict or closely monitor and con¬ trol their use because of seriously degraded air quality. PERSPECTIVE PLOT Computer Graphics Program PERSPECTIVE PLOT (Nickerson 1980), a computer graphics program developed by the USDA Forest Service, can visually model land management activities before they are imple¬ mented. In so doing, this program is fast becoming a powerful tool that allows for proposed designs and impacts (such as ski runs, lift locations, and structures) to be studied from selected viewing positions and adjusted, relocated, or redesigned to meet certain visual objectives. Although origi¬ nally designed as a tool for modeling timber harvest proposals to determine the degree of visual modification that would result, the program is being adapted to model utility corridor proposals, dams, roads, and surface-mining activities. The program is used to visualize the proposed solution, allow¬ ing immediate design changes if the proposed solution is unac¬ ceptable. The designer and decisionmaker can make these design changes and immediately see the changed appearance of the proposed solution. Because of the way the program is designed, the resource manager and designer who use the pro¬ gram need not be computer speeialists. Although originally written for one brand of desktop computer, the program is adaptable to other brands of desktop computers. The actual plotted image of the Hewlett Packard 9845 . In the case of ski area planning and design, the PERSPEC¬ TIVE PLOT program can be used at the master planning level to help indicate possible visual conflicts that might develop because of the general configuration of runs as they are pro¬ posed for the mountain. The program also can be an aid at this level of planning in generally evaluating placement of the major features of the base area, roads, lifts, and other moun¬ tain structures. At the detailed, site-planning stage, the program serves as an excellent guide in the final placement and design of the runs, structures, and roads and will accurately simulate them from critical viewpoints. Specifically, the PERSPECTIVE PLOT program will do the following: • Display proposed run locations as perceived in oblique views. • Show the scale of proposed activities relative to surround¬ ing features and land forms. • Quickly provide comparative differences between various alternative proposals. • Display textural modification in partial-removal timber harvest activities, such as feathering of the edge of ski runs. • Visually display features associated with ski area devel¬ opments (for example, lift line corridors, storage tanks, roads, and mountain structures). • Display screening of planned activities by intervening topography, vegetation, or structures. 24 This actual clearing of ski runs shows how closely the final PERSPECTIVE PLOT simulation depicted the area. Tree shapes can be adjusted to represent the actual appearance of trees. The runs were digitized from the topographic map of the area. 25 The computer printouts can be enhanced by color. V T«jBEAVER CREEK SKI AREA VIEW DIST: <4? INCHES VP:N or VILLAGE 10 0 u> (O rv ?SPEC1TVE RLOTf ru D V in to fs. r>- fsw fs, fv r>. t ■ I < A . CDOjQ-'Cutn^ 7 ^ 3^Tn (SmEfS WITh g^mm LENS"*^ The distorted-square terrain depiction in perspective. An enhanced version of the computer printout of the PERSPECTIVE PLOT depiction. BEAVER CREEK SKI AREA VIEW DIST: >12 INCHES VP IN OF VILLAGE DTM: BEAVER CREEK SKI AREA - 10 Tree edges added to the terrain depiction. Tree massing only, without the terrain model. 26 Detailed Design and Construction Tree massing and lift lines applied to the terrain depiction. Trees can be shown as a combination of hardwoods and softwoods. Detailed site plans and facility designs for the project are pre¬ pared by the permittee, based on the master plan concepts. The Forest Service must approve plans for any project that will affect National Forest System resources; any other authoriza¬ tions that may be needed will be subject to local requirements. Construction may begin only after all plans have been approved. Visual resource management principles must be applied to all phases of the design process, with emphasis on using the design elements discussed earlier. The effects of the project must be analyzed not only from the standpoint of its specific design fea¬ tures but also from the standpoint of the project’s overall design theme. The use of the PERSPECTIVE PEOT computer graphics program, discussed on page 24, can be of great assis¬ tance during this phase of making final design decisions. The highway in the foreground is Interstate 70. Two years later, the effects of the ski area are visi¬ ble everywhere. The major contrast of the ski runs resulted from the straw mulching. 27 Common Areas of Concern Roads Roads are needed for transporting people and supplies to mountain facilities and for moving heavy machinery to con¬ struction sites. Roads also provide access to vegetation treat¬ ment areas, as called for in the vegetation management plan. The visual impact of a road depends largely on its size, where it is located, and how it is molded to the natural terrain. With modern construction equipment and techniques, most of the facility installation on the mountain can be done by air or with equipment designed for overland travel. This is a properly graded road with a shallow drainage ditch. Immediate seeding and mulching will insure a natural appearance in a short period of time. Roads should be constructed so they will last, but visually they should be as unobtrusive as possible. Since traffic ordinarily will be light, roads should be narrow with strategically located turnouts. The visual absorption capability data, described on page 16, will help considerably in determining the best road locations from the visual standpoint. After being designed, roads should be carefully constructed. Tree clearing should be minimized, and cut and fill sections should be blended into the natural terrain. This is especially true where ski runs cross roads, though ski runs should be crossed by roads only when absolutely necessary. All debris, including large rocks, should be used or removed—not simply pushed downhill to the toe of the fill. As soon as possible, all cut and fill slopes should be topsoiled, revegetated, and mulched to prevent erosion. Where excavation exposes light- colored soils that create an undesirable contrast with the sur- The width of this mountain access road is adequate. The cut and fill sections will be fine graded, seeded, fertilized, and mulched. rounding area, efforts should be made immediately to subdue the contrast. Where cut and fill sections would create large scars that cannot be rehabilitated, retaining walls may provide a satisfactory visual solution. Because roads cut across the slope, they will collect runoff water. Consequently, a shallow, lined drainage ditch must be provided on the uphill side. Wherever necessary, culverts must be installed under the road to disperse the water into naturally established drainage areas. Where no natural drainage area is available, the force of the water below the culvert must be dis¬ sipated by a rock bed or a similar surface to prevent erosion around the culvert outlet. The access road to the base area is most important because it offers visitors their first impression of the ski area. The access road should be located to take advantage of the natural ter¬ rain, thereby requiring the least amount of landscape modifica¬ tion. In choosing the road’s location, planners should consider the most pleasant approach to the area. When designing the entrance road, they should consider the users’ safety, snow removal problems, and the area’s appearance during summer and winter. See Volume 2, Chapter 4, “Roads,” of the National Forest Landscape Management series (USDA FS 1977) for more details on visual considerations for road construction. Utilities All facilities in the area are served by at least one utility, such as power, water, sewer, gas, and telephone. To avoid climatic hazards and to improve visual appearance, all utilities should be buried. In addition, they should be located so they can be accessed easily for repair. Burying lines along the main road 28 This is an example of an improperly designed road. Steep cut and fill sections should be avoided, and the road should not be constructed on unstable soils. The cut and fill slopes along this road were well constructed and immediately revegetated to prevent erosion. This road crosses a ski slope, but because of good engineering, it will not interfere with winter use. The cut and fill sections are smooth, and the ditch provides adequate drainage. 29 would provide an easy solution. Certain utility lines could be buried along the edge of the ski runs if the expected incidence of repair is low. Burial of utility lines must be coordinated with all other construction activities to prevent disturbance of areas after they have been graded and seeded. If the lines are buried, the only other impact of utilities will be the switching and metering boxes that are installed above ground. However, vis¬ ibility of these boxes can be minimized by locating them where they will blend with vegetation or buildings and by painting them to blend with the natural surroundings. Where blending is critical from a visual standpoint, the use of architectural screens may be appropriate. Planning utility installations for the total capacity of the area is critical. Plans showing locations of underground lines and aboveground structures will ensure proper blending, will ease access for repairs, and will help prevent damage from other excavations. Water storage tanks can be buried, but they are usually installed above ground. Because of their large size, they should be located where they are not visible. Using vegeta- Electric lines to all mountain facilities were plowed in with minimal disturbance of the ground surface. This job was accomplished in record time with new equipment capable of maneuvering over the moun¬ tain’s steep slopes. tion screening and dark neutral colors and restoring the exca¬ vated area will minimize their visual impact. Microwave reflec¬ tors, repeaters, and substations can also be conspicuous, but if properly located and designed, they can blend into the land¬ scape with little visual contrast. Sewage treatment facilities should be located away from the main use areas. The design and exterior colors of the treatment facilities should blend with the architectural theme of the area and its natural surroundings. To achieve a natural blending with the surrounding area, a landscape plan should be deve¬ loped using natural plant materials found in the area. Because many utility lines are now buried, the visual impact in most instances is negligible. The utility equipment that must be above ground should be designed carefully to fit the desired character of the area. Close coordination with the utility com¬ panies during the planning and design stages can eliminate objectionable visual impacts and the need for expensive screen¬ ing structures or plantings for aboveground utility installations. More detailed information about utilities is available in Volume 2, Chapter 2, “Utilities,” of the National Forest Landscape Management series (USDA FS 1975). Signs Signs serve four basic purposes: they provide direction to dif¬ ferent facilities; identify facilities, features, and hazards; convey rules and regulations; and give information and provide interpretation. 30 Water and sewer pipes usually require extensive excavation. It is important to complete this type of work before the ski runs are revegetated. Dark green was chosen as the color for this water tank because it is surrounded by spruce trees. The reflectivity of the paint will be dulled over time. The appearance of this water tank can be softened with proper landscaping and a color that blends better with the background. Sign designs, supports, and materials must be chosen carefully to create the desired effects. 31 Chairlifts 7&9 M•'* C wK \ ywTi'i i*'<'.*i Chairlift 6 Download I :■ r.'jK *i!i.-:£! WP%1 i'q Sign design should be simple and the message should be clear. s di i J jl Pedestrian circulation in villages should be antici¬ pated and protected by only allowing service vehi¬ cles into the area. 43 A reception center can serve a dual purpose of providing the necessary services to visitors and accommodating the needed administrative space. The town hall, lodge, condominiums, and facilities are combined in this base facility. 44 Ski school areas should be located away from the main traffic areas to avoid interference. designed to provide quick and easy access to the terminals from all points in the base area. Access from the lower runs should be easy and free of dangerous cross traffic. Three aspects of visual quality should be considered; architec¬ tural style, color, and materials. If the terminals are coordi¬ nated with other base facilities and the mountain facilities, then the visual integrity of the site should be ensured. Ski School Area The ski school is a basic component of every ski area. It usu¬ ally consists of a meeting place, a gently sloping open area, and short lifts or tows. It is an introductory area that should be eas¬ ily accessible from the parking area, lodge, and restaurant. Therefore, from the visual standpoint, designers should give primary consideration to the area’s natural appearance in both summer and winter. As on the ski runs, the edge effect of the vegetation should appear natural. The edge should have a variety of species and age classes of trees and shrubs, and it should imitate natural openings within the landscape character type. If summer use is planned, signs that apply solely to winter use should be removable. Permanent structures in the area should be colored to create as little contrast with the surroundings as possible. Recreation Facilities At a major destination resort, a variety of recreation facilities are usually provided for visitors and residents of the area. Dur¬ ing winter, downhill facilities, cross-country ski trails, and ice skating facilities may be provided. In summer, the facilities usually include a golf course, tennis courts, hiking trails, and swimming pools. These facilities are usually located on private land near the village and the residential areas. If properly designed, golf courses serve a dual purpose: they provide for an mportant recreation activity, and they provide open green space within the resort area. From the visual standpoint, this green space helps to integrate the manmade structures with the natural surroundings. It is important to develop a vegetation management plan for golf courses if the vegetation is to be retained or improved. The tennis courts usually have a more pronounced visual im¬ pact because of the paved areas, high fences, and cloth screens, so their location is usually more critical from the visual stand¬ point. With proper landscape treatment, the impact of the ten¬ nis courts can be softened considerablv. 45 The area along this slide on private property was well graded and sodded to prevent erosion. The rest of the area was seeded and mulched. Use of a darker color on the slide would eliminate the con¬ trast that makes the slide so visible. Hiking trails have minimal visual impact. Consistent signing and maintenance should be provided. These trails can serve a dual purpose if they are used for cross-country skiing during the winter. In recent years, alpine slides have been installed in a few ski areas. No matter how carefully the slide is installed, its light color creates a strong contrast that dominates the surrounding landscape and can be seen from considerable distances. The only way this contrast can be reduced is by using a dark- colored material for the slide. If alpine slides are approved in the master plan (as may be the case at a private land ski area) a visual study of the area should be made to determine how to minimize the visual contrast. Residential Developments Residential developments consist of either condominiums or detached homes. As in the village development, regulations and guidelines are the way to ensure that the buildings satisfac¬ torily achieve the desired character of the area. The design guidelines and codes for residential developments need to be written to ensure that the naturally established landscape is protected to the greatest extent possible. Administrative Facilities Once a resort complex reaches the “village” size, it usually requires its own administrative facilities, such as a clinic or small hospital, a fire station, police facilities, road construction and maintenance equipment facilities, mass transit facilities, a village hall, and employee housing which is usually a high- density apartment complex with an access road, parking, and recreation facilities. The size of these developments will depend on the number of employees needed to service the resort com¬ plex adequately and the amount and cost of private land avail¬ able for such facilities. As in other areas, the design theme of the entire area should be carried through to ensure the area’s visual integrity. The visual integrity of these facilities will be achieved by fol¬ lowing the design guidelines. Maintenance Yard A lot of large equipment is needed to maintain a winter sports area. Because this equipment has to be stored, maintained, and repaired, a large, out-of-the-way area with easy access to the slopes has to be planned as a maintenance yard. Unless special design precautions are taken, a maintenance yard can have a negative impact on the appearance of a base area. The equip¬ ment storage area should be screened from view with vegeta¬ tion or with a constructed screen. Such screens usually have a harsh appearance and should be softened by appropriate plant¬ ings and colors that blend with the surroundings. To provide visual continuity, maintenance buildings should be designed to comply with the architectural theme of the area. 46 By following the established design regulations, condominiums can express their own charm in keeping with the design theme of the area. Large areas are required for storing motorized equipment, which may have strong contrasting colors. This is one of the maintenance buildings immedi¬ ately after its completion. Grading and landscaping will blend this and the other maintenance buildings with the surrounding area. Residential development is of major importance in resort complexes. Architectural and landscape design control throughout the development is a key to ensuring the visual integrity of the area. 47 Monitoring In closing, it should be pointed out that the desired results of all the planning, design, and construction activities can be bet¬ ter ensured by monitoring. There are many kinds of monitor¬ ing; that which involves the appearance of ski areas is usually done photographically (still, motion picture, or time-lapse). It can be done rather easily by identifying the important view¬ points and then establishing photo points. Pictures are then taken at time intervals corresponding to initial site investiga¬ tions, seasonal vegetation color and texture changes, precipita¬ tion patterns, and stages of construction. This photographic coverage can be invaluable in the design and planning of both the initial area and its future expansion. It also assists the ski area permittee and the Forest Service in determining how well the desired results are being attained over time. These results demonstrate the application of visual resource management principles, which has been the goal of this book. The Beaver Creek base area and lower mountain be¬ fore any major construction work was done. 1978 — Fall colors should definitely be considered in evaluating the visual impact of any landscape alteration. 48 1979—The ski runs have been cleared, seeded, and mulched, and base area construction has begun. 1980—The parking garage is now visible in the base area, and work has been started on the ski runs on the west mountain. 49 Literature Cited Beaver Creek Resort Company. Beaver Creek design regula¬ tions: Single family and duple.x residences. Vail, CO; 1979a. 44 p. Beaver Creek Resort Company. Beaver Creek design regula¬ tions: The village. Vail, CO; 1979b. 74 p. Nickerson, Devon B. Perspective Plot; An interactive analyti¬ cal technique for the visual modeling of land management activities. R6-TM-031-1980. Portland, OR; U.S. Department of Agriculture, Forest Service, Pacific Northwest Region; 1980. 145 p. U.S. Department of Agriculture, Forest Service. Planning con¬ siderations for winter sports resort development. Washing¬ ton, DC: U.S. Department of Agriculture; 1973. 55 p. U.S. Department of Agriculture, Forest Service. National Forest landscape management: Volume 2, chapter 1: The visual management system. Agric. Handb. 462. Washington, DC: U.S. Department of Agriculture; 1974. 47 p. U.S. Department of Agriculture, Forest Service. National Forest landscape management: Volume 2, chapter 2: Utilities. Agric. Handb. 478. Washington, DC: U.S. Department of Agriculture; 1975. 147 p. U.S. Department of Agriculture, Forest Service. National Forest landscape management: Volume 2, chapter 4: Roads. Agric. Handb. 483. Washington, DC: U.S. Department of Agriculture; 1977. 62 p. Other Publications in the Landscape Management Series U.S. Department of Agriculture, Forest Service. National Forest landscape management: Volume 1. Agric. Handb. 434. Washington, DC: U.S. Department of Agriculture; 1973. 76 p. U.S. Department of Agriculture, Forest Service. National Forest landscape management: Volume 2, chapter 3: Range. Agric. Handb. 484. Washington, DC: U.S. Department of Agriculture; 1977. 44 p. U.S. Department of Agriculture, Forest Service. National Forest landscape management: Volume 2, chapter 5; Timber. Agric. Handb. 559. Washington, DC; U.S. Department of Agriculture; 1980. 223 p. U.S. Department of Agriculture, Forest Service. National Forest landscape management: Volume 2, chapter 6: Fire. Agric. Handb. 608. Washington, DC: U.S. Department of Agriculture; (in press). 51 Appendix —Beaver Creek Design Regulations (excerpts) Design Theme The overriding design philosophy of Beaver Creek is to estab¬ lish a remote village with its own identity, an imaginable place, complementing rather than competing with the natural landscape. The architectural theme for Beaver Creek has been directed at establishing a compatibility between buildings and the natural environment, fulfilling the expectations of visitors as a retreat to the mountains, respecting the historic precedent of moun¬ tain buildings in both Colorado and Europe, and utilizing energy conservation and solar energy applications. As seen from a distance, the Village should be understated and uncomplicated, made up of simple forms and consistent roof lines. In contrast to this, the central pedestrian area of the Vil¬ lage should have an exciting vitality and broad individual expression. In order to more clearly interpret the design theme for Beaver Creek architecture, three levels of perception, e.g., ways in which the community will be observed, have been identified, each with its own set of considerations. ®I979 Beaver Creek Re.sort Company- reproduced with permission from Vail Associates, Inc. Perception Level I—The Village Within the Landscape At a distance the Village is seen either from the mountain look¬ ing down, or from the entry road upon arrival. Due to vegeta¬ tion masses, as well as site lines created by the terrain of the area, the roofs will become the dominant element at this level of perception. At this scale, the Village should be composed of simple understated forms with an overall consistency of materials and color. Roofs shall be simple hip and gable forms. Variety should be a response to changes in topography and exterior spaces. Materials and colors shall be relatively subdued with nonreflec- tive surfaces. The golf course from below and the ski slopes from above will tend to set the Village in the natural and open landscape. Aspen and spruce forests on the east and west will have the effect of fusing the edges of the Village into the landscape. The buildings from the south should open to the sun and from the north be closed to cold exposures. This contrast is similar to the extreme variation of the natural landscape between north and south facing mountain slope environments. Residential areas should blend structures and landscape, respecting natural landforms and existing vegetation. The primary focus should be the Village with an intensity of struc¬ tures contrasting with the low density and undeveloped areas surrounding it. 54 Perception Level II—Building and Public Spaces The second level of perception of the Beaver Creek Village will occur within the streets and public spaces of the project. At this level of perception, the exterior walls become the domi¬ nant element, establishing the overall scale, and defining the public spaces and pedestrian circulation routes within the Vil¬ lage. It is important that the sequence of public streets, walls, and plazas be continuous within the Village, enhanced by minor angular changes and avoiding rigid 90° patterns. Subtle changes within wall and street alignments will create interesting streets and walls with constantly changing frontages and points of focus. The visual expression of the wall shall be predominantly mass at the pedestrial scale, punctuated by window and door open¬ ings. On upper levels, openings shall be not more than 20% of the exposed wall area on the north, west, and east, with unlim¬ ited opening to the south responding to sun exposure and mountain views. Window and door openings should be placed in a casual or random pattern avoiding rigid symmetry, repeti¬ tion, and formal patterns. In order to achieve continuity within the landscape and within the Village itself, it is important to have building-to-building and building-to-public open space connections. These can take the form of overhead bridges, retaining walls, terraces, and private courtyards leading to public plazas and malls. 55 Buildings should express the structure in a rational manner with elements such as massive bearing walls and timber fram¬ ing. Design should avoid visually contradicting structural relationships. The use of materials becomes increasingly important at this level of perception, and materials should respond to the follow¬ ing uses; • Framing Heavy timber, wood trusses, and connection details are encouraged as exposed framing elements. These become especially important in establishing interesting interiors. • Nonstructural Surface Materials—Upper level wall surfa¬ ces which appear to be non-loadbearing can be sheathed in wood siding, which should be left naturally weathered or bleached to complement other natural materials such as native rock. Stucco shall not be used as in-fill material, but rather as an expression of mass. Roofs should be made up of unit pieces of clay tile. • Mass—Generally, the lower levels of the buildings near the pedestrian areas should be expressive of mass and sub¬ stantial structural strength. Materials such as rock or plas¬ ter shall have irregular surfaces without modular patterns, precision lines, or perfectly flat surfaces. The massive por¬ tions of buildings shall have an expression of depth, sub¬ stance and strength, not mere surface coverings. Windows and door reveals should have substantial depths, allowing room for interior nooks and recesses within the walls. Masonry wall colors should be generally warm off-white tones, complementing naturally weathered wood and rock colors. 56 Perception Level III—Building and Landscape Details • Details—Elements such as window and door openings, balconies, trim, graphics, signs, street furniture, water, paving patterns, surface textures and color provide the third level of perception within the Village and offer the opportunity for maximum interest and individual expres¬ sion. It is intended that maximum individual expression be allowed in these details to achieve a richness and vital¬ ity within the Village. Details and trim should avoid refined, highly technical finishes and, where possible, should represent handcrafted quality, especially where they are prominently visible to pedestrians. • Color—The use of color is very important to the visual richness of the Village. While major wall surfaces should be a neutral backdrop of off-white tones, smaller scale elements such as doors, window trim, signs, soffits, and recessed wall areas should introduce a strong palette of color to the Village. • Artwork—The cultural vitality of the area should be expressed through artwork within the Village buildings, streets, and promenades. Sculpture, fountains, ironwork, and wood carving should become integral to the design of buildings and public spaces. 57 • l.ighting —Lighting establishes the mood and awareness of the Village scene during the active evening hours and is therefore critical to the aesthetic and commercial success of the Village. Overall ambient lighting of public streets and spaces should be understated with minimum glare from fixtures. This subdued background light provides the context for the highlighting of architectural features, art¬ work, and planting. Shop fronts should include window signage lighting, which also provides indirect lighting of adjacent pedestrian areas. Light sources should generally be concealed unless used as decorative features. All major projects should engage a professional lighting consultant and their design should be coordinated with adjacent properties. 58 Architecture Roofs All major roofs shall have pitches not less than 6:12 and not greater than 12:12. Major roof forms shall be restricted to gable and hip roofs. Secondary roof forms attached to the major building form may be shed roofs with pitches not less than 4:12. Dormers should be relatively small in proportion to the overall scale of the roof. They should be gable, hip or shed forms. Pedestrian and vehicular areas shall be protected from roof snow shedding where roof pitches exceed 6:12. This can be accomplished through secondary roofs, snow clips and snow fences on roofs. All roof structures shall be designed to con¬ duct rain and snow melt water in such a way as to prevent it from creating a dripping, icing or flooding menace on pedes¬ trian or vehicular areas below. The Design Review Board shall review projects on an individ¬ ual basis to assure that adequate systems and devices are installed to allow safe and effective removal of snow from roofs. In the Village, all roof material shall be flat-profile unglazed tile as approved by the Design Review Board. Flashing, gut¬ ters, and bay window roofs should be copper. All structures in the Village shall have a cold roof assembly or written approval from the Design Review Board for an alterna¬ tive method of preventing ice build-up along the eaves. Outside the Village, roof material shall be unit pieces such as slate, flat-profile unglazed tile, cedar shingles, or continuous vertical boards over built-up roofing. Tile colors shall be blue- gray, green-gray, or brown-gray and should have a weathered appearance. Glazed tiles, metal roofing and asphalt shingles shall not be used. It is recommended that cold roof design be used for roofs over heated interior spaces to avoid ice damage to the roofs and eaves. 59 Building Height Limitations Building height limitation within the Village (Tract A) shall be restricted to 55' from finished grade to a point midway between eave and ridge. Building height limitation outside the Village shall be restricted to 35' from finished grade to a point midway between eave and ridge. The building height definition for complex buildings is as follows; Exterior Walls Major building forms should express a simplicity and direct¬ ness responsive to the heritage of mountain architecture. Com¬ plexity and contradiction of form and expression should be avoided. Major exterior walls should convey a sense of mass through plaster or rock. Window openings in mass walls shall be rela¬ tively small in scale and be used in an informal pattern on the wall, with deep set reveals and varied proportions. Plaster shall have a soft undulating appearance similar to adobe, with an avoidance of sharp edges. Both plaster and rock shall always express mass and not be used as in-fill panels. In contrast to the mass walls, vertical wood siding can be used as a sheathing, especially at gable ends and upper levels. Glass can also be used to contrast with the mass walls on southern exposures (see section on Solar Design Guidelines). Generally, the heavier rock and plaster surfaces shall be below, and visu¬ ally supporting the lighter wood-sheathed elements above. Wall materials should respond to the orientation of the build¬ ing, with the north closed off (small window openings) and the south open to sun exposure (see section on Solar Design Guidelines). 60 Only the following materials shall be used for exterior walls; • Wood siding. In the Village, natural wood (western cedar or redwood) sound tight knot or better, without heavy pigment stain or paint. An Eagle County variance allows non-fire-rated wood up to a height of 50 feet above grade. Where wood is used above 50 feet only NCX-treated red¬ wood is permitted. Outside the Village, natural wood (western cedar, redwood, spruce, or pine). • Plaster (stucco or Drivit/Settef) in warm off-white colors. Refer to the Color Guide. • Rock, approved by the Design Review Board. Rock walls shall have deep reveals between rocks and minimum expo¬ sure of mortar. Violcanic rock andunit masonry are not acceptable as exposed exterior material. Rock walls shall be laid in a random pattern. • Exposed concrete, preferably textured and tinted with a warm tan or brown additive, will require specific written approval of the Design Review Board. 61 Colors The colors of the Village should relate to the levels of percep¬ tion discussed in the Design Theme. From a distance, colors should blend with the natural landscape; the predominate roof color should be the blue-gray tile. Within the streets and public spaces, the enclosing walls should be predominantly warm off- white colors tinted from beige and tan to subtle mauves and earth tones. The details such as window trim, soffits, and graph¬ ics should be accented with rich color against this subdued background. The winter climate of Beaver Creek suggests the use of warm colors—ochre, rust, yellow, orange sienna—for details to en¬ liven the Village streets and provide a psychological and visual warmth to the area. See the Color Guide for specific color descriptions. Windows Window casing shall be wood. Approved finishes are natural, stained, painted or clad. Exterior window trim shall relate to other building materials, either wood or masonry. The use of headers and sills, designed integrally with the wall, is encour¬ aged. Window locations should appear in a random pattern, rather than in a symmetrical, repetitious or formal pattern. Refer to the Color Guide for acceptable exterior window cas¬ ing and rim colors. Windows shall be used in combinations to avoid large uninter¬ rupted glass areas. Windows shall have a double or triple glaz¬ ing. No uninterrupted glass area shall exceed 20 square feet. Mirrored glass is not allowed. If shutters are used they shall be operable and not used merely as an ornament. 62 Historic Preservation The Beaver Creek Valley has had a history typical to many high mountain valleys in Colorado. The valley has seen the passing of Lite Indians, fur trappers, adventurers, loggers, min¬ ers, and ranchers. Each has left a heritage with the valley which can and should be reOected in the architecture and artwork of the present destination resort. While the intent is not to recreate past eras, it is appropriate to respect and recall the times, structures, and people that have influenced the area. Many of the early homestead structures of the valley will be restored as part of the recreation and trail system of Beaver Creek. In addition, there are many historic photographs and artifacts which are available through the Design Review Board for possible incorporation into new buildings and interiors. Many of the personalities, events, equipment, and folklore have been used for trail names on the Beaver Creek mountain and are equally appropriate for names within the Village. The Beaver Creek design theme has incorporated the simple forms, pitched roofs, and native materials of early valley struc¬ tures. New development should further respond to historic influences through interpretative details and artwork. Reference; June B. Simonton, Beaver Creek: The First One Hundred Years (1980). 63 Foundations Foundation walls shall not be exposed for more than 8" in a vertical direction, unless they are faced with wood, plaster or rock as delineated in the section on Exterior Walls, or unless written approval is obtained from the Design Review Board for exposed foundation walls. Such visually exposed concrete or block masonry foundations shall be stained or textured as required by the Design Review Board. Foundations shall be designed by an architect or professional engineer to be consistent with the soils reports for the specific site. Service Areas Each building shall have a service and trash removal area(s) which shall be fenced, walled or bermed from public view, and provide access which does not conflict with pedestrian circula¬ tion. Trash containers shall be inaccessible to wildlife. Fencing or walls shall be compatible with the materials and forms of the building. Refer to section on Walls and Fences. 64 Walls and Fences Within the Village, adjacent to the plaza and mall, walls shall conform with the colors, textures and forms of adjacent build¬ ings and be constructed of the following materials: • Rock approved by the Design Review Board. Rock walls shall have deep reveals between rocks and minimum expo¬ sure of mortar. Volcanic rock and unit masonry are not acceptable as exposed exterior material. Rock walls shall be laid in a random pattern. • Plaster (stucco or Drivit/Settef) applied to a subsurface strong enough to prevent punctures or flex cracking. Plas¬ ter shall have a soft undulating appearance similar to adobe, with an avoidance of sharp edges. • Concrete, tinted tan or light brown, and textured or board-formed. This material will be allowed only if it is designed in a manner which relates to adjacent buildings and surrounding landscape improvements. Wood fences shall not be used in the village. Outside the Vil¬ lage, fences shall be rock walls or a horizontal see-through wood such as split rail or buck fences, except for screening ser¬ vice areas, where fences shall be solid and compatible with the structure. All wood fences, if not rock wall, shall be left natu¬ ral, stained or oiled, but not painted. 65 Patios and Decks Paving material for patios and decks adjacent to the Village pedestrian street shall be similar to, and compatible with, the pedestrian street paving material in both color and size. The paving material shall be red sandstone unless an alternative material is approved by the Design Review Board. Chimneys, Flues and Roof Vents Chimneys and flues shall be designed in such a manner so as not to cause fumigation of ground level areas or adjacent buildings during downslope wind conditions. Chimneys should be located high on the upwind side of the building as the best means to insure adequate disbursement. Vents and flues shall not be exposed galvanized pipe, but rather attempts shall be made to group these roof projections and conceal them from public view. This can be done by enclosing them in forms compatible with the structure. 66 Site Plan Building Siting Building siting within the Village is critical due to the close integration of public spaces and adjacent buildings. This rela¬ tive tightness of spaces within the commercial core area has been established to create the scale of the pedestrian village. In establishing locations and siting, buildings shall relate to adja¬ cent and surrounding structures. It is important to consider the “void” or exterior spaces between buildings which will provide the public spaces, streets and arcades within the Village. Study of these areas should include evaluation of mass models which describe the surrounding buildings, as well as the building under consideration. Building siting within the Village shall relate to the movement and circulation patterns of the Village. This includes a strong integration of retaining walls, walkways, patio decks, and plant¬ er areas which help establish and direct the flow of pedestrian and vehicular traffic. Pedestrian circulation should be continu¬ ous, without interruptions or barriers. All buildings within the Village area will be required to main¬ tain a proper setback for building code and fire regulations from their common and respective property lines. Service access and public arrival points shall be established in the initial site plan studies. Outside the Village, building siting shall be especially respon¬ sive to features of the existing terrain, drainage patterns, rock outcroppings, vegetation, views, and sun exposure. Landscaping and grading for any site shall interface with all adjacent properties. The developer shall indicate the means of accomplishing this interface in his landscape plan. 67 Grading Grading requirements resulting from development shall be designed to blend into the natural landscape. Cuts and fills should be feathered into the existing terrain within the prop¬ erty boundaries. Retaining walls and cribbing should utilize natural materials such as wood timbers, logs, rocks and tex¬ tured, board-formed or color tinted concrete. Slope of cut and fill banks should be determined by soil characteristics for the specific site to avoid erosion and promote revegetation oppor¬ tunities, but in any case should be limited to a maximum of 2; I slope. I'tilities All trunk utility lines and pipes at Beaver Creek are under¬ ground. Connections from trunk lines to individual structures must also be underground. Sewage disposal systems shall be installed pursuant to the regulations of the Upper Eagle Valley Sanitation District. No individual septic and leachfield sys¬ tems, nor individual wells are allowed. Drainage There shall be no drainage across neighboring property lines unless written approval is obtained from the Design Review Board. Within the Village, curbs and gutters are to be used only when severe drainage problems are present. Storm drainage shall be connected to the storm sewer mains wherever practical and shall not be connected into the sanitary sewer system. Outside the Village, drainage patterns within the site may be modified, but the modification must be consistent with the Beaver Creek Master Drainage Plan. There shall be no curbs and gutters without written approval of the Design Review Board. Storm drainage shall not connect into the sanitary sewer systems. In all areas, runoff from impervious surfaces, such as roofs and pavement areas, shall be directed to storm sewers, to natural or improved drainage channels, or dispersed into shallow sloping vegetated areas. Exterior Mechanical and Electrical Equipment All outdoor utility tanks, metering devices, transformers and other similar devices shall be concealed from the view of public spaces and neighboring properties. No exterior antenna shall be erected without specific written approval of the Design Review Board. See the section on Walls and Fences for means of enclosure. 68 Landscape Driveways Driveways leading to building entries or public arrival points within the site boundaries and connecting to the paved portion of any street (including the construction of any culverts, land¬ scaping, maintenance, and snowplowing that may be neces¬ sary) are the responsibility of the owner. Maximum driveway grades shall not exceed 5 percent for the first 20 feet from the roadway, and shall not exceed 10 percent elsewhere. Driveway surfaces shall be asphalt, cobbles, or sandstone pavers. In addi¬ tion, the owner shall comply with all regulations of the Beaver Creek Metropolitan District pertaining to the construction of any part of the driveway built within the District’s road easement. Paths and Walkways Paths and walkways provide the critical pedestrian connections of the Village. Every project must include the design of conve¬ nient pedestrian routes as part of an integrated master plan system for Beaver Creek. Walkways should include points of interest, activities, and design features along their routes. Fountains, benches, sculpture, bridges, and archways should become part of the pedestrian experience. Vertical changes should be accomplished through ramps or stairs with 6 inch risers and 16 inch treads to accommodate ski boots. Surface materials should be rich and varied at focal points using cob¬ bles and sandstone pavers. Connecting links of major routes may be surfaced with asphalt, concrete, or sandstone pavers. Minor paths may use wood chips, crushed rock, or asphalt. Major routes should be a minimum of 6 feet in width and ligh¬ ted for evening use. 69 Erosion Control and Revegetation An initial Erosion Control and Temporary Site Stabilization Plan is required for each project prior to Sketch Plan Ap¬ proval (see section on Design Review Process). A detailed permanent Erosion Control and Revegetation Plan is required prior to Final Plan Approval. These plans shall explain in detail the following: • Measures to control both ground water and surface water runoff; • Temporary measures to retain all eroded soil material on site during construction; • Measures to permanently stabilize all disturbed slopes and drainage features upon completion of construction. The owner/developer shall, for Sketch Plan Approval, list and describe those techniques he plans to use during excavation and construction, and indicate on his Site Plan drawings their locations, construction details, and time of installation. The owner/developer shall, for Final Plan Approval, list and de¬ scribe on his Landscape and Planting Plan those techniques he plans to use upon completion of the project to permanently revegetate and stabilize all disturbed areas and drainage features. The major concerns addressed by both plans shall be the reduction of erosive potential and control of transported sediments. Landscaping and Plant Materials Landscape scale and overall landscape design shall be devel¬ oped so that one senses that new vegetation is integral with the natural mountain landscape and the inherent form, line, color, and texture of the local plant communities. New planting should use plants that are indigenous to the Rocky Mountain alpine and sub-alpine zones and should be located to extend existing canopy edges or planted in natural looking groups. Ornamental plants are recommended only for locations directly adjacent to building masses or in courtyards. Manic¬ ured or groomed yards shall be within areas defined by build¬ ings, fences, walls or other defined edge modifications so that the visibility of these yards is limited to the adjacent building. Opaque plantings at traffic intersections are not permitted. Plant materials used for erosion control shall establish imme¬ diate surface stabilization to prevent soil erosion. Diverse, self- sustaining plant species will be used to provide 80 percent sur¬ face cover within one growing season. 70 Building Siting Any single family, primary; secondary structure or duplex structure built upon any lot within the affected property must be built entirely within the building envelope for such lot. However, with prior written approval of the Design Review Board, minor encroachments outside such building envelope may be permitted for roof overhangs, balconies, service areas, porches, patios, carports, and garages. The purpose of the building envelope is to reduce uncertainty of neighbors as to which view corridors might be impacted in the future by con¬ struction and to help insure that structures blend with the sur¬ rounding landscape, rather than being a dominating feature of the neighborhood community. Building siting shall be responsive to existing features of ter¬ rain, drainage patterns, rock outcroppings, vegetation, views, and sun exposure. Landscaping and grading for any site shall interface with all adjacent properties. The developer shall indicate the means of accomplishing this interface in his landscaping plan. Fences Fences shall be rock walls or a horizontal see-through wood such as split rail or buck fences except for screening service areas where fences shall be solid and compatible with the struc¬ ture. All wood fences shall be left natural, stained, or oiled, but not painted. 71 I ^ 6 So I Ll^ So, 6 c_crjO cP- Cooperative State Research Service Agriculture Handbook No. 618 UNIVERSITY OF ILLINOIS ^ ^ , BGRICULTURE LIBRARY opruce Budworms Handbook \ y Planning Insecticide Application and Timber Harvesting in a Spruce Budworm Epidemic In 1977, the United States Department of Agriculture and the Canada Department of the Environment agreed to cooperate in an expanded and accelerated research and development effort, the Canada/United States Spruce Budworms Program (CANUSA), aimed at the spruce budworm in the East and the western spruce budworm in the West. The objective of CANUSA was to design and evaluate strategies for controlling the spruce budworms and managing budworm-susceptible forests, to help forest managers attain their objectives in an economically and environmentally acceptable manner. The work reported in this publication was wholly or partially funded by the Program. This manual is one in a series on the spruce budworm. canu!A3 Canada United States Spruce Budworms Program April 1984 9 Contents Introduction. Protection Planning. Vulnerability of Budworm Host Trees. Identifieation of Management Goals. Analysis of the Resource. Definition of the Protection Zone. Detailed Hazard Rating. Aircraft Guidance and Targeted Spraying. Harvest Planning. Management Objectives. Forest Management Guidelines. Silvicultural Considerations . . . High Priority for Harvest. Moderate Priority for Harvest . Low Priority for Harvest. No Harvest. Stand Prescriptions. Summary. Literature Cited. AGRICUlTURf U8fc„ APR 1 2 1989 Ml. 4 6 6 6 7 11 12 13 17 17 18 20 23 23 23 24 24 28 29 3 Planning Insecticide introduction Application and Timber Harvesting in a Spruce Budworm Epidemic by John B. Dimond, Robert S. Seymour, and D. Gordon Mott* Until about 1980, spray blocks in spruce budworm protection programs tended to be large, often encompassing several townships, and were geometrically regular in outline. Block design was based on the cost of operating spray aircraft; there were few turns and little flying with spray booms turned off. In the process, stands with relatively few budworm host trees were sprayed along with the highly vulnerable, well-stocked spruce-fir flats. It was believed that any killing of budworms was useful, reducing the likelihood that treated stands would be reinfested. We now realize that spraying has little or no effect in suppressing a spruce budworm outbreak; populations in sprayed blocks are reduced for only a year or two. Rare exceptions are isolated areas with no upwind infestation to recolonize treated areas (Dimond 1976). In a given year, it has seldom been feasible to spray more than 10 percent of the 100 million acres (40.5 million ha) currently infested in Eastern North America. Because spraying cannot suppress outbreaks, its primary purpose is to protect trees from excessive defoliation and prevent mortality. As a result, economic, environmental, and social ' John Dimond and Robert Seymour are with the University of Maine at Orono, in the Entomology Department and the College of Forest Resources, respectively. Gordon Mott recently retired from the USDA Forest Service, Northeastern Forest Experiment Station, Orono, Maine. 4 Figure 1 —Spray acreage (crosshatched areas) on two townships in Maine from 1978 to 1981. Sprayed acres were reduced from about 30,000 to about 12,000 (12,140 to 4,856 ha). considerations dictate that we should spray as little as possible to achieve management goals. This awareness has led to major revisions in the size and shape of spray blocks (fig, 1), a strategy known as targeted spraying. Combined with judicious selection of harvesting options, targeted spraying can significantly reduce the use of insecticides while sacrificing little forest value. In this handbook we describe this process as it has evolved in Maine, though the principles apply anywhere. The discussion will be in two sections; protection, which involves use of chemical or biological insecticides, and harvest planning. 5 Protection Planning Vulnerability of Budworm Host Trees Studies during the current and earlier spruce budworm outbreaks show that vulnerability to budworm damage varies by tree species, stand type, and age (MacLean 1980, 1982; Mott 1980) (table 1). As a result, the resource should not be considered simply as either vulnerable or not, to be sprayed or not. With greater discrimination, managers can elect to protect some land on an ownership frequently, some less frequently, and some rarely or not at all. Identification of Management Goals On small, nonindustrial ownerships, attempts at annual production and removal of spruce-fir forest products may be unrealistic in a budworm outbreak. If markets are available, the vulnerable stands can be harvested, avoiding the investment in spraying them. On large ownerships, sustained yield limits the harvest or salvage approach to a small fraction of the land in the short term. Because spraying is currently the only means of keeping the resource alive, its use must be considered, but can be restricted to only that portion of the total resource that is needed to fulfill management goals. The Green Woods wood supply/forest protection model (Seymour et al., in press) can be used to determine if there is surplus wood. Starting from input data on the nature of a manager’s forest resource, the model simulates the processes of forest growth, harvesting at prescribed levels, removing inventory through budworm mortality, and regenerating killed or harvested acreage. The model predicts the structure of the forest in future years for different levels of harvesting and different amounts of spraying. The area that Table 1 —Vulnerability of forest stand types to spruce budworm damage Vulnerability Tree species Age Composition Basal area of balsam fir' High Balsam fir Overmature Pure host F fiacre 120 M'lha 28 Medium White spruce Red spruce Mature Young^ Mixed wood 75 17 Low Hemlock Black spruce’ Seedlings’ Hardwood 20 5 Nil pines, larches Others Pure nonhost ' From Batzer and Hastings 1981. ^ Vulnerability of young age classes increases if overtopped by or downwind from highly vulnerable stands. ^ Vulnerability of black spruce may be increased in certain situations; reasons for this increased vulnerability have not been determined. 6 Total inventory (cubic feet x 10*) Annual harvest (cubic feet x 10^) 2 6 10 14 Figure 2—Nomogram used to analyze results of the wood-supply model. The contours show changes in the spruce-fir inventory 40 years from now due to changes in annual harvest level and size of the area protected from spruce budworm damage. must be sprayed to maintain a sustained annual harvest can be estimated (fig. 2). Where there is surplus inventory, spraying can be withdrawn, allowing the budwrom to regenerate it for use in the next rotation. Spraying a resource that is not needed cannot be justified. Note, however, that these predictions are only estimates, so caution should be used in accepting the data. Analysis of the Resource Planning and implementing targeted budworm management strategies require accurate, up-to-date maps of forest cover types (fig. 3). Accurate maps should allow the manager to: 1. Determine the total area of stands in various vulnerability categories and assess the spatial distribution of the stands. 7 Protection area (acres X 10'') 8 Inch = 20 Chains or 1320 Feet < ca u (N Tt n Js Ot) H o c/5 Qi u a Ofj < E. s D. o. a iS S af J- -o .2 — a c = C I- u 3 ■> o O CQ :> a. u- u. 'nWjra'—Q.CDC'rs in^ -*njo^a£)X5“”^ 1^1 aJ =! S “P 71 c (U o u, CJU — 7 - S 2 E eg P C ^le'siagsa o Sc/5DD£;£XOt>:iCQ< U £ c eg D, E o c « c .2f Q “O c CQ •a o o ^ -E *t3 *2 ^ O cd •o O X o ^ ^ S -a C ^52 *2 :r ^ ^ o X H c ^ ' E u o. ^ eg w _ 5 £ X -i> eg ^ o cm— "ODr- 3 flj (U 4; :r c/5 >- Qi m :> 2 ^ ->o o > CU aj !— c t) p ^ (U Cl. ^ g O Cl. C tA § ■§ i! '5. Ij ^ ^ -a 'K -a ^ !1 i/)ti.c/)[i.ija.a.co V a in ■" '-■oX S ‘-(jUHx) 2 s " C- ^ ~ ^ "O (/5 "O C eg 5ooDiaaX:>ft: wUf-cQ fu '■ 9 2. Depict major physical features that influence protection planning. Examples are road networks that are essential for harvest planning as well as monitoring budworm populations and spray efficacy, and water bodies and population centers that affect spray buffers and the choice of insecticides. 3. Provide a basis for designing and conducting a forest inventory that is stratified to provide data for the wood- supply analysis. Skilled photo interpreters usually can identify individual tree species; this should be done where possible. The following distinctions are particularly useful: 1. Determine the relative proportions of softwood and hardwood species. Use the following four categories; Softwood (S): more than 75 percent softwood species Softwood-Hardwood (SH); 51 to 75 percent softwood Hardwood-Softwood (HS): 26 to 50 percent softwood Hardwood (H): more than 75 percent hardwood species 2. Within softwood stands, distinguish between budworm host species and nonhost conifers such as northern white cedar and pine. This may allow large areas of nonhost types to be withdrawn from spraying, and result in significant savings. 3. Attempt to discriminate among individual host species in stands where they account for much of the stocking. Assign stands to one of three categories: mainly fir, mainly spruce, or spruce-fir. Note the presence of hemlock, a lesser known budworm host, where abundant. Depending on the results of the wood- supply analysis, all of these stand types might have to be sprayed. However, designating individual species still will be useful for planning harvesting operations (by identifying opportunities for thinning and shelterwood cutting v. clearcutting), and for precise timing of spray applications on the basis of host phenology and budworm development on different host species. 4. Record stand structure, including relative overstory stocking (25-percent categories), height or age class, and history of treatment or natural disturbance if known. These variables are valuable not only for planning spray blocks and harvesting operations but also for conducting accurate forest inventories and wood-supply analyses. In addition to an accurate depiction of forest area, managers also need current information on other elements of forest structure. These must be obtained by on-the-ground inventory procedures. Forest inventories should be designed to allow forest development to be forecast under alternative management strategies. For this purpose, assessing both the age structure of each forest type and the stocking of recently harvested areas is essential. Traditional 10 assessments of current standing volumes and tree mortality, although useful, are not as critical. In measuring age structure, it is more important to assign stands to general developmental categories (e.g., mature, immature, regenerating) than to make precise determinations of tree age through increment cores. Old records, where available, might show when the stand was last harvested or killed by budworm. Historical data on forest growth, obtained from remeasured plots stratified by broad age classes, also are useful in the calibration stage of applying the wood-supply model. Definition of the Protection Zone Use the following rules to classify stands by their need for protection— frequent, less frequent, or none at all: 1. Frequent chemical protection: mature softwood stands with 30 percent or more of the volume in balsam fir. 2. Less frequent chemical protection: mixed wood with more than 6 cords/ acre (38 mVha)- of spruce-fir; softwood stands with 70 percent or more of the volume as spruce or other less vulnerable species; softwood stands less than 10 to 20 years old. 3. No chemical protection: hardwood stands; mixed wood with less than 6 cords/acre (38 mVha) of spruce-fir; stands to be clearcut within 3 to 4 years; ^ Since a standard cord contains air as well as timber, the Forest Service calculates that 1 cord = 90 ft.^ Therefore. 1 cord/acre = 6.2975 m7ha. black spruce stands; any isolated or unprotectable stands in categories 1 and 2 and other acreage not essential to the future wood supply. Note that these rules are general and not fixed. Real vulnerabilities of stands may be greater or less due to variables such as stand location, topographic factors, or extreme intensity of an outbreak. Or some young stands might be shifted to frequent chemical protection to ensure a high growth rate. Note that we list spruce as less vulnerable than fir because spruce deteriorates more slowly. But after deterioration, it may require frequent protection. Using the type maps, attempt to draw boundaries around groups of stands of similar vulnerability, defining spray blocks (figs. 4 and 5). Where difficulties are encountered (e.g., a highly vulnerable stand surrounded by stands of lower vulnerability, or isolated stands too small to comprise a spray block), schedule these stands for quick harvest. Some squaring-off of the mapped blocks will be required for efficient spraying. Blocks as small as 50 to 100 acres (20 to 40 ha) can be successfully treated, providing they have easily defined boundaries such as changes in stand type, to identify the location. Otherwise, blocks of several hundred acres are required. Figure 4—Forest type with stands colored to reflect vulnerability. Red is mostly fir, orange is spruce- fir. yellow is mostly red spruce, green is mixed wood, white is hardwood or recent cuts, crosshatched area is young stands. Detailed Hazard Rating We have described some general rules to be used in making decisions on protection. However, these apply only to average conditions. Further, the land manager will be influenced in protection decisions by statewide or provincewide forecasts of insect abundance and tree condition provided by public budworm survey agencies. Such surveys are extensive and the projected conditions are averaged over broad areas. Within these broad areas, some stands will be in greater than average hazard for the next year, and some less so. The land manager can make more discriminating protection decisions with annual inspections of stands. Where they are not at great hazard, the manager can defer protection for a year or two. In other cases, stands that have deteriorated badly can be scheduled for the next protection program or scheduled for presalvage harvest. Hazard-rating systems combine numerical values for current and previous defoliation, tree vigor, and expected budworm abundance (table 2), and are useful in making protection decisions for individual stands each year. Where access is good, roadside observations and collections may suffice. Where access is poor, aerial surveillance may be required to judge tree condition (McCarthy et al. 1982; Olson et al. 1982; Ashley and Stark. 12 Figure 5—Actual protection plan (crosshatched area) for two townships in northern Maine. Dotted lines are proposed roads to allow harvest of the five zones, in numerical order. undated). Forecasting insect population intensity (Montgomery et al. 1982) may be beyond the resources of many landowners; however, public forest protection agencies or private consultants can usually provide these services. The land manager can often make useful judgments based on annual evaluations of tree condition alone. Figure 6 illustrates four classes of vigor in balsam fir trees. Aircraft Guidance and Targeted Spraying The resulting mosaic of frequently protected blocks, infrequently protected blocks, and no spraying is more difficult to treat accurately than large spray blocks of regular shape. Electronic devices are available for aircraft guidance (e.g., the Loran navigational system). At least one device, the Flying Flagman,^ is designed specifically for insecticide spraying. In the absence of these, the forester responsible for the land can direct the spray aircraft visually from a ^ The use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the U.S. Department of Agriculture, Forest Service, or University of Maine of any product or service to the exclusion of others that may be suitable. 13 Table 2 —Hazard-rating system used by the Maine Forest Service' Category Hazard value Current defoliation Percent Trace 0-5 0 Light 6-20 1 Moderate 21-50 2 Heavy 51-80 4 Severe 81 + 6 Prior defoliation Percent (last 2 years) Trace 0-9 0 Light 10-49 3 Moderate 50-129 6 Heavy-severe 130 + 9 Dead tops Egg-mass deposit Number per 100 ff of foliage None 0 0 Light 1-99 1 Moderate 100-239 2 High 240-399 3 Very high 400-999 4 Extreme 1000 + 5 Tree vigor Good 0 Eair 1 Poor 2 Very poor (no chance of recovery) 3 Hazard rating Range of total values Low 0-6 Moderate 7-15 High 16-22 Extreme 23-26 ' Applies only to balsam fir; none is available for spruce. 14 Figure 6 —Examples of different stages of tree vigor resulting from prolonged attack by the spruce budworm: (A) good vigor; (B) lair; (C) poor; iD) very poor. (Photos courtesy ol the University ol Maine.) D 15 Figure 7—A team of three agricultural-type spray aircraft. Note the guide aircraft (lower right). (Photo courtesy of J. W. Sewall Co.) guitJe plane (fig. 7). The forester will be familiar with all landmarks (e.g., streams, bogs, and roads) and can recognize most stand types from the air. The primary benefits of targeted spraying are • Reductions in acreage sprayed can be achieved quickly. • Total costs of spraying are reduced. • Environmental contamination is diminished. • Human exposure to insecticides may be reduced. • Populations of natural enemies of the budworm will be preserved in untreated refugia and can spread into the sprayed zone. A hypothetical spray plan is shown in figure 8. 16 ■' Insecticide costs will be reduced as acres sprayed are reduced. This will be partially offset by higher application costs due to intricate flight patterns. Harvest Planning Spray infrequently _ No spray Figure 8 —Hypothetical protection plan for a land ownership. Mature softwood is sprayed often. Mixed wood and pure red spruce (partial cut) are sprayed less often. Not sprayed are stands recently clearcut or scheduled for clearcutting, black spruce, hardwoods, and a small, isolated mature softwood stand (S3). The latter can be harvested if accessible. Management Objectives Recommendations for specific forest management practices make sense only in the context of forest management objectives. Here, the wood-supply/ forest protection model is a valuable tool to determine whether the many conflicting goals of the forest landowner can be met. Actual situations fall into two categories, which require different harvesting strategies. 1. Little or no protection is needed or possible; sustained yield of spruce and fir is not critical. In this situation, the harvesting strategy is straightforward. Landowners should try to harvest all vulnerable wood as rapidly as possible before it dies and decays. Success will be limited mostly by marketing and logging considerations. It is possible that much of the wood will go unused because many other landowners will face the same situation. A limited amount of protection may be highly cost- effective, but only to extend the harvest over a longer period. The key point is that landowners in this situation must plan to harvest nonhost species after the relatively short period of mortality and salvage of spruce-fir, or not harvest at all for perhaps decades until the spruce-fir forest recovers. 2. Sustained yield of spruce and fir is required to supply a mill or to provide regular income; long-term commitment to forest protection is necessary. This situation typically is found in the spruce-fir forests of Eastern North America, where the age structure of the resource is badly imbalanced and too much of the forest is composed of old, slow-growing stands vulnerable to the 17 budworm. To ensure the sustained harvest that local forest industries demand, protection may be required for as long as 20 to 40 years, depending on the budworm’s impact and the specific nature of the forest’s age structure. In this situation, managers must recognize at the outset that most of the protection zone—the area defined from the wood-supply and type-map analyses needed to sustain the harvest—will have to be sprayed repeatedly. Harvesting operations should be planned and conducted to reduce spray requirements in the long run as mature stands are harvested and replaced with younger, more vigorous ones. The remainder of this section on harvesting deals only with this second, more difficult situation—how harvesting plans should be devised to minimize protection requirements yet ensure a sustained yield. Forest Management Guidelines 1. Any cultural practice that increases usable forest growth can reduce current protection needs. Typically, budworm- infested forests have a seriously unregulated age structure, dominated by old and overmature stands. Such forests actually may have a surplus of inventory relative to current demand, but their ability to provide a long-term sustained yield may still be uncertain because they lack potential for growth. In this situation, every extra harvestable cord a manager can produce by a certain future year is I cord less than he must “store” by protection until that date. This is basically an economic decision that can be made with the use of the wood- supply model to forecast various scenarios. For example, it might be more beneficial to invest in thinning a young stand precommercially (fig. 9) to accelerate its development than to spray an equivalent, existing volume of wood 10 to 20 times until it is harvested. 2. Harvest should be allocated to protected stands as much as possible. When faced with a severe budworm infestation, managers are tempted to salvage unprotected stands to prevent dead and dying wood from going to waste. This temptation should be resisted. If the wood-supply analysis is done carefully, this unprotected wood is surplus inventory. Harvesting is unnecessary because the designated protected area should be sufficient to sustain the harvest. In many cases, salvage can be counterproductive. First, salvage operations actually delay the process of reducing the protected area by diverting harvesting away from protected stands. In effect, every cord salvaged is a cord that must be sprayed unnecessarily elsewhere. Second, salvage cuts may delay the regeneration and recovery of the unprotected stands. Though unneeded to meet present demands, these stands must provide future wood 18 Figure 9 —Young stands of spruce and fir are scarce in the spruce-fir region and are essential to future wood supplies. A: Early spacing or precomniercial thinning shortens rotations and can change stand composition dramatically in favor of less vulnerable species. B: Protection may be needed in severe infestations to prevent severe defoliation. 19 supplies after all of the protected stands are harvested. Unprotected stands may contain a component of spruce that will survive budworm feeding and respond to release. If these stands are salvaged, these potential survivors are invariably removed along with the dead and dying fir. If a manager cannot physically or economically protect enough area to meet his needs, he faces a difficult dilemma. The harvest must be reduced to a level that can be sustained with the largest feasible protection zone, or it must be acknowledged that a sustained yield is not possible. In this case, salvage operations on unprotected lands will postpone this inevitable choice for only a few short years. 3. Within the protection zone, low- volume stands should be harvested first, saving the high-volume stands (by protection) for last. The key point is that harvest volume should be spread over as many acres as possible to achieve the fastest reduction in protection requirements. This strategy is also the most favorable one economically, provided that incremental harvest costs do not exceed protection costs. After several years of harvesting low-volume stands, volumes in the protection zone become increasingly concentrated on fewer acres, reducing protection costs per unit volume. 4. Areas to be clearcut should be arranged spatially to facilitate spray blocking on the remaining area. In general, operations should be concentrated on perimeters of existing blocks, or in odd-shaped appendages that are difficult to spray operationally. It may not be possible to avoid spraying small clearcut “islands” in larger blocks. 5. Protection should be withdrawn 2 to 4 years before harvesting on areas scheduled for clearcutting. With accurate type maps and careful on-the- ground harvest planning, future clearcuts (fig. 10) can be delineated well in advance. Depending on tree condition, protection can then be withdrawn with no tree mortality before the wood is cut. Protection should not be withdrawn from stands where partial cuts are planned. Here, it is essential to maintain good foliage protection. Silvicultural Considerations The general principles described govern the management of budworm-infested forests as a whole. When these practices are applied to particular stands on the ground, silvicultural factors must be considered. In the context of budworm protection and harvest planning, silvicultural practices should reduce both immediate and future vulnerability of the treated stands, and increase growth rates, especially of less vulnerable species. Reaching these goals will reduce immediate protection requirements and promote a more productive and less vulnerable forest. 20 Figure 10 —Dense, overstocked stands dominated by fir do not respond well to thinning or protection because the crowns are small. These stands should be clearcut (A) and then regenerated (B). 21 Figure 11 —Presalvaging small fir in thinnings reduces stand vulnerability and allows better penetration of spray into residual crowns. 79 The following priority system is offered to guide harvest planning decisions. The system is based primarily on future growth potential and response of individual trees to spray treatments, rather than on their vulnerability to mortality if left unprotected. See Blum and MacLean (1984) for a more general discussion of the silvicultural aspects. High Priority for Harvest 1. High-volume stands that are essential for maintaining sustained yield (as determined from a wood-supply analysis) but cannot be protected for operational reasons. Such stands become apparent immediately after switching to a more targeted protection strategy. They occur as isolated “islands” too small to warrant protection on their own, or may be in spray buffers adjacent to water or populated areas. 2. All balsam fir more than 80 years old or more than 8 inches (20 cm) in d.b.h. In addition to being preferred budworm host trees, such firs usually are infected with heart rot, and represent a high-risk component of the resource that is vulnerable to loss from wind breakage as well as budworm mortality. 3. Merchantable trees in the lower (intermediate and suppressed) crown classes within protected softwood stands. Even in successful spray years, these trees usually receive poor foliage protection because their crowns are not exposed to the spray deposit. As with large-diameter old fir, these trees also represent a high-risk component of the resource that will die if not harvested soon (fig. 11). Moderate Priority for Harvest 1. Spruce and fir in mixed stands. These trees probably will not have to be sprayed as often as their counterparts in pure softwood types, but they may be more expensive to protect. Stocking per acre of spruce and fir is lower, so fewer cords are protected for the same per-acre cost. 2. Understocked spruce-fir residual stands resulting from partial cuts made in the last 30 years. Like mixed-wood types, such stands are more expensive to protect (due to the lower volumes per acre) and may have to be protected as frequently as fully stocked stands. Also, these stands usually are well regenerated, and the continued presence of the residual overstory as a source of budworms may threaten the development of the established reproduction. Old residual stands that have regained full occupancy of the site should not be placed in this category. They do not differ in stocking or regeneration from previously uncut stands. Low Priority for Harvest Dominant and codominant spruce and fir, not in the previous categories, in protected softwood stands. These trees respond well to protection and probably 23 represent the best growing stock available in budworm-infested forests. Even though many of these trees normally would be regarded as mature and over a reasonable rotation age, they still offer the best hope of bridging the gap where age-class distribution is a problem. No Harvest All volumes in unprotected stands. Except for High Priority 1, harvests should be allocated mainly to protected lands. Area is removed from protection more rapidly, and the regeneration of the unprotected stands needed for future wood supply is accelerated. Stand Prescriptions Stand structure will determine whether these guidelines should be implemented as partial cuttings or as clearcuts. Windfirmness of potential residual trees is the primary consideration (Ealk 1980). If the high-priority components (large fir and lower crown classes) account for more than 40 to 50 percent of the stand basal area, their removal probably will render the remaining trees vulnerable to windthrow. A complete overstory removal would then be prescribed even though low-priority growing stock must be harvested in the same operation. Where the high-priority trees represent less than 50 percent of the stand, partial cuttings should be considered (fig. 12). Silviculturally, these operations are both (1) commercial thinnings that presalvage expected mortality and release desirable crop trees, and (2) the initial entry in a two- or three-stage shelterwood silvicultural system. Care must be exercised to leave residual trees uniformly spaced. Marking either leave or cut trees probably will be necessary (fig. 13). Residual stands probably will require protection. Logging costs also will be much higher than with clearcuts due to the smaller wood and lower volumes per acre removed. However, there are many advantages that may offset these drawbacks. Because less volume is removed per acre, harvesting operations cover more area annually. This accelerates roading and harvesting of other high-risk stands that will be clearcut, reducing long-term protection needs on this component of the resource. Protection will be more effective because the lower crowns of residual trees are better exposed to spray droplets after the stand is opened up. Much greater discrimination against high-risk components of the resource is possible since partial harvests are composed almost entirely of this material. Overall forest growth is improved, which reduces long-run protection requirements and improves the wood-supply outlook. Shelterwood cuttings also offer the best opportunity to change species composition of the regeneration in favor of the less vulnerable spruce. 24 Figure 12 —Thinned residual stands of red spruce offer promise as growing stock to bridge a short¬ term gap in age classes (/A) and may improve regeneration of the less vulnerable spruce (B). 25 B Figure 13 —It may be necessary to mark stands for thinnings and shelterwood harvests to control spacing of residual trees and to prevent blowdown. A and B: Large overmature fir and small-diameter 26 intermediate and overtopped crown classes marked for removal in thinning. C and D: Vigorous codominant tirs marked as residuals to prevent large openings in the residual stand. 27 Summary Insecticide spraying will not suppress spruce budworm outbreaks; it can only maintain tree life and growth through an outbreak. The spraying necessary to maintain forest vitality can be reduced if managers will perform the following steps: 1. Analyze fiber needs into the future, and exempt from spraying any of the inventory that will not be needed. 2. Analyze the resource thoroughly so that stands requiring frequent protection, infrequent protection, or no protection can be identified. 3. Map protection zones by frequency of need for protection into spray blocks of practical size. 4. Use harvest strategies that will reduce vulnerability, shifting stands from high to lower vulnerability, or to no vulnerability. 5. Locate roads and harvests so that as vulnerability is reduced, blocks of land can be sprayed less often or removed from protection. Many of the steps recommended here, e.g., wood-supply analysis and thorough resource analysis, will serve many useful forestry purposes in addition to spruce budworm management. 28 Literature Cited Ashley, M. D.; Stark, D. Photo field guide for on-the-ground evaluation of spruce budworm damage (Choristoneura fumiferana [Clem.]) on balsam fir (Abies balsamea. Mill). Unnumbered booklet. Orono, ME: University of Maine, School of Forest Resources; and Augusta, ME; Department of Conservation, Bureau of Forestry; [n.d.]. 21 p. Batzer, H. O.; Hastings, A. R. Rating spruce-fir stands for spruce budworm vulnerability in Minnesota. In: Hedden, R. L.; Barras, S. J.; Coster, J. E., tech, coords. Hazard-rating systems in forest insect pest management; symposium proceedings. Gen. Tech. Rep. WO-27. Washington, DC: U.S. Department of Agriculture, Forest Service; 1981: 105-108. Blum, Barton M.; MacLean, David A. Silviculture, forest management, and the spruce budworm. In: Managing the spruce budworm in Eastern North America. Schmitt, Daniel M.; Grimble, David G.; Searcy, Janet L., tech, coords. Agric. Handb. 620. Washington, DC: U.S. Department of Agriculture, Forest Service; [in press.]. Dimond, J. B. Spruce budworm: further examples of termination of infestations with chemicals. Misc. Rep. 184. Orono, ME; Maine Agricultural Experiment Station; 1976. 8 p. Falk, J. Wind damage in spruce-fir stands—a literature review with recommendation for harvesting methods. Misc. Rep. 225. Orono, ME: Maine Agricultural Experiment Station; 1980. 26 p. McCarty, J.; Olson, C. E., Jr.; Witter, J. A. Evaluation of spruce-fir forests using small-format photographs. Photogramm. Eng. Remote Sensing 48: 771-778; 1982. MacLean, D. A, Vulnerability of fir-spruce stands during uncontrolled spruce budworm outbreaks; a review and discussion. For. Chron. 56: 213-221; 1980. MacLean, D. A. Vulnerability rating of forests in New Brunswick and Nova Scotia to budworm attack. Info. Rep. M-X-132. Fredericton, NB: Canadian Forestry Service; 1982. 21 p. Montgomery, B. A.; Simmons, G. A.; Witter, J. A.; Flexner, J. L. The spruce budworm handbook: a management guide for spruce-fir stands in the Lake States. Handb. 82-7. Ann Arbor, MI: University of Michigan, School of Natural Resources; and East Lansing, MI; Michigan State University, Department of Entomology; 1982. 35 p. Mott, D. G. Spruce budworm protection management in Maine. Me. For. Rev. 13: 26-33; 1980. Olson, C. E., Jr.; Sacks, P. J.; Witter, J. A.; Bergelin, L. A. Spruce budworm damage assessment with 35 mm air photos. Rep. UM SNR/RL 82-lA. Ann Arbor, Ml: University of Michigan, School of Natural Resources, Remote Sensing Laboratory; 1982. 41 p. Seymour, R. S.; Mott, D, G.; Kleinschmidt, S. M.; Triandafillou, P. H.; Keane, R. The Green Woods model— a forecasting tool for planning timber harvesting and protection of spruce-fir forests under attack by the spruce budworm. Gen. Tech. Rep. NE-91. Broomall, PA: U.S. Department of Agriculture, Forest Service. Northeastern Forest Experiment Station; [in press]. 29 a t f 'i . i ^-V . .» .3 ^ww# S* A I ^ ■■‘■«u * n 1983 Handbook of Agricultural Charts United States Department of Agriculture Agriculture Handbook No. 619 (jM Introduction 1983 Agricultural Chartbook Committee Economics Management Staff Debra Ritter Haugan, Editor Susan DeGeorge, Graphic Coordinator Linda Zelder, Assistant Graphic Coordinator Governmental and Public Affairs Edna Carmichael, Editorial Advisor Jim Vechery, Technical Advisor Harris Goldman, Art Director Economic Research Service Tom Frey, Steve Milmoe, Grace Simon, Don Steward Agricultural Cooperative Service Celestine Adams Food and Nutrition Service Johnny Braden Foreign Agricultural Service Maureen Quinn Evelyn Littlejohn Human Nutrition Information Service Joanne Rosenthal Agricultural Research Service Kathleen Scholl Joan C. Courtless Photos of mailbox (page 22), courthouse (page 22), and rooster (page 67) by J. Norman Reid. The Handbook of Agricultural Charts has several new features this year. We have changed our index, mak¬ ing it easier for you to find charts under specific topics. We also show you how you can tie together the infor¬ mation in various charts in our two-color spread, pages 2-3. The chartbook traditionally serves numerous peo¬ ple of varied backgrounds. Some people reproduce the charts in their publications. Others use the charts as visual material to accompany oral presentations. Pro¬ fessors in agricultural colleges use the handbook in their classrooms. We view this handbook as a user- oriented publication, and hope our new features encourage hands-on use. Many people have written or called to ask permission to use material from this handbook. This is a U.S. Government publication and is not copyrighted. You are free to use whatever material you wish without requesting permission. We would appreciate credit for material you use, but this is not required. All years used in the charts and statistical tables are calendar years unless otherwise indicated. Most of the information used to develop the charts was obtained from within the U.S. Department of Agriculture, but some material was provided by other sources, which are footnoted. Please contact those sources directly if you are seeking followup information. Reports related to the topics covered in each section are listed in the back of this handbook. Use the GPO order form to order copies of these reports. Those who need additional statistical information should obtain a copy of Agricultural Statistics, a com¬ panion publication to this handbook. The statistical handbook is published annually by the U.S. Department of Agriculture and is available for sale by the Superin¬ tendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. Use of trade or commercial names does not imply endorsement by the U.S. Department of Agriculture. The chartbook is distributed on a for-sale only basis by the U.S. Government Printing Office. Anyone wish¬ ing to obtain a copy of the chartbook should write the Superintendent of Documents, U.S. Government Print¬ ing Office, Washington, D.C. 20402. Ask for the 1983 Handbook of Agricultural Charts, AH-619, and make your check for $5.00 payable to Superintendent of Documents. Or use the GPO coupon on the last few pages of this handbook. Washington, D.C. 20250 December 1983 y I l‘i':iVcnS!lY OF ILLINOIS /.wMOULVu'Rr: LiORAPY -i 1983 Handbook of Agricultural Charts United States Department of Agriculture Agriculture Handbook No. 619 2 Charts That Tell a Story 4 The Farm 5 Income 7 Assets and Finance 11 Prices 12 Inputs 17 Outputs 18 Land Tenure 19 Farmer Cooperatives 22 Population and Rural Development 23 Population 24 Workforce 25 Farmworkers 26 Income 27 Housing 29 Public Services 30 The Consumer 41 Food Consumption Surveys 31 General Economy 42 Diet Quality 32 Consumer Prices 43 Cholesterol and Fatty Acids 35 Food Marketing Costs 44 Family Economics 37 Food Consumption 46 Unemployment 39 Nutrients in Food at Home 47 Consumer Finance 40 Convenience Foods 48 Home Energy Use 50 Food and Nutrition 51 Food Assistance 52 Food Stamps 54 WIC and Child Programs 55 School Lunches 56 Elderly and School Programs 57 U.S. Trade and World Production 58 U.S. Trade 65 World Production 67 Commodity Trends 79 Commodity Stocks and Grain Transportation 68 Livestock 80 Fats and Oils 71 Dairy 82 Fibers 73 Poultry 86 Vegetables 75 Wheat 87 Fruit 76 Rice 89 Tropical Products 77 Other Grains 92 Tobacco 94 Index 1 Charts That Tell a Story As a reader of the Handbook of Agricultural Charts, you probably have used charts in this handbook to tell your own story, whether you're an economist illustrat¬ ing a report, a policymaker making a speech, or a con¬ sumer tracking new trends. The charts in this hand¬ book are meant to lend themselves to just such uses. Let’s say you’re an educator and want to illustrate to your students some aspects of the quality of life in America today. In the Consumer section, you’ll find chart 133 showing that energy costs run highest in the northeastern States (where oil is commonly used) and lowest in the West. Chart 93 shows that labor, packag¬ ing, and transportation account for 45 cents out of every food dollar. Chart 125 shows that while the unemployment rate averaged 9.7 percent in 1983, the rate varied from 6.1 percent for white married men to 26.6 percent for black single men. Quality of American Life Chart 133 Chart 93 Yearly Household Energy Expenditures by Region What a Doliar Spent on Food Paid for in 1982 West North East North New Pacific Mountain Central Central England Farm value 28c Marketing bill: Other costs SVaC Repairs IV2C— Interest (net) 2c Advertising 2c Fuels and electricity 4c Before tax profits 4 V 2 C Rent and depreciation 4V2C Intercity transportation 5c- Packaging 8c- Labor 32c - 1980 data. Pacific includes Alaska and Hawaii. Source: U.S. Department of Energy. 1982 preliminary. Other costs include property taxes and insurance, accounting and professional services, promotion, bad debts, and miscellaneous items. Chart 125 Unemployment Rates Percent Black includes black and others. Ages 20 to 64. Source: Bureau of Labor Statistics. 2 Or let’s say you’re a farm newspaper editor, and want to give your readers some historical background on corn supplies and prices in the face of this summer’s drought. Drawing on chart 23 from the Farm section, you can show prices received by farmers for corn held fairly steady in recent years, while the export prices for corn dropped in 1982 (chart 166 from the U.S. Trade and World Production section). Chart 224 can help you show your reader that corn supplies for 1983 should total 8.6 billion bushels, down 20 percent from 1982. Let us know how you use our charts to tell your own story—and how we can help you do so. Send us your suggestions. Write Debra Haugan, EMS Information, USDA, Room 440 GHI, Washington, D.C. 20250. Corn Supplies and Prices Chart 23 Prices Received by Farmers For Major Commodities $/cwt. $/cwt. 70 70 50 — ^ 50 30 _ 30 Cattle Hogs 10 _I_^_ \ _^_ 10 _1_^_1_1_ C/lb. $/cwt. 30 15 25 12 — 20 9 — 15 Broilers 6 ~Milk 10 _I_^^^_ 3 _1_^^_ \ _ 1977 82 77 82 Calendar years Chart 224 Corn Supply and Disappearance Billion bushels 1982 estimated, 1983 projected. Supply includes imports. Year beginning October 1. $/bu. $/bu. Chart 166 Export Prices for Major U.S. Crops $ per metric ton Rice Soybeans Wheat Corn Marketing years Average export unit values. Milled rice. 3 The Farm 4 Income After an 11-percent increase between 1980 and 1981, gross farm income declined 3 percent in 1982. Cash receipts, government payments, and nonmoney income continued to rise, but a negative net change in inventory more than offset these slight increases. While production expenses have tripled since 1970, their growth rate has slowed from 8.9 percent in 1980 to 6.5 percent in 1981 and 2.3 percent in 1982. U.S. farm families earned a total income of $62 bil¬ lion from farm and off-farm sources in 1982, down 12 percent from 1981. More than half of total farm family income has come from off-farm sources during the last few years. Per capita disposable personal income of the farm population was $7,355 in 1982, compared with $9,430 for the nonfarm population. Chart 1 Income from Farming $ billion 175 70 72 74 76 78 80 82 1966 68 70 72 74 76 78 80 82 Chart 2 Income of Farm Operator Families $ billion Net farm income includes an adjustment for changes in year-end crop and livestock inventories and represents returns to operator families’ labor, capital, and management. Chart 3 Disposable Income per Capita $ thousand Income from all sources less personal contributions for social insurance, personal tax, and nontax payments. Beginning in 1975, farm income data reflect a change in the farm definition from a place of 10 or more acres with $50 in agricultural sales and under 10 acres with $250 in sales, to a place with $1,000 in sales. 5 Income All farm families together received 62 percent of their total income before inventory adjustment from off-farm sources in 1982. Families operating farms with sales of at least $20,000 reported 32 percent of their total income was from off-farm sources. Families operating farms with sales under $20,000 had to use 4 percent of their total off-farm income to offset losses from farming. Farms with sales over $200,000 represented 4.6 per¬ cent of all farms but 49.1 percent of the cash receipts and 79.4 percent of net income. Farms with sales under $20,000 represented 59.9 percent of the farms, but received only 6.3 percent of cash receipts and had a net loss of 4.5 percent of net farm income. Farms with sales of $20,000 to $39,999 accounted for less than 1 percent of net farm income. Chari 4 Average Farm Family Income All Sources $ thousand 50 40 30 20 10 0 -10 1977 79 81 Net income before adjustment for inventory change for farms with $1,000 in saies. Chart 5 Cash Receipts and Farms by Sales Class Chart 6 Average Net Farm Income by Sales Class % of sales class $ thousand Under $20,000 $ 20 , 000 - $39,999 $40,000- '$99,999 $ 100 , 000 - $199,999 $ 200 , 000 - '$499,999 $500,000- and over Cash receipts Number of farms 1982 data. Net income before adjustment for inventory change. Net income before adjustment for inventory change. Beginning in 1975, farm income data reflect a change in the farm definition from a place of 10 or more acres with $50 in agricultural product sales and under 10 acres with $250 in sales, to place with $1,000 in sales. 6 Income and Assets and Finance Net farm income represents a return to farm opera¬ tors for labor, capital, and management. While such earnings do not always keep pace with inflation, farm- owners have benefited from rising farm values. The value of farm assets including farm households declined for a second year, mainly because the value of real estate, which accounts for 75 percent of assets, fell 6 percent in 1982. Debt on farm assets continued to rise, but at a decreasing rate. Farm assets totaled $1,049 billion in January 1983, while debt reached $216 billion and equity fell to $833 billion. Half of all farm debt was secured by real estate at the beginning of 1983, with 42 percent secured by nonreal estate and the remainder by Commodity Credit Corporation (CCC) price support and storage and dry¬ ing facility loans. Chart 7 Net Farm Income $ billion Chart 9 Farm Debt 1975 77 79 81 83 1983 preliminary. Farm loans outstanding January 1. Chart 8 U.S. Farm Balance Sheet $ trillion 1983 preliminary. Data as of January 1. Includes farm households. Chart 10 Importance of the Three Types of Farm Debt I960 65 70 75 80 7 Assets and Finance The largest sources for real estate loans are Federal land banks and individuals and others. Many creditors in the second group are sellers of farms who provide loans to buyers. Banks and production credit associa¬ tions are the largest sources of nonreal estate loans. Annual change in total farm debt, excluding CCC loans, rose from $2.3 billion in 1970 to $25.6 billion in 1979, then fell to $7.2 billion in 1982. Real estate debt rose to $1.2 billion in 1970 and to $14.0 billion in 1979, then sank to $4.0 billion in 1982, while nonreal estate debt rose to $11.6 billion in 1979, then fell to $3.2 bil¬ lion in 1982. The real estate debt-to-asset ratio on Jan. 1, 1983 rose by 1.3 percent to 14.2 percent, the highest ratio since 1965; the nonreal estate debt-to-asset ratio rose to 38.7 percent. Chart 11 Who Holds the Farm Debt billion 120 100 80 60 40 20 0 1983 preliminary. Production Credit Associations include Federal Intermediate Credit Bank loans to other financial institutions. $ Chart 12 Annual Change in Farm Debt $ billion 1982 preliminary. Difference between debt outstanding at beginning and end of year. Excludes Commodity Credit Corporation loans. Chart 13 Farm Debt as Percentage of Assets Percent 1983 preliminary. Debt is shown as percentage real estate debt to real estate assets and percentage nonreal estate debt to nonreal estate assets. Data as of January 1. 8 Assets and Finance Per farm assets fell 3 percent to $437,000 last year as a result of falling real estate values, while per farm debt rose 7 percent to $90,000, with increases in every debt category. Unrealized capital gains on farm assets (change in value less net investment) showed a net loss of $36 billion in 1982, three times the net loss in 1981. Interest rates on farm real estate loans rose rapidly during 1980-81, leveled off in mid-1982, and began to decline by late 1982. During the first quarter of 1983, seller-financed rates lagged commercial rates by 1-1/2 to 2-1/2 percent. Rates on nonreal estate loans hit record high levels during the third and fourth quarters of 1981, but were down 4 to 8 percent by the second quarter of 1983. Chart 14 Farm Assets and Debt per Farm $ thousand Chart 16 Interest Rates on Farm Real Estate Loans Percent Quarterly data for life insurance companies (new and refinanced loans) and Federal land banks (new loans). Semiannual data tor seller financed, annual beginning in 1980. Federal land bank rates do not include new loan fees or the charge for stock borrowers are required to buy. Chart 15 Capital Gains 1966 68 70 72 74 76 78 80 82 Changes in farm real estate values less net capital investments, mostly unrealized. Other physical assets include machinery and motor vehicles, livestock and poultry, and crops stored on farms. Chart 17 Interest Rates on Farm Nonreal Estate Loans Percent Rates on new PCA loans include service fees. Bank data starting in 1977 are from surveys made by the Federal Reserve System; data from prior years relate to different groupings of banks, collected by the Federal Reserve System and the Federal Reserve Bank of Minneapolis. 9 Assets and Finance U.S. farmland values fell 6 percent in 1982 in nominal dollars. With inflation at 4 percent, this implies a 10- percent drop in the real value of U.S. farmland. The 1982 decline was the third consecutive decline in real value. The 3-year decline is in sharp contrast to an average increase of 6 percent a year during the seven¬ ties. Since February 1980, the real value of U.S. farmland has fallen about 18 percent, leaving the index of real value per acre only slightly above its 1975 level. The largest decline occurred in the Corn Belt, which in 1980 accounted for more than 25 percent of the total value of U.S. farm real estate. In the last 3 years, farm¬ land value per acre in the Corn Belt fell 16 percent in nominal terms and 33 percent in real terms. Chart 18 index of Real Value per Acre of U.S. Farmland % of February 1, 1977 125 " Change in Real Value per Acre from Previous Year Percent 1915 1925 1935 1945 1955 1965 1975 1985 Excludes Alaska and Hawaii. The indexes of real farmland value computed by dividing the nominal land value indexes by the Consumer Price Index. 10 Assets and Finance and Prices U.S. farm real estate taxes levied in 1981 totaled $3,695.5 million, up from $3,450.9 in 1980. Average tax levy per acre of privately owned farmland rose by about 7 percent for the third year in a row, rising from $3.85 in 1980 to $4.12 in 1981. Prices paid by farmers averaged 3.5 percent higher in 1982 than in 1981. Interest rose 10 percent, with smaiier increases of about 6.5 percent for taxes and family living items. Wage rates were up about 3 per¬ cent, while production items rose less than 1 percent. Two years of record or near record harvests coupled with weak export demand resulted in iarge stocks of grain and cotton, driving down the index of prices received by farmers by 9.7 percent in 1982. Chart 19 Farm Real Estate Taxes Doilars Chart 20 Farm Real Estate Taxes per Acre Chart 21 Prices Received and Paid by Farmers Doliars % of 1977 1981 data. Prices paid includes commodities and services, interest, taxes, and wage rates. 11 Prices and Inputs Prices paid by farmers for production items in 1982 increased less than 1 percent over 1981. Farm real estate prices fell in 1982; a 6-percent decline is expected in 1983. Farm machinery prices rose 9 per¬ cent in 1982 and are expected to rise only about 5 per¬ cent in 1983. Agricultural chemical and wage rate increases in 1983 will be about the same to moderately lower; fertilizer prices should also be lower. Prices paid by farmers for commodities and services, interest, taxes, and wage rates rose 3.5 percent during 1981-82. Interest was up 10 percent, with increases of about 6.5 percent for taxes and family living items. Wage rates rose about 3 percent and production items less than 1 percent. Chart 22 Prices of Selected Farm Inputs % of 1977 1982 preliminary, 1983 projected. Farm machinery includes tractors and self-propelled machinery. Chart 23 Prices Received by Farmers for Major Commodities $/cwt. $/cwt. 70 70 50 — 50 30 _ 30 Cattle Hogs 10 1 1_ . L J_ 10 J_^_1_^_ C/lb. $/cwt. 30 15 — 25 12 20 9 - 15 6 Broilers Milk 10 _ ^^^^_ 3 _1_1_ ^^ _ 1977 82 77 82 Calendar years Chart 24 Prices Farmers Pay 1977 78 79 80 81 82 83 1982 preliminary, 1983 projected. Components of the index of prices paid by farmers for commodities, services, interest, taxes, and wage rates. Interest is that payable per acre on farm real estate debt. Taxes are those payable per acre on farm real estate. $/bu. $/bu. 8 8 6 6 4 4 2 Wheat 2 Corn 0 _1_^_1_^_ 0 _1_^^_1_ $/bu. c/lb. Marketing years 12 Inputs Production expenses, estimated on the basis of a planted acre, and receipts less expenses are presented below. Estimates of production costs are based on periodic surveys of producers and are updated annual¬ ly to reflect current yield levels, fertilizer use, and prices paid for inputs. In year-to-year comparisons, per-acre and per-unit costs may change at different rates. Per acre cash expenses for producing major U.S. crops rose slightly in 1982, mainly the result of increases in the costs of seed, chemicals, machinery repairs, and custom operations. At the same time, fertil¬ izer costs fell, due mainly to a decrease in fertilizer use. Net receipts fell dramatically due to lower product prices for almost all commodities. Chart 25 Crop Production Costs Cotton Rice Soybeans Wheat Barley Sorghum Corn $ per acre 29r.97 300.84 Total CaSh eXpenSeS 1981 1982 Oats 77.15 78.24 44.22 25.46 13 Inputs The domestic fertilizer outlook for 1982-83 calls for adequate supplies of nitrogenous, phosphatic, and potassic materials. Total use was down in 1982; use in 1983 should be down further. Plentiful supplies and depressed demand have slowed price increases. Farmers used about 124 pounds of fertilizer nutrients per acre of cropland in 1982, down for 2 years in a row. Fertilizer use slowed during the seventies as rising fer¬ tilizer application over several decades increased the nutrient content of most soils. High fertilizer prices and a depressed farm economy offset the slowdown in increased fertilizer use. Labor inputs have fallen steadily since 1977, while mechanical power and machinery have risen by 5 per¬ cent and agricultural chemicals by nearly 25 percent. Chari 26 Fertilizer Used and Prices Paid % of 1967 Chart 27 Fertilizer Nutrients Used per Acre Pounds per cropland acre Chart 28 Use of Selected Farm Inputs % of 1977 1982 preliminary. 14 Inputs Farmers applied almost 480 million pounds of pesti¬ cides to major field crops in 1982, down 6 percent from 1976. Herbicides accounted for 88 percent of the total, and use rose 12 percent from 1976. Insecticide use fell 60 percent, while fungicide use remained fairly stable. Corn farmers accounted for 55 percent of herbicides and 53 percent of the insecticides appiied in 1982. Soybean farmers appiied 121 miilion pounds of herbi¬ cides, a 50-p8rcent increase over 1976. Herbicide use by cotton farmers has remained stabie, but quantity of insecticides used declined 80 percent during 1976-82. The primary reason for this deciine was the rapid adop¬ tion of synthetic pyrethroids, applied at 0.1 to 0.2 pounds per acre, compared with older materials which were appiied at rates of 1 to 3 pounds per acre. Chart 29 Pesticide Use on Major Fieid Crops Total use Million pounds 1966 1976 1982 102 108 6 Herbicides insecticides ^Fungicides 374 130 8 ¥ 420 54 5 Corn 1966 Miliion pounds 46 24 1976 1982 207 32 232 28 Herbicides Insecticides 216 101 1971 129 1971 6 26 Cotton 1966 Million pounds 6 65 Soybeans Miliion pounds 1966 10 3 1971 20 73 1971 36 6 1976 18 64 Q 'I 01 - 1976 8 1982 16 11 1982 121 5 1982 preliminary data from major producing States, excluding California. Million pounds of active ingredients. 15 Inputs Water use continued to trend upward although the rate of increase fell recently. Agriculture is by far the largest consumer of water; municipal and industrial users withdraw twice as much water as agriculture but consume only one-fifth as much, since a high propor¬ tion is returned to streams. About 43 million acres of farmland were irrigated with onfarm-pumped water in 1980, 22 percent over 1974. Electricity provided the power for nearly half these acres. Most power sources changed only moderately from 1974, but diesel fuel use almost doubled. Sharply higher energy costs and a larger acreage irrigated pushed pumping costs from $570 million in 1974 to $1.9 billion in 1980. Electricity costs dominated the increase in expenditures, while diesel fuel had the larg¬ est percentage increase. Chart 30 Water Use Million acre feet Chart 31 Chart 32 Acreage Irrigated with Onfarm-Pumped Water Energy Cost for Onfarm-Pumped Irrigation Water Electricity Natural gas Diesel LP gas Gasoline 1980 Electricity Natural gas Diesel LP gas Gasoline 1980 16 Inputs and Outputs U.S. farming used about 2.5 percent of the 80 quads (quadrillion BTU’s) of energy used in 1981. Agricultural chemicals and fuel to power machinery accounted for over 1.25 quads of the 2.0 quads used in farming. Energy prices paid by farmers rose sharply during 1973-81, but bulk gasoline and diesel fuel prices fell slightly in 1982. Average LP gas and electricity prices paid by farmers continued to rise in 1982. Total gal¬ lons of gasoline and LP gas used in farming fell almost 8 percent during 1974-82; diesel fuel use rose 23 per¬ cent. Livestock production in 1982 was 2 percent below 1981; crop production was a record 2 percent over 1981. Livestock production has grown nearly twice as fast as population since 1977 and crop production three times faster, leaving large quantities for export. Chart 33 Energy Used in Agricultural Production Chart 35 Farm Fuel Use Biilion gaiions Chart 34 Energy Prices Paid by Farmers 1970 72 74 76 78 80 82 Prices for gasoline represent bulk delivery prices. 1981 and 1982 labor prices not available. Chart 36 Crop and Livestock Production 1977 78 79 80 81 82 1982 preliminary. 17 Inputs and Outputs and Land Tenure U.S. farm output in 1982 was 1 percent below the 1981 record but still 5 percent above the previous 1979 record. Output per unit of input was also 1 percent below the 1981 record. Cropland used for crops rose sharply during 1972-82 due to strong export demand for farm products and the absence of strong acreage control programs. The PIK and other acreage control programs in effect during the 1983 season broke this trend. About 13.5 million acres of U.S. farmland was owned by foreigners, accounting for less than 0.6 percent of all land in the country, and less than 1 percent of ail privately owned cropland, pastureland, and forest land. Individuals accounted for 51 percent of the foreign owners, corporations for 33 percent, and partnerships for 12 percent. Chart 37 Farm Productivity 1977 78 79 80 81 82 1982 preliminary. Chart 39 Concentration of Foreign Ownership of Agricultural Land Chart 38 Crop Production per Acre and Cropland Used for Crops % of 1977 Chart 40 Proportion of Private Agricultural Land that is Foreign-Owned 18 Farmer Cooperatives The 1981 survey of marketing, farm supply, and related service cooperatives accounted for 6,211 cooperatives, 82 fewer than in 1980. The decline reflects cooperatives’ reorganizations (mergers, con¬ solidations, acquisitions) and dissolutions. Member¬ ships in farmer cooperatives totaled 5.3 million, down less than 1 percent from 1980. The long-term decline largely reflects the decreasing number of U.S. farms and farmers. Total net business volume of farmer cooperatives amounted to $71.5 billion in 1981, up 8 percent from 1980. Cooperatives employed 204,000 full-time employees in 1981, nearly 45 percent more than in 1957. Marketing cooperatives had 122,000 full¬ time employees, up 30 percent, and farm supply cooperatives accounted for 80,000, more than 75 per¬ cent above 1957. Chart 41 Farmer Cooperatives in the United States Thousand cooperatives Survey year Total includes a small number of cooperatives that provide specialized related services. Chart 43 Business Volume of Farmer Cooperatives $ billion Survey year Business volume is on net basis; it excludes intercooperative sales, but includes receipts for specialized services provided to patrons. Chart 42 Memberships in Farmer Cooperatives Million members Memberships include duplication \which cannot be eliminated using current reporting methods. Chart 44 Full-time Employees of Marketing and Farm Supply Cooperatives Thousand employees 19 Farmer Cooperatives Four farm commodities marketed by cooperatives in 1981—grain, soybeans, and products: dairy products; livestock and products: and fruits and vegetables— accounted for nearly 84 percent of the net sales of farm products. Petroleum products, fertilizer, and feed dominated production supply sales, together account¬ ing for over 75 percent of total net supply sales. Farmer cooperatives handled 33 percent of the agri¬ cultural products marketed at the first-handler level in 1981. Dairy products: grain, soybeans, and products; and cotton and products contributed the largest per¬ centage of market shares. Farmer cooperatives handled 20 percent of farm sup¬ plies at the first-handler level. Chart 45 Chart 46 Major Farm Products Marketed by Farmer Cooperatives $ billion Grain, soybeans, & products Dairy products Livestock and products Fruits and vegetables 0 .^ 4.5 III Cotton and products 2.1 S Sugar products 1.9 i Rice 1.3 1 Poultry products 1.2 i Nuts ■71! Tobacco .5 I Dry beans and peas ■2| Other products .9| 1981 data. Total net marketing business = $53.4 billion. Wool and mohair included in livestock and products. Major Farm Supplies Handled by Farmer Cooperatives $ billion Petroleum products Fertilizer Feed Farm chemicals Seed Building materials Machinery and equipment Meats and groceries Containers Other supplies ■2 I •’ I 1981 data. Total net farm supply business = $17.1 billion. Chart 47 Chart 48 Share of Products Marketed by Farmer Cooperatives Cotton and products Dairy products Fruits and vegetables Grain, soybeans, and products Livestock, wool, and products Poultry products Other Share of Farm Inputs Purchased Through Farmer Cooperatives Percent Farm chemicals Feed Fertilizer Petroleum products Seed Other supplies and equipment Farmers marketed 26 percent of their products at the first-handler level through their cooperatives in fiscal 1972 and 33 percent in 1981. Farmers purchased a total of 17 percent of farm inputs at the first-handler level through their cooperatives in fiscal 1972 and 20 percent in 1981. 20 Farmer Cooperatives Total assets of 6,293 farmer cooperatives in 1980 exceeded $29.4 biiiion. More than 43 percent of the cooperatives had assets of iess than $1 miiiion, while only 4.1 percent had assets of $10 million or more. Cooperatives with business voiumes of $15 miiiion or more represented 73.2 percent of the gross dollar volume in 1981. Cooperatives in the range of $200 mii¬ iion or more accounted for aimost 52 percent. Marketing cooperatives accounted for 53.8 percent of total net income of aii farmer cooperatives in 1981; farm suppiy cooperatives represented 45.6 percent. Farmers’ equity in their cooperatives was more than $10.9 biiiion in 1981. Equities in marketing coopera¬ tives accounted for 57.6 percent of the total and equi¬ ties in farm supply cooperatives, 42.1 percent. Chan 49 Chart 50 Distribution of Farmer Cooperatives by Size of Assets % of farmer cooperatives Less 0.1- 0.5- 1.0- 5.0- 10.0- 25.0- 100.0 than .49 .99 4.9 9.9 24.9 99.9 and 0.1 over Assets ($ million) 1980 data. Distribution of Farmer Cooperative Business by Size of Cooperative % of business handled 50 “ 40 - Less 15- 25- 100- 500- 1,000 than 24.9 99.9 499.9 999.9 and 15 more Size of cooperative ($ miiiion) 1981 data. Size of cooperative based on gross sales. Chart 51 Net income of Farmer Cooperatives by Major Function Percent Farm suppiies Marketing; Grain, soybeans, and products Dairy products Cotton and products Fruits and vegetabies Pouitry products Other products Chart 52 Farmer Equity in Farmer Cooperatives by Major Function Percent Farm suppiies Marketing: Grain, soybeans, and products Dairy products Fruits and vegetabies Cotton and products Pouitry products 1-6 I Other products 1981 data. Total net income = $1,440.3 million. Other products include dry edible beans and peas, livestock and products, nuts, rice, sugar products, tobacco, miscellaneous products, and specialized services. 1981 data. Farmers’ equity = $10.9 billion. Other products include dry edible beans and peas, livestock and products, nuts, rice, sugar products, tobacco, miscellaneous products, and specialized services. 21 Population and Rural Development 22 Population Over 12 percent of the people living in nonmetro areas in 1980 had moved from a metro area since 1975. Proportions of new nonmetro residents vary from more than 20 percent of the population in many States in the West to less than 10 percent in some Plains and Southern States. Under both current and old farm definitions, the farm share of total population continued its long-term decline. About 5.6 million persons lived on farms in the rural United States in 1982, or 2.4 percent of the Nation’s total. Nearly half of all farm residents lived in the North Central region of the country in 1982. Among the four major racial groups, only persons in the American Indian, Eskimo, and Aleut categories are as likely to live in nonmetro as in metro areas. Chart 53 Chart 54 Metro to Nonmetro Migration, 1975-80 1980 data. Percent of 1980 nonmetro population who lived in metro areas in 1975. Source: Bureau of the Census. Racial Composition of U.S. Population by Residence Percent 71 White 29 85 Black 15 American Indian, 52 Eskimo, and Aleut Asian and 93 Pacific Islander 7 1980 data. Source: Bureau of the Census. • Urban Rural Chart 55 Farm Population Chart 56 Regional Distribution of Farm Population Million persons Present definition includes those living on rural places with $1,000 or more in annual agricultural product sales. Previous definition was those on rural places of 10 or more acres with at least $50 in sales and under 10 acres with at least $250 in sales. 1981 data. Source: Bureau of the Census. 23 Population and Workforce Median age of farm residents in 1980 was about 36 years, compared with the nonfarm median of 30 years. Until mid-century, the farm population was younger, but continued net outmigration of young farm adults altered the farm population’s age composition. Nonmetro unemployment rates have been higher than metro rates since the first quarter of 1980, compared with 1973-79 when the metro rate was higher in all but two quarters. Thirty-two percent of the Nation’s 10.7 million unemployed in 1982 lived in nonmetro places. Manufacturing is diminishing relative to services as a source of employment growth in nonmetro areas. Manufacturing accounted for 24 percent of total non¬ metro wage and salary employment in 1982. Govern¬ ment was more important as a source of jobs in non¬ metro than in metro areas. Chart 57 Median Age of Farm and Nonfarm Residents Age Source: Bureau of the Census. Chart 58 Unemployment Rates for Metro and Nonmetro Areas Percent Quarterly data. Source: Bureau of Labor Statistics. Chart 59 Chart 60 Changing Structure of Wage and Salary Employment % of workers Agriculture, forestry, — fisheries, mining, construction Government Manufacturing Service- producing Metro Nonmetro Metro Nonmetro 1973 1982 Source: Current Population Survey, Bureau of the Census. Components of Wage and Salary Employment Growth, 1973-82 % of growth Agriculture, mining, and construction includes forestry and fisheries. Other includes transportation, communications, and public utilities; finance, insurance and real estate; and private household workers. Source: Current Population Survey, Bureau of the Census. 24 Farmworkers The number of hired farmworkers fell over 30 percent over the last two decades, stabilizing at about 2.6 mil¬ lion during the seventies. Total days of farmwork done by hired farmworkers rose. As farms have become fewer and larger, hired farmworkers have gradually replaced farm family members in the farm workforce. Most white farmworkers were between ages 14-24, while the majority of Hispanics, blacks, and other minorities were 25 years and over, suggesting that white farmworkers tend to move out of farmwork into other activities as they become older. Much of the hired farm workforce consisted of those not in the labor force most of the year but attending school or keeping house. Whites were more likely than minority workers to be in these activities. Chart 61 Hired Farmworkers and Days Worked Million workers Million days worked Data for 1978 and 1980 interpolated—data not available. Regular and year-round worked 150 or more days a year, seasonal worked 25-149 days, and casual worked less than 25 days. Chart 62 Chart 63 Age Distribution of Hired Farmworkers by Raciai/Ethnic Group and Sex Age White Hispanic Black and other 65 + 55-64 45-54 35-44 25-34 18-24 14-17 35 0 35 35 0 35 35 0 35 % of racial/ethnic group by sex 1981 data. Employment Status of Hired Farmworkers by Racial/Ethnic Group % of racial/ethnic group 22 Hired 52 39 farmwork 19 Nonfarm 12 work 9 Not in labor force: 51 All 32 47 40 Attending 12 school 24 White Hispanic iiiiiii Black and other 1981 data. Employment status based on worker’s major activity during the year. 25 Income Median family income, in constant dollars, remained fairly stable over the past decade. Nonmetro incomes lagged those in metro areas, while nonmetro blacks’ income was half that of nonmetro whites in 1981. Earned income was the largest source of personal income, although both transfer payments and income from investments accounted for a larger part of the total. Transfer payments such as social security and unemployment compensation accounted for a larger portion of income in nonmetro than metro areas. The number of persons with poverty level incomes has risen sharply since 1979. The poverty rate was higher in nonmetro areas. Although the nonmetro poverty rate was higher among blacks and the elderly, more nonmetro people in poverty were white and nonelderly. Chart 64 Median Family Income Chart 65 Components of Personal Income $ thousand Percent 30 Metro Nonmetro White 100 75 50 25 0 .V.V«V«VVi.Vi‘ Metro Non¬ metro X‘X'X*X*X-X mmm X*X'X*X*X'X' K-Kii-Kiii* Metro Non- metro Transfers Dividends, interest, and rent Labor and proprietor income 1969 1980 In 1981 constant dollars. Median is the middle value with half below and half above. Source: Bureau of the Census. Transfers include Social Security, payments from other government retirement programs, Medicare, unemployment compensation, and welfare. Source: Bureau of Economic Analysis, U.S. Department of Commerce, Chart 66 Chart 67 Persons in Poverty Characteristics of Persons in Poverty Millions Source: Bureau of the Census. % of metro or nonmetro poor Married 36.5 Metro couple 53.9 Female 40.2 householder 26.3 Nonmetro White Black Age 65 and over 62.9 75.3 33.3 21.9 10.3 14.9 1981 data. Source: Bureau of the Census. 26 Income and Housing Over two-thirds of poor families in nonmetro areas had at least one worker, well above the number of metro poor families who did. While welfare assistance accounted for a small amount of personal income in both metro and nonmetro areas, participation in the supplemental security income (SSI) and food stamp programs in 1980 was higher in nonmetro than metro areas. Inadequate housing continued most prevalent in the South, and more common in nonmetro than metro areas in all regions. Among nonmetro households with annual incomes below $7,000, the percentage of inadequate housing was nearly three times that of households with incomes of $15,000 or more. Inadequate housing was particularly high among blacks, reflecting their lower median income. Chart 68 Chart 69 Workers Among Poverty Families Participation in Income Maintenance Programs Percent % of population 2 or more workers Supplemental Security Income 1.83 1.64 2.33 1 worker Aid to Families with Dependent Children 4.57 4.89 3.66 9.05 No workers Food stamps 8.64 10.20 U.S. Metro Nonmetro Metro Nonmetro 1981 data. Source: 1981 Current Population Survey, Bureau of the Census. 1980 data. Food stamps data excludes 10 States not reporting data on a county basis. Source; U.S. Department of Health and Human Services, and Food and Nutrition Service, U.S. Department of Agriculture. Chart 70 Chart 71 Percentage of U.S. Housing That is Inadequate, by Region 1981 data. West includes Alaska and Havwaii. Inadequate housing lacks complete plumbing and/or has more than one person per room. Complete plumbing includes hot or cold piped water, bath or shower, and flush toilet. Source: Bureau of the Census. Inadequate Nonmetro Housing Household income Race Tenure % of households with inadequate housing Under $7,000 $7,000-$14,999 $15,000 and over Black Other 9.1 4.9 13.5 29.0 6.3 Owners Renters 6.1 13.1 1981 data. Source: Bureau of the Census. 27 Housing New housing construction recovered modestly in metro areas in 1982, but new housing starts in non¬ metro areas were the lowest in over a decade. High interest rates, rising energy costs, and increasing taxes made housing less affordable for many. During 1974-81, the percentage of household income devoted to housing rose considerably, particularly among renters. Households purchasing their homes during times of lower housing prices and interest rates had lower housing costs than recent purchasers. Ownership of housing was far more prevalent among nonmetro than metro households. The percentage of ownership rose slowly among nonhispanic blacks and whites, but fell among Hispanics since 1970. Mobile homes continued to be more common in nonmetro than in metro areas. Chart 72 New Housing Starts Million units Source: Construction Reports, Housing Starts, Bureau of the Census. Chart 73 Housing Costs % of income Owners Renters 28.2 Metro Nonmetro Metro Nonmetro Includes cost of mortgages, taxes, insurance, and utilities for owners; gross rent for renters. Source: Annual Housing Survey, 1974 and 1981, Bureau of the Census. Chart 74 Chart 75 Percentage of Popuiation in Owner-Occupied Homes Mobile Homes Metro Nonmetro % of racial/ethnic group in own homes All Black Hispanic All Black Hispanic Total Black occupied Hispanic occupied Source: Census of Housing 1970, and 1981 Annual Housing Survey, Bureau of the Census. Source: Census of Housing 1970, and 1981 Annual Housing Survey, Bureau of Census. 28 Public Services Almost all rural people have access to a hospital within a reasonable driving distance. Nearly as many rural residents have access to an emergency room or intensive care unit, but not to many advanced treat¬ ment facilities. Virtually all rural communities have fire protection, though service may be inadequate for some. Two of every five rural communities, mainly unincorporated areas, lack complete fire hydrant service. Few rural communities outside incorporated areas but most incorporated communities have a wastewater treatment plant. More than half the communities have plants with adequate capacity. Personal incomes have risen more rapidly than local government costs in over half of all rural counties, but revenue burdens have risen for some local governments. Chart 76 Chart 77 Fire Protection Services in Rural Communities % of rural communities With no fire protection 2 ;i services ij:;:; Have fire trucks not stored at a 7 fire station Lack complete coverage by hydrants or have 41 low-tank truck capacity 1980 data. Source; National Rural Community Facilities Assessment Study. Wastewater Treatment Facilities in Rural Communities % of communities with own system Average flow: Served by a wastewater treatment plant No plant but plan to build one Average flow of less than 80% of designed capacity is considered necessary to avoid overloading in times of peak use. Source; ERA Wastewater Needs Survey, 1978. Chart 78 Chart 79 Nonmetro Counties with Rising Revenue Burden Hospital Facilities in Rural Communities % of counties Urbanized Less urbanized Totally rural Adjacent counties Nonadjacent counties Adjacent counties Nonadjacent counties Adjacent counties Nonadjacent counties 1972-77 data. Rising revenue burden is locally raised general revenue which Increased faster than personal income. Source; Bureau of Census and Bureau of Economic Analysis, U.S. Department of Commerce. % without facility within 30 miles Hospital Emergency room Intensive care unit Hospital blood bank Electroencephalo¬ graph Pediatrics dept. Premature nursery Hemodialysis 2 1977 data. Source; American Hospital Association. 29 The Consumer 30 General Economy Following 3 years of stagnant economic growth, real GNP in 1982 was about even with 1979. Nominal GNP grew but more slowly than in the past due to reduced inflation and economic stagnation. Recovery was underway by the first quarter of 1983. Real disposable income in 1982 was only 3.8 percent above 1979 lev¬ els. Adjusted for population growth, real incomes grew less than 1 percent during 1979-82. Nominal income continued to rise, aided by tax cuts, but more slowly than in the past. Food and beverage expenditures accounted for 18 percent of disposable personal income in 1982, down from 19 percent in 1978. Consumers increased their rate of savings to 6.5 percent of income in 1982. Civilian unemployment stood at 10.0 percent in June 1983, up from 9.8 percent in June 1982. Chart 80 Chart 81 Gross National Product Disposable Personal Income 1983 preliminary. Seasonally adjusted annual rate. Source: U.S. Department of Commerce. 1979 80 81 82 83 1983 preliminary. Seasonally adjusted annual rate. Source: U.S. Department of Commerce. Chart 82 Personal Income and Expenditures Chart 83 Reasons for Unemployment $ trillion Percent New entrants Reentrants Job leavers Job losers 12.9 21.7 7.0 58.4 1983 preliminary. Seasonally adjusted annual rate. Source: U.S. Department of Commerce. June 1983 data seasonally adjusted. Percentage of unemployed. Source: Bureau of Labor Statistics. 31 General Economy and Consumer Prices Americans spent about 13 percent of their disposable income on food in 1979, compared with the 80 percent spent by rural residents of many developing countries. Domestic retail food prices rose 4 percent in 1982, the smallest increase in recent years. The smaller increase can be attributed in part to a low 1-percent rise in the farm value of food, resulting from large sup¬ plies of farm foods and weak demand. Many countries continued to experience rapid infla¬ tion, even as the world entered a recessionary period in 1981. Israel’s 5-year span of inflation translated into an annual rate of 76 percent. A number of developing and centrally planned countries, meanwhile, put a ceiling on retail prices of many basic commodities, thus limit¬ ing inflation. Chart 84 Share of Consumer Expenditures for Food Chart 85 Food Prices: Retail and Farm Value Sudan India Jordan Sierra Leone Mexico Portugal Thailand Soviet Union Italy Poland Zimbabwe Hong Kong Australia United States Percent 65 56 54 53 40 38 37 34 29 28 25 23 17 13 1979 data, except for Sudan, 1975; Sierra Leone, 1977; Portugal, 1976; and Zimbabwe, 1977. Source: UN National Accounts of Statistics and national sources. % Of 1967 Source: Retail prices, all food. Bureau of Labor Statistics. Farm value of domestically produced foods, U.S. Department of Agriculture. Chart 86 Increase in World Consumer Prices Israel Brazil Turkey Zaire Costa Rica Portugal Iran Kenya Ivory Coast Thailand United States India Singapore Hungary West Germany Japan Burma % of 1977 2,964 1,575 mrnmmmmm 220111111111 193 min 176111111 168 mmrnm 159 mmam 148 mrnm 133 mmm 130 im 126 iS] 125 11111 loom 1982 data, except for Hungary and Burma, 1981. Source: International Financial Statistics, International Monetary Fund. M 32 Consumer Prices Food prices in 1982 rose 4.0 percent, the smallest increase since 1976. Food prices rose less than the general inflation rate in 7 of the last 8 years, with a rise of 2 to 3 percent expected in 1983. Retail prices in 1983 for crop products changed very little from those in 1982. Vegetable prices rose only slightly while fruit prices fell. Large supplies of vege¬ table oils and cereal grains dampened increases in the Consumer Price Index for fats and oils, and cereals and bakery products. Retail prices for livestock products also changed little, with most increases attributable to supply disruptions from cold wet weather early in the year. Red meat prices and poultry prices remained near 1982 levels. Dairy product prices rose 2 percent. Chart 87 Consumer Price Index for Selected Crop Products % of 1967 1983 forecast. Source: Bureau of Labor Statistics. Chart 88 Consumer Price Index for Selected Livestock Products % of 1967 1983 forecast. Source: Bureau of Labor Statistics. Chart 89 Changes in Consumer Price Index for Food Percentage change 33 Consumer Prices One way to find good buys among meats and meat alternates is to compare the costs of amounts providing equal protein. A 3-ounce serving of cooked lean beef, pork, turkey, chicken, or fish provides some 20 grams of protein, 1/3 of the recommended dietary allowance (RDA) for a 20-year-old man. While the economy- minded shopper can substitute beans, peanut butter, and eggs for the more expensive meat, poultry, and fish, well over a serving of some meat alternates is required to supply equal protein. In USDA’s low-cost food plan, a week’s food at home In June 1983 cost $44.50 for a younger couple and $39.90 for an older couple, assuming all food was pur¬ chased at a store and prepared at home. A week’s food cost $62.60 and $80.80 for families with two younger and two older children, respectively. Chart 90 Cost of Vs of a Day’s Protein from Meats and Meat Alternates Beef rib roast Cents 119 1 Sirloin steak 88 m Haddock, fillet 76 Pork roast 65 Beef chuck roast 59 Frankfurters 53 American cheese 50 Ground beef, lean 44 1 Ham, whole 39 Tuna 37 Eggs, large 26 Chicken or turkey 24 m Beef liver 24 Peanut butter 23 1 Dry beans 10 m m Average retail prices in Washington, D.C. metropolitan area, June 1983. One-third of Recommended Dietary Allowance for 20-year-old man. Cost of a Week’s Food, by Family Type Thrifty Low-cost Moderate- plan plan cost plan - Liberal plan Dollars Couple, age 20-54 34.50 44.50 56.90 67.00 Couple, age 20-54 with: 42.30 54.10 67.70 81.10 Two children: Age 1-5 49.10 62.60 78.10 93.60 Age 6-11 59.20 75.80 95.00 113.70 Age 12-19 63.20 80.80 101.10 121.00 Child, age 15-19 50.10 64.30 80.50 96.40 Couple, age 55 or over 31.20 39.90 49.50 59.00 June 1983 data. All meals at home or taken from home. Chart 91 Cost of a Week’s Food by Family Type Dollars 100 - Couple with two children couple Age of children June 1983 data. All meals at home or taken from home. USDA Low-Cost Food Plan. 34 Food Marketing Costs Consumer expenditures for domestically produced farm foods are forecast at $306 billion in 1983, about $9 biilion higher than in 1982. The increase was the resuit of higher marketing costs since farm values are forecast to fall. Over the last 5 years, increases in the marketing biii have accounted for over 85 percent of the increases in food expenditures. Marketing costs wiil rise by about 4.9 percent in 1983, compared with 5.9 percent in 1982. Labor, pack¬ aging, and transportation costs make up over 63 per¬ cent of the total marketing bili. These costs combined have risen by $50.7 biliion since 1977. The marketing bili accounted for 66 percent of total consumer expenditures for at-home food consumption in 1982 and 83 percent of consumer expenditures for away-from-home consumption. Chart 92 Components of Consumer Expenditures for Farm Foods $ billion Chart 93 What a Dollar Spent on Food Paid for in 1982 Farm value 28c Marketing biil: Other costs SVaC Repairs IVac Interest (net) 2c Advertising 2c Fueis and- electricity 4c Before tax profits 4y2C Rent and depreciation 41 / 2 c Intercity transportation 5c Packaging 8c- Labor 32c - 1982 preliminary. Other components include business taxes, corporate profits, energy, depreciation, rent, advertising, and numerous other costs. 1982 preliminary. Other costs inciude property taxes and insurance, accounting and professionai services, promotion, bad debts, and misceilaneous items. Chart 94 Components of the Food Dollar Spent for At Home and Away from Home Consumption At home Away from home 35 Food Marketing Costs Grocery store food prices will average 1.0 to 1.5 per¬ cent higher in 1983, the smallest annual increase in 16 years. About 80 percent of this will come from a higher farm-to-retail price spread, or charges for processing and marketing foods after they leave the farm. The price spread will rise about 4 percent in 1983 because of rising wages and salaries of workers and other such costs. The small 1983 food price rise resulted in large part from a 4-percent fall in the farm value of commodi¬ ties. Farm share of retaii food prices will probably average about 33 percent in 1983, down from 35 percent in 1982. Animal products generally have the highest shares, and the more highly processed crop products the lowest. Chart 95 Components of Increases in Retail Food Prices Chart 96 Farm Prices and Food Marketing Costs % change in retail price 10 ~ 6 - 4 - 2 - 0 _ 1981 -Higher prices for - fish and imported TTrrrr- fOOdS Higher farm value “ ^ Higher farm-to-retail ^ price spread — 1983 forecast. Farm value and farm-to-retail price spread from U.S. farm food market basket. Total price change from food-at-home index, Consumer Price Index. % of 1967 1983 forecast. Farm value represents prices received by farmers for commodities equivalent to a fixed market basket of foods. The price spread is the difference between the farm value and retail cost of the market basket and represents all charges for processing and marketing functions. Chart 97 Chart 98 Farm Share of Retail Food Prices Eggs Dairy products Poultry Meat products Average for market basket of farm foods Fresh fruits and vegetables Fats and oils Processed fruits and vegetables Bakery and cereal products 1982 data. Based on the payment to farmers for the commodities equivalent to a market basket of foods and the retail price. Marketing Bill, Farm Value, and Expenditures for Farm Foods $ billion 1982 preliminary, 1983 projected. For domestic farm foods purchased by civilian consumers for consumption both at home and away from home. 36 Food Consumption Both total and per capita food consumption fell in 1982, due to decreases in consumption of both animal and crop products, while the U.S. population rose near¬ ly 1 percent. Decreases in pork, eggs, and animal fats consumption offset increases in beef and chicken con¬ sumption. Egg consumption fell from 1981-82. Plain whole milk consumption fell 2 percent in 1982, while consumption of other milk rose nearly 1 percent. Coffee and tea use fell 2 percent. Dairy products con¬ sumption rose over 1 percent in 1982, due to increases in cheese and butter consumption. Butter use alone rose nearly 4 percent, while cheese and cottage cheese consumption rose 11 percent. Fluid milk and cream consumption dropped 1 percent, while frozen dairy products consumption held steady. Chart 99 Population and Food Consumption 1967 72 77 82 Total food consumption based on retail weight using constant retail prices as weights. Chart 101 Per Capita Consumption of Beverages % of 1967 1982 soft drink consumption estimated. Chart 100 Per Capita Consumption of Food % of 1967 Chart 102 Per Capita Consumption of Selected Dairy Products % of 1967 37 Food Consumption Animal products consumption feii 1 percent in 1982 due to decreases in red meat and dairy product use. Poultry consumption rose nearly 2 percent, and egg use rose almost 1 percent. Consumption of crop prod¬ ucts feli siightiy. A 9.5-percent decline in fruit con¬ sumption and a 0.7-percent drop in consumption of cereal products offset increases in vegetables and sugars and sweeteners consumption. Consumption of fresh fruits feii 7.4 percent while pro¬ cessed fruits use feii 8.7 percent. Continued growth in fresh vegetable consumption helped offset a 2-percent drop in processed vegetable consumption, for an increase of 1.9 percent in totai vegetable consumption in 1982. Totai fats and oiis use rose in 1982 due to increases of 2.4 percent in animal fats use and 0.4 per¬ cent in consumption of vegetabie oils. Chart 103 Per Capita Consumption of Seiected Animal Products % of 1967 Chart 105 Per Capita Consumption of Fruits and Vegetables % of 1967 Chart 104 Per Capita Consumption of Selected Crop Products % of 1967 Vegetables exclude potatoes, peas, beans, and melons. Chart 106 Per Capita Consumption of Fats and Oils % of 1967 38 Nutrients in Food at Home Households in the spring portion of the 1977-78 Nationwide Food Consumption Survey (MFCS) allocat¬ ed 12 cents of their home food dollar to milk and milk products and obtained 60 percent of all calcium and about 30 percent of all riboflavin, phosphorus, and vita¬ min provided by home food supplies. Households spent 34 cents of each dollar on meat, poultry, and fish, and obtained large proportions of vitamin P'' 0 ’ tein, vitamin Bg, and iron. The share of the food dollar devoted to fruits and vegetables, 20 cents, provided 80 percent of ascorbic acid (vitamin C) and 51 percent of vitamin A in the diet. The 12-cent share allotted to grain products yielded 48 percent of the thiamin, and 35 percent of the iron found in household diets. Chart 107 Selected Nutrients Supplied by Food Groups Milk and Milk Products % of nutrient supplied Calcium 60 Riboflavin 31 Phosphorus 30 Vitamin 3^2 29 Protein 19 Magnesium 16 Food energy (calories) 13 12 % of the food dollar Fruits and Vegetables % of nutrient supplied Ascorbic acid 80 Vitamin A 51 Vitamin Bg 26 Magnesium 24 Thiamin 17 Iron 17 Food energy (calories) 10 Calcium 10 20 % of the food dollar Meat, Poultry, and Fish % of nutrient supplied Vitamin B .,2 54 Protein 47 Vitamin Bg 34 Iron 32 Phosphorus 27 Food energy 25 (calories) Riboflavin 21 Thiamin 20 Grain Products 0/ /o Thiamin 48 Iron 35 Riboflavin 29 Food energy 24 (calories) Vitamin Bg 22 Magnesium 21 Phosphorus 20 12 % of the food dollar Other foods accounted for 22% of the food dollar. Source; USDA Nationwide Food Consumption Survey, 1977-78, 48 States, spring. 39 Convenience Foods Convenience foods are fully- or partially-prepared foods which transfer significant time, culinary skill, or energy from the homemaker’s kitchen to commercial food processors and distributors. MFCS data estimated use of convenience foods in U.S. households. Basic convenience foods included commercially-processed, single-ingredient foods such as canned or frozen produce. Complex convenience foods included mixtures with built-in timesaving features, energy inputs, and/or culinary expertise, such as canned and frozen entrees. Manufactured conven¬ ience foods included processed foods with no home counterpart such as cereals. Nonconvenience foods included fresh unprocessed foods, home-preserved foods, and products used as basic ingredients in home recipes. Chart 108 Share of Weight and Cost of Food Used at Home by Convenience Category Percent Pounds Manufactured convenience Complex convenience Basic convenience Nonconvenience Cost Chart 109 Weekly Value per Household of Food Used at Home by Convenience Category Dollars Manufactured convenience Complex convenience Basic convenience 8.56 Nonconvenience 25.69 Manufactured: commercially-processed foods having no home counterpart (such as ready-to-eat cereal). Complex: commercially- processed multi-ingredient mixtures. Basic: commercially-processed single-ingredient foods. Nonconvenience: fresh foods or basic processed foods used as ingredients (such as flour). Manufactured: commercially-processed foods having no home counter¬ part (such as ready-to-eat cereal). Complex: commercially-processed multi-ingredient mixtures. Basic: commercially-processed single¬ ingredient foods. Nonconvenience: fresh foods or basic processed foods used as ingredients (such as flour). Chart 110 Share of Nutrients in Food Used at Home by Convenience Category % of nutrient energy (calories) Per household member per day. For fat and carbohydrate, values are based on 21-meal-at-home equivalent persons. For other nutrients, values are based on adult-male equivalent persons in terms of the Recommended Dietary Allowances (RDA). For definitions of coavenience categories, see charts 108-109. Food Consumption Surveys Of all respondents participating in the individual phase of the MFCS during 1977-78, 77 percent had at least one snack during the 3 days reported. The young¬ est group of children had the largest percentage of snackers, but among young men and women, the per¬ centage was almost as large. The proportion of snack¬ ers decreased among older adults, with a larger decrease among women than men. The contribution of food groups to food energy (calories) and selected nutrients was based on infor¬ mation collected on the kinds and amounts of food used by households in 7 days during the household phase of the MFCS, 1977-78. The nutritive value of foods reported included food eaten by people in the household and food discarded in the kitchen and at the table, such as trimmable fat on meat. Chart 111 Individuals Consuming Snacks Chart 112 Age % of individuals Contribution of Food Groups to Food Energy and Nutrients Food energy (calories) Individuals reporting at least one snack in three days. Source; USDA Nationwide Food Consumption Survey, 1977-78, Individual Phase, 48 States, spring. Source; USDA Nationwide Food Consumption Survey, 1977-78, Household Phase, 48 States, spring. 41 Diet Quality More than two-thirds of all respondents participating in the individual phase of the MFCS met or exceeded the 1980 RDA for protein, phosphorus, riboflavin, nia¬ cin, and vitamin B^ 2 - Intakes of vitamin A, thiamin, and vitamin C met or exceeded the RDA for half the respondents. Fewer individuals met or exceeded the RDA for food energy (calories), calcium, iron, magnesi¬ um, and vitamin Bg. Intakes were based on reports of 3-day diets collected from over 36,000 individuals dur¬ ing a 1-year period in 1977 and 1978. Most individuals reported that they did not use any vitamin or mineral supplements. Proportionately more infants, children under 6, and older women used sup¬ plements than did other groups. Chart 113 Percentage of Individuals Meeting Four Levels of RDA for Thirteen Nutrients Food energy (calories) Protein Calcium Iron Magnesium Phosphorus Vitamin A Thiamin Riboflavin Niacin Vitamin Be Vitamin C 'A I I I 25 50 75 % of individuals 100 Below 50 percent of RDA K^//\ 70-99 percent L. J 50-69 percent 100 percent and over 1980 Recommended Dietary Allowances. Chari 114 Use of Vitamin and Mineral Supplements Age Under 1 1-2 3-5 6-8 Males and females 9-11 12-14 15-18 19-22 Males 23-34 35-50 51-64 65-74 75-K 9-11 12-14 15-18 19-22 Females 23-34 35-50 51-64 65-75 75-1- Am Am AM _ mmmA 1 wm/w/. 1 w/Mm. 1 0 V//A Use regularly Use irregularly I I I 25 50 75 % of individuals 100 ] Do not use I Not reported 42 Cholesterol and Fatty Acids Types of fat in the U.S. food supply changed as the total fat level rose since 1909-13. Total saturated fatty acids (TSFA) rose 8 percent. Unsaturated fatty acids— oleic and linoleic—rose 28 and 186 percent, respec¬ tively. Despite an increase from the meat, poultry, fish group, TSFA were 5 percent lower in 1981 than in 1967-69 due to use of less butter and lard. Use of more margarine, shortening, and edible oil accounted for higher linoleic acid. Cholesterol in the food supply fell from 507 to 484 mg per capita per day since 1909-13. Eggs remain the primary source of cholesterol, although use fell. Cholesterol from the meat, poultry, fish group rose. Cholesterol from the dairy and fats and oils groups fell due to decreased use of whole milk, butter, and lard. Chart 115 Cholesterol in the U.S. Food Supply, by Food Group 28 ;;;13: ■ >x«x»x*x*x*x*: 25 8 ^ 49 ^: 35 ^ 45 ^ 1909-13 1947-49 1967-69_ 507 575 531 484 Milligrams per capita per day Chart 116 Fat in the U.S. Food Supply, by Food Group 37 37 1909-13 1947-49 1967-69 124.5 141.0 157.0 162.7 Grams per capita per day Chart 117 Saturated Fatty Acids in the U.S. Food Supply, by Food Group Percent 39 33 34 1909-13 1947-49 1967-69 49.8 54.5 57.1 Grams per capita per day 1981 54.0 Chart 118 Linoleic Acid in the U.S. Food Supply, by Food Group Percent 32 39 WMM *X*X*X*X*X*J*X;! 56 1909-13 1947-49 1967-69 Dairy products —Meat, poultry, and fish — Fats and oils —Other foods 1981 9.0 13.7 19.8 Grams per capita per day 25.7 43 Family Economics One of every 3 dollars saved in 1982 was placed in life insurance and pension plans. The proportion of individual savings held in savings accounts during 1981-82 doubled from 14 to 28 percent because of the popularity of new "super NOW" and money market deposit accounts. Farm women are more likely to have a joint savings account, a joint charge account, and share an obligation to repay a loan than to have indivi¬ dual accounts and loans. One in three has her own savings account and revolving charge account; one in five has sole responsibility for repaying a loan. The 1981 median income of women 65 years and older was only 58 percent of that reported by men in that age group. Over half of elderly women had incomes under $5,000, compared with less than one- quarter of elderly men. Chart 119 Distribution of Individual Savings 1981 1982 Other tangible assets include consumer durables, nonresidential fixed assets, and inventories. Source: Federal Reserve Board. Chart 120 Chart 121 Farm Women’s Responsibility for Financial Accounts Savings Revolving credit Loans % of farm women 31.9 90.9 33.1 Alone 56.8 jwith someone 21.0 1980 data. Income of the Elderly Under $5,000 1981 data. Median income; men, $8,173; women, $4,757. Source: Bureau of the Census. Women Men 44 Family Economics Annual costs of raising farm children usually rise with the age of the child. No substantial difference in costs by sex appear until age 13, when costs for farm boys are higher than for farm girls. Costs of raising farm boys and girls to age 18 at the moderate level are $99,119 and $96,554, respectively. At all cost levels, housing and food make up the greatest proportion of expenses for southern, urban children. The costs of raising these children through age 18 range from $41,631 at the thrifty level to $90,624 at the moderate level. The cost of raising North Central, rural, nonfarm chil¬ dren to age 18 at the moderate level is $77,789. The child’s shares of family housing and food are the greatest expenditures, 34 and 23 percent, respectively. Chart 122 Annual Cost of Raising Farm Children Chart 123 Cost of Raising Southern, Urban Children Age 1 5 9 13 17 $ thousand June 1983 data. Moderate cost level. Chart 124 Cost of Raising North Central, Rural, Nonfarm Children Housing $ thousand 3.0 Clothing 4.3 6.2 Medical care Education .3 .7 2.1 L other June 1983 data. Birth to age 18. 45 Unemployment Between 1981 and 1982, unemployment rates rose more for black men than for black women and whites. The unemployment rate for 1982, which averaged 9.7 percent, varied from 6.1 percent for white married men to 26.6 percent for black single men. Unemployment rates for the 50 States and the Dis¬ trict of Columbia in 1982 ranged from 5.5 percent in South Dakota to 15.5 percent in Michigan. Rates were generally lowest in the central United States. Weekly earnings of female householder families, were least affected when a household member became unemployed. The earnings of these families fell 10 per¬ cent; those of male householder families decreased 26 percent, and the earnings of married couple families fell 30 percent. Chart 125 Unemployment Rates 1974 76 78 80 82 Black includes black and others. Ages 20 to 64. Source: Bureau of Labor Statistics. Chart 126 Weekly Earnings of Families with Unemployed Members Married couple Female householder Male householder $ per family 496 347 253 227 || Without I unemployed II members With unemployed members 403 299 1982 data. Source; Bureau of Labor Statistics. Chart 127 Unemployment Rates by State Percent 5.5-5.9 6.0-7.9 8.0-9.9 ^10.0-11.9 m 12.0-15.5 1982 data. Alaska, 9.9 percent; Hawaii, 6.7 percent; and District of Columbia, 10.6 percent. Source: Bureau of Labor Statistics. 46 Consumer Finance Since 1960, consumers have spent between 13 and 15 percent of disposable income on repayment of credit obligations. Consumer debt rose to 16 percent during 1977-79. Personal bankruptcy filings in 1982 were down about 7,000 filings from 1981. Compared with the traditional level-payment mort¬ gage, a growing equity mortgage uses increasing monthly payments to pay off the loan in about 15 years. A graduated payment mortgage uses increasing month¬ ly payments to compensate for initial payments too low to cover interest due; total debt on this mortgage increases for a period of 5-8 years before payments are large enough to begin amortizing the loan. Interest rates for money market and variable ceiling certificates and money market funds varied 7 to 9 per¬ cent during 1980-83. Chart 128 Consumer Debt Burden % of disposable income First quarter for 1982. Source: Federal Reserve Board. Chart 130 Outstanding Principal Balance on Four Mortgages $ thousand Loan of $60,000, 12.5 percent, 30 years (except for growing equity mortgage). Source: U.S. Department of Housing and Urban Development. Chart 129 Number of Personal Bankruptcies Filed Thousands 500 - Source: Administrative Office of the U.S. Courts. Chart 131 Interest Rates by Instrument 1980 81 82 83 Certificate and passbook rates as offered by commercial banks. Source: Federal Reserve Board. 47 Home Energy Use Electricity use has grown as a primary fuel in heating homes, although natural gas continues to be used in 6 of every 10 homes. Oil continues to decline in impor¬ tance; only 17 percent of all houses were heated with oil In 1981, down from 32 percent in 1960. Household energy expenses are highest in the northeastern States where oil is a prominent fuel in home heating, and lowest in the West. More than half of all homes are now air-conditioned, a marked increase in the past 10 years. The increase was especially dramatic in non-SMSA areas where air conditioning use nearly doubled, twice the increase in SMSA areas. Increasingly more homes have replaced room units with central air conditioning systems. Chart 132 Primary Fuels Used in Home Heating Percent Data not available for electricity prior to 1950. Source: Census of Housing 1940, 1970; and 1981 Annuai Housing Survey, Bureau of the Census. Chart 133 Yearly Household Energy Expenditures by Region West North East North New Pacific Mountain Central Central England 1980 data. Pacific inciudes Aiaska and Hawaii. Source: U.S. Department of Energy. Primary Fuels Used in Home Heating 1950 1960 1970 1981 Utility or LP gas 12,385 1,000 homes 25,537 38,820 50,235 Fuei oii or kerosene 9,687 17,159 16,473 14,481 Electricity 283 933 4,876 15,514 Coal 14,831 6,456 1,821 361 Wood 4,270 2,237 794 1,893 Other 788 223 266 102 None 582 478 395 .590 Total 42,826 53,023 63,445 83,176 Source: Census of Housing 1950-70 and Annual Housing Sur¬ vey, 1981, Bureau of the Census. Chart 134 Homes with Air Conditioning Percent _Central system Room units 58.5 39.2 29.4 12.3 26.9 29.1 1970 1981 SMSA 54.0 28.5 23.5 7.5 30.5 21.0 1970 1981 Non-SMSA 48 SMSA is Standard Metropolitan Statisticai Area. Source: Census of Housing, 1970, and 1981 Annual Housing Survey, Bureau of the Census. Home Energy Use Increasingly more households are improving the weatherization of their homes. Attic or roof insulation is generaliy a better energy-saving investment than storm doors or storm windows and is used more extensively in all regions of the country. Eight of 10 homes in both metro and nonmetro areas have some attic or roof insulation, while about two-thirds have storm doors or windows. During the first half of 1983, gasoline prices remained at 1982 levels, while the price of electricity rose slightly. Utility gas prices rose 19 percent over 1982 levels, while the cost of fuel oil fell almost 10 per¬ cent. Automobile ownership costs increased as the size of the vehicle increased. Each step down in car size saved a minimum of 10 percent in overall costs for a 12-year period. Chart 135 Homes with Weather Protection Chart 136 One or more storm windows One or more storm doors Any attic or roof insulation % of owner-occupied homes 62.6 66.4 60.2 64.0 84.2 83.0 Non- SMSA 1980 data. Data not available on adequacy of existing insulation. SMSA is Standard Metropolitan Statistical Area. Source: 1980 Annual Housing Survey, Bureau of the Census. Homes Receiving Increased Weather Protection in 1980 SMSA J bMbA windows 8.3 % of owner-occupied homes )MSA Non-SMSA Storm doors Attic insulation 4.8 5.0 8.2 7.6 Wall 5.5 insulation 5.7 '•v»v»vlv» Weather- 21.9 stripping 16.5 SMSA is Standard Metropolitan Statistical Area. Source: 1980 Annual Housing Survey, Bureau of the Census. Chart 137 Change in Energy Prices 1967 71 75 79 83 Annual averages 1967-82; June data for 1983. Source: Bureau of Labor Statistics. Chart 138 Cost of Owning and Operating an Automobile $ thousand 40 “ $39,994 30 20 10 0 $25,701 Tax Insurance Parking/tolls Gas/oil Maintenance Original cost Large Inter- Com- Sub¬ mediate pact compact Van 1981 data. Costs are for owning a car over a 12-year period. Source: U.S. Department of Transportation. 49 Food and Nutrition 50 Food Assistance USDA expenditures for food assistance totaled about $17.6 billion for fiscal 1983, up from $15.6 billion in fis¬ cal 1982. The purchase requirement was eliminated for the food stamp program in 1979 and application procedures for the elderly were simplified in 1980, and Puerto Rico switched from the food stamp program to a nutritional assistance program in July 1982. Value of food stamps issued has increased substan¬ tially in recent years, although with Puerto Rico out of the program, the total fell slightly in fiscal 1983. The increases in former years were due to greater partici¬ pation and adjustment in coupon allotments to reflect changes in food prices. The average monthly food stamp bonus per person was about $43.00 for fiscal 1983. The amount of stamps received is based on net income and household size. Chart 139 USDA Funding for Food Assistance $ billion 1983 preliminary. Fiscal years. WIC is the Special Supplemental Food Program for Women, Infants, and Children. Food Stamp Program for 1983 includes nutritional assistance for Puerto Rico. Chart 140 Participants in the Family Food Assistance Programs 1977 79 81 83 1983 estimated. Fiscal years. Includes nutritional assistance to Puerto Rico. Chart 141 Value of Food Stamps Issued Chart 142 Average Monthly Food Stamp Bonus per Person $ billion Dollars 1983 estimated. Fiscal years. Bonus is the portion of food stamp allotment received free. Purchase was eliminated in early 1979; thereafter, bonus equals total food stamp allotment. 1978 1979 1980 1981 1982 1983 1983 estimated. Fiscal years. Bonus is portion of food stamp allotment received free. Purchase requirement was eliminated in early 1979; thereafter, bonus equals total food stamp allotment. Constant dollars (deflated by CPI for food at home) are 1967 dollars. 51 Food Stamps Deductions from gross income substantiaiiy affect the distribution of food stamp househoids by income. In 1981, 60 percent of participating househoids had net incomes beiow $200 per month, but oniy 22 percent had gross incomes that low. About half of participating househoids had real gross incomes beiow $200 per month (in 1977 constant doiiars), with the iargest per¬ centage in the $100-$200 range. Food stamp allotments increase as the size of the househoid becomes iarger, but at a decreasing rate, unless income changes. Participation in the food stamp program has traditionally changed in line with the unempioyment rate. During 1975-79, unemployment and participation both trended downward, but since then the general trend has been upward. Chart 143 Distribution of Food Stamp Househoids by Monthly income Income None $1-$99 $100-$199 $200-$299 $300-$399 $400-3499 $500-$599 $600-3699 $700 and over % of households Chart 144 Distribution of Food Stamp Households by Real Gross Monthly Income Income None $1-399 $100-3199 $200-3299 3300-3399 $400-3499 3500-3599 3600-3699 $700 and over August 1981 data. Net income is gross income less deductions allowed August 1981 data. Real gross monthly Income is the actual income by food stamp legislation. adjusted to 1976 dollars. Chart 145 Monthly Income and Average Food Stamp Allotment Dollars August 1981 data. Net monthly income is gross income less deductions allowed by food stamp legislation. Chart 146 Unemployment Rate and Participation in the Food Stamp Program Million persons Percent 52 Food Stamps Participation in the food stamp program rose in each region excluding Puerto Rico in 1983, with the largest increases in the Midwest and Southwest regions, accounting for 43 percent of total participation. Eligibil¬ ity guidelines and benefit levels are applied uniformly to all regions. Bonus variations reflect differences in income levels, household size, and other qualifying characteristics. Average bonus per person historically rises faster than the CPI for food at home. Rising deductions from gross incomes, coupled with food prices outpacing net incomes of participants, have contributed to rising bonus levels per person since 1979, when legislation was liberalized. This trend was intensified in 1983 when food price increases slowed and the rate of unemployment was high. Chart 147 Chart 148 Food Stamp Participation by Region Food Stamp Benefits per Person by Region Northeast Mid-Atlantic Southeast Midwest Southwest Mountain Plains Western Northeast Mid-Atlantic Southeast Midwest Southwest Mountain Plains Western Dollars 1983 41.50 / 38.08 1982 42.88 38.72 43.13 39.06 44.90 .s 40.19 42.87 38.94 42.12 38.57 39.53 35.80 1983 estimated. Fiscal years. Mid-Atlantic excludes Puerto Rico. 1983 estimated. Fiscal years. Mid-Atlantic excludes Puerto Rico. Chart 149 Change in Food Prices and Food Stamp Bonus Chart 150 Totai Food Stamp issuance by Region % of 1974 $ million Northeast 112.2 : 98.6 Mid-Atlantic 124.6 107.0 Southeast 209.2 184.6 Midwest 200.3 163.6 Southwest 113.5 93.1 Mountain 56.2 Plains 45.8 Western 114.2 96.6 1983 1982 1983 estimated. Fiscal years. Mid-Atlantic excludes Puerto Rico. 53 WIC and Child Programs After declining in 1982, meals served under the child care program rose about 9 percent in 1983. The increase is due iargeiy to a rise in the number of meals served in day care homes. Food donated under the FNS programs was up almost 30 percent from last year. Most of the rise was due to the speciai food distribution program which began in January last year. Food distri¬ buted under the child nutrition programs and other pro¬ grams also increased. Participation in the WIC program in 1982 was above year earlier leveis in all regions, with the largest share of participation in the Southeast and Midwest regions. Participation in the WIC program was record high in fis¬ cal 1983. About half the participants are children, with the other half divided between women and infants. Chart 151 Meals Served in Child Care Food Program Chart 152 Cost of USDA Food Donated Million meals Billion dollars Child nutrition Special food Other programs distribution 1983 estimated. Fiscal years. 1983 estimated. Cash-in-lieu is cash given instead of commodities. Chart 153 WiC Program Participation by Region Chart 154 Participants in the WIC Program Northeast Mid-Atlantic Southeast Midwest Southwest Mountain Plains Western 1983 estimated. Fiscal years. Mid-Atlantic excludes Puerto Rico. Million persons 1983 estimated. Fiscal years. WIC is the Special Supplemental Program for Women, Infants, and Children. 54 School Lunches Participation in the national school lunch program (NSLP) in the 1982-83 schooi year was up about 1 per¬ cent from that a year eariier due to more children receiving free iunches. About 22 percent of all children participating in the NSLP and 24 percent of those receiving free lunches were in the Southeast. Partici¬ pation was above that a year earlier in ali regions except the Midwest and Northeast. Househoids with oniy one chiid are the most common of those receiving school lunches free or at reduced prices. About 73 percent of participating children are from households with fewer than three chiidren; only 4 percent are from households with 5 or more children. About 50 percent of households with children receiving lunches free or at reduced prices had incomes beiow $10,000 annually in 1981. Chart 155 Chart 156 Children in the National School Lunch Program Million persons National School Lunch Program Participation by Region Northeast Mid-Atlantic Southeast Midwest Southwest Mountain Plains Western 0 1 2 3 4 5 Miiiion persons 1983 estimated. Fiscal years. 1983 preliminary. 9-month averages. Chart 157 Free and Reduced Price School Lunch Participants by Household Income Income Under $2,500 $2,500 - $4,999 $5,000 - $7,499 $7,500 - $9,999 $10,000-$12,499 $12,500-$14,999 $15,000 and over 1981 data. Source: Bureau of the Census. Chart 158 Free and Reduced Price School Lunch Participants by Number of Children in Household % of households 43 Number of children 1981 data. Source: Bureau of the Census. % of households 55 Elderly and School Programs Expenditures on the nutrition program for the elderly were almost doubled in 1983 from 5 years earlier. USDA contributed almost $4 billion in cash and food to various child nutrition programs in fiscal 1983. .This included the school lunch and breakfast programs, summer feeding program, special milk program, and child care feeding program. Participation in the school breakfast program was up 1.5 percent during the 1982-83 school year after de¬ clining 8 percent the previous year. The increase was in the number of participants receiving free or reduced price meals. About 90 percent of children in the pro¬ gram received free or reduced price meals. After a period of decline, 1983 participation in the summer food service program was up 3.5 percent from the pre¬ vious year. Chart 159 USDA Cost of the Nutrition Program for the Elderly $ million Chart 161 Children in the School Breakfast Program Million persons Chart 160 USDA Contribution to Child Nutrition Programs $ billion Chart 162 Children in the Summer Food Service Program Million persons 56 U.S. Trade and World Production 57 U.S. Trade The share of domestic agricultural production export¬ ed fell for the second consecutive year in 1982 as record farm output came during a period of declining v^orld demand. Agricultural exports as a share of cash receipts fell from 26 percent in 1981 to 22 percent in 1982. The ratio of wheat exports to production fell to its lowest level since 1976-77. Likewise, coarse grain exports were just over one-fifth of domestic production, the lowest figure in 10 years. As a result of these imbalances, acreage reduction programs were used to curtail output. The only U.S. share of world exports to increase in 1982 was for coarse grains, at 58 percent. The U.S. share of wheat exports fell from 44 to 38 per¬ cent, while the cotton market share fell below 30 per¬ cent for the first time in 5 years. Chart 163 U.S. Exports: Share of Domestic Production and World Trade Percent Percent Percent Percent Percent Percent 58 U.S. Trade U.S. agricultural export volume in 1982 fell precipi¬ tously to 152 million tons, the lowest level since 1979. Even an 11-percent decline in export prices was not able to overcome falling demand, stiff competition from other suppliers, and an appreciating dollar. After a 10-percent appreciation in 1981, the dollar gained another 9 percent against principal foreign currencies in 1982, further eroding the competitiveness of U.S. products. Export growth of the late seventies and early eighties was aided by a relatively low-valued dollar—and has been hampered by its current appreciation. Soybeans have risen the furthest from their low in 1979 at 34 per¬ cent, followed by corn at 30 percent, cotton at 20 per¬ cent, and wheat at 18 percent. Chart 164 U.S. Agricultural Trade Indicators Million metric tons % of 1971 % of 1977 % of 1971 % of 1971 % of 1971 Foreign currency value of the U.S. dollar, weighted by relative size of agricultural trade with the United States, adjusted for inflation by use of a Consumer Price Index for the countries involved. An increasing value indicates that the dollar appreciated against the basket of currencies represented in that commodity market. 59 U.S. Trade The agricultural trade surplus fell 20 percent to $21.4 billion in 1982, while the nonagricultural trade deficit remained at $56.6 billion. The record total trade deficit of $35.2 billion was largely due to the drawing power of an appreciating dollar. The index of prices received by farmers fell 4 percent in 1982, reflecting the fact that U.S. demand alone can¬ not support a U.S. farm sector operating at full capaci¬ ty. Policy decisions on feeding in Japan and Europe, for example, are becoming as important to U.S. farmers as feed relationships in the Corn Belt. U.S. agricultural exports assisted by Commodity Credit Corporation programs totaled nearly $1.6 billion in 1982, 10 percent below 1981. Korea, Portugal, Brazil, and Mexico combined accounted for 78 percent of the credit extensions. Chart 165 U.S. Trade Balance Chart 166 Export Prices for Major U.S. Crops $ billion $ per metric ton Rice Soybeans Wheat Corn Average export unit values. Milled rice. Chart 167 U.S. Farm Sales Aided by CCC Programs Chart 168 U.S. Agricultural Exports and Farm Prices $ billion Commodity Credit Corporation. Credit terms up to 36 months. Other commodities include rice, sorghum, barley, tobacco, tallow, cottonseed oil and meal, linseed oil and meal, and sunflowerseed. $ billion % of 1977 150 130 110 90 - 70 50 60 U.S. Trade The value of U.S. farm exports fell 15 percent to $36.6 billion in 1982, the first decline since 1975. Over half this downturn was attributable to lower export volume. Exports of corn, sorghum, wheat, and rice combined were nearly 12 million tons lower in 1982. Bulk grains and oilseeds are the crux of U.S. farm exports, accounting for 80 to 85 percent of total agri¬ cultural export volume. Despite a decline of over $2 billion, Asia remained the largest U.S. farm export market. Led by Japan, the largest U.S. market since 1962, Asia boasted 4 of the top 10 U.S. markets—Korea, China, and Taiwan. Japan and Taiwan purchased a wide range of products, from bulk grains to highly processed commodities. Korea and China confined their purchases to grains, oilseeds, and raw cotton. Chart 169 Value of U.S. Agricultural Exports by Commodity $ billion Chart 170 Volume of U.S. Agricultural Exports by Commodity Million metric tons Chart 171 U.S. Agricultural Exports to Asia $ billion Chart 172 U.S. Agricultural Exports to the People’s Republic of China $ billion 61 U.S. Trade Taiwan became the third largest market for U.S. cot¬ ton in 1982, moving ahead of China, and was the sixth largest soybean market and the seventh largest corn market. U.S. exports of commodities subject to variable levies in the EC, primarily grains, fell 20 percent in 1982 because of greater feeding of soybean meal (mostly from the United States) and domestic wheat. U.S. agricultural exports to Eastern Europe fell by nearly half in 1982, owing to a severe financial crisis. Poland, our largest customer in the region, was denied access to CCC credit in 1982 due to its imposition of martial law. The Soviet Union purchased 11.4 million tons of wheat and corn in 1982, bringing total farm imports from the United States up to $1.9 billion. Chart 173 U.S. Agricultural Exports to Taiwan $ billion Chart 174 U.S. Agricultural Exports to the European Community $ billion Farm products subject to variable import duties under EC’s Common Agricultural Policy. The EC includes Belgium, Denmark, France, West Germany, Ireland, Italy, Luxembourg, Netherlands, United Kingdom, and Greece. Chart 175 Chart 176 U.S. Agricultural Exports to Eastern Europe U.S. Agricultural Exports to the Soviet Union $ billion Bulgaria, Czechoslovakia, German Democratic Republic, Hungary, Poland, Romania, Yugoslavia, and Albania. $ billion 62 U.S.Trade The falling price of oil constrained a number of OPEC countries from purchasing U.S. farm commodities in 1982. Iran, Venezuela, and Nigeria were particularly hurt, pulling agricultural exports to OPEC down 19 per¬ cent. Grain exports were most notably affected. Export sales to the three largest African markets— Egypt, Nigeria, and Algeria—feil 21 percent in 1982, matching the drop in export saies to all of Africa. These three countries accounted for two-thirds of the United States-African market in 1982. Over 30 percent of these sales, mostly grains, vegetable oils, and inedible tallow, were concessional sales. Mexico, Venezuela, and Brazil have become the larg¬ est markets for U.S. farm products in Latin America. Wheat is the major export, with saies in 1982 falling 13 percent to 17.6 miilion tons. Chart 177 U.S. Agricultural Exports to OPEC Nations $ biilion OPEC: Organization of Petroleum Exporting Countries. Chart 179 U.S. Agricultural Exports to Latin America $ billion Chart 178 U.S. Agricultural Exports to Africa $ biiiion Chart 180 U.S. Agricultural Exports to Mexico $ billion 1974 80 78 63 U.S. Trade U.S. farm exports to less developed and centrally planned countries fell almost 20 percent in 1982, while farm exports to industrialized markets fell 11 percent. Eastern Europe and Latin America were particularly strapped by liquidity and debt financing problems, thus restricting their purchases of U.S. agricultural products. Western Europe became the largest supplier of agri¬ cultural products to the United States in 1982, ahead of South America and Asia. In the midst of declining U.S. imports. Western Europe was able to expand its sales of processed pork, alcoholic beverages, fruit juices, and prepared vegetables. Agricultural imports in gen¬ eral fell 9 percent in 1982, led by a $1.3-billion decline in raw sugar imports. Chart 181 U.S. Agricultural Exports to Major Areas $ billion Adjusted for transshipments through Canada. Chart 182 U.S. Agricultural Exports by Destination $ billion Adjusted for transshipments through Canada. Chart 183 Origin of U.S. Agricultural Imports Chart 184 U.S. Agricultural Imports by Commodity $ billion $ billion 20 15 10 0 1974 Fruits, vegetables, and nuts includes bananas. Other includes dairy products, oilseeds and products, crude rubber, and other imports. 64 World Production World production of agricultural commodities over the past 15 years has increased at an annual com¬ pound rate of about 2.2 percent, but only 0.4 percent per capita. Developed, developing, and centrally planned coun¬ tries reached record production levels during 1982, contributing to a record high for world output of agri¬ cultural commodities. Output in the developing countries has increased 3 percent annually over the past 15 years, higher than that of other groups. Population increase was nearly equal to the production gains, however, and production per capita rose only slightly, 0.5 percent annually. The annual increase in output is lowest for the developed countries, but their output per capita is higher. Chart 185 Changes in World Agricultural Production % of 1969-71 average Annual Compound Growth Rate, 1968-82. % of 1969-71 average 65 World Production World grain production (wheat, coarse grains, and milled rice) hit a record 1,540 million metric tons in 1982/83, with the United States accounting for nearly 22 percent of the total. U.S. acreage reduction pro¬ grams and a severe drought should reduce this share to 15 percent in 1983/84, and lower total world output by 6 percent. World grain consumption increased significantly in 1982/83 for the first time in 5 years, led by a 10- million-ton increase in U.S. feed use. World grain exports fell 7 percent in 1982/83. The United States held 58 percent of world grain stocks at the end of 1982/83, up from 25 percent in the midseventies. Chart 186 World and U.S. Grain Production, Utilization, Carryover, and Trade Billion metric tons Billion metric tons 1.6 1.2 .8 .4 0 1974 76 78 80 82 Million metric tons Million metric tons 66 Commodity Trends 67 Livestock Generally weak prices have discouraged world cattle producers from rebuilding herds. Meat consumption was relatively unchanged as weak economies held down demand. U.S. beef and veal production for 1982 declined 1 percent from the 1981 level, while imports of beef and veal rose 11 percent. Value of U.S. exports of livestock, meat, and meat products dropped 3 percent to $3.1 billion in 1982. The leading export earners were hides and skins at $769 million: lard and tallow at $638 million; and red meat at $587 million. U.S. imports of red meat in 1982 rose 11 percent above 1981 levels, bringing total red meat imports to 2.6 million pounds (carcass weight equivalent). Chart 187 Cattle in Major Beef-Producing Countries Million head Inventory taken as close to January 1 as possible. Chart 189 Meat Consumption in Major Producing Countries Kilograms per capita per year 125 ~ 1982 data. A kilogram is about 2.2 pounds. Meat consumption is in carcass-weight basis. Poultry consumption data not available for New Zealand. Chart 188 U.S. Exports of Livestock Products $ billion Chart 190 U.S. Imports of Red Meat Billion pounds Carcass-weight equivalent. 68 Livestock The inventory of all cattle and calves on U.S. farms and ranches totaled 115.2 million head at the beginning of 1983. The Jan. 1, 1984, cattle inventory should range from unchanged to down 1 percent. Total red meat and poultry consumption in 1983 was 3 to 4 percent above 1982 levels, a new record. Expanding hog production and a large drought-induced cattle slaughter resulted in higher meat production in the second half of 1983. Large total meat supplies, despite modest economic improvement, held down prices. Cattle slaughter rose 0.9 million head in 1982, and slaughter in the first half of 1983 rose slightly above that period of 1982. Hogs marketed in 1982 fell 9 mil¬ lion head; marketings for the first half of 1983 were 0.8 million head below that period of 1982. Chart 191 Cattle on Farms Million head Cattle on farms as of January 1. Beef cows are those that have calved. Chart 193 Cattle on Feed and Marketings Million head 12 - Quarterly data for 13 States. Chart 192 Fed Cattle Marketed by Feedlot Capacity Million head Data are for 13 States. Chart 194 Market Hogs and Pig Crops Million 50 “ Market hogs Pig crops—December-February, March-May, June-August, and September-November. Market hogs on farms—December 1 previous year, March 1, June 1, September 1, and December 1. Quarterly data for 10 States. 69 Livestock The 115.2 million cattle on farms in 1983 were 0.4 million head below the total a year earlier. Commercial beef production in 1983 rose about 3 percent above production in 1982. Beef production in 1984 is expect¬ ed to fall as weather conditions improve and cattle numbers stabilize. The number of sheep and lambs on farms on Jan. 1, 1983, was estimated at 11.9 million head. That was about 8 percent below the inventory in 1982, contrast¬ ing with the 1-percent increase in the JanuaYy 1982 inventory. Lamb and mutton production in 1983 was about 2 percent higher than that of the previous year. Production is expected to decline in 1984. Chart 195 Cattle Numbers and Beef Production Million head Billion pounds 40 30 20 10 0 Chart 196 Sheep Numbers, Lamb and Mutton Production Million head Billion pounds 1983 forecast. Sheep and lambs on farms January 1. 70 Livestock and Dairy Hog prices in 1983 should decline $7 to $9 per cwt from the mid-$50’s in 1982, reflecting the gains in pork production in the second half of 1983. Cattle and lamb prices in 1983 should average slightly below prices last year. Retail prices for pork are expected to fall about 3 percent in 1983 due to larger production. Beef prices should remain about unchanged, reflecting large total meat supplies. Meat prices should rise in 1984, as sup¬ plies fall due to the drought-induced inventory cut¬ backs over 1983-84. Beef consumption was unchanged in 1982. Poultry consumption rose by nearly 3 percent, while pork con¬ sumption fell over 9 percent. Milk production rose almost 2 percent in 1983, a result of increased milk production per cow and more cows. Chart 197 Livestock Prices Received by Farmers $ per cwt Chart 199 Per Capita Consumption of Meat % of 1967 Chart 198 Retail Meat Prices C per pound Chart 200 Milk Production, Number of Cows, and Milk per Cow % of 1977 71 Dairy The milk-feed price ratio fell in 1983, but remained above the 1981 ratio. The average all-milk price during 1983 was unchanged, while feed prices were higher. Supplies of milk and dairy products, on a fat-solids basis, rose to 158.3 billion pounds in 1982. Use fell in 1983, while production increased and government stocks expanded despite large donations. Per capita sales of "other cheese" and low-fat milk have risen about 50 percent in the past 10 years, while sales of fluid and canned whole milk are both down about 30 percent. Government purchases of milk solids continued high in 1983, due to another large increase in milk production and lower commercial disappear¬ ance. Chart 201 Milk/Feed Price Relationship % of 1977 1983 forecast. 16-percent feed price is the average paid by farmers for 16-percent protein dairy concentrate. Milk/feed price ratio is the pounds of 16-percent feed equal in value to 1 pound of milk sold to plants. Chart 202 Milk Supply, Use, and Stocks Billion pounds 1983 forecast. Stocks as of December 31. Chart 203 10-Year Change in per Capita Dairy Product Sales Percentage change 1973-82 Other cheese 53.6 Low-fat fluid milk American cheese Fluid cream Ice cream -5.0 - 11.8 -19.2 -25.0 -27.9 -30.4 -48.0 20.3 9.4 1-6 Butter Ice milk Cottage cheese Sherbet 48.7 Fluid whole milk Evaporated and condensed milk Nonfat dry milk Chart 204 Milk Solids Removed from the Market by CCC Programs % of marketings 1983 forecast. Deliveries to the Commodity Credit Corporation (CCC) after domestic unrestricted sales. 72 Dairy and Poultry Consumer expenditures for dairy products continued to rise slower than for all food in 1983. CCC net pur¬ chases of $2.7 billion were about 13 percent of dairy farmers’ cash receipts in 1983. Poultry and egg exports fell in 1982 because of the strong dollar, reduced earnings by some purchasers, and strong competition from other exporting countries. Exports in 1983 should be near 1982 volumes. Exports of young chicken fell 30 percent in 1982 and account¬ ed for 4 percent of estimated total production. Japan was the largest importer of broiler meat, followed by Singapore and Jamaica. Turkey meat exports fell 19 percent in 1982. Ger¬ many was the largest importer with 12 million pounds. Egg exports fell 32 percent in 1982 and accounted for 3 percent of production. Chart 205 Consumer Expenditures and CCC Net Expenditures for Dairy Products % of 1977 % of farm cash receipts 1982 forecast. Farm cash receipts from marketings of milk and cream. Commodity Credit Corporation. Chart 206 U.S. Exports of Pouitry Products Million pounds of poultry 1972 74 76 78 80 82 Poultry is ready-to-cook weight. Million dozen eggs Eggs are shell eggs plus shell-egg equivalent of egg products. 73 Poultry Egg producers cut production 12 million dozen in 1982 from the 5,819 million dozen in 1981. Producers reduced costs by keeping hens longer and reducing purchases of replacement pullets. In 1983, producers should sell enough old hens to have a larger decline in the number of layers. Eggs per layer were up sharply through May 1983. Higher feed costs in 1983 should mean lower output than in 1982. Farm prices for eggs may decline slightly in 1983. Broiler farm prices should average 1 to 3 percent below 1982’s 26.8 cents per pound. Broiler production, up 1.5 percent in 1982, should expand about 3 percent in 1983. Increased turkey production during 1983 has weakened prices, and the farm price of turkeys in 1983 is expected to fall 5 percent from 1982. Chart 207 Eggs: Changes in Production and Farm Prices % change from year earlier 1982 preliminary, 1983 forecast. December 1 previous year through November 30 current year. Chart 209 Broilers: Changes in Production and Farm Prices % change from year earlier 1982 preliminary, 1983 forecast. December 1 previous year through November 30 current year. Chart 208 Eggs: Rate of Lay, Production, and Number of Layers % of 1967 1982 preliminary, 1983 forecast. December 1 previous year through November 30 current year. Chart 210 Turkeys: Changes in Production and Farm Prices % change from year earlier 74 Poultry and Wheat Per capita egg consumption in 1983 should fall 6 eggs from 265 eggs per capita in 1982. Per capita con¬ sumption of processed eggs should remain about steady while shell egg consumption falls. Both per cap¬ ita chicken and turkey consumption shouid rise in 1983, with chicken consumption up about 1 pound from 53 pounds in 1982, and turkey consumption up about haif a pound from 10.8 pounds consumed per person in 1982. The 1982 worid wheat harvest rose aimost 6 percent from 1981. An improved crop in the Soviet Union and other major producing countries more than offset the reduced crop in Australia. U.S. wheat growers harvest¬ ed about 14 percent fewer acres in 1983 due to partici¬ pation in acreage reduction programs, but hit record yields of nearly 40 bushels per acre. Chart 211 Per Capita Consumption of Poultry and Eggs Pounds of poultry 75 50 25 0 Number of eggs 1971 73 75 77 79 81 83 1982 preliminary, 1983 forecast. Pouitry is ready-to-cook weight. Processed eggs converted to shell equivalents. Chart 212 Chart 213 Major Wheat Producers U.S. Wheat Acreage, Yield, and Production Million metric tons % of 1970-74 average 75 Wheat and Rice Expanding world wheat demand led to increased world exports in 1981, most by the United States. Increased sales to South and Central American coun¬ tries led to a higher level of U.S. wheat and flour exports in 1981, countered somewhat by a 3-million- ton fall in shipments to Europe. An 18-million-ton rice production increase in China in 1982 more than offset the drought-reduced crop in India, leading to a 6-million-ton increase in world pro¬ duction. Strong participation in the U.S. rice program reduced harvested acreage from 1981’s record to 3.25 million in 1982. Nationally, yields averaged 4,742 pounds per acre, compared with 4,819 in 1981. Farmers are expected to harvest just under 2.3 million acres of rice, with yields averaging 4,637 pounds per acre. Chart 214 Major Wheat and Flour Exporters Chart 215 Destination of U.S. Wheat and Flour Exports Million metric tons 120 - 100 80 - Other Argentina Australia United States 1977 78 79 80 81 Million metric tons 1977 78 79 80 81 1981 preliminary. Includes wheat equivalent of flour and products. Market year beginning July 1. Grain equivalent. Marketing year beginning June 1. Chart 216 Major Rice Producers Chart 217 U.S. Rice Acreage, Yield, and Production Million metric tons 500 “ 400 - 300 - 200 - 100 - Other Indonesia India % of 1970-74 average 1982 preliminary. Data are for rough rice. Crop years. Aug. 1, 1983, indications. 76 other Grains Weak domestic and foreign demand offset lower rice production in 1982, raising ending stocks to an alltime high of 66.6 million cwt. U.S. rice exports fell to 69 mil¬ lion cwt, their lowest in 6 years. Domestic demand was slack, keeping disappearance down. The world reces¬ sion, affecting the purchasing power of many importing countries, led to a 15-percent fall in coarse grain exports in 1982. The combination of the payment-in-kind (PIK) pro¬ gram and a 2-month drought cut feed grain average acre yields to about 2 metric tons, and reduced har¬ vested acreage and production to their lowest levels since 1974. Feed grain production for 1983 may total 163 million tons, much lower than the 255 million tons in 1982. Total concentrates consumed during 1982 were 178 million tons. Chart 218 Rough Rice Supply and Disappearance Million cwt 1982 preliminary, 1983 projected. Year beginning August 1. Supply includes imports. Chart 220 Feed Grain Production and Acreage 1973 75 77 79 81 83 Chart 219 World Exports of Coarse Grains Million metric tons 1982 preliminary. Includes cornmeal, oatmeal, barley malt, and corn starch. Excludes Intra-EC trade. Marketing year beginning July 1. Chart 221 Feed Concentrates Fed Million metric tons 1982 preliminary, 1983 projected. Feed fed to livestock and poultry. Year beginning October 1. 1983 based on August indication. Year beginning October 1. 77 other Grains High-protein feed use during 1983 should reflect oilseed production 5 to 7 percent under 1982. Total high-protein feed consumption may total about 22 mil¬ lion metric tons, about 6 percent below tonnage in 1982. Fewer eggs and laying hens account for the reduced high-protein feed consumption. Corn supply for 1983 should total 8.6 billion bushels, down 20 percent from the total in 1982. A decline in harvest of 3.2 billion bushels was partially offset by record carryover stocks of 3.4 billion bushels. Domestic use and exports will decline somewhat in 1982/83, but ending stocks will fall to about a billion bushels. The reduced supply of corn will hold the sea¬ son average farm price well above that of a year earlier and likely above the record $3.11 a bushel in 1980/81. Chart 222 Chart 223 High-Protein Feed Use Feed Grain and High-Protein Feed Prices 1973 75 77 79 81 83 1982 preliminary, 1983 projected. Year beginning October 1. Forty-tour percent crude protein equivalent. Grain proteins include gluten feed and meal, and brewer and distiller dried grains. Animal-marine proteins include tankage, meat meal, marine byproducts, and milk products. Other oilseed meals include cottonseed, linseed, peanut, sunflower, and copra. 1974 76 78 80 82 1982 preliminary. Year beginning October 1. Prices for feed grains are those received by farmers. High-protein feed prices are wholesale at principal markets. 1982 based on October-July average. Chart 224 Corn Supply and Disappearance Billion bushels Chart 225 Corn Prices $ per bushel 1982 estimated, 1983 projected. Supply includes imports. Year beginning October 1. 1982 estimated, 1983 projected. Year beginning October 1. 1982 St. Louis #2 yellow based on October-July average. 78 Commodity Stocks and Grain Transportation With a record wheat carryover for the 1983/84 mar¬ keting year and disappearance projected to be slightly lower, stock levels should continue to be record high going into 1984/85. The first downturn in U.S. grain production in 2 years will reduce total supplies of all grains 12 percent from the record in 1982/83. Exports and domestic use should remain near last season’s record, causing yearend stocks to fall about 33 percent. About 95 percent of grain shipped by rail moves in 100-ton covered hopper cars. Rail rates for farm prod¬ ucts have risen slightly less rapidly than those for all goods shipped. A slackening rate of increase for rail rates during 1982 probably resulted from slow econom¬ ic activity and nearly constant or reduced railroad operating costs. Chart 226 Wheat Supply and Disappearance Billion bushels 1982 preliminary, 1983 projected. Suppiy inciudes imports. Year beginning June 1. Chart 228 Carloads of Grain Shipped by Rail Million cars Chart 227 Total Grain Suppiy and Disappearance Million metric tons 1982 preiiminary, 1983 projected. Supply includes imports. Year beginning October 1 for corn and sorghum; June 1 for oats, bariey, wheat, and rye; and August 1 for rice. Chart 229 Change in Raii Freight Rate For Agricultural Products 79 Transportation and Fats and Oils Barge shipments of grain rose to record levels in 1982, recommencing the growth of the seventies. Two important trade routes, from the U.S. Gulf of Mexico to Northern Europe and to Japan, reflect the variability in ocean freight rates. Rates in 1982 were the lowest since 1978 due to the world recession and increases in the size of the world merchant fleet. Deregulation of fresh fruit and vegetable shipments by rail in 1979 does not appear to have reversed the long-term shift of produce traffic from refrigerated rail cars. Deregulation of piggyback shipments in 1981, however, has probably brought about the tripling of pig¬ gyback volume since 1980. Peanut production was down 14 percent in 1982, reflecting the decrease in acreage and only a slight improvement in yields. Chart 230 Barge Shipments of Grain, Interior River Points Billion bushels Chart 232 Fresh Fruits and Vegetables Shipped by Truck and Rail Million cwt Piggyback included in rail before 1980. Chart 231 Ocean Freight Rates from U.S. Gulf $ per metric ton Chart 233 Peanut Acreage and Production Miliion acres Billion pounds Production is farnners’ stock basis. Year beginning August 1. 80 Fats and Oils World soybean production in 1982/83 increased 10 percent over the 1981/82 level. Brazil showed a 17- percent increase over the previous year’s drought- reduced crop, while the United States, the major pro¬ ducer, increased its share of the world total to 65 per¬ cent in 1982/83. Total U.S. production for 1982/83 was a record 2.28 billion bushels. Value of U.S. soybeans and products exports was $8.4 billion in fiscal 1982, up 4 percent from 1981. Soybean export values rose 8 percent and soybean oil export values, 9 percent; soybean meal export value fell 9 percent. U.S. exports of soybeans in 1981/82 totaled a record 25.3 million metric tons, up 28 percent over the 1980/81 total. Shipments to the EC were up 36 percent above those a year ago and exports to Spain more than doubled. Chart 234 Major Soybean Producers Million metric tons 1982/83 preliminary. Revisions have been made in all countries. Soybean production split year includes Northern Hemisphere crops harvested in the months of the first year shown combined with Southern Hemisphere and certain Northern Hemisphere crops harvested in early months of the following year. Chart 235 Value of U.S. Exports of Soybeans and Products $ billion Fiscal years; October-April for 1983. Chart 236 Destination of U.S. Soybean Exports Million metric tons September-May, 1983. Transshipments via Canada to unidentified countries not separately reported prior to January 1973. Year beginning September 1. Chart 237 U.S. Soybean Production, Use, and Carryover Billion bushels Domestic use includes crushings, seed, feed, and residual. Year beginning September 1. 81 Fats and Oils and Fibers World sunflowerseed production in 1982/83 totaled a record 16.6 million metric tons, up 14 percent from the previous year and 8 percent above the previous record of 15.3 miilion tons in 1979/80. U.S. sunflowerseed production rose to 2.7 million tons in 1982/83, but was stiii 22 percent beiow the record 3.4 miliions tons in 1979/80. The United States is the worid’s second larg¬ est sunflowerseed producer. The 1982/83 world cotton crop was about 67.5 mil¬ lion bales, 3.3 million bales below the previous year’s record 70.8 miliion bales. Outputs were lower In the United States, Soviet Union, India, Mexico, and Argenti¬ na, but higher in China, which has dispiaced the United States as the worid’s largest cotton producer. World cotton consumption in 1982/83 should increase to 66.7 miilion baies, 1.0 miilion bales above 1981/82. Chart 238 U.S. Cottonseed Acreage and Production Million acres Million tons Chart 240 World Cotton Production and Consumption Chart 239 World Production of Sunflowerseed Million metric tons ‘*8 im Other Million baies 80 60 ^ 40 20 0 1982 estimated. Bales of 0.218 metric ton (480 pounds net). Year beginning August 1. 82 Fibers World cotton area was estimated at 32.3 million hec¬ tares in 1982, 1.2 million hectares below the 1981 record. Although total U.S. area declined, China and Pakistan had significant increases, with total foreign area reaching a record 28.4 million hectares. World cotton exports should fall 17.9 million bales in 1982/83, 2.5 million bales below 1981/82 exports. U.S. exports should drop to 5.1 million bales, the lowest since 1976/77. World cotton prices fell during the first 6 months of the 1982/83 season, due to large supplies and slack textile demand. The Index "A" Northern European price fell to a seasonal low of 69.04 cents per pound C.I.F. in November 1982 before recovering to 80.23 cents per pound C.I.F. in April 1983. Chart 241 World Cotton Area Chart 242 World Cotton Exports Million hectares Marketing year beginning August 1. Million bales 20 - United States Foreign 1982 preliminary. Bales of 0.218 metric tons (480 pounds net). Year beginning August 1. Chart 243 World Cotton Prices C per pound C.I.F. prices, Northern Europe, quarterly averages. Index “A” Is the average price of the cheapest 5 of 10 styles of cotton marketed. In August 1981, In¬ dex “A” was changed from SM 1-1/16" to M 1-3/32." The quarterly average for the USSR for February-April 1983 is based on the average February price, since no cotton was offered for sale during March or April. 83 Fibers U.S. cotton production was 12.0 million bales in 1982/83; disappearance totaled about 10.7 million bales. Exports totaled about 5.2 million bales, down 1.3 million from 1981/82. Mill use was about 5.5 million bales, and stocks on Aug. 1, 1983 were about 7.9 mil¬ lion. U.S. consumption of fibers was 48.0 pounds per person in 1982, down 5.4 pounds from the previous year. Cotton, wool, and manmade fibers all showed declines. U.S. mill use of wool today is one-fourth to one-fifth the quantity used 30 years ago due to greater use of manmade fibers. Domestic wool consumption has not declined as much due to rising wool or wool-blend imports. In the last decade, Americans used slightly less than 1 pound of wool in apparel in each year, com¬ pared with almost 2 pounds during the early sixties. Chart 244 U.S. Cotton Production, Use, and Carryover Million bales • --I [ I i-j-L— ] 1 1 ii 1-.1111 lilt [•.•.•.•r i 1978 79 80 81 82 1982 preliminary. Year beginning August 1. 480-pound net weight bales. Ending carryover. Chart 246 U.S. Production, Imports, and Consumption of Raw Wool Million pounds 1983 estimated. Clean basis. Production includes shorn and pulled wool. Imports include duty-free and dutiable raw wool. Mill consumption includes apparel and carpet raw wool. Domestic consumption includes mill consumption plus raw wool equivalent of net textile trade balance. Chart 245 U.S. per Capita Consumption of Fibers Pounds 1982 preliminary. Mill consumption adjusted for fiber equivalent of trade balance in textile manufactures. All fibers do not include flax and silk. Chart 247 U.S. per Capita Consumption of Apparel Wool Pounds 1961 65 70 75 80 Mill consumption of raw wool plus raw wool equivalent of net imports of apparel wool textiles. 84 Fibers Foreign wool prices are generally higher than domes¬ tic wool prices due to its better quality and strong demand by major wool importing countries. Wool prices in the first and second quarters of 1983 fell from the highs reached in 1981 due to lower mill demand. World wool production in 1982/83 was an estimated 3.56 billion pounds clean, down 1 percent from the pre¬ vious year’s production. Although drought in Australia and the Soviet Union slowed production, output rose in New Zealand, China, Uruguay, and Pakistan. Manmade fiber use has increased fourfold since the early sixties. Noncellulosic fibers have displaced cellu- losic and natural fibers entirely or have been used in blends because of their superior properties and com¬ petitive prices. Chart 248 Wool Prices 0 per pound Clean basis. For fine wool: graded territory 64’s (20.60-22.04 microns) staple 2-3/4" and up delivered to U.S. mills; Australia 64’s, type 62 duty-paid delivered to U.S. mills. For medium wool: graded territory 58’s (24.95-26.39 microns) staple 3-1/4" and 60’s (23.50-24.94 microns) staple 3" and up delivered to U.S. mills; Australia 58/60’s type 423/3 duty-paid delivered to U.S. mills. Price not quoted for domestic wool, fourth quarter 1982. Chart 249 World Production and Consumption of Raw Wool Biliion pounds 1982 preliminary. Clean content weight. Production data on a marketing year basis. Chart 250 U.S. Shipments of Manmade Fiber Billion pounds Nylon, polyester, acrylic, olefin, glass, and spandex are noncellulosic fibers. Rayon and acetate are cellulosic fibers. 85 Vegetables Increases in population and per capita vegetable consumption in the past 10 years have resulted in increases in fresh vegetable production. Processed vegetable production has also risen due to more use of processed tomatoes and frozen vegetables. Strong export demand for dry beans pushed production and prices up during 1979-81, but prices and output fell during 1982-83 due to sluggish export demand. Recent increases in per capita consumption of all vegetables is primarily due to higher fresh vegetable consumption, especially salad vegetables. Total per capita potato use, fairly stable from year to year, has varied with the size of the crop during the past decade. Processed potato production was buoyed in 1982 by high consumption of frozen potato products. Chart 251 Fresh and Processed Vegetable Production Million tons Fresh includes melons. Processing portion of broccoli, carrots, and cauliflower included with processing crops beginning in 1972. Excludes other commercial production in States where estimates are not made separately. Chart 253 Per Capita Consumption of Vegetables Pounds 1982 preliminary. Fresh includes dehydrated onions and excludes melons. Frozen and canned on fresh-weight basis. Chart 252 Dry Bean Production and Price Million cwt or $ per cwt Chart 254 Per Capita Consumption of Potatoes Pounds 1972 74 76 78 80 82 1982 preliminary. Processed on fresh-weight basis. 86 Vegetables and Fruit Value of U.S. vegetable exports in 1982 fell 7 percent to $721.5 million. A sharp drop in onion exports to Japan was largely responsible for the decline. Fresh and processed vegetable imports reached a record $897.1 million in 1982. Mexico, the leading supplier, accounted for half the total. Fresh and canned toma¬ toes, peppers, cucumbers, and canned mushrooms were the principal products imported. U.S. fruit exports grew steadily over the past decade, but the global recession and a strong dollar reduced their export sales by 8 percent in 1982 to $1.38 billion. Fresh and processed citrus, apples, raisins, grapes, dried prunes, fruit cocktail, and canned peaches were the leading fruit exports. Fruit imports excluding bana¬ nas were a record $1.08 billion in 1982, nearly one- third greater than 1981. Chart 255 Destination of U.S. Vegetable Exports $ million Chart 257 Destination of U.S. Fruit Exports $ billion Chart 256 Origin of U.S. Vegetable Imports $ million Excludes melons, dried beans, and dried peas. Chart 258 Origin of U.S. Fruit Imports $ million Includes melons; excludes bananas. 87 Fruit The 1981/82 citrus production, at 12.1 million tons, was down 20 percent from a year earlier, with a sharply smaller orange crop the chief contributing factor. Ontree returns for oranges averaged sharply above returns a year earlier. Per capita citrus fruit consump¬ tion was up slightly as increased frozen concentrated citrus consumption more than offset lower consumption of other citrus items. The 1982 noncitrus production totaled 14.8 million tons, up 17 percent from 1981, reflecting the signifi¬ cantly larger apple and grape crops. Per capita non¬ citrus consumption was estimated at 102.0 pounds in 1982, compared with 110.0 pounds in 1981. Although the 1982 estimates reflect the discontinuation of data on processed pineapple products, per capita consump¬ tion of noncitrus fruit still declined. Chart 259 Citrus Fruit Production and Farm Prices % of 1960 1981/82 preliminary. Production of all citrus fruits. Season average growers’ prices weighted by production. Crop years. Chart 261 Noncitrus Fruit Production and Farm Prices 1970 72 74 76 78 80 82 1982 preliminary. Production of 15 major fruits. Season average growers’ price weighted by production. Chart 260 Citrus Fruit Consumption Pounds per person 1969/70 73/74 77/78 81/82 1981/82 preliminary. Fresh-equivalent basis. Canned and chilled includes fruit and juice. Chart 262 Noncitrus Fruit Consumption Pounds per person 1982 preliminary. Fresh-equivalent basis. Canned includes fruit and juice. 88 Tropical Products U.S. expenditures on cashew nut imports dropped notably in 1982. Decreased nut unit values brought the level of expenditures down despite an increase in total import volume. The value of U.S. tree nut exports fell for the second consecutive year in 1982, with notable declines in the unit value of shelled almonds and in the volume of inshell walnut exports. A 10-percent smaller world cocoa crop was harvest¬ ed during 1982/83. Prices of imported cocoa beans in New York rose from 78 cents a pound in January 1983 to nearly $1.00 in August. U.S. per capita cocoa con¬ sumption rose to 3.8 pounds (bean equivalent) in 1982. U.S. green coffee imports rose to 17.4 million bags in 1982, up 5.2 percent from 1981. Imports from Latin America and Africa were up nearly 400,000 bags and 800,000 bags, respectively. Chart 263 U.S. Tree Nut Imports and Exports $ million Imports primarily Brazil nuts, cashews, and pistachios; exports primarily almonds, pecans, and filberts. Chart 264 U.S. Cocoa Imports and Prices Million pounds C per pound Price is the average of nearest three active futures trading month on the Coffee, Sugar, and Cocoa Exchange. Chart 265 Origin of U.S. Coffee Imports Million bags 1982 preliminary. Green coffee. Bags of 60 kilograms each. 89 Tropical Products Coffee is the leading agricultural commodity imported by the United States. In 1982, green coffee imports rose slightly in value to $2.72 billion from $2.62 bil¬ lion in 1981. Imports in 1982 averaged $1.18 cents a pound, com¬ pared with $1.20 cents in 1981. On a monthly basis, prices were highest in May at $1.23 and lowest in October at $1.13. U.S. per capita coffee use fell slightly to 10.1 pounds (green bean equivalent) in 1982. Green coffee prices fell from $1.27 a pound in January 1983 (1976 ICA) to $1.22 in March, then recovered to $1.26 in August. Coffee roastings through the first 8 months of 1983 were lagging about 2.5 percent behind those of 1982. Chart 266 World and U.S. Coffee Prices $ per pound Roasted for U.S. and green bean for world. ICA is International Coffee Agreement. 1968 ICA based on composite price of Colombian mild arabica, other mild arabica, unwashed Brazilian arabica, and robusta coffees. 1976 ICA (first year of such prices) based on composite price of other mild arabica and robusta coffees. Chart 267 U.S. Green Coffee Imports and Prices Million bags C per pound Imports exclude roasted or soluble coffee. Import price, f.o.b. basis. Bags of 60 kilograms each. Chart 268 U.S. Coffee Consumption Chart 269 U.S. Sugarbeet and Sugarcane Production Pounds per capita 1982 preliminary. Green bean equivalent. Million tons Crop year beginning September 1. 90 Tropical Products Domestic beet sugar production was up in 1982 over the previous year, whiie cane sugar production remained about the same. Total imports were down due to heavy stock levels at the beginning of the year, to decreased consumption, and to reduced exports. The Western Hemisphere continued to be the largest supplier of foreign sugar consumed in the United States, although total volume imported from that source was less during the year. Imports from the Philippines and other sources also declined in 1982. U.S. consumption of sugar has declined steadily since 1975, while consumption of high fructose corn sirup has increased fivefold. Chart 270 Sources of Sugar Used in the United States Million metric tons 12 Philippines Other Total Western Hemisphere Domestic cane 0 V.*. j: Domestic beetj; X Jlk Jii iilii ill 1974 Raw sugar. 76 78 80 82 Chart 271 U.S. Sugar Prices 0 per pound Chart 272 Per Capita Consumption of Caloric Sweeteners Sugar 75.5% Glucose corn sirup 14.9% Dextrose 4.2%- HFCS 4.2%- Other 1.2%- 1975 MFCS: High fructose corn sirup. 91 Tobacco Total U.S. tobacco production is forecast at 1.51 bil¬ lion pounds, 24 percent below the 1.98 billion pounds in 1982. Both flue-cured and burley tobacco use was down in 1982. The record large 1982 burley crop increased supplies 10 percent. A sharply reduced crop in 1983 will lower stocks of both burley and flue-cured, but ample supplies are available. Price-support rate for flue-cured was $1.70 a pound and $1.75 for burley. The 1983 flue-cured tobacco supply is about 3.3 times the size of the 1982 supply. Carryover next July will decline. With about 40 percent of the crop sold through the end of August, grower prices averaged $1.68, 2 cents below last season’s prices. The relative¬ ly high U.S. price tends to restrict domestic use, limit exports, and encourage imports. Chart 273 Burley Tobacco: Supply, Price, Use Billion pounds per pound 1982 preliminary, 1983 forecast. Trade stocks include manufacturers' and dealers’. Crop year beginning October 1. Chart 274 Flue-Cured Tobacco: Supply, Price, Use 2 1 Production Loan stocks Trade stocks Billion pounds 4 0 1970 Supply per pound 200 50 Billion pounds 2 0 1970 75 80 85 Disappearance Price Support level 150 100 1 1982 preliminary, 1983 forecast. Trade stocks include manufacturers’ and dealers’. Crop year beginning July 1. 92 Tobacco World unmanufactured tobacco production for 1983 is forecast at 6.06 million tons, down 10 percent from the record 1982 crop. Lower production in the United States, China, India, Brazil, Korea, Italy, Cuba, Bulgaria, and Poland will more than offset expected increases in Canada, Zimbabwe, Malawi, Pakistan, and South Africa. Large unmanufactured leaf stock levels from 1982 discouraged 1983 world output for every leaf type except oriental tobacco. Production of flue-cured tobacco is estimated at 3.01 million tons. U.S. per cap¬ ita use of tobacco products fell again in 1982, with per capita cigarette use reaching the lowest level since 1957. U.S. cigarette manufacturers used an estimated 1.2 billion pounds of tobacco (unstemmed processing weight) in 1982. Chart 275 Unmanufactured Tobacco Production Million metric tons 1983 forecast. Chart 277 Tobacco Use in Cigarettes Chart 276 Consumption of Tobacco Products % of 1967 1983 preliminary. Per male 18 and over; except cigarettes, per person 18 and over. Data prior to 1979 do not include results of 1980 census. Data for chewing tobacco in 1982 and 1983 not included because not comparable to previous years. Chart 278 Cigarettes Produced and Tobacco Used Billion cigarettes Billion pounds 93 Index (by chart number) Assets 8, 13-15, 49 Cattle (see also livestock) 23, 187, 191-193, 195, 197 Cocoa 184, 264 Coffee 101,184,265-268 Consumer 80-138, 205 Consumption: Crop 87, 100, 104, 240, 246 Livestock 88, 103, 189, 199 Food 99, 100 Per capita 100-106, 199, 211, 245, 247, 253, 254, 272 Convenience foods 108-111 Cooperatives (see Farmer cooperatives) Corn 23. 25, 29, 164, 166, 167, 221, 224, 225 Cotton 23, 25, 29. 163, 164, 167, 169, 170, 238, 240-245 Crops 25, 29, 36, 38, 87, 100, 104 Dairy 23, 88, 97, 102, 107, 115-118, 200-205 Debt 9-14, 78, 128 Economy, general 80, 125, 128-130 Elderly 121,159 Employment 44, 59, 60, 63, 68 Energy 32-35 Home 132-138 Exports; U.S. 163-182, 188, 206, 214, 215, 235, 236, 255, 257, 263 Foreign 183-185,214,219 Family 64, 68, 91, 122-124, 126, 140 Farm, farmers 1-52,55-57 Farmer cooperatives 41-52 Fats and oils 97, 106, 115.118 Feed grains 220-223, 2^7, 228 Fertilizer 26-28, 33 Fibers 240-250 Food: Prices 85,89,91-95,97,155 Consumption (see also Consumption per capita) 99, 100 Marketing 85, 92-96, 98 Food stamps 69, 141-150 Fruit 97, 104, 105, 107, 169, 170, 184, 232, 257-262 Hired farm\workers 61-63 Hogs 23, 194, 197, 199 Housing 70-75 Imports 165, 183, 184, 190, 256, 258, 263-265, 267, 270 Income: Farm 1-8, 51 Personal 2, 64, 65, 81, 82, 121, 126, 143-145, 159 Inputs 22-35, 37 Interest rates 16,17,131 Land 18, 38-40 Livestock 36, 88, 169, 170, 187, 188, 190, 197 Meat 88,90,97, 107, 115-118, 184, 189, 190, 198, 199 Metro-nonmetro comparisons 53, 58, 59, 65, 66, 68, 69, 74 Nutrition 90. 107, 110, 112-118 Nuts 169,170,184,233,263 Population 53-57, 99 Poultry and eggs 23, 88, 97, 115-118, 189, 199, 206-211 Poverty 66,67,68,107 Prices: Livestock 88, 90, 197 Crop 87, 166, 243, 248 Food 85, 89, 91-95, 97, 155 Retail 85,95-97,198 Farmer 21-24, 85, 96-98, 168, 207, 209, 210, 259-261 Production: Domestic (see also individual commodities) 37, 38, 163, 185, 186 World 185,186 Public programs 69, 139-162 Race 54, 62-64, 71, 74, 75 Real estate 9, 10, 12-21 Rice 25, 163, 166, 216-218 Rural communities 76-79 Savings 82, 119, 120 School lunches 155-158 Sheep 196, 197 Soybeans 23, 25, 29, 163, 164, 166, 167, 234-237 Sugar 104,184,269-272 Sunflov/erseeds 239 Taxes 19-21 Tobacco 163, 273-278 Transportation 33, 228-232 Unemployment 58, 83, 125-127, 146 Vegetables 97. 104, 105, 107, 169, 170, 184, 232, 251-256 Water 30-32 Wheat 23, 25, 163, 164, 166, 167, 212-215, 221, 226 Wood 246-249 Women, farm 120 94 FOR MORE INFORMATION . . 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To receive this newsletter, send your name and address to: ERS Abstracts (CBK) U.S. Department of Agriculture Room 4305-South Washington, D.C. 20250 CARE TO COMMENT? Would you care to comment on the organization or presentation of this hand¬ book of charts? Do you have any sugges¬ tions on how we can make it more useful to you, the user? Are there any new topics you would like to have included in next year’s edition? Let us hear from you. Write to Debra Haugan, EMS Information, USDA, Room 440 GHI, Washington, D.C. 20250. United States Department of Agriculture Washington, D.C. 20250 OFFICIAL BUSINESS Penalty for Private Use, $300 Postage and Feesgj United; Department AC THIRD CLASS BULK I Q(^3o tho. If^D Spruce Budworms Handbook Managy^ the BudworWin E Forest Service Cooperative State Research Service Agriculture Handbook No. 620 This publication reports research involving pesticides. All uses of pesticides must be registered by appropriate State and/or Federal agencies before they can be recommended. CAUTION: Pesticides can be injurious to humans, domestic animals, desirable plants, and fish or other wildlife—if they are not handled or applied prop¬ erly. Use all pesticides selectively and carefully. Follow recommended practices for the disposal of surplus pesticides and pesticide containers. The use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the U.S. Department of Agriculture of any product or service to the exclusion of others that may be suitable. United States Department of Agriculture Forest Service Cooperative State Research Service Agriculture Handbook No. 620 October 1984 UNIVERSITY OF ILLINOIS SGRICU|,TUR£ tlBRSfiK Spruce Budworms v Handbook ^ Managing the Spruce Budworm in Eastern North America Daniel M. Schmitt, David G. Grimble, and Janet L. Searcy,^ Technical Coordinators (\GR1CUUWE ftPR I 2 1989 nF n I ’Respectively, Program Manager and Applications Coordinator, Canada-United States Spruce Budworms Program, Broomall, Pa.; and Information Coordinator, Canada-United States Spruce Budworms Program, Washington, D.C. In 1977, the United States Department of Agriculture and the Canada Department of the Environment agreed to cooperate in an expanded and accelerated research and development effort, the Canada/United States Spruce Budworms Program (CANUSA), aimed at the spruce budworm in the East and the western spruce budworm in the West. The objective of CANUSA was to design and evaluate strategies for controlling the spruce budworms and managing budworm-susceptible forests, to help forest managers attain their objectives in an economically and environmentally acceptable manner. The work reported in this publication was wholly or partially funded by the Program. This manual is one in a series on the spruce budworm. Canada United States Spruce Budworms Program Contents Introduction—Daniel M. Schmitt Chapter 1: General Biology of the Spruce Budworm and Its Hosts—Robert L. Talerico. . l Hosts and Range. 2 Description of Life Stages. 3 Life Cycle and Habits. 6 Some Factors Affecting Spruce Budworm Populations. 7 Overview. 10 Selected References. 10 Chapter 2: Integrated Pest Management—Gary A. Simmons, Wilf Cuff, Bruce A. Montgomery, and J. Michael Hardman . 11 Basic Biology of the Spruce Budworm/Spruce-Fir Forest . 13 Knowledge Base Needed to Make Management Decisions. 14 Decision Processes and Management of the Spruce Budworm/Spruce-Fir Forest . 15 Fitting IPM Tools into Forest Management. 19 Concluding Remarks. 19 Selected References. 20 Chapter 3: Survey and Detection—Douglas C. Allen, Louis Dorais, and Edward G. Kettela . . 21 Surveys for Sparse Populations. 23 Surveys for Outbreak Populations. 25 Defoliation Surveys. 32 Cost of Survey and Detection. 35 Selected References. 36 Chapter 4: Damage Assessment—John Witter, Don Ostaff, and Bruce Montgomery. 37 Impact on Trees. 38 Impact on Stands. 44 Regional Impacts of the Spruce Budworm. 52 Techniques to Assess and Predict Impact. 54 Rating Systems. 56 Forest Growth Models . 60 Selected References. 61 Chapter 5: Economics of Spruce Budworm Management Strategy—Lloyd C. Irland and Kenneth L. Runyon . 65 Property Already Infested. 66 Strategic Decisions. 67 Definition of an Economic Pest. 67 Economic Impact of Spruce Budworm. 68 Identifying Response Options. 69 Cost of Pest Management Eunctions. 74 Evaluating Alternative Strategies. 75 Special Cases. 80 Summary. 81 Selected References. 81 Chapter 6: Silviculture, Forest Management, and the Spruce Budworm—Barton M. Blum and David A. MacLean. 83 Vulnerability. 85 Long-Term Silvicultural Tactics. 86 Salvage Operations. 94 Long-Term Regional Management Strategies .... 97 The Problem with Silvicultural and Management Strategies—A Lack of Quantification. 100 Selected References. 101 Chapter 7: Microbial and Other Biological Control—J. B. Dimond and O. N. Morris . . . 103 Nature of B.t. 104 Early Use of B.t. Against the Spruce Budworm. . 105 Current B.t. Products. 106 How to Use B.t. 107 Usage Patterns. 109 Host Tree Species. 110 Vigor of Spruce Budworm Populations. 110 Additives and Mixing. Ill Handling and Safety. 112 Ground Applications. 112 Other Biological Control. 113 Selected References. 114 iii Chapter 8: Chemical Control—Patrick J. Shea and P. Chandra Nigam. 115 Why Chemical Insecticides?. 118 Federal and Provincial/State Responsibilities .... 119 Classification of Chemical Insecticides. 119 Registered Chemical Insecticides. 120 Considerations for Planning and Organizing Aerial Operations . 123 Aerial Spraying. 126 Evaluation of Efficacy . 128 Safety and Pesticide Use. 128 Euture Use of Insecticides. 130 Selected References. 131 Chapter 9: Spruce Budworm Management Planning—Limiting Environmental Impacts— Joan Garner Trial and Peter D. Kingsbury ... 133 Aquatic Ecosystem Components. 137 Terrestrial Ecosystem Components. 137 Evaluation System.139 Example Assessment.139 Selected References.140 Selected Sources.140 Appendices. 141 Appendix 1—Projection Methods. 142 Appendix 2—Incorporating IPM in Eorest Management. 166 Appendix 3—Principal Laws Governing Handling and Application of Forest Insecticides. 171 Appendix 4—Federal. State, and Provincial Offices for Current Information on Insecticides for Spruce Budworm Suppression . 172 Appendix 5—Aerial Spraying—Checklist. 174 Appendix 6—Acknowledgments. 176 Index . 177 iv Introduction Daniel M. Schmitt' The spruce budworm, Choristoneiira fumiferami (Clemens), is one of a handful of forest insects whose populations can increase explosively to encompass the host range in a short time. Such an epidemic irrupted in the decade of the seventies. Mounting concern over its effects prompted the Canadian and U.S. Governments to organize the Canada-United States Spruce Budworms Program (CANUSA) in 1977. The Program was initiated to stimulate total forest protection planning for budworm- susceptible forests and to develop new. more environmentally sensitive technology for its implementation. This handbook is intended to provide professional foresters, forest entomologists, subprofessionals, and technical personnel in these disciplines, as well as nonindustrial landowners, with facts relevant to forest and forest pest management operations in budworm territory. Material in the handbook is arranged for ready access to topics of interest. The first chapter introduces the reader to the general biology of the budworm and host species. The second chapter discusses integrated pest management (IPM). In keeping with the theme of this handbook, it is treated from the standpoint of the forest practitioner, not the systems analyst. Systems and biomodelling approaches to budworm management are thoroughly considered in other CANUSA publications. The sequence of later chapters indicates operations required for any systematic approach to integrated pest management. The geographic scope of the handbook is the range of the susceptible forest. Although the forest associations of susceptible types are dominated by the boreal forests, the region is by no means homogeneous in vegetation, budworm populations, or political-economic relations that affect forest practice. ' Program Manager, Canada-United States Spruce Budworms Program, USDA Forest Service, Broomall, Pa. The three major budworm host species are balsam fir {Abies balsamea [L.J Mill.), white spruce (Picea glauca [Moench] Voss), and red spruce (Picea rubens Sarg.). White spruce is a transcontinental species and balsam fir nearly so, its western range petering out in northeastern Alberta. Both species are components of all major forest associations within the scope of the handbook; however, their relative east-west abundance differs. In general, the white spruce component increases from east to west, whereas balsam fir increases from west to east. Almost pure stands of balsam fir are not uncommon in northeastern Maritimes forests. Red spruce is important in Nova Scotia, southern New Brunswick, Quebec, Maine, New Hampshire, Vermont, and New York. In Maine, southern New Brunswick, and southern Quebec, red spruce replaces white spruce as the dominant spruce in spruce-fir forests. In addition to the west-east shifts in species composition, which probably result from gross climatic and soil differences, there are also west-east differences in stocking and forest pattern. Although individual trees reach about the same size regardless of region, subject chiefly to local site conditions, stocking is much higher in eastern than western forests. Basal areas of spruce-fir forests in the eastern part of the region frequently exceed 120 ftVacre (28 m^ha), whereas in the western area they rarely exceed 100 ft-/acre (23 mVha). Likewise, in the West, spatial extent of spruce-fir stands is less and the complexity of hardwood- softwood patterns is greater than in the East, reflecting distinctive differences in land-use history. Finally, the sociopolitical influences, though different in each Province and State, also tend to sort out along a west-east axis, with some significant exceptions. Sociopolitical factors have no biological relevance. Yet they define (mostly in terms of local and often professional perceptions, rather than in law) the package of acceptable forestry practices. V Selected References Chapter authors provide, wherever possible, separate treatments of the eastern and western parts of the region. For convenience we call them the Maritime and the Great Lakes forests. The Maritime forests, as defined here, include the susceptible forests of Newfoundland. Prince Edward Island, Nova Scotia, New Brunswick, eastern Quebec, Maine, New Hampshire, Vermont, and northern New York. The Great Lakes forests are the susceptible forests of Michigan, Minnesota, Wisconsin, Ontario, and the western half of Quebec. In addition, the authors provide information, where appropriate, in the context of both outbreaks and low-level populations. The significance of the distinction becomes ever more clear as the reader progresses through chapter 2. To provide the breadth of coverage required, the authors have had to rely on numerous sources, published and unpublished. If it were possible, I would acknowledge every source. Since it is not, a general admission of our debt to all contributors enables us to acknowledge also all professional foresters and entomologists who have ever dealt with the budworm problem in their professional capacities. Personnel from the Green River project, sponsored by the Canadian Forestry Service in the late fifties, come readily to mind, but there are many others. My point is that progress is seldom the result of bold leaps into the unknown, but rather the extension of, and sometimes new directions for. paths first explored years ago. Hopefully, the CANUSA Program will be remembered in this light. Whatever the life of its achievements, the CANUSA effort is a first and significant benchmark in international forestry research and development. We have already seen international coordination of forestry research in other disciplines since the Program started in 1978, and further across-the-border cooperation is certain to follow. Jennings, D. T.; Knight, F. B.; Hacker, S. C.; McKnight, M. E. Spruce budworms bibliography. Misc. Rep. 213. Orono, ME: Maine Life Sciences and Agricultural Experiment Station; 1979. 687 p. Knipling, E. F. The basic principles of insect population suppression management. Agric. Handb. 512. Washington, DC; U.S. Department of Agriculture; 1979. 659 p. Little, Elbert L., Jr. Atlas of United States trees. Vol. 1. Conifers and important hardwoods. Misc. Publ. 1146. Washington, DC; U.S. Department of Agriculture, Forest Service; 1971. 9 p. -h200 maps. Rowe, J. S. Forest regions of Canada. Publ. 1300. Ottawa, ON; Department of the Environment, Canadian Forestry Service; 1972. 172 p. U.S. Department of the Interior, Geological Survey. The national atlas of the United States of America. Washington, DC: U.S. Department of the Interior, Geological Survey; 1970. 417 p. VI ■A’i ;’*5tS^Jfl^-i.*'-^-‘A‘ -^■i i-?*^ Robert L. Taleiittb® ' Research Coordinator, Canada-United States Spruce Budworms Program. USDA Forest Service, Broomall, Pa: The author is presently affiliated with MicroGeneSys, Inc., West Haven, Conn, Hosts and Range The spruce budworm {Choristoneiira fwnifenina [Clemens]) is the most widely distributed and destructive defoliator of spruce-fir forests in North America. This native insect poses a threat to over 150 million acres (60 million ha) of susceptible forest in the Eastern United States and Canada. Larvae feed on a number of conifers, but balsam fir (Abies halsamea [L.j Mill.), white spruce (Picea glaucci [MoenchJ Voss), and red spruce (Picea rubens Sarg.) are the major hosts in Eastern North America. Species occasionally attacked include black spruce (Picea mariana [Mill.] B.S.P.), eastern hemlock (Tsuga canadensis [L.] Carr.), tamarack (Larix laricina [Du Roi] K. Koch), and white pine (Pinus strobus L.). A C Regional differences in the forest types of Eastern North America vary from west to east. In the Lake States region, balsam fir, white spruce, and black spruce are the major sources of food. These conifers occur in patches averaging 15 to 25 acres (6 to 10 ha) that are separated by hardwood or mixed-wood stands. In Maine and the Canadian Maritimes Provinces, the patchy pattern gives way to extensive areas of softwoods. In this region red spruce becomes a major component of the forest. The spruce budworm can be found from Virginia to Newfoundland, and west across Canada throughout the boreal forest region to the McKenzie River near 66° N (Powell 1980) (fig. 1.1 A-D) or wherever the principal hosts are found. 2 Figure 1.1—Ranges of spruce budworm hosts across Canada and the United States. A: Balsam fir. B: White spruce. C: Red spruce. D: Black spruce. Description of Life Stages Egg Female budworms lay about 180 eggs in clusters or masses of about 20 eggs each. Occasionally, egg masses with up to 60 eggs are found. The elongated clusters vary from 0.04 to 0.40 inch (1 to 10 cm) in length. The eggs overlay one another like shingles on a roof (figs. 1.2-1.4). When first laid, both individual eggs and masses are light green. Larva All larvae progress through a series of developmental stages and molt between stages, shedding their outer skin. The life stage between molts is referred to as an instar. “Instar” is a convenient descriptive term for indicating larval size and development stage. Generally, budworm Figure 1.3 —Unhatched egg mass. Figure 1.4 —Hatched egg mass. Figure 1.2 —Egg masses on spruce needles. (Photos for figures 1.2-1.8 courtesy of Therese Arcand, Canadian Forestry Service. Laurentian Forest Research Centre, Ste. Foy, Que.) 3 Figure 1.5 —Fully grown larva. 4 Figure 1.6 —Pupa. Figure 1.7 —Male moth, often gray. larval development requires six instars from hatching to pupation. First-instar (Li) larvae are very small—0.8 inch (2 mm) in length. The body is yellowish-green with a light to medium brown head. Successive instars are larger and darker. Sixth-instar (Le,) larvae range from 0.75 to 1 inch (2 to 2.5 cm) in length. The body is dark brown with yellowish spots along the back. The head capsule is dark brown or black (fig. 1.5). The larva may appear to have a greenish cast if food is visible in the digestive tract. Pupa A newly formed pupa ranges from 0.5 to 0.75 inch (1.3 to 2 cm) in length and may be either green or yellow, with no apparent color difference between the sexes (fig. 1.6). With age, the pupa darkens to a dark gray or dark brown. Adult Moths are usually grayish with dark brown markings on the wings (figs. 1.7 and 1.8) and have a wingspan of about 0.75 inch (2 cm). Color pattern varies: some moths have a more brownish or reddish tinge with the gray markings. At rest, the moth appears bell-shaped. Figure 1.8 —Female moth, often brown. 5 Life Cycle and Habits The spruce budworm has a 1-year life cycle (fig. 1.9). The rate of development of each stage depends upon climatic factors that vary with geographic regions; thus calendar times are only approximations. In the Northeastern United States and Canada, moths lay their eggs in July. Egg masses are usually deposited on the undersides of needles, but occasionally they appear on the top surface of the needle or overlapping upper and lower surfaces, and at times even on the bark. Egg masses are generally found on shoots on the outer perimeter of the tree crown. The eggs hatch in about 10 days to 2 weeks. Hatching of first-instar larvae is usually complete by mid-August, when one of the two major dispersal periods occurs. Small larvae (L 1 -L 2 ) react photo-positively to light and move toward the branch tips. During this activity, some larvae may spin down on silken threads and be carried away by air currents. Such movement or dispersion spreads the larvae over a wide area, but many larvae are also lost. Larvae remaining on host foliage rarely feed but spin cocoonlike shelters (hibernacula) within which they soon molt to the second instar. The budworms overwinter in this stage, preferably on old flower scars or bark scales, or where lichens grow on branches. In April or May of the following year, second-instar larvae emerge from their hibernacula. Again, in response to light, the larvae move toward the branch tips, and the second major airborne redistribution occurs. Some larvae drop on silken threads and are blown about by air currents. Most small-larval mortality occurs during the two dispersal stages. When these larvae land on suitable host foliage, they begin to feed. Larvae prefer to eat the more nutritious staminate flowers of balsam fir, when available. However, most larvae become established in needles of 1-year-old foliage, while a few mine directly into the expanding vegetative buds. Typically, only one balsam fir needle is mined, and the larva either molts to the third instar within the confines of the needle mine or soon after leaving the needle. By late May or early June, third-instar larvae begin feeding on the newly opened vegetative buds. Larvae feeding on staminate flowers remain in place until the food supply is exhausted; then they move to the new, expanding foliage. Late-instar larvae (L 4 -Lf,) are found from early June to early July. Sixth-instar larvae consume most of the foliage. At sparse population levels, larvae feed on needles of current shoots. Sixth-instar larvae normally web two or Winter—Hibernation 2nd Instar Figure 1.9 —Typical life cycle of the spruce budworm. 6 Some Factors Affecting Spruce Budworm Populations more shoots together, forming a feeding shelter. When populations reach outbreak levels and all new foliage is consumed, the larvae are forced to feed on old foliage. This phenomenon, called back-feeding, can result in noticeably smaller pupae and smaller egg masses, and fewer eggs are produced. As foliage is depleted, larval movement increases, and many larvae drop from the defoliated trees and feed on understory host seedlings and young trees. The late-larval stage is considered the most critical in budworm survival. While feeding on expanding shoots, larvae are exposed to parasites, predators, disease, and unfavorable weather. Late-larval survival is greatest when the weather is warm and dry in late June and early July; survival is less when this period is characterized by cold, wet weather. The specific factors that cause budworm populations to oscillate over time are still under investigation. Two new theories have been proposed. One indicates that outbreak collapse is not due to spraying or lack of food but is more dependent upon local climate and the effects of disease and parasites on the budwbrm population.- The other theory proposes “zones of abundance” where outbreaks and damage vary with climate and forest type (Hardy et al. 1983, Hamel and Hardy 1980). Pupation occurs within the feeding shelters or other protected locations. It begins in late June and lasts from 8 to 12 days. Moths are present in the field from late June to mid-August. Adults live about 2 weeks, during which time they do not eat. The male locates the female for mating when she releases a sex pheromone, or attractant scent, from small glands near the tip of the abdomen. This biological perfume is effective over long distances. The pheromone plume permeates the forest and establishes an odor gradient by which the males are able to locate females. Prevailing winds and convectional breezes aid in dispersing this odor throughout the forest. Once mated, females generally do not fly until they have laid some eggs. After laying most of their eggs, though, females are active fliers. Given suitable weather conditions, both male and female moths may be transported great distances by winds and storm fronts. Such long-range dispersal affects population trends and brings the budworm to new areas. Host Characteristics Spruce budworm populations fluctuate dramatically over large areas. Just what causes rapid buildup is not completely understood, but factors such as large areas of mature or overmature balsam fir and spruce or several consecutive years of dry, sunny spring and summer weather, or a combination of these two factors have been implicated in helping outbreaks to start. Normally, foliage and insect development are synchronized so that buds and needles are developing just as the insects are emerging from their overwintering hibernacula. Red and black spruce buds usually open later in the spring than those of balsam fir and white spruce. Thus, red and black spruce buds may be less favorable to the development of small larvae. The quality and quantity of fir and spruce foliage available for budworm feeding can affect population levels. These levels are also influenced by the density of fir and spruce, stand structure, and stand age distribution. Budworm survival is greatest in maturing spruce-fir stands and lowest in isolated or young stands, and stands with few spruce-fir stems per acre. The type of stand and forest prone to budworm damage is discussed in chapters 4 and 6 . Predators Various natural factors interact to dampen population buildups and keep populations at low levels. Predation by birds, insects, spiders, and disease microorganisms collectively cause substantial mortality to sparse budworm populations. However, once populations irrupt into outbreak proportions, natural control agents are less effective in controlling budworm numbers. The reproductive capacity of the pest exceeds the regulatory roles of natural enemies. When the budworm population is low, birds are effective in preying on large larvae, pupae, and adults. Birds such as the evening grosbeak, solitary vireo, golden crowned kinglet, white-throated sparrow, chickadees, and several warbler species actively feed on budworm, especially when raising their fledglings. Our current belief is that birds adversely influence sparse budworm populations, but the effect of avian predators on outbreak numbers is unknown. ■ Personal communication: T. Royama, Maritimes Forest Research Centre. Fredericton. N.B. 7 When increasing populations of spruce budworm first defoliate mature fir. bird populations double. Initial abundance of budworms attracts many species of birds, even species that normally eat few insects. As upper canopy foliage is depleted, tree crowns die, budworm populations decline, and birds move to other localities. Regenerating fir stands improve bird habitat, particularly where hardwood seedlings are mixed with fir. Invertebrate predators such as ants, other insects, spiders, and mites have a role in limiting spruce budworm numbers. Spiders are one of the most abundant predator groups in the spruce-fir forest, and all stages of the budworm are susceptible. General feeding insects such as lacewings and ladybird beetles eat budworm eggs. The spruce coneworm {Dionctria reniculelloides Mutuura & Munroe) has been found feeding on budworm pupae. Parasites Many insects parasitize the spruce budworm (Tides and Woodley 1984), but only 13 species are relatively common (table 1.1). Some attack only the budworm, and their life cycles coincide with that of the host, while others attack a large number of hosts besides the budworm. Parasites could play an important regulating role between outbreaks, but when other factors become favorable for budworm survival (suitable weather, extensive area of mature suseptible forest), the parasite is slow to respond to increasing host density. Sometimes a relationship develops where budworm population growth simply outstrips that of the parasites and their effectiveness decreases. Unfortunately, researchers have reported only limited observations of parasite activity in sparse budworm situations. The parasites Apanteles fumiferanae (Viereck) and Glypta fumiferanae (Viereck) are relatively specific to the budworm and do not require alternate hosts. These parasites do not respond rapidly to increasing budworm numbers. Most budworm parasites do require other hosts—a feature that hampers the parasites’ ability to respond when budworm outbreaks develop. Normally, other factors (unfavorable weather, lack of suitable food) bring about the collapse of an outbreak; parasites only speed up the collapse. Numerous attempts have been made to introduce domestic and foreign parasites into spruce budworm populations in an effort to control the pest without chemical intervention. To date, none of these tries have been successful. Table 1.1—Common parasites of the spruce budworm in the Northeastern United States and Canada Stage attacked Parasite species Insect family Egg Trichogramma minuturn Riley Chalcidae Small larvae Apanteles fumiferanae Braconidae (1 st-4th (Viereck) instar) Glypta fumiferanae (Viereck) Ichneumonidae Synetaeris tenuifemur (Walley) Ichneumonidae Large larvae Meteor us trachynotus Braconidae & prepupae Viereck (5th & 6th Actia interrupta Curran Tachinidae instar) Aplomya caesar (Aldrich) Tachinidae Lypha setifacies (West) Tachinidae Pyryxe pecosensis (Townsend) Tachinidae Pupae Ephialtes Ontario (Cresson) Ichneumonidae Phaeogenes maculicornis hariolus (Cresson) Ichneumonidae Itoplectis concptisitor (Say) Ichneumonidae Omotoma fumiferanae (Toth.) Tachinidae Diseases The budworm is infected by a variety of microorganisms, including viruses, bacteria, protozoa, and fungi. Only occasionally do these microorganisms result in a high rate of mortality. Such instances coincide with abnormal weather conditions and affect the late larvae. This phenomenon occurs unexpectedly over large geographic regions, and a specific causal organism is difficult to identify. Sublethal infections of larvae also act to control budworm populations by affecting mating success, longevity, and fecundity of the moths. Four types of viruses (nuclear polyhedrosis, granulosis, cytoplasmic polyhedrosis, and an entomopoxvirus) have been isolated from native budworm populations. Each occurs at very low levels, so their influence is minor, but it is always lethal. We have minimal opportunities to initiate a viral epizootic in a population because the solitary feeding behavior of the larvae limits the chance for passing on the infection through contamination and contact with other budworms. 8 Naturally occurring bacterial infections of budworm larvae are reported as rare events. Cultures from dying or recently dead larvae are usually diagnosed as saprophytes or at best some pathogen exploiting a convenient food source resulting from another injury. Nosema fumiferanae (Thompson) is the most common protozoan attacking the budworm. This microsporidian attacks all life stages. Infected larvae usually develop into funetional adults, but they are smaller and not as vigorous as noninfected individuals. Infection lowers the fecundity of females. Epizootics caused by fungal pathogens are sporadic and confined to localized areas. At times, Erynia radicans (Brief.) Humber, Ben-Ze, Ev and Kenneth; and Entomophthora egressa MacLeod & Tyrrell have been found to cause significant mortality in Newfoundland. Optimal conditions for fungal development and infection occur when the weather is moist and warm. The opposite conditions retard development and infection rates. This extreme set of weather requirements limits the usefulness of fungi for control purposes. Certain pathogenetic organisms do infect the budworm, but their occurrence and effect are very erratic or dependent upon particular weather conditions. Until these factors can be controlled or specifie strains developed through artificial culture, the use of pathogens in budworm suppression will continue to be primarily experimental. Associates When examining foliage for spruce budworm larvae, we often find other larvae of the same or an allied family that also feed upon fir and spruce (Lindquist 1982). Table 1.2 lists some of these associates that can be found throughout the eastern range of the budworm. An expert is needed to identify many of these larvae. These and other larval associates can be important competitors of the budworm for food and shelter. This competition could influence the budworm’s survival on fir and spruce. Table 1.2—Common larval associates of the spruce budworm Common name Scientific name Eastern blackheaded budworm Acleris variana (Fernald) Spruce coneworm Dioryctria reniciilelloides Mutuura & Munroe Spruce needleminer Endothenia albolineana (Kearfott) “Redstriped needleworm” Griselda radicana Heinrich Spruce bud moth Zeiniphera canadensis Mutuura & Freeman “Yellow spruce budworm” Zeiraphera fortunana (Kearfott) 9 Overview Selected References The spruce budworm is the most widely distributed, destructive forest insect in North America. Even though the budworm has been the focus of considerable research over the past 50 years, there are still facets of its biology, population dynamics, and interactions with the host that are not thoroughly understood. Readers who want additional information on budworm biology and ecology should consult Kucera and Orr 1981, Miller 1975, Morris 1963, and Prebble and Carolin 1977. The following chapters of this manual discuss these subjects in greater detail. Hamel, Louis; Hardy, Yvan. Caracterisation des foyers d'infestation de la tordeuse des bourgeons de I'epinette. II. Les aspects climatologiques. Rapport Final 1979- 1980. Ste. Foy, PQ: PUniversite Laval, Le Fonds de Recherches Forestieres; 1980. 45 p. Hardy, Y. J.; Lafond, A.; Hamel, L. The epidemiology of the current spruce budworm outbreak in Quebec. For. Sci. 29; 715-725; 1983. Kucera, D. R.; Orr, P. W. Spruce budworm in the Eastern United States. For. Insect Dis. Leafl. 160. Washington, DC; U.S. Department of Agriculture, Forest Service; 1981. 7 p. Lindquist, O. H. Keys to lepidopterous larvae associated with the spruce budworm in Northeastern North America. Ottawa, ON; Canadian Forestry Service; 1982. 18 p. Miller, C. A. The spruce budworm; how it lives and what it does. For. Chron. 51: 136-138; 1975. Morris, R. F., ed. The dynamics of epidemic spruce budworm populations. Memoirs Entomol. Soc. Can. 31. Ottawa, ON: Entomological Society of Canada; 1963. 322 p. Powell, J. A. Nomenclature of nearctic conifer-feeding Choristoneura (Lepidoptera; Torticidae): Historical review and present status. Gen. Tech. Rep. PNW-100, Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station; 1980. 18 p. Prebble, M. L.; Carolin, V. M. Spruce budworm Choristoneura fumiferana (Clem.). In: Important forest insects and diseases of mutual concern to Canada, the United States and Mexico. Ottawa, ON: Canada Department of Forestry and Rural Development; 1977; 75-80. Tides, David A.; Woodley, Norman E. Spruce budworm parasites in Maine; a reference manual for collection and identification of common species. Agric. Handb. 616. Washington, DC: U.S. Department of Agriculture, Forest Service, Canada/United States Spruce Budworms Program; 1984. 10 rS-*. yi- i* 'A-w i ^,>4'{''--j)>^>^J: Vt'; -V f ■ V-T..A ■It-'®®?* ■'■■*'' *5 f* Chapter 2 Gary A, Simmons, Wilf Cuff, Bruce A. Montgomery, and J. Michael Hardman' ' ■ ^ ' Gary Simmons: Entomology Department. Michigan State University, East Lansing. Wilf Cuff; Maritimes Forest Research Centre. Canadian Forestry Service, Fredericton, N.B. Bruce Montgomery: School of Natural Resources, The University of Michigan, Ann Arbor. Michael Hardman: Agriculture Canada, Kentville, N.S. Protecting the forest from pests is just one component of forest management. In ideal circumstances, it fits comfortably within forest management objectives and procedures and helps people manage and utilize the forest resource as efficiently as possible. Integrated pest management (IPM) is one approach that can help ensure favorable economic, environmental, and sociological consequences of management and utilization of the spruce- fir forest resource in Eastern North America. Today, IPM is defined in general as an ecologically based pest control strategy that relies heavily on natural mortality factors such as natural enemies and weather and seeks out control tactics that disrupt these factors as little as possible. IPM uses pesticides, but only after systematic monitoring of pest populations and natural control factors indicates a need. Ideally, an integrated pest management program considers all available pest control actions, including no control action, and evaluates the potential interaction among various control tactics, cultural practices, weather, other pests, and the crop to be protected. The authors of this definition (Flint and Van Den Bosch 1981) also point out that an IPM program is comprised of six elements: • People—the IPM program developers and decisionmakers; • The information and knowledge necessary to make pest management decisions; • A means of monitoring the condition of the resource, pest numbers, and pest mortality factors; • Decisionmaking criteria—the level of damage and pest abundance needed for management actions to be taken; • The methods used to manipulate pest populations; and • The tools of those manipulations. Effective 1PM programs incorporate these six elements to deal with pests in economically efficient yet environmentally sound ways. Over the years, several IPM principles have become established that help in meeting this objective: 1. The presence of a pest species does not necessarily justify control action. In fact, existence of a pest population below the level where it causes economic injury is desirable, to encourage the presence of natural enemies such as parasites and predators. 2. The ecosystem is the management unit: pests are just a small part of it. Any manipulation of the ecosystem can influence the myriad overlapping components and pest populations in ways both desirable and undesirable from society’s point of view. We will never be able to fully analyze and comprehend detailed ecosystem dynamics. But if we are sensitive to the complexities and interactions, with existing information we can proceed more carefully when making decisions to manipulate portions of the ecosystem. 3. Use of natural enemies is encouraged. In practice, this means that efforts are made to alter the environment in ways that do not disrupt the natural mortality factors that help keep pest populations in check. This could mean augmenting natural enemies and trees resistant to budworm, or perhaps utilizing silvicultural practices that reduce the probability of economic damage from budworm. 4. Any control techniques could have unexpected or undesirable side effects. The use of chemical pesticides has dramatically illustrated this point with its associated “three R’s”—resistance of the target pest population to pesticides, resurgence of the target pest and secondary pests, and residues of undesirable chemicals in the environment. But any technique by itself could result in undesirable consequences. Thus, evaluation and revision of actions should always be built into an IPM program. 5. An interdisciplinary approach is essential. The IPM system must be a component of overall management. To adequately develop and implement an IPM system requires interdisciplinary cooperation. The disciplines of meteorology, engineering, sociology, pest control, plant and animal physiology, mathematics, and economics could be tapped to collect information and formulate management strategies. Naturally, not all of the named disciplines would be needed in every application of 1PM. 12 Basic Biology of the Spruce Budworm/Spruce-Fir Forest The application of IPM to forestry is relatively recent, although the basic IPM philosophy has always been implicit in forestry practice. The long-term nature of forest production, the long-term exposure of the forest to potential pests, and the limited (per unit area) economic returns from forests create circumstances that encourage use of a variety of pest prevention and control methods. Foresters have also extensively used techniques to appraise damage and assess pest abundance. These monitoring tools have provided damage forecasting to be used in making decisions during pest outbreaks or epidemics. In 1974, IPM in forestry received a considerable impetus with the USDA Combined Forest Pest Program and its three subprograms; Douglas-fir tussock moth, gypsy moth, and southern pine beetle. The ultimate objective of each program was to develop improved, IPM-based management programs for the forests affected by each pest. The CANUSA Program in eastern Canada and the Eastern United States began with a similar objective but different conditions. Considerable research had already been conducted on spruce budworm and spruce-fir forests, and a wide variety of management programs were already in use when CANUSA began. In some instances an IPM philosophy had already been adopted. This meant that the research and development program did not have to start from scratch; rather, emphasis would be given to promising developments that could be added to an IPM program. As this handbook illustrates, new technology was added to forest and budworm monitoring, budworm controls, silviculture, environmental assessment, and economic decisionmaking. Each of these topics will be covered in subsequent chapters. When we try to describe spruce-fir stands across Eastern North America, the words “diverse” and “variable” come to mind. Erom one State/Province to another (henceforth referred to as regions) there are different tendencies in successional patterns. Red spruce, for example, does not exist in Central North America. Among regions there are differences in average stand area and in average distance between stands. This means that from region to region there are differences that influence budworm outbreak potential. Individual stands differ in age, composition, and growth rate. Such individual stand differences will have an influence on natural mortality factors of the budworm, both biotic and environmental. The behavior of budworm populations over time will not be exactly the same in any two stands. And just as different stands influence budworm populations differently, so too will budworm populations influence spruce-fir stands differently. Some individual stands carry epidemic budworm infestations for long periods and consequently suffer considerable tree mortality and growth loss. Other stands evidence low populations of budworm for short times and may suffer little tree mortality and growth loss. (In theory, they may even be stimulated to grow faster.) Many stands fit somewhere between these two extremes. Managers and landowners must consider this variability in the spruce-fir forest and in the spruce budworm population. One way of doing this is to use existing understanding of those processes controlling the diversity. It is unfortunate that budworm experts cannot always agree about the generality of many of their facts, especially those relating to budworm population dynamics. With these disagreements in mind, we will try to summarize what we know of the basic biology of the spruce budworm and the spruce-fir forest. The spruce budworm and spruce-fir forests have been associated at least since the end of the last ice age. Hence, the spruce budworm is resident wherever spruce and fir are found. Some of the time spruce budworm populations are sparse and fluctuate at very low densities undetected by man. At other times, populations of the insect irrupt to levels numbering millions of larvae per acre over regions covering millions of acres of forest. Generally, outbreaks last 5 to 15 years and nonoutbreak periods about 30 to 40 years. 13 Knowledge Base Needed to Make Management Decisions The budworm has been viewed as a natural forest manager in that the oldest stands in a region will often sustain the greatest mortality during an outbreak. Such mortality results in the establishment of new, vigorous stands. Also, it is conceivable that budworm attacks can “thin” younger, dense stands, thereby encouraging vigorous growth. From a regional perspective, spruce budworm outbreaks seem to occur at regular intervals over the long run. It may be that as the age of the forest creeps up and the time interval since the last outbreak lengthens, the probability of an outbreak increases. Further, it has been suggested that the probability of an outbreak is enhanced in one area if, to the west, an outbreak has already occurred. Under the influence of large-scale weather systems, budworm moths can be blown many miles into new territory. Egg-carrying female moths can disperse in massive numbers over distances ranging up to 150 mi (240 km) or more (Greenbank 1980). Through this mechanism, outbreaks can move long distances from west to east in wavelike fashion. Thus it would be well for decisionmakers to view control of budworm outbreaks from a regional perspective even broader than that encompassed by State or Provincial boundaries. In the context of a single stand (henceforth referred to as a “local” perspective), outbreaks are highly unpredictable in the short run. Even though regionwide conditions may suggest an impending outbreak, we cannot anticipate with any accuracy when or where one will begin, how high population densities will become, or when the outbreak will collapse. Local conditions in a stand will help determine the fate of eggs deposited there. The density of eggs, the presence and abundance of natural enemies, the quality and quantity of food available, and local environmental conditions are all variables that intluence budworm population survival and the effects of budworm on the stand at the local level. These local qualities vary greatly from stand to stand and from one budworm generation to the next. Obviously, natural control agents keep budworm populations at low levels between outbreaks. Unfortunately, we know very little about these processes because of the enormous costs of studying budworm during nonoutbreak periods. It is during these periods that budworm populations are so sparse that sometimes we are unable to detect them, let alone study the processes regulating them. In spruce budworm/spruce-fir terminology, “monitoring” means watching over or checking on the growth and development (or stagnation and decadence) of the forest and observing changes in spruce budworm numbers. Monitoring is done because management cannot truly be accomplished without the ability to observe change. Monitoring data represent one source of knowledge about the forest and the budworm, but they supply information only up to the present. To try to see into the future, researchers have developed mathematical models. (Such projection methods are described further in appendix 1.) Forest managers have utilized forest monitoring and noncomputerized projection processes for centuries. Forest inventories describe current conditions, and volume tables permit projections of future conditions. In the case of the spruce budworm/spruce-fir forest, the budworm population can change rapidly. Because the forest usually changes slowly, forest inventory data are obtained infrequently at the stand level. In the United States, for example, this is regularly done at 10-year intervals. On the other hand, budworm population data are obtained yearly when populations reach observable levels. During outbreaks, both budworm population data and forest damage information are often obtained yearly. In setting up a program of monitoring, we relate the cost of monitoring to the information content it yields. Though the cost of obtaining information about forest stands is quite high, it is offset because reliable stand projection tables can be used to “fill in” information for many years. The cost of obtaining information about the budworm and its biological controls is also high, but it cannot be offset against our ability to project what populations of the budworm will do in the future. We are required, therefore, to monitor the budworm more frequently through time than we monitor the forest. 14 Decision Processes and Management of the Spruce Budworm/Spruce-Fir Forest In our context, a decision process is that set of mental activities needed to deal with the budworm, i.e., to allocate forest-directed actions, budworm-directed actions, or no actions at particular times and places. Some decisions are made at the regional (State/Provincial) level because it is efficient to do so or because these governments are charged with the responsibility for the social well-being of their citizens. Some decisions are made at the local (stand) level, often because the issue of concern does not generalize to the regional level and should be dealt with in isolation. We have associated the regional view with the organization of government because doing so provides the best overlap with the regional population dynamics of budworm. But because budworms disperse over distances larger than some of the States/ Provinces in Eastern North America, the association is not as good as one might like. We have not associated the local level of decisionmaking with any organization, although the temptation is to equate it with private companies. This would be unwise because the basis of the local level is the stand—the fundamental unit of forestry of interest to all landowners. Any decision process, whether it influences regional or local activities, must begin with a management objective. This can either be explicitly stated or implied from the circumstances. To decide on the objective, people need information describing current circumstances along with projected results from taking a particular action or doing nothing. Once the decision is made and action or no action is taken, change in the budworm/forest complex will take place. Hopefully, such change favors reaching the objective, which can be measured only by monitoring the results of the decision. This information is then added to the pool of knowledge about the universe of concern, and further actions or no actions are taken to better meet the objective. Decisionmaking begins with a policy directive and passes through a planning process along the way to an operational program used for implementing the plan. (A more formal discussion of these levels is given in appendix 2.) Decisions at both the regional and local levels follow a policy-to-planning-to-operation decisionmaking scheme. Policy Policies initiate planning activities and set broad limits within which planning and operations take place. Policymaking is a wide-ranging activity, based on the decisionmakers’ mixture of intuitive and rational argument. Economic conditions often dictate policy; the survival of the landholding company may depend on protecting its future source of timber; the government, charged with the social well-being of its citizens, has to consider subunits of economic conditions, such as unemployment level, gross regional product, and taxes collected. Policymakers may evaluate environmental quality variables. The current state of the spruce-fir resource and production capabilities of the mills will be carefully considered. As policymakers consider each option, they project (1) the cost of meeting a policy directive, and (2) the probability of planning a successful operational program to meet the directive. The end result of such deliberations is a policy to do something. As the policy directive is sent on to planning and operations teams, events may change, necessitating a further policy formulation exercise and a revised policy directive. Policy processes relating to budworm have occurred over much of the spruce-fir region of North America, especially in areas where spruce and fir have traditionally contributed heavily to regional economies. Quebec, New Brunswick, and Maine come particularly to mind in this regard. Recent major policy changes in Quebec, Maine, New Brunswick, and Nova Scotia typify the ongoing policymaking process. In Quebec, the overall forest protection effort was reduced to treating only those forests accessible to the mills and thus available for providing timber in the future. In Maine, shifting responsibility for aerial spraying from a State agency to the local level was attempted. In New Brunswick, forest management efforts have been intensified. In Nova Scotia, aerial spraying operations for budworm control were considered in light of an impending outbreak but rejected. 15 Planning and Operations As is clear from the examples of the previous paragraph, revised policy directives can result from both situations—an ongoing outbreak and an incipient outbreak. In explaining in more detail the planning and operations levels, we find it useful to consider the case of an impending outbreak. Here the planning and operations levels of decisionmaking are conveniently separated in time, unlike the case where an ongoing infestation suggests a serious problem ahead, requiring a quick policy reformulation and an even quicker plan and operational program. In Figure 2.1, we present a decision process that generalizes those steps involved in planning. In the decision process, objectives consistent with the policy directive must be defined. Here we highlight the steps of figure 2.1 by way of an example; a thorough explanation of this diagram and its relation to the planning exercise is provided in appendix 2. Assume a forest company’s major objective is to harvest a certain quantity of spruce-fir each year through the next decade. At this time budworms are sparse, but an outbreak in the next 10 years is possible. To sustain this yield, a management plan must be developed. A forest monitoring (inventory) program must be instituted so the managers can calculate projected forest growth rates. To maintain knowledge of budworm population fluctuations and locations of potential negative impacts, budworm monitoring and projections are also needed. Forest inventory data and growth projections are reviewed as management plans are made and revised. Budworm considerations are also included, usually on a stand-by¬ stand basis, according to the probability of that stand sustaining damage during an outbreak. High-risk, valuable stands of harvestable age are favored during the harvest cycle. In this way, harvesting is a tool for reducing potential negative impacts of budworm over the long run. Stands of harvestable age with no value or costing more to harvest than the returns they yield receive no action. Generally, these stands are inaccessible or nearly so, or lightly stocked, or they cannot be justifiably harvested based on economic, sociological, and/or ecological criteria. Potentially valuable stands of merchantable age (20 years and older) are the focus of decisions aimed at optimizing yield and minimizing risk to spruce budworm in the long run. In these cases, current-condition information is reviewed and projected in light of management objective(s). If objectives are being met and the long-term budworm risk is minimal, then a no-action decision is appropriate. If objectives are not being met or budworm risk potential is high, then managers must consider various stand manipulations. The environmental, sociological, and economic issues resulting from each option will also be considered. Finally, management selects and implements the option providing the best solution measured against management objectives. Response actions to decisions can be (1) no action, (2) actions directed toward the forest, or (3) actions directed toward the budworm. Decisions affecting action or no-action directed at the forest tend to be focused on a timespan of several to many years, while decisions directing action or no action against the budworm tend to be done annually, reflecting in part the rates of change of the components being managed. The no-action response has been common, particularly in the Lake States region. Usually, this response has not been the result of collective decisionmaking but rather the result of a lack of any decisionmaking. Actions directed toward the forest could include such things as subsidizing mills, regulating the harvest, building and maintaining road networks, encouraging management through tax incentives, etc. The nature of stand management is such that regional, forest-directed actions are difficult to distribute equitably over a region. When considering regional decision response actions directed at the budworm, we often think of the Northeastern United States and the Maritimes Provinces of Canada. Spray programs have been conducted for nearly 30 years in States and Provinces. But these programs are not truly regional in that decisions to participate are still made by those people responsible for managing local parcels of land. Regional coordination is merely a tactic to reduce the local cost. Ultimately, the programs are employed for local forest protection rather than regional management of budworm populations. Monitoring of budworm populations coordinated by a State, Provincial, or Federal agency is a regional activity; but just as in the case with the forests, monitoring of populations is not a management action per se. 16 Figure 2.1 —Flow diagram of a decision process that might be appropriate for management activities in nonoutbreak and outbreak periods. If a budworm outbreak does occur, an operational program will be added to the management decision process. In much the same way that a wildfire becomes an additional consideration, so does a budworm outbreak. However, the budworm outbreak develops, spreads, subsides, and exerts its impact on an ownership more slowly than a fire. In this section we highlight the steps of figure 2.1 as they apply to the operational plan of decisionmaking {see also appendix 2). Monitoring budworm populations usually provides several years of lead time before tree mortality. Translated in terms of harvesting schedules, those high-risk stands of harvestable age would remain unchanged in the harvest schedule. Those stands considered unmanageable (the ones slated for no action) would be left alone. Merchantable stands of intermediate age, at risk because of budworm, would be the focus of additional consideration. Monitoring budworm populations and stand conditions is the first step in this annual decision process. If the projected result of the budworm/stand interaction does not deviate from the management objective for that stand, then nothing further needs to be considered. If it does, then management options directed toward budworm populations are formulated. Results of each option are measured against objectives based on the environmental, sociological, and economic criteria. Management then selects the option providing the best apparent solution. During outbreaks, forest-directed efforts are focused on actions directed at recovering potential losses. These actions generally are the salvage responses discussed in chapter 6. These actions are usually directed at stands of harvestable age. Stands of intermediate age require actions directed at optimizing production and helping the stands resist sustaining economic damage during outbreaks. For practical purposes, budworm-directed actions are confined to chemical or biological pesticide sprays. Chapters 7 and 8 discuss conceivable actions, their state of development, and their advantages and disadvantages. Techniques other than chemical and biological pesticides are either incompletely developed or are too expensive to use at this time. After chosen activities are implemented, management evaluates the results. Sometimes this is an informal procedure where managers casually look at results some months later. In a more formal evaluation, data are obtained in the form of insect numbers, stand mortality, and the like. In some cases, no additional evaluation besides regular monitoring of budworm populations and stand conditions is employed. 18 Fitting IPM Tools into Forest Management Concluding Remarks In an earlier section we described the knowledge base needed to make regional management decisions, i.e., monitoring and modelling. In the previous section, we described decisionmaking from its biological extremes (regional and local) and its organizational components (policy, planning, and operations). Some monitoring and modelling tools of IPM have a long history of use in decisionmaking. Monitoring (i.e., forest inventories) is the obvious example, but tree mortality hazard-rating models have been used in various regions for decades. The inventor of a better monitoring scheme or a better tree mortality hazard-rating model does not have to be concerned about marketing his or her product. But many of the modelling tools currently available have not been used in decisionmaking. There are a variety of explanations: the models do not address real problems; the models provide a single, all-encompassing answer that reduces the decisionmaker to a naive consumer of model output; the model addresses a class of problems not yet addressed by decisionmakers, and hence needs marketing; and so on. It is not possible to address these issues here. Perhaps it is sufficient that you be aware of the existence of a variety of difficulties—real or imagined—with fitting IPM tools into decisionmaking. If you wish to pursue this subject in some detail, please read appendix 2. Of those factors influencing spruce budworm and spruce-fir, most are not controllable through our management actions. At best, we can hope to “steer” the forest in desirable directions. In reality, however, the budworm and the forest more greatly influence what we do than our actions influence the insect/forest complex. IPM is a philosophy that prompts us to deal with biological and socioeconomic uncertainties. Rather than providing us with a recipe for dealing with specific problems, IPM gives us a broad framework within which specifics can and will change. 19 Selected References Flint, M. L.; Van Den Bosch, R. Introduction to integrated pest management. New York: Plenum; 1981. 240 p. Greenbank, D. O.; Schaeffer, G. W.; Rainey, R. C. Spruce budworm (Lepidoptera: Tortricidae) moth flight and dispersal; new understanding from canopy observation, radar and aircraft. Memoirs Entomol. Soc. Can. 110: 1^9; 1980. Montgomery, B. A.; Witter, J. A.; Simmons, G. A.; Rogan, R. G. Forest management; integrated forest protection. In; The spruce budworm manual for the Lake States. Tech. Man. 82-6. East Lansing, MI; Michigan Cooperative Forest Pest Management Program; 1982: 18-21. Stark, R. W. Integrated pest management in forest practice. J. For. 75: 251-254; 1977. Stark, R. W. Integrated forest protection: a successful marriage of technology and ecology. Weyerhaeuser Lecture Series. Toronto, ON: University of Toronto, Faculty of Forestry; 1980; 3-19. Waters, W. E.; Stark, R. W. Forest pest management; concept and reality. Ann. Rev. Entomol. 25: 479-509; 1980. 20 • f i • ^ j.‘/1Saii * '>'? Chapter 3 Survey and Detection r. :• • ■' ‘''^-/'^-i-’^v.''^' '• - . . .'V- , -H' Douglas C.' Allen, Louis Dorais, and Edward G. Kettela' •'•iitr-'-.-.' >.: ■•fe .. *- ■- - "-‘iv ' Douglas Allen: State University of New York, College of Environmental Science and Forestry, Syracuse. Louis Dorais: Ministere de FEnergie et des Ressources, Service d’Entomologie et de Pathologie, Quebec, P.Q. Edward Kettela: Canadian Forestry Service, Maritimes Forest Research Centre, Fredericton, N.B. Effective management of eastern spruce-fir forests is contingent on prompt detection of spruce budworm populations that have a high potential for defoliation and damage. Detection surveys, the first line of defense in effective forest protection, must be timely and cost effective. Costs are often a major obstacle in forestry because the unit monetary value of the resource to be protected is sometimes less than the cost of protecting the resource. For crisis prevention, managers must be able to forecast increases in budworm populations early enough to permit necessary alterations in the forest management plan or to facilitate selection of economically and ecologically appropriate control tactics. Once a course of action has been established, it is prudent and necessary to sample the population further to evaluate the outcome of past decisions and determine future needs. Following detection, managers may want to implement a biological evaluation to document the effects of natural mortality or assess the extent and severity of damage. Damage evaluations are described in chapter 4; here we discuss the utility and application of techniques currently used to detect spruce budworm populations, estimate population trend, and determine extent of defoliation. Often, forest management decisions must be made in the context of different spruce budworm population regimes. For example, it is desirable to detect a numerical change in trend that portends a shift from sparse population conditions (absence of significant defoliation) to an incipient condition (high probability of significant future defoliation). On the other hand, a biological evaluation must also frequently be made after the budworm has rendered significant levels of defoliation (outbreak). Techniques discussed in this chapter, except for those most recently developed, are used in one form or another by all States and Provinces within the range of spruce-fir forests. Frequently, however, a technique utilized in one region is modified to accommodate different forest conditions, management objectives, or economic constraints that prevail in another jurisdiction. This lack of uniformity makes it difficult to compare and interpret data, and often precludes recommending a standard method. The discussion below is limited to general methods and major variations in their application or interpretation of results. Details of technique development are found in the reference list that immediately follows the chapter. Much of the material presented in this section was taken from these sources, which we gratefully acknowledge. This condensation of published information was infused with comments gleaned from interviews and communications provided by Federal, Provincial, State, and industrial sources. 22 Surveys for Sparse Populations Light Traps Spruce budworm moths, like many insects, are attracted to ultraviolet light (e.g., fluorescent black light). A trap that utilizes such a light source (fig. 3.1) provides a relative measure of insect abundance and population trend when operated for several consecutive years in the same location (Sanders 1980, Simmons 1980). Light traps are frequently used in agriculture as a survey tool and effectively detect increasing trends in sparse populations. Examination of 15 years of spruce budworm light-trap catches from 10 sites in Maine showed that annual catch revealed an acceleration in the rate of population increase, 4 to 7 years before defoliation was evident. Thus, light-trap catches can predict budworm outbreaks while there is still time to plan control tactics or perform silvicultural manipulations to lessen budworm damage. Time-series light-trap data may also disclose large-scale migratory flights of the kind believed to precipitate outbreaks. Light traps are relatively inexpensive to make but expensive to purchase commercially. A major drawback is that several species of insects are attracted to the light and trapped along with the spruce budworm. Sorting collections and counting budworm takes a lot of time. Pheromone Traps Since the sex attractant (pheromone) produced by female budworm moths was characterized in the early 1970’s, attempts have been made to use pheromone-baited traps to monitor annual trends in budworm populations or to predict budworm egg and larval densities or defoliation. This technique is potentially more useful than light traps because materials are less expensive and trap catch is selective. Also, the commercially available pheromone, Fulure (95;5 blend of (E)- and (Z)-l 1-tetradecenal), is a potent attractant that is very effective when used in sparse populations (e.g., <1.0 larva per 18-inch [45-cm] branch tip). The attractant is imbedded in either a laminated flake (1 by 1 inch, 2.5 by 2.5 cm) or hollow fiber, which is suspended inside the trap immediately below the cover. Recent field trials suggest that a pheromone trapping system will provide land managers with useful information on the status of local spruce budworm populations. For example, pheromone-baited traps can monitor changes in sparse populations where other sampling methods are impractical. Also, this tool can be used as an early warning system to detect mass migrations of males. Figure 3.1—Black light trap. Currently, two types of traps are used—the Pherocon ICP trap and a newly designed covered funnel trap (fig. 3.2). The ICP model has a replaceable sticky bottom whose efficacy decreases as trap catch increases because effective trapping area is reduced. Even when baited with lures that contain low concentrations of synthetic pheromone, relative to what the females produce, traps placed in stands that support sparse populations may quickly saturate (fill with males). Because the pheromone is so attractive, the average number of moths caught per trap varies little throughout a range of budworm densities. For example, L3-L4 populations that average 1 and 10 larvae, respectively, per 18-inch (45-cm) branch tip may result in similar trap catches unless bottoms are frequently replaced. 23 Moths that enter the covered funnel trap are killed by vapors released from a piece of Vapona (resin impregnated with dichlorvos) placed in the bottom of the funnel. This trap does not saturate; and, because moths collect in the funnel, once traps are placed in the field they do not have to be serviced. Currently, a single five-trap cluster with a minimum of 131 ft (40 m) between traps is recommended for trap deployment (fig. 3.3). Research has not yet defined the minimum stand size to which results from a single cluster can be applied. Recent field tests have demonstrated a relationship between the average number of moths caught per trap and the preceding (i.e., same generation) density of L3-L4 per 18-inch (45-cm) branch tip. However, forest managers would benefit more from a technique that predicts future events (i.e., next generation) when making decisions concerning budworm control. Pheromone-baited traps are operational, but more field testing is needed to refine our ability to interpret results. 40m ♦ 3 Figure 3.3—Design for deployment of pheromone- baited spruce budworm traps. Figure 3.2—Pheromone traps used for spruce budworm detection or evaluation. A: Prototype covered funnel trap. B: ICP trap. 24 Surveys for Outbreak Populations Egg Mass Sampling at this life stage is one of the most commonly used methods to determine population trend. Knowledge of egg-mass abundance and condition provides land managers with an early and relatively reliable indication of potential damage, especially in high populations. This timely information expedites planning for future management activities. In this regard, it is important to sample both fir and spruce in mixed stands to obtain an accurate picture of egg-mass abundance and potential for budworm defoliation. Population estimates based solely on samples from balsam fir often do not correctly portray the status of budworm. The intensity of this survey varies between geographical regions and political units, but generally pole pruners are used to remove three to six full-length branches (Ontario, Quebec, Newfoundland), four 3-ft (1-m) branch tips (Maritimes), or one to three 18-inch (45-cm) branch tips (Lake States) from the midcrown of each of 3 to 10 dominant or codominant balsam fir per sample cluster. Maine currently samples 3-ft (1-m) branch tips from the midcrown of each of three spruce and three fir at each sampling point. One recommendation for number of trees per cluster and number of clusters per plot cannot be made at this time. One plot (i.e., location of sample trees) is established for every 2,470 to 29,650 acres (1,000 to 12,000 ha) in an intensive survey. Extensive surveys use one plot for every 37,064 acres (15,000 ha) or 25 mi (40 km) of road. “Intensive” and “extensive” are relative terms that reflect the number of sample plots per unit area of forest. The smaller the area to which we apply sampling results, the more intensive the survey. To avoid excessive aging of the egg masses, sampling starts as soon as egg laying ceases. This may occur as early as late July in parts of New Brunswick or in late September in Newfoundland, depending on regional phenology. Light traps or pheromone traps may be used to time egg-mass surveys properly. The most common method of timing, however, is to look for green (i.e., recently deposited) egg masses. Budworm density is expressed as number of egg masses per 100 ft- (9.3 nr) of foliage: total number of egg masses found total surface area of foliage Two methods are used to determine foliage area: (1) multiply total branch length by branch width at its widest dimension and divide by 2 (i.e., L x W/2), or (2) multiply foliated length times width at midpoint of foliated branch (i.e., L x W). Egg masses from the previous year (grey) and masses where parasitism (black) is >50 percent should not be counted. The accuracy of egg-mass counting by individuals should be periodically checked to control error (Simmons and Fowler 1982). When extensive checking of worker accuracy is not practical, an estimate of average accuracy should be developed for each worker. The average proportion of egg masses that an individual overlooks should be determined, and egg-mass counts should be adjusted accordingly for each of three population levels: light, moderate, and heavy. The excessive tedium and time associated with human examiners may be overcome in the future, when an automated egg-mass counter becomes available (fig. 3.4). Preliminary tests of a prototype unit indicate that this machine will detect egg masses with comparable accuracy to human counters, but with substantial savings in time and cost. This tool is not yet commercially available. 25 F532856 Generally, when a survey of balsam fir or spruce reveals less than 100 egg masses/100 ft^ (9.3 mO of foliage, light defoliation is expected; 100 to 240 egg masses/100 ft- and >240 egg masses/100 ft- indicate a potential for moderate and high defoliation, respectively. Ontario is more conservative and categorizes infestation levels of 1 to 53, 54 to 215, and >215 egg masses/100 ft- of foliage as light, moderate, and severe, respectively. Egg-mass density in the Lake States is frequently expressed as number of masses/15-inch (38-cm) branch. Two branches (in Wisconsin) or three branches (in Minnesota and within the USD A Forest Service, State and Private Forestry) are taken from the mid- to upper crown of each of three dominant or codominant trees to predict defoliation (table 3.1). Figure 3.4 —Automated spruce budworm egg-mass counter, developed during the CANUSA Program and being refined at the Forest Service’s Missoula (Mont.) Equipment Development Center. The basic components include a conveyor belt housing, photomultiplier tubes, power supply, and computer terminal. A sequential sampling technique developed for balsam fir in the mid-1950’s is used, especially in Canada, to place populations into one of three infestation levels. A single midcrown branch is removed from each of three (New Brunswick), five (Quebec), or six (Ontario) randomly selected trees and, as above, population intensity is expressed as number of egg masses/100 ft- of foliage. Interpretation of plot data varies between regions (table 3.2). 26 Table 3.1—Prediction of spruce budworm defoliation in the Lake States, based on egg-mass density (from Montgomery et al. 1982) Average egg masses per 15-inch Organization (38-cm) branch Expected defoliation Minnesota, Dept. <0.1 None to light Nat. Resources 0.1 to 1.7 Moderate >1.8 Heavy Wisconsin, Dept. <0.5 Light to moderate Nat. Resources 0.5 to 1.5 Moderate to heavy >1.5 Heavy to severe USDA, Forest Serv- <0.2 Light (<26%) ice. State and 0.2 to 0.5 Moderate (26 to 50%) Private Forestry 0.6 to 0.9 Heavy (51 to 75%) >1.0 Severe (>75%) Table 3.2—Decision tables currently used for sequential sampling of spruce budworm egg masses (from Dorais and Kettela 1982) Geographic Branch Cumulative number of egg masses per region number 100 ft- (9.3 mO of foliage Infestation level Low Medium High Ontario, 1 > 391 Maine, 2 < 5 — > 541 Maritimes 3 < 45 117 to 188 > 692 4 < 84 216 to 338 > 842 5 <117 249 to 485 > 986 6 <155 287 to 635 >1 1,135 Infestation level Low Uncertain High Quebec, 1 — 0 to 337 > 337 Newfoundland 2 — 0 to 505 > 505 3 <315 315 to 672 > 672 4 <482 482 to 839 > 839 5 <689 689 to 1 ,006 >1 1,006 Overwintering Larval Survey Before larvae enter diapause in the second instar, commonly referred to as the L, stage, they spin a silk purselike structure (hibemaculum) in the tree crown, beneath bark scales or in other protected locations. The technique used to measure abundance at this juncture (September to mid-March) in the budworm’s life cycle is less expensive than egg-mass sampling. It may also provide a more reliable estimate of expected population levels because the sample is obtained after the effects of egg parasitism, adult dispersal, and initial larval dispersal have taken place. This type of survey is frequently used to check results of egg-mass surveys, to assess overwintering mortality and adjust infestation forecasts, or to identify stands that are candidates for chemical spraying. The foliated portion of a full-length branch is removed with a pole pruner from the midcrown of each of three balsam fir (Quebec, Maritimes, Newfoundland) or three fir and three spruce (Maine) trees per plot. Each branch is cut into small sections and larvae are then “extracted” from the hibemacula by soaking the dissected branch for 4 to 8 hr in a 2-percent solution of NaOH (caustic soda). For best results, the solution should be heated to 122° F (50° C) and agitated once or twice an hour. Branches are then thoroughly rinsed in water and solutions from both the soak and rinse are filtered through a coarse sieve (0.8-mm mesh), followed by a finer sieve (0.2-mm mesh). The former retains needles; the latter collects fine bark debris and larvae. Larvae and debris are washed from the fine sieve into a 4,000-ml separation funnel. Ten drops of 4-percent methylene blue are added to the solution (this stains the plant material), and sufficient hexane is introduced to form a 30-mm layer on top of the aqueous solution. The mixture is vigorously shaken and then allowed to settle. Much of the debris will settle, and larvae collect at the oil-water interface. Larvae are taken out of solution, put onto filter paper, and counted. Samples should be collected in early fall to maximize recovery of larvae. Late samples are more difficult to extract because older hibemacula resist dissolution. When the objective is to evaluate the effects of overwintering mortality, sampling must be delayed until early spring. Branches are first placed in emergence cages; and when larval activity ceases, the caustic soda wash is used to extract dead larvae. 27 The number of overwintering larvae per branch may be used to evaluate population levels or predict defoliation (table 3.3). The relationship between overwintering population density and expected infestation levels may vary between regions. This association is probably influenced by age of infestation, stand characteristics, and user bias. Large Larvae (L,-L^) Larval sampling becomes more difficult once the insect inhabits expanding buds, staminate flowers, or current year’s foliage. Budworm larvae, like those of many tortricids, are apt to move if disturbed. Sampling during these stages must be done with care. Even though this relatively late sample allows little time to make management decisions, assessment of population density during this phase of the budworm’s life cycle provides the best measure of expected damage. Large-larval sampling is most frequently used to identify candidate stands for spraying, to determine the efficacy of direct control measures, to time direct control properly, or to time placement of pheromone traps. Timing of large-larval samples is important to assess abundance of early-stage larvae (L 3 -LJ properly and to avoid the confounding effects of between-plot variation in rapid-acting mortality, relative to budworm development, that may occur during later stages (L 5 -LJ. Density of large larvae is usually expressed as number of budworm per 18-inch (45-cm) branch tip, but number per whole branch or per 100 ft- (9.3 mO of foliage may also be used. Five to 10 18-inch midcrown tips are collected with pole pruners from each of 5 to 10 dominant or codominant trees per plot. The required number of trees sampled in low populations may be higher because a minimum of 25 larvae, and preferably 100 to 200 , from both spruce and fir are needed to determine development. Sampling should be repeated every 2 to 3 days until budworm has attained the desired stage. One of two classification systems (table 3.4) may be used to determine stage of development (instar) for a sample of 100 to 200 insects. Bud phenology as defined by Auger’s bud classification system (fig. 3.5) is frequently used to derive a bud development index (table 3.5). A sample of 25 to 50 shoots per plot is needed to accomplish the latter. The index is a Table 3.3 —Relationships between number of overwintering spruce budworm larvae per branch and expected infestation level (from Dorais and Kettela 1982) Geographic region Number of larvae per whole branch Number of larvae per 100 fF (9.3 m9 of foliage Forecasted infestation Maritimes 1 to 6 Low 7 to 21 Medium 21 to 40 High >40 Extreme Ontario 1 to 25 Low 26 to 65 Medium >66 High Quebec, 1 to 100 Low Newfoundland 101 to 300 Medium 301 to 650 High >651 Extreme Maine 0 to 175 Low 176 to 500 Medium 502 to 1,100 High > 1,100 Extreme Table 3.4 —Head capsule sizes that identify stage of larval development for spruce budworm Instar Flead capsule width (mm)' Body length (mm) Head capsule width (mm)- 1 0.24 <1.5 Females 0.26 Males 0.26 2 0.30 1.5- 3.5 0.30 0.30 3 0.46 3.0- 5.0 0.42 0.42 4 0.70 5.0- 9.0 0.68 0.68 5 1.09 10 . 0 - 12.0 1.18 1.12 6 1.66 15.0-24.0 1.80 1.68 ' F. A. Titus. 1977. Unpublished Report, Maritimes Forest Research Centre. Frederiction, N.B. - McGugan (1954). 28 useful way to anticipate damage by comparing bud development to that of the insect (fig. 3.6). When the weather is unusually warm, budworms develop more rapidly than the buds; and the insect can inflict more damage due to its relatively large size. Cool, wet weather, on the other hand, slows budworm development; and buds become large in relation to the insect. Under these circumstances, more food is available and damage is relatively small. Alternatively, a developmental index that utilizes knowledge of the relationship between temperature and budworm growth may be used to classify a larval population (table 3.6). When development of early-larval stages is assessed, it may be desirable to process branches through the caustic soda wash after the foliage has been visually examined. This added procedure provides information on rate of development (percent emergence), and it helps to prevent a bias assessment that results when a portion of the overwintering population has yet to emerge. Information on the location of larvae may also help to establish the general stage of development. For example, small and wandering spruce budworm caterpillars are usually L,’s that have recently emerged from overwintering sites. Budworms that are found mining needles and buds or feeding in staminate (male) flowers are usually L,’s or Lj’s, and through Lg larvae usually reside on current year’s foliage. Stands that warrant direct control are frequently identified by sampling instars 3 and 4, which predominantly reside on developing buds or shoots. Samples are weighted in terms of plant vigor by expressing larval density according to the number of buds available to the budworm on each 18-inch (45-cm) branch sampled (fig. 3.7). In Quebec, only stands where mean larval density per bud or shoot exceeds 0.05 are considered viable candidates for chemical spraying. Because budworm larvae, especially instars 5 and 6 , tend to drop when disturbed, sampling should be done in a way that minimizes insect loss. This is usually accomplished by catching the sample in a basket attached beneath the cutting head of the pole pruner or with a special clamp that prevents the branch from indiscriminately dropping once it is cut. The use of baskets can be time consuming and cumbersome, but the accuracy gained is worth the effort when sampling the final instars (Lj-LJ. As many as 30 to 60 percent of these older larvae may be lost when branches are removed without some form of restraining mechanism. Table 3.5 —Example of calculation for Auger’s bud development index. Index is plotted on figure 3.6 to determine prevailing stage of spruce budworm development (from Dorais and Kettela 1982). Bud class number 1 2 3 4 5 Total Number of shoots (25 to 50 per plot) 0 5 5 40 1 51 Index calculation; 1. (1 x0) + (2x5) + (3x5) + (4x40) + (5x 1) = 190 2. 190/51=3.7 Table 3.6 —Computation example for spruce budworm development index based on degree days above threshold of 5° C (from Dorais and Kettela 1982) A. Numerical assignment Budworm development Number in sample 1 100 % of larvae in hibernation 0 2 peak L 2 0 3 peak L 3 25 4 peak L 4 50 5 peak L 5 25 6 peak Eft 0 7 peak pupae 0 8 100 % adult emergence 0 (25 B. Index = X 3) + (50 X 4) + (25 X 5) - = 4.0 100 C. Development index Budworm development Degree-days above 5°C 1.0 100 % hibernation 45 2.0 peak Lt 100 3.0 peak L 3 170 4.0 peak L 4 240 5.0 peak L 5 330 6.0 peak Lf, 440 7.0 peak pupae 550 8.0 100 % adults — 29 Class I Class II Figure 3.5 —Auger's balsam fir bud classification system. 30 Balsam fir bud development index Figure 3.6 —Relationship between spruce budworm larval development and development of balsam fir shoots (Quebec data). Defoliation (%) 100 Figure 3.7 —Expected defoliation of balsam fir as a function of spruce budworm mean larval density (L,-Lj) (Quebec data). Defoliation Surveys Evaluation of Spray Efficacy Efficacy of a control treatment is frequently determined by comparing prespray population density with postspray density, after subtracting the effect of natural larval mortality. Natural mortality is estimated by comparing prespray and postspray samples from check (unsprayed) plots. Abbott's formula, or a variation, is then used to determine mortality due to treatment effects. For example. Percent survival Percent survival Percent killed i^i check plot in treatment plot by treatment ~ Percent survival in check plot It is assumed that similar levels of natural mortality occur in treatment and check plots, that natural mortality can be accurately measured, and that there is no increase in check plot populations resulting from immigration or other phenomena. Frequently, these assumptions are not met, so results using Abbott’s formula must be carefully interpreted. Prespray samples are taken prior to emergence from hibernation (caustic soda wash for L,) in special cases where a population fix is desired before larvae enter the buds. Usually, however, prespray samples are taken at peak of third-instar development. Postspray samples are usually taken 4 to 7 days following treatment, and again during peak abundance of pupae. For large-scale spray programs—^247,100 acres (100,000 ha)—one plot is established for every 10,000 to 15,000 acres (4,000 to 6,000 ha) treated. There need to be one-third to one-half as many check plots as treatment plots. For example, treatment of 494,200 acres (200,000 ha) requires approximately 40 treatment plots and 15 check plots. A treatment plot consists of as many as 50 or as few as 3 dominant or codominant spruce and fir trees, depending on the time available. Check plots consist of 3 to 15 trees. One to five 18-inch (45-cm) midcrown branch tips are removed from each tree, placed in bags, and transported to a central facility for examination. When samples are taken before budworm larvae enter the buds, the sample unit is one full-length branch per tree. In this instance, the posttreatment sample unit must also be a full-length branch. Ground Defoliation estimates obtained by the techniques described here are usually expressed in terms of broad categories. The significance of varying levels of annual budworm defoliation depends on such things as extent of previous damage, species, stand site conditions, and management objectives. As a rule of thumb, if a tree retains 50 to 60 percent of the current year’s foliage, it will survive. Tree mortality is likely to occur only when annual defoliation of new foliage exceeds 60 to 70 percent during each of 5 consecutive years. Fettes Method —This technique was developed to estimate budworm defoliation and to assess degree of foliage protection following chemical treatment for balsam fir, but it has also been used for spruce. When this method is used to assess spray efficacy, estimates may be made concurrently with pupal surveys and usually on the same branches. Several modifications exist, and each requires removal of a branch or several branch tips from the midcrown of three or more trees per stand. A visual determination is made of the percentage of needles missing from each current-year shoot on the branch or a sample of 20 to 25 tips per branch. Each current-year shoot is placed in one of 12 categories (fig. 3.8), and percent defoliation per branch or tree is determined by averaging the midpoints of each category. For example, assume that a branch tip has 15 current-year’s shoots, and 7 shoots are assigned to category 1 (0 to 10 percent of needles missing), 4 to category 2 (10 to 20 percent), and 4 to category 3 (20 to 30 percent). Mean defoliation for the branch tip is 13 percent (table 3.7). If three branch tips are removed per tree, then an estimate of percent defoliation for that tree is determined by averaging the values obtained for each branch tip. When a tip is missing because the bud was mined by spruce budworm, the absent tip is placed in category 12. When used to evaluate spray efficacy, the percentage of foliage saved is determined from check-plot data that represent population levels comparable to those in treatment plots. For example: Percent Expected Observed foliage = defoliation defoliation saved Expected defoliation ^ where the estimate of expected defoliation is obtained by comparing prespray population densities in check plots with resulting (expected) defoliation levels (fig. 3.7). 32 60 + 70 70 + 80 80 + 90 90 + 99 100 100 + Figure 3.8 —Fettes method of estimating spruce budworm defoliation of balsam fir. Numbers above each shoot represent percent defoliation; lower numbers indicate defoliation categories. Table 3.7 —Use of Fettes method to determine percentage defoliation Defoliation category Number of tips in category Mean percent defoliation by category 0 0 xO 1 7 x5 2 4 X 15 3 4 x25 4 0 x35 5 0 x45 6 0 x55 7 0 x65 8 0 x75 9 0 x85 10 0 x95 11 0 X 100 12 0 X 100 (7 X 5) + (4 X 15) + (4 X 25) Mean defoliation = — 13% 15 A different method is used in Maine to assess foliage protection in large-scale tests. Forty-tree sample lines, 20 trees each of spruce and fir, are replicated three times for each treatment evaluated and in corresponding check areas. One 18-inch (45-cm) branch tip is removed from the upper midcrown of each tree. Ten shoots on each branch are examined in the field, and defoliation of each shoot is rated according to the Fettes method. Data are pooled to obtain an estimate of stand defoliation. Ocular Evaluation —Visual examination of clipped branches and use of binoculars to assess foliage condition in standing trees are relatively expedient methods to estimate defoliation. With practice, observers may be able to provide adequate information on broad categories ot defoliation at relatively little cost. Defoliation assessments from the ground are usually accomplished with foliage collected during egg-mass or L, surveys; therefore, sampling intensity is similar. Additional information on previous defoliation (e.g., condition of 2 - and 3 -year-old foliage), presence of dead tops, and abundance of budworm-killed trees can be obtained along with estimates of current defoliation. This information on tree and stand vigor may help to determine future control needs and identify stands that are candidates for salvage cuts {see chapter 6 ). Defoliation categories vary from one region to the next, but generally defoliation of current-year's foliage ^30 percent is considered light, 30 to 70 percent moderate, and >70 percent heavy or severe. 33 In some regions, binoculars are used to estimate whole-tree crown defoliation. A 13-category system is used to determine average expected and observed defoliation (table 3.8) for two species groups: fir/white spruce and red spruce/black spruce. Average defoliation is computed for sprayed and unsprayed plots. The level of defoliation in sprayed plots is then compared to level of defoliation in unsprayed check plots that had a similar prespray budworm density. The accuracy of whole-tree defoliation estimates is enhanced if crowns of sample trees are conceptually divided into thirds and average stand defoliation is based on the average of these three levels. The validity of any ocular estimate is influenced by observer experience, observer bias, and previous defoliation. These variables must be considered in order to attain a level of accuracy within the limits required for surveys. Aerial Surveys—Sketch Mapping Ground surveys to extensively map spruce budworm defoliation may be prohibitively expensive, but when done on a limited basis they can provide supporting information that is necessary to properly interpret aerial survey data. Most aerial surveys currently used to document previous damage and intensity of current budworm defoliation involve sketch mapping. This technique, like all aerial methods, takes advantage of foliage discoloration and changes in tree appearance that result from budworm feeding. Information from sketch maps may be used to determine the effectiveness of a spray program, to identify future treatment areas, or to isolate stands where harvesting should be concentrated. Sketch mapping is a relatively simple and inexpensive way to locate infestations and estimate the number of acres associated with the three broad categories of defoliation intensity; 1. Light—Slight reddish-brown tinge to margin of tree crown, especially in the upper third of the crown; <30-percent defoliation of new foliage, no dead tops. 2. Moderate—Obvious reddish-brown color throughout crown, 30- to 70-percent defoliation of new foliage, <10 percent of tops dead. 3. Heavy—Extensive reddish-brown discoloration throughout stand; >70-percent defoliation of new foliage; >10 percent of tops dead and tree mortality evident (gray crowns). Mapping is usually done with fixed high-wing aircraft but occasionally with helicopters. The most common airspeed is approximately 106 mi/h (170 km/h) at an altitude of 560 to 1,970 ft (170 to 600 m), depending on terrain, aircraft, and sponsoring organization. Distance between Eight lines varies Table 3.8—Defoliation categories used in New Brunswick to make whole-tree defoliation estimates Species group Category Percent defoliation Fir/white spruce 0 0 T (trace) 1 to 5 1 6 to 15 2 16 to 25 3 26 to 35 4 36 to 45 5 46 to 55 6 56 to 65 7 66 to 75 8 76 to 85 9 86 to 95 10 a 96 to 100 (needles almost all missing, some shoot axils remaining) 10 b 96 to 100 (all needles and shoot axils destroyed) Red spruce/ 0 Nil black spruce Light <30 Moderate 31 to 69 Severe >70 from one region to another; lines may be as close as 1.2 mi (2 km) or up to 8 mi (13 km) apart. In some areas, watersheds are used to guide mapping rather than flight lines. Information is initially sketched on a relatively large-scale map (e.g., 1:62,500) and later transferred to smaller scale maps. Mapping may also be done directly on small-scale maps (e.g., 1:250,000) or photo maps. Some users prefer these because they make it easier to determine the location of defoliated areas. Sketch mapping depends heavily on experience, or the observer’s ability to recognize defoliation classes. The person must also be familiar with the area being surveyed in order to map defoliation accurately. More sophisticated remote sensing techniques, such as the use of satellite imagery, conventional color photography, or infrared photography, have been used only on an experimental basis to map defoliation. See chapter 4 for details. 34 Cost of Survey and Detection Forest managers must carefully balance the cost of using survey and detection methods against the benefits to be derived. The precision (repeatability) of sampling estimates is directly related to sampling intensity. The latter generally reflects differences in such things as number of sample units per tree, number of trees per plot, and number of plots per stand or region. For some managers, all that may be desired is the ability to classify populations or expected defoliation into broad categories. Others may require more precise measures. These different needs are reflected in the sundry approaches used to implement the techniques described earlier. Table 3.9 presents examples of costs, in terms of personnel time or dollars, associated with several of the methods described. These estimates include travel time, equipment, and onsite implementation of a technique. Multiple estimates occur whenever data were provided by different agencies. Table 3.9 —Cost estimates for spruce budworm survey and detection Type of sample Estimated cost ($ or time) Currency and survey location Egg mass $50-$52/3- to 5-branch plot $5 3/4-branch plot 1981 Canadian 1982 U.S. (Maine) Overwintering larval (L 2 ) 2.5 person- days/5- tree plot $47/5-tree plot $40/5-tree plot 1981 U.S. (Vt.) 1982 U.S. (Maine) 1980 Canadian (P.Q.) Large larval $20/3-tree plot 1980 Canadian (N.B.) (L 3 -L 6 ) $29/5-tree plot (lab cost = $2.50/branch) $73/40-tree line (lab cost = $2.50/branch) 1982 U.S. (Maine) 1982 U.S. (Maine) Spray evaluation $650/5-tree plot 1980 Canadian (full sequence including pre- and postspray samples and evaluation of insect develop¬ ment every 3 days for 40 days) Aerial defoliation $0.10-$0.25/km- 1980 Canadian survey $ 0 . 10 /ha 1981 U.S. Ground defoliation $0.28-$0.30/3- to 5-branch plot 1981 Canadian' survey $0.40/ha 1981 U.S. ' Usually done during the egg-mass survey. 35 Selected References Abbott, W. S. A method of computing the effectiveness of an insecticide. J. Econ. Entomol. 18; 265-267; 1925. Dixon, W. H.; Houseweart, M. W.; Jennings, D. T. How to examine branches for spruce bud worm egg masses. Orono, ME; University of Maine, Cooperative Forest Research Unit; 1978. 16 p. Dorais, L.; Kettela, E. G. A review of entomological survey and assessment techniques used in regional spruce budworm, Choristoneura fumiferana (Clem.) surveys and in the assessment of operational spray programs. Report of the committee for standardization of survey and assessment techniques to the Eastern Spruce Budworm Council. Quebec, PQ; Quebec Department of Energy and Resources; 1982. 43 p. Fettes, J. H. Investigations of sampling techniques for population studies of the spruce budworm on balsam fir in Ontario. Ann. Tech. Rep. 14. Sault Ste. Marie, ON; Forest Insect Laboratory; 1950. Fowler, G. W.; Simmons, G. A. More accurate estimators for budworm egg mass density (Lepidoptera; Tortricidae). Great Lakes Entomol. 13; 151-157; 1980. Kemp, W. P.; Trial, H., Jr.; Stuble, D. Sampling and analysis design for experimental insecticide monitoring. Tech. Rep. 12. Augusta, ME; Maine Department of Conservation, Bureau of Forestry; 1979. 32 p. MacLean, D. A.; Lidstone, R. G. Defoliation by spruce budworm; estimating by ocular and shoot-count methods and variability among branches, trees and stands. Can. J. For. Res. 12; 582-594; 1982. McGugan, B. M. Needle-mining habits and larval instars of the spruce budworm. Can. Entomol. 86; 439-545; 1954. Miller, C. A.; Kettela, E. G.; McDougall, G. A. A sampling technique for overwintering spruce budworm and its applicability to population surveys. Info. Rep. M-X-25. Fredericton, NB; Canadian Forestry Service; 1971. 11 p. Montgomery, B. A.; Witter, J. A.; Simmons, G. A.; Rogan, R. G. The spruce budworm manual for the Lake States. Tech. Man. 82-6. Ann Arbor, MI; Michigan Cooperative Forest Pest Management Program; 1982. 66 p. Morris, R. F. A sequential sampling technique for spruce budworm egg surveys. Can. J. Zool. 32; 302-313; 1954. Morris, R. F. The development of sampling techniques for forest insect defoliators, with particular reference to the spruce budworm. Can. J. Zool. 33; 226-294; 1955. Ramaswamy, S. B.; Carde, R. T. Nonsaturating traps and long-life attractant lures for monitoring spruce budworm males. J. Econ. Entomol. 75; 126-129; 1982. Sanders, C. J. A summary of current techniques used for sampling spruce budworm populations and estimating defoliation in eastern Canada. Rep. O-X-306. Sault Ste. Marie, ON; Canadian Forestry Service, Great Lakes Forest Research Centre; 1980. 33 p. Sanders, C. J. Sex attractant traps; their role in the management of spruce budworm. In; Mitchell, E. R., ed. Management of insect pests with semiochemicals; concepts and practice. New York; Plenum; 1981; 75-81. Simmons, G. A. Use of light trap data to predict outbreaks of the spruce budworm. Info. Rep. 80-b. East Lansing, MI; Michigan State University, Department of Entomology; 1980. 13 p. Simmons, G. A.; Chen, C. W. Approaches to assessing insecticide efficiency in spruce budworm (Lepidoptera; Tortricidae) control programs. Can. Entomol. 107; 1205-1209; 1975. Simmons, Gary A.; Fowler, Gary W. How to apply bias adjustment for spruce budworm egg mass counts. Info. Rep. 82-11. East Lansing, MI; Michigan Cooperative Forest Pest Management Program; 1982. 11 p. 36 Impact on Trees Insect impact is any effect that insect activity has on forest resources. Impact can be positive, negative, or negligible. “Damage” implies a harmful or negative effect. Thus, damage assessment involves evaluation of this negative effect. The information in this chapter will be discussed under the following headings; impact on trees, impact on stands, regional impacts, techniques to assess and predict damage, rating systems, and forest growth models. From the forest manager’s point of view, the impact of the spruce budworm on individual trees is negative. This damage includes growth loss, cone and seed mortality, top-kill, and tree mortality. The effect of the spruce budworm on a given tree is largely dependent upon the number of budworm larvae, number of years when larvae are at outbreak densities, tree condition, tree species, and position of tree within the forest. The sequence of events associated with uncontrolled spruce budworm outbreaks usually follows the general pattern shown in table 4.1. Growth Loss Budworm defoliation affects the growth of individual trees in terms of stem diameter and height. Balsam fir is extremely sensitive to defoliation. The first year of insect feeding on the current year’s foliage (fig. 4.1) reduces diameter growth in the upper part of the stem. Studies in Nova Scotia showed that 60- to 100-percent defoliation of the current year’s needles reduced stem growth by 20 and 50 percent after 1 and 2 years, respectively. For mature Table 4.1 —Succession of events associated with a spruce budworm outbreak on balsam fir Years of severe defoliation ' Impact 1 Flowers and cone crops die. Radial growth loss occurs in the upper crown. 2 to 3 Small roots begin to die. Radial growth loss occurs over the entire stem. Height growth ceases. Some treetops die. 4 to 6 Suppressed trees in the understory and mature and overmature trees in the overstory begin to die. Tree growth and wood production nearly cease. 7 to 15 Budworm populations begin to collapse. More trees die, particularly balsam fir. Some seedlings and saplings die. Dead trees begin to deteriorate as a result of disease, secondary insect attack, and wind breakage. Protective cover in deer yards is diminished. ' Seventy-tive percent or more of current year’s growth. 38 Figure 4.1 —Balsam fir tree with more than 60— percent defoliation of new needles. balsam fir with 70- to 80-percent crown length, diameter growth loss at breast height may occur 2 or 3 years after the first year of severe defoliation (75 percent or more of current year’s needles) (fig. 4.2). For 25- to 30-year-old, evenly spaced balsam fir trees with 70- to 80-percent crown length, diameter growth loss occurs in the same year as the first severe defoliation. Severe defoliation for 2 to 6 consecutive years reduces radial increment by 30 to 90 percent, relative to radial increment without budworm feeding. We have only limited information on growth loss for hosts other than balsam fir. Available data suggest that volume reduction is less for spruce, particularly black spruce, than for balsam fir. Damage appears first and is most severe toward the top of the tree. Translocation of nutrients and water may be disrupted, causing the terminal leader to die. Top-kill (fig. 4.3) usually begins during the third year of an outbreak. When top-kill does not occur, height growth during outbreak years generally ranges from zero to one-third that of normal growth. Tree height often decreases by an average of 1 to 12 ft (0.3 to 3.7 m) when tops die. Top- kill is more severe and more frequent in trees in the lower crown classes, which are already at a competitive disadvantage to neighboring trees. Total number of dead tops often reaches 50 percent or more. Figure 4.2 —Differences in growth loss along stem during first year of outbreak. 39 Figure 4.3 —Top-kill. Table 4.2 —Relationship between stem diameter at which top-kill stops, stem deformity, and likelihood of fungal invasion (from Raske, unpublished data) Diameter where top-kill stops Stem deformity Likelihood of entrance by heartwood fungi {Inches) (Cm) <0.4 <1.0 None Not likely 0.6 to 1.5 to Sweeps in stem. Likely 1.2 3.0 forked top 1.4 to 3.5 to Crooks, forked Virtually assured 2.8 7.0 tree ' >2.8 ' >7.0 Crooks, knees, multiple tops Virtually assured ' Deformities are likely to be so severe that growth of merchantable wood is prohibited above the diameter where the top-kill stopped. The diameter of the stem where the top-kill stops is related to the recovery of the leader or tree. If the top is killed down to a diameter of 2.8 inches (7 cm) or more, then severe deformities and invasion by heartwood fungi are very likely (table 4.2). Cone and Seed Mortality The spruce budworm inhibits seed production in two ways. There is a direct loss when the budworm feeds on flowers’ and cones. Also there is an indirect loss when trees are unable to flower because they have been weakened by budworm defoliation. Small larvae feed on flowers, and large larvae feed on cones. The amount of flower damage varies by host species and by the degree of synchronization between larval emergence and the period when flowers are present. The effects of defoliation on flower production are greatest for black spruce, intermediate for red and white spruce, and least for balsam fir. Light defoliation is sufficient to inhibit seed production in black spruce. Moderate to severe loss of new balsam fir foliage reduces flower production by 50 percent after 1 year and by 75 percent after 2 or more years. Cone flowers that survive spruce budworm attack continue their development toward becoming mature cones but remain vulnerable to damage. On all host species, a spruce budworm population large enough to cause severe defoliation of the new shoots will ^ Technically, conifer flowers are called strobili. 40 completely destroy all the cones that survived beyond the flower stage. At lower infestation levels, some cones may survive; but this number is usually small and varies with host tree species, level of infestation, and initial size of the cone crop. Damaged cones that reach maturity are small and bear few sound seeds. Overall, very few seeds are produced during a severe outbreak. Root Mortality Effects of defoliation by the spruce budworm are evident below the soil as well as above it. A high proportion of small roots, less than 0.1 inch (2 mm) in diameter, die when balsam fir trees are severely defoliated. Mortality of small roots may exceed 75 percent when defoliation of current growth reaches 100 percent for several years. Root death reduces the amount of water absorbed by the tree. Young, vigorously growing trees are generally able to regenerate new roots and survive. Mature trees or trees of poor vigor often lack this ability and die. When root recovery does occur, it usually follows foliage recovery by 2 or 3 years. Spruce roots take longer to d-ie or recover than balsam fir roots. Dead roots may serve as avenues for the entry of several decay fungi, including shoestring root rot (Armillaria) and butt rots. Lightly damaged trees appear to be able to resist the growth of these decay fungi; but, in more severely damaged trees, butt rots may develop after recovery. Physiology Needles produce carbohydrates and growth hormones and help regulate water movement. A tree’s major physiological responses to needle loss are changes in internal water stress and in supplies of carbohydrates and hormones. The consequences of defoliation vary with the age of needles removed, because the ability of needles to produce metabolites and to transpire changes markedly with age. The budworm removes the most efficient units of photosynthesis, transpiration, and hormone synthesis when it feeds on the current year’s needles. The tree is not entirely defenseless to budworm attack: it can compensate for loss of needles by (1) forming larger buds on surviving shoots, thereby producing larger shoots in the following year; (2) forming shoots from lateral buds that previously had been prevented from flushing; (3) preferentially allocating metabolites to new foliage production at the expense of stem, root, and reproductive growth; and (4) retaining older needles longer. At present it is impossible to accurately predict a particular tree s response to repeated light or moderate defoliation. The factors determining the tree’s ability to compensate for loss of foliage are not all known, and their interactions are not fully understood. The major external factors are those that directly affect the tree’s physiological condition (e.g., carbohydrate and nitrogen status, shoot/root ratio, age, genotype, ratio of photosynthetic to respiration tissue, tree phenology in relation to rate and severity of budworm feeding, and abundance of flowers and adventitious buds). Unfortunately, prediction is further complicated by the fact that a physiological condition favoring regrowth after defoliation—for example, a high foliar nitrogen concentration—can at the same time also favor budworm population growth. Heavy defoliation results in death because so many needles are lost that the tree ultimately becomes unable to produce enough metabolites to support both respiration and regrowth. Thus, severe defoliation, in effect, starves the tree. A tree can tolerate this stress for up to a maximum of about 5 years before succumbing. Stress and Predisposition to Other Pests Repeated removal of the current year’s needles and/or shoots by spruce budworm feeding results in reduced tree vigor and makes the tree more susceptible to other pest problems, such as bark beetles and fungi. In healthy conifers, attacks by bark beetles such as the spruce beetle and the eastern larch beetle are normally repelled by a copious flow of resin that fills the gallery of the attacking beetle and forces it out. Weakened trees are unable to produce enough resin to repel repeated beetle attack. A tree under stress from defoliation emits chemicals that insects such as the spruce beetle can use to identify weakened trees. Once they establish the initial attack, the beetles emit powerful aggregating chemicals (pheromones) that result in mass attack of the host. Damage by these insects can be significant. Studies in Nova Scotia in 1980 have shown that more than 25 percent of the merchantable volume of spruce-budworm-infested stands of white spruce were dead or dying from beetle attack. Over 0.5 billion fL (14 million m'), or 35 percent of the total volume of white spruce, was killed by the spruce beetle in the Gaspe Region of Quebec during 1930-34. 41 Many fungi are associated with spruce-fir stands. Their role is generally secondary, involving the deterioration of dead or moribund trees. However, several root and butt rots—in particular shoestring root rot—can attack and kill living trees. Shoestring fungi are normally present in the soil. When healthy roots come in contact with infested roots or soil, the fungus colonizes the outer bark of the healthy root. The fungus kills the root by girdling it and moves up the root, eventually girdling the root collar. Healthy trees form a callus, and the advancing root and root collar infestions are checked. Weakened conifers attacked by shoestring fungi fail to check the advancing fungal growth (fig. 4.4). A study by Whitney (1978) in northwestern Ontario revealed that shoestring fungi were present in the roots of 42, 31, and 36 percent of 1,497 balsam fir, black spruce, and white spruce trees, respectively. Examination of balsam fir in a New Brunswick stand with an 8-year history of budworm defoliation showed that over 65 percent of the dead trees and more than 55 percent of the living trees with greater than 75-percent total defoliation had signs of shoestring rot at the root collar (Ostaff 1983). This fungus usually remains in tissues beneath the ground, but other important root-rotting fungi can extend into the wood about 6 ft (2 m) above ground. Losses resulting from root rot, in the form of dead or wind-damaged trees, butt cull, and growth reduction, were found to average from 25 to 40 percent of the merchantable volume in natural balsam fir stands 65 to 75 years of age. Infected trees die gradually (indicated by a few red branches) or suddenly (all foliage turns red in the same season). Tree Mortality Repeated removal of the current year’s foliage eventually results in tree mortality. Trees that have lost more than 75 percent of their total foliage usually do not recover. The first trees to die are those in the suppressed and intermediate crown classes that are overtopped by balsam fir or white spruce. The exact number of years of severe spruce budworm defoliation that will cause mortality varies with tree species, vigor, and age, and stand density. Some fir trees in the codominant and dominant crown classes die after about 5 years of repeated severe defoliation of current year's growth. Tree mortality can take place 1 or 2 years earlier when all current year's shoots are destroyed and the larvae resort to feeding on older foliage. White spruce and red spruce trees die after 6 or 7 years of severe defoliation. Black spruce intermixed with, or growing in the vicinity of, balsam fir and white spruce can be killed, but black spruce trees in pure stands usually survive outbreaks. Seedlings and saplings can be killed during severe infestations, when large larvae disperse to the understory in search of food. Deterioration of Wood Fiber Forest managers should be aware that changes do occur within the stems of trees shortly before and following tree death so as to maximize financial returns when harvesting dead trees. The stem is invaded by a succession of organisms, usually starting with insects and followed by fungi. The result is a continuous process of disintegration and decay. Direct degradation of stem wood by insect activity in killed balsam fir is limited (e.g., the deep, wide tunnels of sawyer beetles can account for about 1 percent in direct fiber loss in the premanufacture of pulp). In stands where tree mortality has occurred for several years, populations of some insects, such as weevils, can increase to the point where they successfully attack and kill weakened trees. Insects are accompanied or followed by fungal invasion, with insect activity ceasing after 1 or 2 years. The first sign of fungal deterioration is a reddish-orange discoloration of the outer sapwood. The wood usually remains firm. The next stage of deterioration involves a progressive softening of the outer sapwood, characterized by an orange, stringy appearance. This defect is caused by a sap-rotting fungus, Polyporus abietimis Dicks ex Fr., responsible for about 95 percent of the advanced (unfirm) sap rot in budworm-killed balsam fir. High populations of the balsam fir bark beetle have been associated with increased levels of this sap-rotting fungus. The moisture content of stems of defoliated trees, particularly the sapwood, drops rapidly following tree death, making the stems brittle. In mechanical harvesting operations, which subject the stems to a whipping action, up to 70 percent of the dead stems may be broken. Transportation costs can be affected since broken trees can reduce average truckloads by as much as 20 percent; and if costs are based on weight, the same volume of logs can weigh as much as 35 percent less than logs cut from living trees. 42 Figure 4.4—White fungal growths of shoestring root rot fungus. The yield and quality of pulp and paper produced from budworm-killed trees can be seriously affected by fungal deterioration. Sap stain has little effect on fiber strength or chip quality; but losses in brightness, particularly in the stone groundwood process, do occur. When trees with sap rot are utilized, the debarking process may remove only half of this defect with the remainder entering the chipper, resulting in a higher proportion of pin chips, fines, and powder, and a lower proportion of acceptable chips. Sap rot reduces chemical pulp strength because the fungi and pulping process combine to shorten the fibers and make them more flexible, seriously affecting tear strength. Budworm-killed trees should be pulped chemically, whenever possible, because mechanical processes cause more serious reductions in brightness and strength. Sulfite and kraft pulp yields from dead trees are slightly lower. The brightness of sulfite pulp is generally affected more than that of kraft pulp, while kraft pulp appears to sustain somewhat greater strength reduction. The main problems encountered in the kraft process have been identified as pulp yield loss, quality decrease, increased alkali consumption, nonuniform pulping, and increased recovery- boiler loading. When budworm-killed trees are used in any pulping process, they should be mixed as uniformly as possible with living trees to minimize problems with cooking, pulp freeness control, and energy consumption. The lumber and sawmill industry is making more use of budworm-killed material. But one study on spruce revealed that 40 percent of the lumber volume was downgraded by such defects as sap stain, sap rot, wood borer mining, and drying check, resulting in a 21-percent reduction in product value. Volume losses are incurred because heavy slabbing and trimming are usually necessary. Balsam fir used for dimension stock production should be harvested as soon as possible after death, preferably within a year. Recent studies suggest that both spruce and balsam fir timber from budworm-killed trees make waferboard ot an acceptable quality. However, the wafer yield tends to decrease with increasing sap rot content. 43 Impact on Stands For centuries the North American boreal forests have experienced periodic spruce budworm outbreaks. Fir and spruce usually regenerate after a spruce budworm outbreak, reaching maturity in 50 to 60 years. At about that time, another outbreak may occur. In this section, we cover (1) stand factors that can lead to severe impact, and (2) the effects of the outbreak on the stand. Stand Factors The factors that can increase the amount of volume loss and tree mortality in spruce-fir stands are listed in table 4.3. These factors certainly interact, and one or all factors are generally associated with damaged stands. The relationships discussed in the table usually hold true, but there is great variation within the entire boreal forest on the question of relating specific stand factors to budworm impact. Some of this variation in budworm impact may be due to poor information on the inventory of the forest, specifically relating to site differences. In other words, stands called pure fir are often something else—spruce-fir and hardwoods, fir-spruce, etc. Table 4.3 —Factors that increase the amount of damage (volume loss and tree mortality) in a spruce-fir stand General factor Condition leading to severe damage Intensity and duration Stand mortality usually increases of outbreak with the severity and length of the outbreak. Species composition Stands with large balsam fir components have greater potential for mortality than stands composed mostly of spruce and hardwoods. Stand age Mature fir stands (60 years or older) Stand density High basal area of balsam fir, red spruce, and white spruce Stand structure Open stands in which spike tops of host species protrude from forest canopy Site condition Poorly drained stands, abnormally dry or wet Stand size Extensive stands of mature host trees (except black spruce) Stand location Stands located downwind (often east) of the current outbreak Topography and Stands growing at elevations latitude lower than 2,300 ft (700 m) and south of 50° latitude Fir mortality 60 m^/ha A Mature stands (HW < 20%) y = 1.00X - 1.21 (r^ = 0.98, n = 26) Spruce mortality 60- m^/ha B 40 Mature stands y = 0.31x + 0.89 (r^ = 0.54, n = 13) Figure 4.5 —Relationship between tree mortality and basal area for balsam hr and spruce (from MacLean 1980 ). 44 Stand Age and Density —Stand age and density affect the impact of spruce budworm outbreaks on trees and stands. Conversely, budworm outbreaks affect the age-class distribution, primarily by recycling stands from mature age classes to younger age classes. Differences in percent mortality of stands after budworm outbreaks vary between immature and mature stands, and among the different stand densities. Studies throughout Eastern North America indicate that fir mortality in mature stands is consistently high. Fir mortality in immature stands and spruce mortality in mature stands are generally lower but much more variable (figs. 4.5, 4.6). In general, mortality in mature fir stands ranges from 70 to 100 percent, while mortality in immature stands varies from 30 to 70 percent (MacLean 1980.) Mortality of fir and spruce increases as their density increases within the stand. Species Composition and Stand Structure —Spruce budworm outbreaks are less likely to occur in stands with a mixture of spruce-fir and nonhost species. Once a sustained outbreak occurs, there is generally very little difference in the amount of fir mortality in a pure, mature fir stand or in mature stands with a mixture of fir, spruce, and nonhost trees (fig. 4.6). Some outbreaks kill all host species within the stand. However, percent mortality is greatest in stands with the highest proportion of balsam fir, followed in descending order by white spruce, red spruce, and black spruce. Percent fir mortality decreases as the percent of nonhost basal area increases. Spruce and balsam fir in two-storied stands under hardwood cover are less exposed to damage from spruce budworm. Open stands in which spike tops of host species protrude from the forest canopy may suffer more damage. Fir Mortality Spruce Mortality Percent of plots in each mortality class A. Mature stands B. Immature stands C. Mature stands D. Immature stands Mortality classes (percent of stand dying) Figure 4.6 —Distributions of fir and spruce mortality during budworm outbreaks (from MacLean 1980). 45 Site Conditions —Stand mortality is not evenly distributed within a Province or State. Such differences may be partially due to site conditions (fig. 4.7). Several site classification systems are being developed in North America. One logical approach is to break an area into ecosystem units that are consistently found in the stand. These ecosystem units can be distiguished by differences in physiography, soils, and vegetation. Individual characteristics such as drainage, topography, slope, aspect, depth of organic matter, soil texture and pH. and plant species groups may be incorporated into a site classification scheme. To date, the relationship between site classification units and stand mortality is unknown. In general, stands on abnormally dry or wet sites usually sustain more damage. Stand Size and Location —Damage may increase with an increase in the continuity and size of the stand. Stands located downwind of a current outbreak are likely to be infested. Survival of dispersing larvae and adults is greater in large, continuous stands than in small, scattered stands. Figure 4.7 —Variation in site conditions of balsam fir stands. Topography and Latitude —Budworm survival and stand damage usually decrease at elevations higher than 2.300 ft (700 m) and at latitudes north of 50°. Late spring frosts are common in these areas and often kill young larvae directly by freezing them or indirectly by killing their food, young foliage. The Effects of the Outbreak on the Stand Stand mortality (fig. 4.8) usually increases with the duration and severity of the outbreak. However, the spruce-fir ecosystem is complex. Such complicated interactions impede our efforts to predict damage exactly in any specific local area. Tlie budworm affects the forest, and the forest affects the budworm. No component is mutually exclusive: a change in one part of the ecosystem affects, and is eventually affected by, the other parts. The stand factors in table 4.3 affect the food source of the budworm. However, other factors such as weather and natural enemies (e.g., birds, spiders, parasitic wasps and flies, and diseases) have a major effect on the population dynamics of the budworm. Likewise, the structure of the forest affects the survival of natural enemies. 46 Jigure 4.8— Current defoliation (red phase), total defoliation, and tree mortality caused by budworm in a spruce-fir stand. 47 Defoliation by the spruce budwoim often results in volume loss and successional changes at the stand level. Other impacts at the stand or regional level may include changes in number and type of wildlife, increased susceptibility to wildfires, recreational and esthetic concerns, and economic losses. Volume Loss —Defoliation results in loss of diameter and height growth for individual trees and may eventually kill them. Most volume loss is attributable to reduction in stem diameter growth. Growth increment is reduced about 50 to 75 percent by several years of severe defoliation. Reduced height growth also accompanies severe infestations, but its effect on volume is small compared to the effect of diameter loss. Height growth loss is more severe and prolonged in immature stands than in mature stands. For example, 20 years after the end of a bud worm outbreak in young stands in New Brunswick, average tree height in damaged stands was 12 to 15 ft (4 to 5 m) less than average tree height in undamaged stands (Baskerville and MacLean 1979). Forest management decisions and plans are often dependent upon the ability to predict volume production in the future. If budworm outbreaks are influencing the rate of production, this must be taken into account. For the purpose of simplification, we can assume two different situations regarding spruce budworm outbreaks. The first situtation, in untreated stands or those with limited protection, is a 10- to 15-year outbreak that causes growth loss and kills trees. Following such an outbreak, the stand is either recycled to a younger age class (if there is heavy mortality and the stand is lost from the merchantable inventory) or a significant portion of the stand remains and it can be considered part of the current inventory. The second type of outbreak situation exists when a large-scale forest protection program is in place, limiting mortality and possibly growth loss. Some growth loss occurs with the most stringent protection program, reducing volume increment for the duration of the outbreak. Two recent studies provide data on the impact of defoliation on a stand basis. Kleinschmidt et al. (1980) studied 20 fir-spruce stands in Maine and found that stands which suffered light defoliation for 5 years showed Table 4.4 —Reduction of volume increment in fir-spruce plots in Maine resulting from varying degrees of nonfatal defoliation (from Kleinschmidt, Baskerville, and Solomon 1981) 5-year defoliation history (for fir) Annual fir growth loss after 5 years’ defoliation Mean cumulative fir growth loss (Percent) (Percent) (M^lha) (Ffiacre) Light (<20%) 0 0 0 0 Increasing for 4 years (from roughly 20% to 90%) 40 12 4 57 Increasing for 5 years (from roughly 20% to 90%) 40 19 7 106 Severe for 5 years (continuous 90% to 100%) 60 34 15 212 Increasing for 4 years, sprayed in 5th year 55 30 17 241 Increasing for 3 years, sprayed in 4th year 30 18 13 184 negligible growth loss, whereas severe defoliation for 5 years resulted in a 60-percent annual growth loss, or a cumulative loss of 34 percent over the 5-year period. This cumulative growth loss was equivalent to 214 ftVacre (15 mVha) of wood production lost to the stand during 5 years of nonfatal defoliation. Other results from the study are presented in table 4.4. A second study, by Baskerville and MacLean (1979), considered development of fir plots that suffered mortality and growth loss during an outbreak in northwestern New Brunswick in the 1950’s. Recovery of these stands was studied over a 20-year period following collapse of the budworm outbreak. Recovery in terms of volume per acre was poor, although surviving trees had increased growth rates. Only 1 of 10 plots regained its predefoliation volume 15 years after defoliation ceased. Projection of stand development to age 75 further suggested that on the average, plots that suffered budworm-caused mortality and growth loss would have only slightly more than one-half the projected volume without defoliation. 48 Losses resulting from budwoim attack vary between stands, regions, and outbreaks. These variable losses have an important influence on the types of stands that will follow. Succession and Regeneration Changes —A spruce-fir forest of similar composition often grows back after a spruce budworm outbreak destroys a susceptible forest. This cycle is not dependent upon human intervention—it occurred many times, long before people first harvested the spruce-fir forest. The phenomenon of fir replacing fir promotes great long-term stability in structure and species composition {see also chapter 6). Moderate and light defoliation rarely cause a significant permanent change in stand composition. The abundance of forbs and shrubs in the forest understory may increase due to openings in the canopy. In heavier infestations, larvae may spin down in large numbers from denuded overstory trees to feed on seedlings and saplings. Percent seedling mortality is usually low. However, up to 100-percent seedling mortality occasionally occurs in sections of a stand. Quite often the proportion of spruce or balsam fir increases within a stand following a budworm outbreak. This depends on site conditions, weather history, severity of the outbreak, and amount of mechanical damage from harvests. Over the entire region, the proportion of budworm host species appears to remain stable. Studies throughout Eastern North America indicate that forest succession shows a strong regional dependence. Even within a region, spruce-fir regeneration will vary from site to site. Over most of the budworm’s range, 500 to 1,000 coniferous seedlings per acre (1,235 to 2,470/ha) are needed to reach a minimum stocking level of 40 percent or more over a 50-year rotation. Ghent et al. (1957) recorded 20- to 65-percent seedling mortality in the first 5 years following a budworm outbreak. Wildlife —Spruce budworm outbreaks affect more than just trees and stands. As an outbreak progresses, the number and types of wildlife change. It is well known that budworm impact is not uniform over large areas. Thus the effects of the outbreak will be different throughout a forest and will change from year to year. Changes in the ecosystem are temporary and often predictable. The composition and density of wildlife communities in spruce-fir are affected by three closely related habitat features: stand composition (percent mix of hardwoods and softwoods), stand structure, and spruce budworm population density. In general, greater plant variety gives greater animal variety—more species but fewer individuals per species. Over the course of a spruce budworm outbreak, and the spruce-fir life cycle for that matter, populations of some wildlife species are reduced for several years while other species gain a temporary advantage. The species associated with mature spruce and fir may decrease when tree crowns begin to die. As a new forest regenerates under standing dead timber, bark-probing and cavity-nesting birds may benefit, as will rabbit, moose, deer, masked shrew, and weasel. As the regeneration matures, different fauna will flourish. During a spruce budworm outbreak, the total number of birds per stand often doubles (Crawford and Jennings 1982). The initial abundance of budworms attracts many species of birds (especially songbirds) and even species that normally eat few insects. As upper canopy foliage is depleted and tree crowns die, budworm populations fall and birds move away. Regenerating fir stands improve bird habitat, particularly where hardwood seedlings are mixed with fir. Mature spruce-fir stands contain little browse for ungulates, such as deer and moose. Regenerating stands with a mixture of fir and hardwoods, particularly aspen, tend to increase browse for 10 to 20 years. But budworm outbreaks tend to reduce cover and shade for ungulates, which need some conifer cover for concealment and good winter shelter. In some regions, the significance of budworm damage may be as important on wildlife, especially winter deer cover, as on the timber resource. Wildfire —Historical records indicate that past spruce budworm infestations have been followed, within a few years, by severe forest fires. The Miramichi Fire of 1825 in New Brunswick, and the 1948 Chapleau-Mississagi Fire in Ontario are prominent examples. There is strong qualitative evidence that budworm damage increases the amount of dead, dry material available for combustion. This situation also increases fire intensity and, in combination with increased fuel loadings, hampers tire- control efforts. 49 Forest fire behavior in spruce-budworm-killed balsam fir stands has been studied since 1978 in Ontario. In all, six successful fires were conducted with the following general results (Stocks, unpublished data). Spring fires, or those occurring prior to the greening-up of understory vegetation, behave explosively, even under conditions of moderate fire danger. Total balsam fir crown involvement occurs immediately after ignition (fig. 4.9), and spread rates in the range of 150 to 300 ft/min (45 to 90 m/min) are common. Large amounts of peeling balsam fir bark are transported in the convection column, which can cause spot fires downwind. Balsam fir fuel is almost completely consumed with only boles left smoldering after the fire Figure 4.9 —Typical spring tire behavior in a dead balsam fir stand showing complete crown involvement and extensive fuel consumption. front passes (fig. 4.10). Fuel arrangement is not a critical factor in spring fires in this fuel type because .the fires behave explosively whether tree crowns are intact or on the ground. In the first few years following defoliation and tree mortality, summer fires, occurring after understory vegetation green-up, spread very slowly if at all. The tree canopy is just beginning to open, and the understory vegetation proliferates very quickly. This moist, green layer restricts any interaction between dry ground and 50 Figure 4.10 —Typical scene immediately after a spring lire in a dead balsam fir stand. crown fuels, effectively nullifying fire spread. After 10 to 15 years, however, enough dead surface fuel accumulates through tree breakdown to overcome the dampening effect of understory vegetation. Summer fires will then spread through the fuel complex. Summer fires in this fuel type can still present major control difficulties despite exhibiting significantly slower spread rates and lower intensity levels than spring fires under similar fire-weather conditions. The Ontario experimental burning program in budworm- killed balsam fir has definitely shown that fire potential is significantly increased for a number of years following actual tree mortality. Crown breakage and windthrow, and resultant increased surface fuel loadings, peak 5 to 8 years after the tree mortality. Forest fire potential is greatest during this period, decreasing gradually as balsam fir fuel on the ground begins to decompose and understory vegetation continues to proliferate. 51 Regional Impacts of the Spruce Budworm Esthetics and Recreation —Most people have their own definitions of favorite visual esthetics or optimum sites for recreational activities. For the sake of brevity, let’s assume that people prefer a living forest that contains some diversity, some continuity, unobstructed long-range views, and a closed canopy for a sense of security. Spruce budworm outbreaks do not enhance visual esthetics. Budworm outbreaks can create problenns along highways, canoe routes, and wilderness trails, and in shelterbelts, picnic areas, and parks. Hanging larvae and dead branches are unappealing to most tourists and recreationists. The homeowner whose spruce or fir tree is being severely defoliated may express particular concern. In general, these are short-term problems that are relieved when a new forest takes over a site or a protection program saves the stand or tree. Economics —Ultimately, spruce budworm damage must be related to the monetary value of the resource. Economic losses are extremely difficult to estimate. The most common technique is to compute the difference between the quantity or quality of resources in the areas that have been damaged by budworm and what that quantity or quality would have been without spruce budworm infestations. Difficulties arise throughout all parts of this analysis. How much of the loss is directly attributable to budworm feeding? What is normal yield? Are stumpage values true indicators of nonarbitrary prices? Are noncommodity valuations fair or real? And finally, should the economic analysis include nonproductive or inaccessible areas, damaged by the budworm but of no commercial value to people? Evaluation of these resources and spruce budworm impact is discussed in chapter 5. Radial-growth studies by Blais (1982) produced evidence that the spruce-fir forests of eastern Canada have experienced at least seven outbreaks since 1700, each extending over millions of acres. Uncontrolled budworm outbreaks have usually resulted in severe and widespread tree mortality (table 4.5). Eastern Canada During the last 5 years, the spruce budworm was the most destructive forest pest in Canada. The average annual wood depletion from mortality and growth reduction resulting from defoliation by this insect for the 5-year period 1978-82 is estimated to be 1.5 billion ft’ (42.5 million m’) (table 4.6). This estimate, which exceeds that for any other pest, is equivalent to about two-thirds of the annual harvest and about one-half the annual allowable cut of softwoods in eastern Canada. In some areas, populations of other insects such as the spruce beetle and eastern larch beetle have increased rapidly in stands weakened by repeated budworm defoliation, and these pests in turn have attacked and killed trees. Table 4.5 —Volume of spruce-fir killed by the spruce budworm in eastern Canada, Maine, and Minnesota (from Montgomery el al. 1982/?) Mortality estimate' Year Region Million m' Million cords Percent of total host volume 191()-early Eastern Canada 447 200 40-50 1920’s 1909-1919 Maine 55-67 25-30 •> 1912-carly Minnesota 45 20 ’ 67 1920’s 1914-21 New Brunswick 11 5 ’ 75 1943-55 Northwestern Ontario 38 17 58 1967-80 Eastern Canada 186 83 •> 1967-80 Ontario 18 8 ’ 60 ' Conversion factor: I cord (79 ft') = 2.237 m'. Cubic feet and metric conversions of measurements expressed in cords should be viewed as estimates because of assumptions involved in the conversion process. In other chapters in this book, the Forest Service standard has been followed (1 cord = 90 ft' = 2.55 m'). ’ Not available. ' Includes only balsam fir. ' Merchantable volume. 52 The total area of moderate to severe defoliation in Ontario Eastern United States and eastward in 1981 was 94.1 million acres (38.1 million Over the last several years, spruce budworm impact has ha). In eastern Canada, dead and dying trees occurred expanded in some States, remained the same in others and within an area of 62.3 million acres (25.2 million ha). dropped to low levels elsewhere (table 4 7) Table 4.6 —Regional impact of the spruce budworm in eastern Canada' from 1978-82 (from regional depletion estimates compiled by the Canadian Forestry Service and corresponding Provincial agencies) Province Area of moderate to severe defoliation Area of tree mortality Annual tree mortality Annual estimated growth loss Newfoundland (Thousand ha)' 343 ’331 (Thousand m') ■’3,517 -’801 Nova Scotia 508 1,248 3,340 " 1,029 New Brunswick 1,017 4,961 5,032 ^ 352 Quebec 11,139 9,131 ■’ 14,765 ■’ 4,922 Ontario 15,735 8,961 12,134 1,537 ' Data not available for Prince Edward Island. ’ To calculate English measurements, use the following equivalents: 1 ha = 2.471 acres 1 m’ = 35.3 fP or ca. V 2 cord ^ Average based on estimates for period of 1977-81. Balsam fir only. In Maine, budworm population and defoliation levels have been increasing, especially in Washington County and in the northwestern counties. Populations are building in lightly defoliated areas and intensifying in areas with heavy defoliation. Balsam fir and hemlock mortality increased sharply in 1982. Spruce is just beginning to die, with red spruce dying quicker than either white or black spruce. In New Hampshire and Vermont, budworm outbreaks are concentrated in the northern tier counties. Defoliation has been reported since the early 1970’s, and mortality has been increasing annually since 1980. In the Lake States during the early 1980’s, the total area with visible defoliation has stabilized in the Cloquet Valley State Forest (northern Minnesota), remained scattered at low levels throughout Michigan’s Upper Peninsula, and virtually disappeared from Wisconsin. Despite reductions in population levels, tree mortality continues throughout the Lake States. Table 4.7 —Three-year trend in area visibly defoliated by spruce budworm in the Northeastern United States State 1980 1981 1982 (Acres) (Ha) (Acres) (Ha) (Acres) (Ha) Maine 5,000,000 2,023,500 4,000,000 1,618.800 7,300.000 2,956.000 Michigan 859,000 347,637 161,000 65,157 116.000 47,000 Minnesota 103,000 41,684 110.000 44,517 126.731 51.288 New Hampshire 90,000 36,423 42,000 16,997 10,000 4,000 Vermont 111,000 44,922 94,000 38,042 150,000 61.000 Wisconsin 439,000 177,663 84.000 33,995 2,000 809 Total 6,602,000 2,671,829 4.491.000 1.817,508 7,704,731 3,120,097 53 Techniques to Assess and Predict Impact Estimates of current defoliation and tree mortality are required (1) to monitor stand conditions, (2) to determine cutting priorities and the building of access roads to minimize losses, and (3) to determine the need and plan for a protection program. Techniques used to assess tree mortality include aerial surveys and ground checks, remote sensing, and cruises and permanent ground plots. Aerial Surveys and Subsequent Ground Checks Areas and levels of current defoliation and stand mortality plus estimates of the percentage of susceptible species are mapped directly onto 1:50,000 to 1:250,000 scale maps by observers flying in fixed-wing aircraft. Semipermanent or permanent ground plots involving .v number of trees (usually 50 to 100) are established in areas where mortality has been mapped to confirm the presence and degree of mortality. An aerial survey is the first step in an intensive damage-assessment system. Remote Sensing Sensors can be classified as photographic (e.g., aerial cameras where the image is recorded on a sensitized film utilizing the visible and near-infrared portions of the electromagnetic spectrum) or nonphotographic (e.g., optical-mechanical detectors that can utilize the thermal infrared part of the spectrum). Either type of sensing system may be mounted in an aircraft, spacecraft, or unmanned satellite. Damage Assessment Using Photographic Sensors —The following factors must be considered when assessing damage with photographic sensors: (1) camera—35 mm, 70 mm, 230 x 230 mm (9x9 inch), multispectral, or panoramic; (2) film—black and white, black and white infrared, color, false color, or color infrared; (3) scale— large (1:1,200 to 1:4,000), medium (1:4,000 to 1:20,000), or small (1:20,000 or smaller); and (4) time of photography. To assess current defoliation, aerial crews should photograph stands shortly after the budworm has completed feeding, since the partially consumed foliage adheres to the feeding tunnels of the larvae, giving the tree a reddish color for most of the summer. To assess total defoliation, take photographs during late fall, when the influence of hardwoods and ground vegetation on photo interpretation is reduced. On black-and-white photographs, damage is interpreted from pattern, texture, tone, shape, or shade. On color photographs, tone is replaced by color; and the effects of damage are recorded as a change in either shape or color. Subtle color patterns in foliage are dramatically emphasized on false-color or infrared photographs. Damage can be determined when trees are completely or almost completely defoliated on medium-scale (1:15,840) photographs, although many trees will be missed. Small-scale (1:60,000) color infrared (Hall 1982) or standard color composites or band 5 black-and-white Landsat images where the contrast to surrounding areas was high (Harris et al. 1978) can be used to assess damage when large areas of total defoliation occur. Large-scale photographs (1:1,200 to 2,400) are required to assess damage when defoliation is extremely variable. Damage Assessment Using Nonphotographic Sensors —Nonphotographic sensors record the intensity of radiation for unit areas (called picture elements or pixels) in a number of spectral channels, e.g., 4 channels on the Landsat III satellite or 11 channels on some airborne multispectral scanners. The unit areas on the ground are scanned at different wavelengths, producing numerical values proportional to the intensity of light reflected from each area. The size of the pixel or area depends on the type of scanner and the altitude of the aircraft or spacecraft. Landsat III produces a geometrically corrected pixel size of 50 m X 50 m, while scanners mounted in aircraft can produce pixel sizes as small as 1 m X 1 m. Analysis of digital data involves reconstructing the image using the intensity values for each pixel; selecting the channels that best depict the damage; and classifying the image using complementary aerial photography, sketch mapping, or ground surveys as support data. In one classification process (supervised classification), areas of known damage levels (called training areas) are outlined on the computer image. For each area, the computer calculates the mean intensity value of all of the pixels within the training area, the standard deviation, and other statistics. The computer then classifies the total image by determining if the intensity levels of each pixel are close to the characteristic values obtained for each damage level. The end product is a color-coded output image displaying the relevant pixels characterized by damage levels (fig. 4.11). 54 STRETCHED L LIGHT B ARIES PHOTOGRAPHIC PRODUCT - BARREN LAKE NS SUPERUISED CLASSIFICATION -9 CHANNELS 5 CLASSES- OUER DEFOLIATION LEUELS E EXTREME S SEUERE M MODERATE CHANNEL 9 BLONDONN Using supervised classification techniques of damage assessment in all forest stands is difficult because differences in reflectance caused by varying hardwood components and crown closure of stands may mask the damage levels. Four levels of total defoliation (light, 0 to 33 percent; moderate. 34 to 66 percent; severe. 67 to 90 percent; and extreme, greater than 90 percent) were classified with 25-percent accuracy using a supervised Figure 4.11—Levels of budworm damage determined by digital analysis of airborne multispectral scanner data. classification of 4.5-m resolution. The data were acquired using an 11-channel airborne multispectral scanner over Cape Breton Island. 55 Rating Systems Poor differentiation was found between adjacent defoliation levels. In a digital analysis of Landsat data, Hogan and Madding (1979) found that two levels of infestation (moderate and extensive) could be identified and accurately mapped in spruce-fir stands. However, the investigators concluded that this method was impractical until resolution is improved and cost of the processing equipment reduced. The newer generation satellites such as Landsat IV may provide better techniques for detecting and quantifying damage caused by the spruce budworm because of their improved spatial resolution, spectral responses, and improved frequency of coverage. Cruises and Permanent Ground Plots Various types of plots have been used in conjunction with mortality surveys or research on permanent plots. The two main plot types are fixed-area plots, 0.025 to 0.20 acres (0.01 to 0.08 ha), or prism-point sample plots. Prism plots are faster and more efficient to sample and are ideal for determining mortality in terms of basal area. Fixed-area plots are worthwhile where precise estimates of parameters such as number of stems per acre or mortality in terms of stems per acre are required. After analyzing plots on Cape Breton Island containing primarily fir and spruce, researchers concluded that 8 to 15 relatively small plots, either prism or small fixed-area, should be used within a stand for sampling budworm-caused tree mortality. For estimating annual mortality, the prism system requires slightly fewer plots for a given accuracy level than the 0.125-acre (0.05-ha) fixed-area plots. Both of these types required substantially fewer plots than the 0.025-acre (0.01-ha) plots. For estimating cumulative mortality to ± 10-percent precision level, the 0.125-acre (0.05-ha) type required the fewest plots (8), while prism plots required 11, and the 0.025-acre (0.01-ha) plot size required 15 plots (MacLean and Ostaff 1983). In Michigan, Karpinski and Witter (1982) determined the optimum plot size and number of plots needed to sample forest parameters related to spruce budworm impact. They found that for most parameters, three 0.10-acre (0.04-ha) plots per stand are optimum when the precision of estimates and evaluation time per plot are considered. Other types of plots involve a line plot where all the trees falling along a fixed width and length are assessed, or a fixed number of trees of the required species, selected at random, are assessed for mortality and tree condition. To manage spruce-fir forests effectively, the forest manager must be able to predict the type and amount of damage from the spruce budworm. Studies on tree mortality during spruce budworm outbreaks support the idea of differential damage in balsam fir stands with considerable variation in the amount of tree mortality occurring between stands during an outbreak. Several rating systems have been developed to assist the forest manager in determining the vulnerability of the forest to spruce budworm damage. Terminology, Objectives, and Uses Four terms are often used when discussing information on rating systems involving the spruce budworm and spruce-fir stands: 1. Susceptibility —likelihood that a stand will be attacked by the spruce budworm 2. Risk-Rating System —a ranking of spruce-fir stands according to their susceptibility to the spruce budworm 3. Vulnerability —likelihood of damage to the stand once budworm attack occurs 4. Hazard-Rating System —a ranking of spruce-fir stands according to their vulnerability to the spruce budworm These concepts are interrelated insofar as susceptibility determines the severity of attack and hence the level of damage likely to occur. Vulnerability may also be affected by factors other than stand characteristics, such as individual tree condition. Most rating systems currently being used in spruce-fir stands rate the vulnerability of a stand. Rating systems for the spruce budworm concentrate either on short-term or long-term objectives. Many of the rating systems now used in Eastern North America emphasize short-term objectives. These rating systems help managers determine which stands need to be sprayed or salvaged during the next year or two; they have usually been called hazard-rating systems in the past. Long-term rating systems are based on the concept of vulnerability and have been referred to in the literature as hazard-rating systems, rating systems, or vulnerability indexes. These systems are used to help the forest manager reduce the vulnerability of the forest over time. Managers sometimes use the long-term rating systems to select areas requiring protective spraying, to schedule salvage operations, and to select cutting areas. 56 Hazard-Rating Systems for Determining Protective Spraying and Salvage Operations Hazard-rating systems for determining protective spraying and salvage operations fall into two categories: systems based on data collected from the ground or from images obtained by remote-sensing techniques. Systems Based on Data Collected from the Ground —These systems involve a short-range, year-to- year procedure that identifies high-hazard areas and provides a guide to forest managers as they plan chemical and microbial spray programs or salvage operations for the Table 4.8 —Hazard-rating system used in Maine during 1982 (Trial, unpublished information) Current defoliation Trace (0-5%) Light (6-20%) Moderate (21-50%) 2 Heavy (51-80%) 4 Severe (81% +) 6 Light (10^9%) 3 Moderate (50-129%) 6 Severe (130% -I-) 9 Value Previous defoliation' Value- 0 Trace (0-9%) 0 1 Egg mass and overwintering larval deposit^ Second-instar Category Egg mass’ larvae’ Value Light 0-99 0-175 1 Moderate 100-239 176-500 2 High 240-399 501-1099 3 Very high 400-999 1100 + 5 Extreme 1000 + 1100 + 5 Total hazard rating Tree vigor Value Category Hazard value Good (current foliage healthy) 0 Low 0-6 Fair (shoot production moderate) 1 Moderate 7-15 Poor (some growth capacity) 2 High 16-22 Very poor (nil) 3 Severe 12-26 ' The 2 previous years’ needles. * Add 3 points if there are trees with dead tops in the area (10 to 20 percent of the trees). ' Number of budworm egg masses/100 ft’ (9.29 nr’) of foliage. (To calculate egg masses per mr divide the ranges given in this column by 9.29.) ^ Number of second-instar budworm larvae/100 ft' (9.29 nr) of foliage. (To calculate L 2 per nr. divide the ranges given in this column by 9.29.) next year. A hazard rating is determined for each stand or forest by assigning values to parameters such as current defoliation, previous defoliation, tree vigor, and the density of egg masses or second-instar larvae. The value for the stand is determined by summing the values for each parameter. The hazard-rating system used in 1982 in Maine is presented as an example (table 4.8). All of the short-term hazard-rating systems used in Eastern North America are similar. However, the exact values assigned to each parameter may be different, and the technique used to measure the parameter may be different. Systems Based on Photo-Interpretation —A self- instructional manual (Olson et al. 1982) is available to assist forest managers in assessing damage and estimating future damage due to spruce budworm activity. Techniques described are based on inexpensive 35 mm aerial photographs. This rating system provides an index that can be used to rank stands in terms of probability of future damage. The stand-rating value is determined by adding up values derived from three stand variables; proportion of stand in host species, average tree-condition ranking for the stand, and existing percent mortality of host species (table 4.9). Techniques used in this rating system are operational, but the specific numbers used to calculate stand-rating values are preliminary and may need to be modified for use in specific localities. Forest managers may use the stand¬ rating values to rank stands that need to be harvested (salvage operation) or protected (spray program) during the next 1 to 3 years. This technique can be adapted and used with a 70 mm camera system. Rating Systems for Long-Range Planning A rating system used in Minnesota to estimate potential fir mortality in spruce-fir stands is presented in table 4.10. This system relies primarily on the basal area ot balsam tir and on percent of nonhost species at the time that the outbreak begins. To estimate the potential for dead balsam fir from spruce budworm attack: 1. Determine the basal area per acre of balsam fir in the stand. 2. Determine the percent ot the total basal area that is made up of balsam fir and spruce. 3. Find the potential for dead balsam fir where these values intersect on the table. 57 Table 4.9 —Stand-rating values obtained from 35 mm photographs and used to predict amount of potential damage (modified from Olson et al. 1982 and McCarthy et al. 1983) 1. Average stand defoliation rank Value Trace (0.0-1.2) 0 Light (1.3-1.9) 1 Moderate (2.0-2.9) 2 Heavy (3.0-4.0) 3 2. Stand mortality Value Low (0-9%) 0 Medium (10-29%) 2 High (30-49%) 4 Severe (>50%) 6 Table 4.10 —Estimated balsam fir mortality 5 years after attack by the spruce budworm on trees 4 inches (10 cm) d.b.h. and up (from Batzer and Hastings 1980) Balsam fir basal area Percent of basal area occupied by balsam fir and spruce 20 4.6 40 9.2 (ft-/acre) 60 80 (m7ha) 13.8 18.4 100 23.0 120 27.6 Percent of balsam fir dead 40 0 22 48 60 68 72 50 0 35 55 65 72 76 60 0 45 62 71 76 79 70 15 55 68 76 80 83 80 35 65 77 81 84 87 90 55 75 83 86 89 90 100 75 88 90 91 93 93 species Stand density value Open Avg. Dense 1 f 2 2 2 4 3 4 6 Stand-rating value' Category Rating value Low 0-4 Moderate 1 OO High 9-10 Severe 11-15 estimated as a function of preoutbreak balsam fir basal area and the percent stand composition in aspen. Average dead balsam fir basal area per acre is used to estimate potential impact in the central portion of the Peninsula. Dead balsam fir basal area on stands in the Western Upper Peninsula with at least 44 ftVacre (10 mVha) of balsam fir basal area is estimated as a function of preoutbreak balsam fir basal area, percent stand composition in balsam fir, and stand position on an east-west gradient. The mean dead balsam fir basal area per acre is used to estimate potential impact on stands in the Western Upper Peninsula with less than 44 ft-/acre of balsam fir basal area. 3. Proportion of stand in host Proportion of host species <30% 30-60% >60% ' Stand-rating value is obtained by adding the values of variables 1.2, and 3. A system developed to predict the amount of balsam fir basal area mortality from budworm attack in stands located on mineral soils in Michigan's Upper Peninsula is presented in table 4.11. Factors that influenced budworm impact in the Upper Peninsula were (1) the length of time the outbreak had been in progress, which varied locally throughout the Peninsula; (2) the amount of balsam fir present in the stand; (3) site factors, particularly drainage; and (4) past and present land management practices. Dead balsam fir basal area in the Eastern Upper Peninsula is In eastern Canada, a rating system has been proposed to help the forest manager determine the vulnerability of the forest to budworm attack at a management unit level. This vulnerability index is based on the combined volumes of balsam fir and white spruce, maturity of balsam fir, combined volumes of black and red spruce, and climate (table 4.12). The accuracy and utility of this system depend on the availability of forest inventory data. Another potential hazard-rating system relates tree vitality to fir mortality. The Shigometer is an instrument that measures electrical resistance in a tree’s cambial zone. When the electrodes indicate that resistance is at a high level, then tree vitality or the physiological health of the tree is poor. If it can be shown that poor-growing stands have a greater probability of mortality during spruce budworm outbreaks, then indexing by cambial electrical resistance may be useful in a long-range hazard-rating, system (Davis et al. 1980). 58 Table 4.11— Estimated potential impact to balsam fir basal area (ft-/acre) in Michigan's Upper Peninsula (from Lynch and Witter, unpublished data)' A. Stands located in the Eastern Upper Peninsula Preoutbreak balsam fir basal area (ftVacre) Percent basal area 25 50 75 100 125 150 in aspen 0 23 {Basal 46 area 68 in ff/acre) 91 114 136 20 18 40 63 86 108 131 40 12 35 58 80 103 126 60 7 30 53 75 98 120 80 2 25 47 70 93 115 95 0 21 43 66 89 111 B. Potential impact (± SE) in stands located in the Central Upper Peninsula 1.0 ± 1.2 C. Potential impact (± SE) in stands located in the Western Upper Peninsula with less than 44 ftVacre (10 mVha) of balsam fir basal area 1.3 ± 1.6 D. Stands located in the Western Upper Peninsula with at least 44 ftVacre (10 mVha) of balsam fir basal area 1. Stand component 50% (by number of stems) balsam fir Preoutbreak balsam fir basal area Range of 50 (ft-Vacre) 75 100 125 150 township 28 12 (Basal area in ft-lacre) 21 30 39 48 32 16 25 34 43 52 36 21 30 39 48 57 40 25 34 43 52 61 44 30 39 48 57 66 Stand component 70% (by number of stems) balsam fir Preoutbreak balsam fir basal area Range of 50 (ftVacre) 75 100 125 150 township 28 0 (Basal area in fflaere) 5 14 23 32 32 1 10 18 27 36 36 5 14 23 32 41 40 10 19 28 36 46 44 14 23 32 41 50 Stand component 90% (by number of stems) balsam fir Preoutbreak balsam fir basal area Range of 50 (ftVacre) 75 100 125 150 township 28 0 (Basal area in ff!acre} 0 0 7 16 32 0 0 3 12 21 36 0 0 7 16 25 40 0 3 12 21 30 44 0 7 16 25 34 ' To calculate metric measurements, use this conversion: I ft'/acre x 0.2296 = m’/ha. 59 Forest Growth Models Table 4.12 —Vulnerability index used to rate fir vulnerability to spruce budworm attack in eastern Canada (from Blais and Archambault 1982, MacLean 1982) (1) Combined vol¬ (2) Maturity of fir umes of fir (percent > and white spruce (mVha)' 60 years) (Vr) Rating (Mr) Rating 1-6 1 1-20 1 7-13 2 21-40 2 14-20 3 41 + 3 21-27 4 28-34 5 35^1 6 42^8 7 49-55 8 56-62 9 63 + 10 (3) Combined vol¬ (4) Climate- umes of black (Cr) Rating spruce and red warm-dry 8 spruce (mVha) warm-wet 4 (Vr2) Rating cool-dry 4 1-6 1 cool-wet 0 7-13 2 14-20 3 21-27 4 28-34 5 35-41 6 42-48 7 49-55 8 56-62 9 63 + 10 (5) Calculation of vulnerability index (V.I.) V.I. - (Vr X Mr) + 'Vr2 + Cr (6) Vulnerability classes V.I. Class 0-7 Low 8-15 Moderate 1^24 High 25 + Very high An obvious extension of understanding the relationships between budworm-caused defoliation and tree growth and mortality is incorporating these relationships in a mathematical or simulation model of the system. This allows forecasts or projections to be made for a wide variety of situations. Forest growth models for the spruce budworm/spruce-fir forest are discussed in appendix 2. Another approach for modelling growth in defoliated stands is to modify or add to an existing stand growth model. This strategy is being followed for the western spruce budworm, where CANUSA researchers are linking the Stand Prognosis Model (Wykoff et al. 1982) with a western spruce budworm population dynamics model currently under development. Hopefully, in the future, a variety of models will be available to assist forest managers in making yield projections for stands under different levels of budworm attack. ' To calculate English measurements, use these equivalents: 1 m’ = 35.3 ft^ or ca. Vi cord 1 ha = 2.471 acres ^ warm = mean annual temperature of 36.5° F (2.5° C) or more cool = mean annual temperature below 36.5° F (2.5° C) dry = precipitation of 35.5 inches/yr (902 mm/yr) or less wet = more than 35.5 inches/yr (902 mm/yr) ’ Volume added only when the rating of Vr is >4. 60 Selected References Barnes, B. V.; Pregitzer, K. S.; Spies, T. A.; Spooner, V. H. Ecological forest site classification. J. For. 80; 493-498; 1982. Basham, J. T. Preliminary report on the rate of deterioration of spruce budworm-killed balsam fir, and its relationship to secondary stem insects. Info. Rep. O-X-314. Sault Ste. Marie, ON: Canadian Forestry Service, Great Lakes Forest Research Centre; 1980. 20 p. Basham, J. T.; Belyea, R. M. Death and deterioration of balsam fir weakened by spruce budworm defoliation in Ontario. Part III. The deterioration of dead trees. For. Sci. 6: 78-96; 1960. Baskerville, G. L.; MacLean, D. A. Budworm-caused mortality and 20-year recovery in immature balsam fir stands. Info. Rep. M-X-102. Fredericton, NB; Canadian Forestry Service, Maritimes Forest Research Centre; 1979. 23 p. Batzer, H. O. Net effect of spruce budworm defoliation on mortality and growth of balsam fir. J. For. 71: 34-37; 1973. Batzer, H. O.; Hastings, A. R. How to rate spruce-fir vulnerability to budworm in Minnesota. St. Paul, MN; U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station; 1980. Belyea, R. M. Death and deterioration of balsam fir weakened by spruce budworm defoliation in Ontario. Part I. Notes on the seasonal history and habits of insects breeding in severely weakened and dead trees. Can. Entomol. 84: 325-335; 1952. Belyea, R. M. Death and deterioration of balsam fir weakened by spruce budworm defoliation in Ontario. Part II. An assessment of the role of associated insect species in the death of severely weakened trees. J. For. 50: 729-738; 1952. Binotto, A. P.; Locke, R. R. The impact of budworm damaged fir on pulp quality. Pulp Pap. Can. 82(1); 32-37; 1981. Blais, J. R. Mortality of balsam fir and white spruce following a spruce budworm outbreak in the Ottawa River watershed in Quebec. Can. J. For. Res. 11; 620-629; 1981. Blais, J. R.; Archambault, L. Rating vulnerability of balsam fir to spruce budworm attack in Quebec. Info. Rep. LAU-X-51. Sainte-Foy, PQ: Canadian Forestry Service, Laurentian Forest Research Centre; 1982. 22 p. Brown, C. E. A cartographic representation of spruce budworm, Choristoneiira fumiferana (Clemens), infestation in eastern Canada, 1909-1966. Publ. 1263. Ottawa, ON: Canadian Department of Fish and Forestry Services; 1970. 4 p. Crawford, H. S.; Jennings, D. T. Relationships of birds and spruce budworms—literature review and annotated bibliography. Bibliog. Lit. Agric. 23. Washington, DC: U.S. Department of Agriculture, Forest Service; 1982. 40 p. Davis, W.; Shortle, W.; Shigo, A. Potential hazard-rating system for fir stands infested with budworm using cambial electrical resistance. Can. J. For. Res. 10: 541-544; 1980. Fowler, G. W.; Witter, J. A. Accuracy and precision of insect density and impact estimates. Great Lakes Entomol. 15: 103-117; 1982. Ghent, A. W. Studies of regeneration in forest stands devastated by the spruce budworm. 11. Age, height, growth, and related studies of balsam fir seedlings. For. Sci. 4; 135-146; 1958. Ghent, A. W.; Fraser, D. A.; Thomas, J. B. Studies of regeneration of forest stands devastated by the spruce budworm. 1. Evidence of trends in forest succession during the first decade following budworm devastation. For. Sci. 3; 184—208; 1957. Hall, R. J., comp. Uses of remote sensing in forest pest damage appraisal: proceedings of a seminar; 1981 May 8; Edmonton, AB. Info. Rep. NOR-X-238. Edmonton, AB; Canadian Forestry Service, Northern Forest Research Centre; 1982. 60 p. 61 Harris, J. W. E.; Dawson, A. F.; Goodenough, D. Evaluation of Landsat data for forest pest detection and damage appraisal surveys in B.C. Into. Rep. BC-X-I82. Victoria, BC; Canadian Forestry Service, Pacific Forest Research Centre; 1978. 12 p. Hatton, J. V. Debarking wood losses and chip quality of deadwood; spruce budworm-killed softwoods in New Brunswick. Tappi 61(12); 43-46; 1978. Hatton, J. V. Utilization of deadwood in pulping: current studies on the processing of spruce budworm-killed balsam fir. Pulp Pap. Can. 2(3); 81-91; 1981. Hiscock, H. I.; Hudak, J.; Meades, J. P. Effect of sap rot on pulping properties of balsam fir killed by the eastern hemlock looper in Newfoundland. Info. Rep. N-X-161. St. John’s, NF; Canadian Forestry Service, Newfoundland Forest Research Centre; 1978. 41 p. Hogan, H. E.; Madding, R. P. Digital analysis of Landsat data for detection and mapping of spruce budworm infestation. lES Rep. 103. Madison, WI; University of Wisconsin, Environmental Monitoring and Data Acquisition Group, Institute for Environmental Studies; 1979. 32 p. Hudak, J.; Raske, A. G., eds. Review of the spruce budworm outbreak in Newfoundland—its control and forest management implications. Info. Rep. N-X-205. St. John’s, NF; Canadian Forestry Service, Newfoundland Forest Research Centre; 1981. 280 p. Hunt, K.; Hatton, J. V. Predicting the kraft pulping behavior of decayed pulpwood. Pulp Pap. Can. 80(3): 55-57; 1979. Karpinski, C., Jr.; Witter, J. A. Plot size and number of plots needed to assess spruce budworm impact. Can. J. For. Res. 12; 332-336; 1982. Kleinschmidt, S. M.; Baskerville, G. L.; Solomon, D. S. Reduction of volume increment in fir-spruce stands due to defoliation by spruce budworm. Res. Pap. Fredericton, NB; Faculty of Forestry, University of New Brunswick: 1980. 37 p. Knox, S. Aerial evaluation of damage from spruce budworm attack in New Brunswick; new methodology. Tech. Rep. 80/T/03. Fredericton, NB: Forest Protection Ltd.; 1981. 11 p. Lawrence, R. D.; Houseweart, M. W. Impact of the spruce budworm in the Maine spruce-fir region, 1975-1979. Res. Bull. 3. Orono, ME: University of Maine, Cooperative Forestry Research Unit; 1981. 106 p. Leckie, D. G.; Gougeon, F. A. Assessment of spruce budworm defoliation using digital airborne MSS data. In; Proceedings of the 7th Canadian symposium on remote sensing; 1981 September 8-11; Winnipeg, MB; 1981; 190-196. Lee, T. H.; Field, D. B. Degrade and decay of spruce-fir timber following spruce budworm attack—a review. CFRU-lnfo. Rep. 2. Orono, ME; University of Maine, School of Forest Resources and Maine Life Sciences and Agricultural Experiment Station; 1978. 46 p. MacLean, D. A. Vulnerability of fir-spruce stands during uncontrolled spruce budworm outbreaks: a review and discussion. For. Chron. 56: 213-221; 1980. MacLean, D, A. Impact of defoliation by spruce budworm populations on radial and volume growth of balsam fir; a review of present knowledge. Wien, Austria: Mitteilungen Der Forstlichen Bundesversuchsanstalt 142: 293-306; 1981. MacLean, D. A. Vulnerability rating of forests in New Brunswick and Nova Scotia to budworn attack. Info. Rep. M-X-132. Fredericton, NB: Canadian Forestry Service, Maritimes Forest Research Centre; 1982. 21 p. MacLean, D. A.; Ostaff, D. P. Sampling size precision relationships for use in estimating stand characteristics and spruce budworm caused tree mortality. Can. J. For. Res. 13; 548-555; 1983. 62 McCarthy, J.; Olson, C. E., Jr.; Witter, J. A. Evaluation of spruce-fir forests using small-format photographs. Photogram. Engin. Remote Sens. 48: 771-778; 1982. McCarthy, J.; Olson, C. E., Jr.; Witter, J. A. Assessing spruce budworm damage with small-format aerial photographs. Can. J. For. Res. 13: 395-399; 1983. Miller, C. A. The feeding impact of spruce budworm on balsam fir. Can. J. For. Res. 7: 76-84; 1977. Mog, T. P.; Witter, J. A. Field techniques for assessing the impact of the spruce budworm (Lepidoptera: Tortricidae) in Michigan’s Upper Peninsula. Great Lakes Entomol. 12: 213-218; 1979. Mog, T. P.; Lynch, A. M; Witter, J. A. Impact of the spruce budworm (Lepidoptera: Tortricidae) on the Ottawa and Hiawatha National Forests, 1978-1980. Great Lakes Entomol. 15: 1-24; 1982. Montgomery, B. A.; Simmons, G. A.; Witter, J. A.; Flexner, J. L. The spruce budworm handbook: a management guide for spruce-fir stands in the Lake States. Handbk. 82-7. East Lansing, Ml: Michigan Cooperative Forest Pest Management Program; 1982a. 35 p. Montgomery, B. A.; Witter, J. A.; Simmons, G. A.; Rogan, R. G. The spruce budworm manual for the Lake States. Tech. Man. 82-6. East Lansing, Ml: Michigan Cooperative Forest Pest Management Program; 1982/?. 66 p. Morrison, D. J. Armillaria root disease. A guide to disease diagnosis, development and management in B.C. Info. Rep. BC-X-203. Victoria, BC: Canadian Forestry Service, Pacific Forest Research Centre; 1981. 15 p. Murtha, P. A. A guide to air photo interpretation of forest damage in Canada. Publ. 1292. Ottawa, ON: Canadian Forestry Service; 1972. 63 p. Olson, C. E., Jr.; Sacks, P. J.; Witter, J. A.; Bergelin, L. A. Spruce budworm damage assessment with 35 mm air photos: a training manual. Rep. 82-1 A. Ann Arbor, Ml: University of Michigan, School of Natural Resources, Remote Sensing Laboratory; 1982. 41 p. Ostaff, D. P. Wood quality of dead and dying balsam fir—the incidence of armillaria root rot. MFRC Tech. Note 82. Fredericton, NB: Canadian Forestry Service, Maritimes Forest Research Centre; 1983. 3 p. Ostaff, D. P.; Newell, W. R. Spruce mortality in Nova Scotia caused by the spruce beetle Dendroctonus rufipennis Kby. Info. Rep. M-X-122. Fredericton, NB: Canadian Forestry Service, Maritimes Forest Research Centre; 1981. 8 p. Piene, H. Effects of insect defoliation on growth and foliar nutrients of young balsam fir. For. Sci. 26: 664-673; 1980. Redmond, D. R. Mortality of rootlets in balsam fir defoliated by the spruce budworm. For. Sci. 5: 64-69; 1959. Reeves, R. G., ed.-in-chief. Manual of remote sensing. Falls Church, VA: American Society of Photogrammetry; 1975. 2144 p. Sanders, C. J. A summary of current techniques used for sampling spruce budworm populations and estimating defoliation in Eastern Canada. Info. Rep. O-X-306. Sault Ste. Marie, ON: Canadian Forestry Service, Great Lakes Forest Research Centre; 1980. 33 p. Schoeneweiss, D. F. Predisposition, stress and plant disease. Ann. Rev. Phytopathol. 13: 193-211; 1975. Schooley, H. O. Effects of spruce budworm on cone production by balsam fir. For. Chron. 54: 298-301; 1978. Schooley, H. O. Damage to black spruce cone crops by the spruce budworm. Info. Rep. N-X-187. St. John’s, NF: Canadian Forestry Service, Newfoundland Forest Research Centre; 1980. 15 p. 63 Sinclair, S. A.; Garrett, B.; Bowyer, J. Potential lumber grade yields from balsam fir and spruce budworm killed balsam fir. Timber Prod. Bull. April-May 1981: 10-11. Sinclair, S. A.; Barnes, D. P.; Govett, R. L. A preview of balsam fir utilization research. North. Logger Timber Proces. 30(7): 16-28; 1982. Stage, A. R. Prognosis model for stand development. Res. Pap. INT-137. Ogden, UT: U.S. Department of Agriculture. Forest Service, Intermountain Forest and Range Experiment Station; 1973. 32 p. Weed, D. Spruce budworm in Maine: 1910-1976 infestations and control. Augusta. ME: Maine Department of Conservation. Maine Forest Service; 1977. 100 p. Whitney, R. D. Root rot of spruce and balsam fir in northwestern Ontario. I. Damage and implications for forest management. Info. Rep. O-X-241. Sault Ste. Marie, ON: Canadian Forestry Service, Great Lakes Forest Research Centre; 1976. 49 p. Whitney, R. D. Root rot of spruce and balsam fir in northwestern Ontario. 11. Causal fungi and site relationships. Info. Rep. O-X-284. Sault Ste. Marie, ON; Canadian Forestry Service, Great Lakes Forest Research Centre; 1978. 42 p. Wykoff, W. R.; Crookston, N. L.; Stage, A. R. User’s guide to the stand prognosis model. Gen. Tech. Rep. INT-133. Ogden, UT: U.S. Department of Agriculture. Forest Service, Intermountain Forest and Range Experiment Station; 1982. 112 p. 64 Chapter 5' iSliK.f |i '-i;.; ' ' •- ■ V,'-' ■'•■,. .» tV .>'iT'‘; r^;'- ■•-:■; i, ■'■• V-' :.; •:,.4V’ ,0 ■«.* .0 •.. t’ '.'••■ ■ .-'m,;'•'■■• ^; - ; v :■ - ^•• ^ ’ ,’,. ■•>--i’. '•■••■■'''■ . ,• i'fT • .• \j->’ Economics of Spruce Budworm ManageiiwnC§trhte . ;i5S® Lloyd C. Irland and Kenneth L. Runyon' ' State Economist for Maine. Augusta, Maine; and Economist, Maritimes Forest Research Centre, Fredericton, N.B. Property Already Infested Budworm management practices, like any forest practice, must pass tests of financial, technical, and logistical feasibility. This chapter outlines a systematic approach to developing and analyzing sound management strategies for private or public lands. Because of the vast diversity of resource conditions and markets, you will have to tailor the actual strategy employed on your land. No one else can construct a sensible management plan for you. Lack of relevant pest management experience and data precludes our treating the interesting case of long-term silvicultural management (see chapter 6). Preventive management would include planning and actions to decrease the probability of future outbreaks and, in the event of an outbreak, to minimize its adverse effects. So this chapter deals primarily with the problems faced by a manager in developing a management strategy for a large property that is already infested and suffering mortality. Most of the management decisions to be made entail risk: no one can assure you that every management practice will work precisely as planned. While we are writing with land managers—public and private—in mind, we hope that pest management specialists will find these ideas useful also. 66 Strategic Decisions This chapter emphasizes making strategic decisions about the forest. In our view of budworm management strategy, the manager first identifies the available response options. This requires simultaneously identifying the critical constraints that must be met by the options and by their outcomes. Usually, constraints will be reexamined several times as decisions are refined. Finally, the manager selects a management program—a mix of specific tasks and treatments scheduled over time—from the available alternatives. Techniques for carrying out financial calculations to compare options are well described elsewhere. We do not discuss the impact of tax considerations on decisionmaking. After obtaining professional tax advice, each landowner should estimate the additional impact of tax considerations on these decisions. There are several different groups or classes of land managers. These include Provincial and State governments, large private owners with processing facilities, large private nonindustrial owners, and small-woodlot owners. Objectives, alternatives, and criteria for choice differ substantially for each group. For example, governments are generally concerned with maintaining or expanding employment and incomes for society at large. Private industrial companies are guided by their desire to profit from timber growing and processing. Nonindustrial owners cannot appropriate benefits from processing; therefore, their interest is in returns from timber sales. Management alternatives available and costs vary by size of ownership. Small-woodlot owners cannot use chemical insecticides in many areas because of environmental or health regulations. High costs may keep the same owners from applying biological treatment. The large landowner with thousands of acres to treat may be able to apply sophisticated combinations of chemical and biological control. Definition of an Economic Pest Spruce budworm is a native insect that causes heavy mortality of spruce and fir over large areas in a short time. This tact alone does not make the insect an economic pest. Across the range of fir and spruce in North America, there are large regions, generally in mid-continent, where the fir resource occurs in scattered stands or in mixtures and is being harvested at a low rate due to lack of market demand. Limited areas in Quebec, New York, and New England also fit this description. In all these areas, spruce budworm is not an economic pest now. But in northern Maine, the Gaspe, and most of the Atlantic Provinces, different conditions exist. In the Northeast, much of the total resource is fir and spruce, these species loom large in the annual wood consumption, and, in some areas, the current spruce-fir harvest exceeds the long-term potential yield under present management practices. Because markets have not developed for them, the other species of this vast region are often underutilized. In addition, forest products industries are the backbone of the rural economy in the Northeast. For these reasons, extensive and costly spray programs have been undertaken since the 1950's. These efforts have succeeded in maintaining a living forest and thereby retaining options for the future. In this short review it is impossible to account for all of the diversity within this vast area. In the later examples, conditions in the Great Lakes and Maritime regions are depicted; but the closing illustrative example deals only with the Maritimes, to save space. 67 Economic Impact of Spruce Budworm Spruce budworm damage affects management decisions at two levels: the treatment of the individual stand, and the management strategy for the entire property (see chapter 3). This section considers stands of high spruce-fir composition; our general remarks may not be applicable in stands or regions where spruce and fir make up halt ot the stocking or less. Individual Stand The economic impact of budworm on the individual stand has two dimensions: its impact at a point in time, and its impact over time. Although risk ratings have been deVised, predicting the ultimate level of losses in a given stand is not a precise matter. For this section, we ignore this uncertainty. The ultimate level of loss will depend on spray history, site characteristics, stand vigor, age, fir stocking, and perhaps random factors. Budworm-caused mortality is often patchy and discontinuous, so that a mapped stand may contain areas of widely differing tree condition. Figure 5.1 schematically illustrates typical loss histories, based on studies of budworm damage. In a sense, the comparison with yields of undamaged stands is artificial and overstates losses, since in our scenario over time there will be no unattacked stands. Even the most vigorous spraying program cannot keep stands on that hypothetical undamaged growth curve once defoliation has begun. In fact, it can be argued that the conventional concept of “growth loss" is really an illusion based on hypothetical rather than actual growth relationships in nature. While growth reduction is a highly significant effect of budworm feeding, reduction will occur naturally in undisturbed stands. Feeding, however, speeds up this process. The figure shows that in stands of low vulnerability, net growth ceases soon after heavy feeding starts, but decades later the initial level of volume is recovered or exceeded. In highly vulnerable stands, the merchantable volume may soon fall to zero. Net merchantable volume per acre Figure 5.1 —Impact of budworm damage on unsprayed individual spruce-fir stands (schematic). Most mature spruce-fir stands already contain a high volume of dead and moribund wood, due to their extreme overstocking. Mature stands also sustain continued blowdown and normal mortality of suppressed trees. This mortality is in addition to butt rot on some sites, and simple aging that brings fir stands into overmaturity and breakup after age 50 to 60. Budworm damage simply accelerates the process of volume decline. The fact that stand vigor may be weakening before attack complicates silvicultural management responses. In the early years of defoliation, budworm impact is visible mainly in the accelerated death of suppressed and intermediate trees. Many of these are not of economic value and would be smashed or left behind in logging. It is not uncommon for mature spruce-fir stands to contain 5 cords or more per acre (31.5 mVha) of small material, some dead. As the merchantable trees begin to dry out, die at the tops, and succumb, the economic losses arise. In highly vulnerable stands, economic value will plunge rapidly after the dominants and codominants begin to die (4 to 7 years after onset of heavy defoliation). In immature stands, a somewhat different picture appears. Common wisdom has held that mortality in “young” stands (age 10 to 40 years) will be tolerable, and even may provide a free heavy thinning. But 68 Identifying Response Options enough counterexamples exist that we must regard young pure-fir stands as highly vulnerable. Until this issue is clarified, we cannot recommend precommercial treatments in such stands. Because the interval before harvest is so long, spraying can be considered only if the organization places an extremely high value on future fir harvests. Where specific policy considerations dictate, however, such stands might be treated. A Large Forest Property The spruce budworm is the key natural factor responsible for the general uniformity of age classes over a large area. Because the budworm imposes a rapid reduction in spruce-fir growing stock over a short period, the insect hinders the manager's ability to achieve three critical management objectives: 1. Maintain a steady annual flow of spruce or fir timber. 2. Maintain a high level of tree size and quality. 3. Achieve, over time, a regulated distribution of spruce-fir age classes that will maximize long-term productivity. The economic impact of budworm damage on a forest property depends on many factors. The most critical are 1. Mix of host stands by age class, condition, and stocking; 2. Proportion of the forest area that consists of host stands; 3. Expected severity of future mortality and growth reduction; and 4. Current and expected growth-cut ratio for host species. These factors vary across the spruce-fir region and among individual properties in a given area. In addition, the seriousness of these conditions depends on the revenue and wood supply constraints and options facing each manager. For two adjacent properties with identical forest conditions, there might be quite different budworm management strategies. Efforts to cope with budworm damage may impose costly disruptions on plans for roads, logging camps, and other facilities. Finally, the costs of spraying will have a major impact on the land management budget. The balance of this chapter describes our suggestions for developing sound strategy to master these difficulties. Before you can devise a management strategy, you must identify a list of response options. These need to be appraised for technical, logistical, and financial feasibility. When this analysis is complete, you will have screened out the obviously inapplicable approaches to the problem. We cannot specify in this manual all of the particular outcomes and costs for the different conditions under study. Foresters need to consider past experience, consult with local experts, and use common sense to estimate current conditions and predict future trends in wood requirements and forest condition. Many of the appraisals made in this process will carry a high degree of uncertainty and will result in decisions with high inherent risk. For example, there can be no guarantee that a damaged stand will not blow down after a partial cut, or that a spray treatment will provide the hoped-for result. In assessing options, managers must make some provision for escalating costs due to inflation, and for the possibility that stumpage value may not rise apace with costs. The key principle throughout is to select that strategy that (1) yields maximum improvement in the future yield and net present value of the property; and (2) meets the constraints on timber flow, budgets, and other factors set by management. During and after an outbreak, a typical large property will yield far more dead and moribund wood than the manager can salvage before it rots. This means that all treatments (harvest, spray, salvage) must be applied only to the most productive sites. Since few properties possess precisely delineated site class maps, foresters will have to make judgments about targeted treatments on the ground. The definition of “most productive sites” varies for each property, based on commonsense evaluation of the overall situation. This rule of concentrating on the best sites is meant as a guideline and a test of actual plans; like all of our other guidelines, it will conflict with constraints and at times with other objectives. Nonetheless, managers looking at the long-term productivity of their property should continually return to it as the basis for their strategy. The rule of most productive sites also applies to all harvesting, because there will be far more trees to cut than can be handled. Harvesting—clearcut or partial cut—is the best means of controlling future stand development and hence should not be wasted on low sites or low-value stands. 69 Table 5.1 —^Stand treatment options for budworm-infested fir Stand treatment alternative Costs Comments Abandon None Unless a cost is attached to elevated fire hazard Harvest/salvage and regenerate a) Salvage dead, dying stands. 2% to 10% higher logging cost than undamaged timber, but wood is worth less Cost increase depends on timber condition, local factors, mill technology. b) Presalvage—cut damaged stands before dead. Small—depends on local conditions of incremental cost c) Sell damaged wood at discount. None Revenue lost is an illusion. d) Natural regeneration. Accept it. Herbicides to release None $50/acre ($ 124/ha) May be acceptable. May be required to meet spruce-fir harvest constraints. e) Release established understory regeneration. None f) Site preparation, plant, and herbicide release $100 to $300/acre ($247 to $741/ha) Avoid whenever possible. Partial Cut a) Fir-only cuts Higher logging cost All are risky. Cover more acres b) Shelterwood, timber stand improvement, or other commercial harvest Higher logging cost May help avoid brush stage Marketing and process changes Costly Require long-term perspective. The facts on future fir supply and product markets will determine these. Spraying $6 to $ 15/acre/year ($15 to $37/ha/year) Costs will equal or exceed values of annual growth, but spray is the only means of treating large areas. Anticipatory treatments Applicable only if outbreak is judged to be a decade or two away a) Block clearcut young thicket. Low yields per acre Consider, especially where energy chip market permits. b) Space and thin in favor of spruce. $100 to $200/acre ($247 to $494/ha) Future yield benefits c) In planting, avoid the most vulnerable spruces. Risky; yield may be lower. Modify harvest schedules a) Accelerate fir harvest. Depends on roads and markets b) Compensate by reducing cut of other species. Dpends on markets and mill requirements Acquire pest management information a) Air photos and mapping $0.10 to $0.15/acre ($0.25 to $0.37/ha) b) Larval, egg-mass, and tree condition surveys $0.15 to $0.25/acre ($0.37 to $0.62/ha) 70 To meet special needs or constraints, you may harvest or treat low-site lands, but you should recognize that each acre so treated represents a lost opportunity to treat a more productive acre elsewhere. One obstacle to focusing treatments only on high-site land will normally be the cost and organizational difficulty of completing roads to all of that land. In addition, proximity to mills or the infeasibility of fine tuning treatments may lead you to deviate from the general rule. The fact that dead fir stumpage will be available in excess of the capacity to use it means that its true economic value to the landowner is zero. To the manager, a resource like dead and dying fir that cannot possibly be exhausted is essentially a free good. It has no economic value if it cannot be used. If dead trees remained useful for decades, then they would have a positive value. But since they decline in usefulness in a few years, however, such trees have no opportunity cost or value to the organization. For this reason, they may be sold at a discount, abandoned, or otherwise handled in a way that does not call for the same stumpage return required of healthy timber. For this reason also, efforts to keep fir alive by spraying or other means must be justified by critical harvest schedule constraints or long-term considerations. One example is a mill that requires a minimum volume of green fir, when costs of converting it to use other species are prohibitive. Such conditions exist on some properties, especially in the Maritimes. Finally, the zero value of dead fir—harvestable or not— means that management choices must be made on the basis of whatever future stand can be retrieved from a given situation, and on the basis of site conditions. Other things being equal, rational managers will go past dead and dying stands on poor sites to attend to promising opportunities on the best sites. Table 5.1 lists options with brief annotation. It must again be emphasized that no general guides can be given: local experience, expertise, and judgment must be employed throughout. Abandon All host acres with unmerchantable stocking should be abandoned, not sprayed or otherwise treated. Consideration should be given to going beyond this and abandoning all fir and spruce on all of the lowest site acres on the property. A rule occasionally advocated is to abandon all stands that cannot or will not be cut within 5 to 10 years. Such a rule may result from a careful analysis but should not be assumed at the outset. As discussed earlier, abandonment costs nothing. In some stands (fir mixed with nonhost spp.), growth in surviving trees over a decade or two will fully restore the lost volume and more, though not always in the desired species. Planned abandonment can materially simplify the structure and reduce the awesome scale of the budworm problem facing the manager. Abandonment may pose a threat from fire. In the Great Lakes region, budworm damage increases fire risk and raises the hazard of a serious fire once one has started {see chapter 4). Information is not as definitive for other geographic areas. Managers have to determine fire hazard by consulting with local fire-control experts. Harvest and Regenerate In the early stages of a serious outbreak, there is an understandable temptation to try to salvage all damaged stands. A few years’ experience is sufficient to demonstrate the folly of such an effort. Experience has shown that the areas in need of presalvage shift yearly, based on changes in the infestation and in spray programs. As it becomes impossible to keep up with these shifts, and becomes clear that total losses will outrun salvage capacity anyway, managers search for more sensible strategies. Efforts to salvage all stands can be optimal only under extremely limiting conditions, conditions that probably cannot be achieved in the real world: (1) an aggressive spray program is judged financially feasible; (2) a firm commitment of 10 to 15 years to such an eflort exists; (3) it is anticipated that virtually complete protection can be achieved so that salvage volumes will be small and hence all timber can be used. Under these conditions, the pileup ot dead wood could be held to reasonable levels. 71 It has even been argued that dead trees should never be cut, since only by cutting living trees can any impact be exerted on budworm habitat and on future treatment costs. Refusing to cut dead trees may sound extreme, but managers should nunind themselves that dead wood costs more to cut and is worth less at the mill. Salvage may not make sense even in the short run. Few managers will be able to cut on as much as one-third of their property in the critical first decade. To the extent possible, then, they should harvest stands on high- productivity sites and the most valuable stands. The most attractive prospects are those where overstory removal will release established natural regeneration. In some areas, such stands are uncommon due to overstocking and to budworm damage to seed crops of preferred species. If dead and damaged wood can be sold—even at deep discounts—without simply competing with green timber, then it should be done. Developing new markets for energy chips or pellets may be worthwhile. It remains to be seen to what extent waferboard plants will be able to use such wood. Again, harvesting dead wood for sale should occur on the best sites only. In the Lake States, fir commonly occurs in mixture with aspen and other species. Clearcutting these stands will usually yield a fully stocked hardwood stand from sprouts. Over time, a fir understory will become established; this can be grown to maturity, if desired, after harvesting the hardwood. In most of the spruce-fir region, progress is being made in devising systems for artificial regeneration. These will include site preparation as needed, improved planting stock, and herbicide or other treatments to control competing vegetation. It is not easy to predict total costs in advance, but they can reach $200 or more per acre ($494/ha). Therefore, artificial regeneration should be used only on the best sites or where erosion or esthetic considerations dictate rapid reestablishment. In heavily damaged stands, managers should provide larger-than-usual uncut or protective buffer strips for streams, an inexpensive option. Larger buffer strips also reduce erosion into streams. Artificial regeneration should be handled in terms of the general plan for the property. In many areas, planted stands will fill with fir volunteers anyway; later treatments to deal with overstocking should be anticipated. Properly implemented, planting and culturing new stands on the best sites will improve the long-term potential yield significantly and, by shortening rotations, may accelerate the achievement of a balanced age-class structure. Partial Cuts Partial cutting in budworm-damaged stands is a potentially useful but risky practice that still excites debate among foresters: Disadvantages Risk of increased windthrow in residual stand Lower volume per acre cut; somewhat higher logging cost Greater expense in sale preparation and logging supervision May require more new roads than clearcuts Often too few spruce or nonhost trees are present to retain a windfirm or well-stocked stand. No guarantee that residual spruce stands will survive further budworm feeding Advantages Can cover acres faster Can store spruce on the stump at least a few years May improve spruce representation in regeneration Helps avoid brush stage that normally follows clearcutting—potential saving of $200-1-/acre {$494/ha) (without interest) v. artificial regeneration In mixed stands, reducing fir stocking can reduce vulnerability of remaining trees. Foresters will have to evaluate and balance these advantages and disadvantages in setting prescriptions for fir-only, shelterwood, or other partial cuts in spruce-fir stands. In so doing, several larger points should be considered. For example, in a well-advanced outbreak, each cord of spruce cut is a cord of fir that will rot, since time and markets will not allow the harvest of all mortality. Secondly, covering more acres and avoiding artificial regeneration costs may have enough value to justify taking risks with residual stands. 72 Marketing and Process Changes These can be costly and complex, and describing them is beyond the scope of this chapter. Clearly, adjusting marketing goals or production processes is worth undertaking only if a significant 5- to 10-year reduction in supply of green fir is critical to the financial survival of a mill. Under such conditions, which are probably the exception rather than the rule, marketing and process changes, to a point, will be competitive with spraying. Spraying When it is necessary to protect a large acreage of host forest over many years, spraying is the only available alternative. But managers considering spraying must face the following facts: 1. Spraying should not be considered unless a commitment of 5 years or longer to a program can be made. No one can predict how many treatments will be needed over how long a period, but we do know that a year or two of treatment is likely to be worthless. 2. Spraying will cost from $6 to $ 15/acre ($15 to $37/ha) for annual treatment. Costs may be held to the lower end of the range if aircraft are readily available, if low-cost chemical insecticides are used, if the total project is large, and if airbases can be located within 5 to 10 miles (8 to 16 km) of spiay blocks. To the extent that these conditions cannot be met, costs will approach or exceed the $ 15/acre figure {see table 7.2). 3. In Maine, spraying costs have risen 20 percent per year, or faster than timber prices. Until a serious drop in the inventory has an effect on stumpage prices, this trend will continue. By 1990, it could cost more than $30/acre ($74/ha) to spray for budworm; however, costs for some treatments (e.g., B.t.) are being reduced significantly. 4. A trained organization to handle spray projects must be developed. For a substantial long-term commitment, acquisition of equipment, airstrips, and even aircraft may be warranted. This part of the effort is normally, but not always, carried out by State or Provincial agencies. In view of these costs, spraying should be prescribed only where the following conditions are met: 1. Timber will not be cut for 2 to 5 years but will be required in years 5-20. 2. Substituting other species for fir can be done only at very high costs in market and mill process changes. 3. The “strategic” benefits of retaining an inventory of owned wood are substantial. The high cost of spraying requires that treatment blocks be carefully selected on the basis of site quality, future growth potential of the current stands, location relative to mills, fir stocking per acre, and other considerations. With the unbalanced, mature age-class distributions common today in spruce-fir forests, it is unrealistic to attempt to protect the entire inventory. Given fir’s short life expectancy, total protection cannot be achieved. Analysis usually shows that a higher annual yield can be obtained from a smaller inventory with a better age-class distribution. But with the cost of spraying at its present level relative to timber values, it is not economically feasible to achieve a regulated condition in less than one rotation. Anticipatory Treatments Even in the midst of an outbreak, managers should consider several anticipatory treatments. These should be applied in younger, overstocked stands with strong spruce components ranging in age from 5 to 40 years. Because of the cost and risks of anticipatory treatments, most managers will be able to apply them only on a limited scale, where budworm risks seem lowest. Precommercial thinnings in overstocked stands can cost upwards of $ 100/acre ($247/ha). They may reduce—not eliminate—vulnerability to budworm by reducing fir content; they will speed growth in merchantable volume and may advance the age at which treated stands can be cut. Thinning in very young stands has dramatic benefits in improving future merchantable growth and may also be used to reduce fir stocking. In many areas today, past underutilization of fir means that there are few stands that present these treatment opportunities. One valuable side benefit of such a program is that it will help motivate the buildup of crews, machines, and experience in treatments which will be important in the future. 73 Cost of Pest Management Functions Modifying Harvest Schedules When a major budwoim outbreak looms, it is natural and appropriate to increase the harvest of fir and spruce. In the past, inadequate markets have prevented most managers from accelerating harvests in anticipation of a budworm outbreak. Mill capacity and markets constrain efforts to accelerate fir harvest. The technical ability to substitute fir for other species depends on the processes being used and products being made. Though one company has added a sawmill and waferboard plant, few organizations can be expected to make such expensive alterations. An increase in fir cut can have the negative outcome of reinstituting an unbalanced class distribution for the future, but the short time available for salvage limits this problem. Budworm-caused mortality itself is the cause of the imbalance—cutting will not make it worse, but can only improve the situation. In the future, we can expect better markets and the chance to cut stands at younger ages, so that current overcutting need not perpetuate a serious, long-term imbalance. If possible, the harvest of any long-lived species (e.g., spruce) that can later substitute for fir should be reduced during the postoutbreak period. Of course, the alternatives for modifying harvest schedules depend on the initial age-class structure, on the level of cut in relation to long-term potential yield, and on possibilities for product substitution. To identify and evaluate response options, land managers must have information on the vulnerability of stands to growth loss and mortality (see chapters 4 and 6). Managers need to know stand characteristics and conditions as well as current and projected budworm population levels. Of course, this information is obtained on an ongoing basis and not just after an outbreak. Characteristics such as species composition, stocking, and age may be available from conventional inventories, but in general, the detail is not sufficient to predict stand vulnerability. Particularly critical are data on the proportion of host species (i.e., balsam fir, the spruces), stand structure (the distribution of species and volumes by dominance), and age or maturity class. Large-scale (1:10,000-15,840) color or infrared aerial photography appears to be the most reasonable approach, but at present this is done mainly on an experimental basis. Costs for photos, interpretation, and mapping currently range from $0.10 to $0.15/acre ($0.25 to so.40/ha) for areas of about 2 million acres (809,400 ha). For small, high-value properties, a larger photo scale might be desirable, but costs are higher. Stand condition or vigor is generally classified by the amount of growth loss, top-kill, and mortality. Condition changes from year to year, as a function of the intensity and duration of defoliation. It is also affected by soil moisture, site quality, and inherent vigor of the trees. Monitoring or damage assessment is most often done by aerial survey followed by ground checks. Large-scale color photography may be used, but annual photo expeditions can be expensive for large areas. Damage survey costs are difficult to estimate because these surveys are often conducted as part of operational cruises or in conjunction with egg-mass surveys. Current and projected budworm population levels are based on egg-mass surveys in late summer followed by larval sampling in winter and early spring. Damage assessment and insect population data are then used to prepare stand hazard ratings to help managers select harvesting and spray treatments. Costs for surveying aerial defoliation, egg-mass deposition, and tree condition, and analyzing data vary considerably by methods and size of area. A rough approximation would be $0.15 to $0.25/acre ($0.37 to $0.62/ha) for areas over 1 million acres (404,700 ha). (For more detail on survey and detection costs, see chapter 3.) In addition, costs for environmental monitoring must be included as a management function. 74 Evaluating Alternative Strategies Since most land managers face one or more conditions that limit a sophisticated financial analysis, it is useful to set out a commonsense approach to developing a strategy. Sometimes it is feasible to develop for a given property harvest scheduling models that will enable managers to prepare estimates of present net worth which will be useful for decisionmaking (see appendix 1, table 1). In general, however, such modelling is not being done, for the following reasons. First, policy constraints as to harvest level, budgets, or pesticide use may dominate all other considerations. Second, there are insufficient data on the timber resource, its age structure, and its response to budworm damage with and without control methods applied. The analysis would thus be no better than the assumptions needed to fill these gaps. Third, the necessary guesswork on appropriate treatment costs, market alternatives, and interest rates lends an air of unreality to a sophisticated financial analysis. Finally, staff capability and budgets may limit the preparation of these analyses. Our approach consists of guidelines on the realistic valuation of losses and the cost of protecting growth, and a set of criteria for comparing alternative plans. It is illustrated by an application to a hypothetical forest. Valuation of Losses The first principle is to use care in valuing losses. It is tempting to value all potential losses at current stumpage rates. This is misleading for several reasons; 1. Much of the lost volume is not salvageable due to stocking or roading constraints. Such timber should be valued at zero on the stump. 2. The sheer volume of timber likely to die without spraying means that much of it cannot be cut before it decays beyond usefulness. For decisionmaking purposes, then, that standing timber is valued at zero since it can never be sold. The greatest benefit of spraying is precisely here—it raises the value of this timber from zero to some positive value. 3. Under particular conditions, stumpage values may not be the only consideration—roadside or delivered wood values may be applicable, but only rarely. 4. In some areas, all foreseeable needs for fir and spruce can be met even with no control program. Where this is true, the value of the lost fir and spruce is zero. 5. For some organizations, using the available substitutes for fir and spruce is extremely costly. In such a case, “shadow prices” for stumpage in excess of current market prices should be used.- Recall that you are valuing wood over decades into the future, during which entire mills and marketing strategies will be reconstructed. 6. For tax reasons or strategic reasons, a company may place a higher value on internally produced timber than the current market price level of purchased timber. 7. In some areas, it may be prudent to assume that the future real price of timber will rise significantly enough to change the cost-effectiveness of a given strategy. This may be due to expected long-term trends, or it may be due to the imminent opening of a new mill which will give value to currently unmarketable timber. Each manager must sift through these considerations to arrive at a sound basis for appraising losses and hence for valuing the timber saved by investing in treatments. The purpose of this step is to introduce a more realistic understanding of the true financial impact of budworm damage on the enterprise. Protecting Future Growth Potential There is a natural impulse to try to salvage dying and dead trees, so as to avoid “waste.” There is also an impulse to spray or otherwise treat stands with high volumes per acre, regardless of access, site, or other considerations. These impulses violate key economic principles. The thoughtful manager remembers that each dollar spent, or cord harvested, precludes some other use of that dollar or cord. The manager’s key constraints will always be the management budget and the harvest level. He or she will always wish to spend more or to cut more spruce-fir in the short run. But the mills or markets can consume only so much. In contrast, dead and dying trees are the most rapidly growing resource, and cannot all be used over time. Therefore, their true long-run value approaches zero. The manager must aim the chosen strategy at protecting the future growth potential of the property. Strategies that protect future potential (measured by age structure and stand condition) are usually more costly in the short run than strategies that maximize salvage of host wood in the short run. Nonetheless, salvage has its short-run direct costs too, in higher logging expenses and lower wood value. - Shadow prices are internally calculated prices that diverge from market prices to reflect ta,\. strategy, or other important constraints The argument that the value of dead fir is zero is the same as saying that its shadow price is zero. 75 It is easy to imagine strategies that successfully employ widespread spraying and intensive salvage and also succeed in reducing the future productive potential of a property. In fact, this has been done. Since the short-term financial pressures may be in this direction, managers must work hard to think of the long run. The short-run strategies will almost always be superior in traditional financial analyses. A manager interested in the long-run productivity of the property will need to deploy more sophisticated arguments to make the case. Criteria for Judging a Strategy Several simple criteria will assist in comparing alternative plans; 1. Does the plan meet the organization’s timber flow and other resource management constraints (e.g., wood quality, species mix)? 2. Is the plan financially sound—does it represent a responsible use of limited funds? 3. Can the plan be implemented under anticipated staff and logistical constraints? 4. Can you imagine another plan that is more attractive? 5. Test the constraints. Can you identify acceptable relaxations of constraints that would reduce the cost of coping with budworm? For example, if you can accept 10-percent reduction in fir harvest in the second decade, how does this affect the cost of the plan? 6. Calculate the cost of the plan per unit of wood saved from loss. Is this cost acceptable in relation to current costs and to expected conditions? 7. What effects will the plan have on future forest structure? 8. What is the loss if some key assumptions are proven to be mistaken? How sensitive is the plan to error in its data and assumptions or to changing conditions? 9. Social aspects. Are there aspects of this plan that will lead to conflicts with important outside constituencies? Can these be modified or can we “sell" the plan to those groups? Dealing with the Future No land management organization with a 5-year time horizon need ever worry about the budworm. A cut-out- and-get-out operator would simply accelerate the cut and depart—budworm would be a nuisance, but not a management problem. Long-Term Analysis —Dealing with the long-term impact of the budworm on the forest and on the time pattern of its output is the challenge for management. This requires that policy decisions be made about the acceptable future time pattern of fir and spruce output, about desired future forest structure (age class, species, condition), and about the acceptability of different response options. Computer models of forest structure can display the consequences of different strategies. Discount Rates —It is possible to condense all of these considerations into an analysis. But such an analysis requires so many assumptions as to be virtually untenable as a basis for decisions by senior management. The most serious difficulty is that such an analvsis requires choosing a discount rate to bring future costs and returns to a common point at the present. Today, strong private companies and the Federal Governments of the United States and Canada are borrowing at unprecedented interest rates. There is simply no point in evaluating budworm management (or other forestry) investments at the nominal rates implied by these conditions. It is possible to develop rationales for using low (3-percent to 6-percent) rates in the financial analysis, but a description of them would take us too far afield. Using discounted net present values at low rates like 3 percent to 6 percent can assist mangers in assessing the desirability of different plans. But we argue that such simplified financial criteria should be secondary to the broader, policy-oriented criteria discussed above. We feel this way because the budworm and the activities used to combat it are not marginal questions like the replacement of a pump or filter in a mill. The insect and management’s responses to it affect the entire structure of the forest and will affect the choices available to future generations of managers. Decisions of such scope cannot be collapsed into rankings of simple numbers. Such oversimplified analysis conceals uncertainty and obscures the true structure of the problem from senior decisionmakers. Example of Strategic Analysis: Maritimes Region To illustrate our approach, we show a hypothetical million-acre (404,700-ha) forest in the Maritimes region, which includes Maine. For the Maritimes forest, we illustrate key forest traits and develop a hypothetical strategic plan. The example is descriptive and judgmental, so you should not try to find the basis for every number in 76 it. The example does not illustrate any particular property or management strategy known to us. The strategy on your own property would differ based on wood requirements and other constraints. Costs and timber values are also hypothetical, but we feel they are representative of the conditions. In the Maritimes region and Maine, owners vary their approach from no-spray and extensive management, to intensive planting and thinning combined with spray, and all stops between. The example is worked out in tables 5.2, 5.3, and 5.4 with no further narrative comment. An alternative way to structure an analysis is by using decision trees. Many examples are available in the literature (notably Talerico et al. 1978). Table 5.2—Hypothetical Maritimes forest and budworm strategy screening approach' Conditions Developing options* 1. Acreage 1 ,000,000 1. Host acres to ignore for 2. Acres of spruce-fir budworm planning (stands with a. Total 300,000 <5 cords/acre in live fir) 50,000 b. With at least 5 cords/acre 2. Accessible acres on which in live fir trees 250,000 silviculture has chance to delay or 3. Acreage in which host composition is eliminate problem 100,000 a. Fir 75% to 100% 150,000 3. Total spruce-fir acres to be b. Fir 40% to 75% 50,000 harvested in 3 years c. Fir <40% 50,000 a. Current 50,000 4. Growth-cut ratio on spruce-fir b. Accelerate fir cut 70,000 a. Current 0.8 4. Acres in which spray not b. Expected 0.5 feasible or not allowed 5. Average net growth in spruce-fir in cords/acre (near settlements and water) 100,000 (in stands with 75% to 100% host material) 5. Acres in which salvage or a. Preoutbreak 0.3 silviculture not feasible 200,000 b. Current 0.0-0.1 6. Collating options 3-5, and c. Potential in managed stands conditions 1-6 gives on best sites 0.6 + a. Acreage suited for silvi- 6. Stumpage values (U.S. dollars) 10.00 cultural treatment 60,000 b. Acreage for presalvage or Depends on actual data salvage per year and judgment c. Acreage for spray per year Depends on actual data and judgment d. Annual acreage of green Depends on actual data timber to harvest in normal and judgment fashion * Notes on assumptions employed: 1. Acres below 5 cords/acre are deleted. 2, 3, 5, 6. Acreages are estimates used to illustrate contrasting conditions. ' For metric conversions, use these equivalents: 1 ha = 2.471 acres 1 cord = 2.55 m' 77 Table 5.3 —Tentative strategy for Maritime property. 5-year plan' Activity 1. Raise spruce-fir harvest from 20,000 to 25,000 acres/year by a. Selling more to others, even at distress rates b. Replacing other species at mills with spruce-fir 2. Silvicultural program a. Harvest selectively 5,000 acres/year for fir-only and other partial cuts in suitable mature stands b. Precommercially thin stands aged 40-60 on good sites to boost vigor, cut fir composition, and presalvage normal mortality (assume net wood value low). 1,000 acres/year c. Plant clearcut areas and nonstocked high sites with nonhost species. d. Space trees in stands age 10 or younger to reduce fir stocking and boost growth and vigor. Plantations and natural stands. 1.000 acres/year 3. Salvage a. Salvage stands only on high sites or where location, stocking or other advantages result in highly favorable current wood cost. Consider salvage where desirable for safety, fire risk, esthetic or other considerations. 4. Spraying a. Spray 20,000 acres/year of seed production areas, intensively thinned mid-aged stands and recently partially cut stands on high sites." b. Spray up to 200,000 acres of distant stands that cannot be cut in this planning period. Cost None. Will produce net revenue. Any needed discounts on stumpage will not be a true loss since trees will die anyway. Higher logging costs. $5/cord = $50/acre at 10 cords/acre cut rate = $250,000 total Net cost = SI00 +/acre Total $ 100,000/year Uncertain—only costs above normal planting effort are attributable to budworm. $150 + /acre Total cost $ 150,000/year Cost increase in dead, dying stands may = 10% of roadside cost, or $3.00/cord $6.00/acre Total = $ 120,000/year Assume 75% of these are treated on average each year = 150.000 acres (a)$6.00 = $900,000/year Total spray $1,020,000/year Comment Use to improve future age-class distribution and raise revenue to help finance silviculture and spray. By deferring or eliminating clearcuts, these treatments may save $100 +/acre in planting and regeneration cost. May also improve future age-class distribution. Not all treatments will succeed. Many owners are planting already and would have small incremental costs. Risky. These stands cannot be guaranteed against further attack. They may need to be sprayed. The marginal value of this wood to the firm may be zero; it costs more than green and is worth less. Why cut it? Won’t save on spraying. Policy decision Costs/acre may grow faster than wood values; the same outlay may need to be duplicated in the next 5-year period. ' For metric conversions, use these equivalents: 1 ha = 2.471 acres 1 cord = 2.55 m' - Not necessarily the same acres each year. In parts (a) and (b) of this e.xample. note that local experience may vary widely. The figure of 75% used in 4(b) is an estimate that seems reasonable for Maine conditions and is a prudently high figure chosen for a sound cost analysis. Overoptimistic land managers (and sprayers) have been frequently disappointed in the past. 78 Table 5.4 —Sample strategy analysis' Summary statistics Spray Silviculture Total Acres treated 170,()00/year (average) 7,000/year — Cost per year $1,020,000 Cost per 5 years $5,100,000 Cost per year a. per cord of spruce-fir cut (assume 200,000 cords) $5.01 b. per acre of total property $1.02 Present net worth, annual - cash flow profiles, and other calculations. Impact on age-class structure and allowable cut. $500,000 $2,500,000 $1,520,000 $7,600,000 $2.50 $7.51 $0.50 — as needed - $1.52 Qualitative Questions 1. Does this program provide maximum improvement in future forest structure and yield? 2. Do the silvicultural treatments offer other benefits not considered here? 3. Are these costs reasonable in relation to the long-term strategic benefits and to current costs? 4. Is this program administratively and logistically feasible? 5. What is the effect of the relaxation of each constraint used here? 6. Can you "sell" this to senior management and to outside constituencies? 7. What happens if some key assumptions are mistaken? 8. Can you invent a better plan? ' For metric conversions, use these equivalents; 1 ha = 2.471 acres 1 cord = 2.55 m’ 79 Special Cases The previous discussion deals with large forest properties managed for timber. There will be special cases in addition, in which specific constraints dominate decisions. While the basic principles for addressing these instances are the same, they call for brief comment. As before, this discussion assumes a current outbreak infesting mature or overmature host stands. Small Nonindustrial Forests Because of past owner indifference and poor markets, many small private woodlots in eastern Canada and the Northeastern United States are overstocked with mature fir and spruce. Trees are often in deteriorating condition with thin crowns, buttrot, and increasing windthrow. Often, the owners are unaware of the severity of budworm damage and have no long-term forest management goals for the properties. As a generalization, it is never profitable, in a private or social sense, to spray such woodlots, even ignoring nontimber dimensions of the problem. In these woodlots, all efforts should be made to facilitate marketing and salvage of threatened stands. Salvage is sensible for the small owner since the owner can sell all of the damaged wood, while a large owner cannot. The best advantage of small lots is that they are usually accessible. The stands should be cut in the most conservative fashion, to leave the largest possible residual growing stock volume per acre. If wind or other mischance damages residual spruce-fir, a return for salvage is easy. If small machines or horses are used, owners will be able to market a larger proportion of the wood, including the dead, than the typical large industrial owner. If the lot is principally spruce-fir, the owner may have to accept a long delay until the next harvest if the early salvage cuts are too heavy. It is on these tracts that the costs of decades of neglect are the most clear and visible. Seed Production, Research, and Amenity Areas There are small areas whose values are so high for seed production, research, or amenity that intensive protection is justified as a matter of policy. There may be no clearly measured value per acre of these stands, but in the judgment of responsible managers, they must be protected. The need is to protect future benefits, not past investments. In some portions of the budworm’s range, these are the only stands given intensive protection. Managers should be prepared for the possibility that very costly spray treatments may be required every year for an indefinite period. This fact justifies the inclusion of intensive silviculture, if appropriate, and even avant-garde methods such as harvesting buffers of nearby host trees, mass pheromone trapping, and inundative releases of parasitic wasps to assist in achieving foliage protection. Wilderness Areas An entirely appropriate management choice, often required by law or other binding policy commitment, is the nonuse of pesticides in wilderness areas and parks. In these areas, natural forces do their work unhindered. In the middle stages of an outbreak, managers may view such areas as sources of insects that will reinfest nearby sprayed stands downwind. This may in fact be true, until the trees in the wild area die. During that time, the uncontrolled infestations give scientists unparalleled opportunities to study the natural dynamics of budworm- forest interactions. Areas Where Pesticides Are Banned These areas pose the most difficult and costly choices. No-spray areas vary from carefully designated and well-justified buffer strips near sensitive streams and settlements to entire States and Provinces. Since it is impossible to salvage all of the budworm-caused mortality over any large area, the use of planned stream and settlement no-spray buffers represents a sound policy of taking losses near sensitive areas. The decision imposes zero real costs on the economy, though it certainly may complicate management for individual owners. Spray bans affecting whole States, however, represent a serious decision. Such bans remove the most cost-effective tool for dealing with many budworm-damaged stands simultaneously. Since these are public and not private decisions, they are beyond the scope of this discussion, but forest managers must assure that policymakers understand the consequences of not spraying for the forest. 80 Summary Selected References This chapter offers advice for developing a budworm management strategy for a large forest property.' Our discussion is addressed to land managers responsible for mature spruce-fir forests that have sustained heavy budworm damage, as is the case regionwide in the early 1980’s. Our analysis can be distilled into the following general recommendations: —The manager’s task is to develop a long-term strategy. Choices about spraying and silviculture should fit with long-term objectives and constraints for forest structure and output. It is not useful to apply detailed financial analysis to different treatments in individual stands. —Focus exclusively on the impact of alternative strategies on long-term forest productivity. Strategies that rank high in short-term dollar terms may actually reduce future long-run output, and may not minimize long-run cost. —Concentrate all treatments—spray, salvage, harvest, timber stand improvement—on the best sites, except where specific stand conditions offer high payoff opportunities to increase future growth, or where location or other factors dictate otherwise. —Think critically about placing values on future timber losses and on losses prevented. In most cases, managers will never be able to salvage all of the dead and dying wood, even if they mount an effective spray program. This means that the value of dead wood is effectively zero in the usual case. This fact can radically change the attractiveness of alternative strategies. —The manager’s scarce resources are management dollars for spray and silviculture, forester time, and outlets for wood. These scarce resources have many alternative uses in upgrading future forest output and condition. They can be squandered by pursuing illusory short-term cost savings. ' See references for some useful examples of previous analyses. * Baskerville, G. Report of the task force for evaluation of budworm control alternatives. Fredericton, NB: Province of New Brunswick, Department of Natural Resources; 1976. 210 p. * Baskerville, G. L.; Weetman, G. F. Forest management at Nova Scotia Forest Industries, Ltd. Case Study. In: F. L. C. Reed and Associates, Ltd. Forest management in Canada, Vol. IF For. Manage. Inst. Rep. FMR-X-103. Ottawa, ON: Canadian Forestry Service; 1978: 1-1 to 1-27. * British Columbia Ministry of Forests. Evaluation of the western spruce budworm problem in British Columbia. Victoria, BC: British Columbia Ministry of Forests; 1977. 153 p. Clark, W. C.; Jones, D. D.; Holling, C. S. Lessons for ecological policy design: a case study of ecosystem management. Ecol. Model. 7: 1-53; 1979. Crosby, John S. Guide to the appraisal of wildfire damages, benefits, and resource values protected. Res. Pap. NC-142. St. Paul, MN; U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station; 1977. 44 p. Hall, T. H. Toward a framework for forest management decision-making in New Brunswick. Rep. TR-78. Fredericton, NB; Province of New Brunswick, Department of Natural Resources; 1978. 83 p. Howse, G. M. Losses from control of spruce budworm and other insects in the boreal mixedwood forest. In: Canadian Forestry Service and Ontario Ministry of Natural Resources. Boreal mixedwood symposium, proceedings. 1981 September; Thunder Bay, ON. Ottawa, ON: Canadian Forestry Service; 1981; 239-251. Lawrence, R. K.; Houseweart, M. W. Impact of the spruce budworm in the Maine spruce-fir region, 1975-79. Orono, ME; University of Maine, Cooperative Forestry Research Unit; 1981. 106 p. * Starred items are excellent examples of the application ot strategic thinking and economic analysis to the budworm problem. 81 Marty, Robert. A guide to economic evaluation of spruce budworm management opportunities in the East. Agric. Handb. 627. Washington. DC: U.S. Department of Agriculture, Forest Service, Canada-United States Spruce Budworms Program; [in press]. * Mott, D. G. Spruce budworm protection management in Maine. Maine For. Rev. 13 (Summer): 26-34; 1980. (See also papers by Elwell. Swenson, and Corcoran in the same issue.) * Newfoundland Department of Forest Resources and Lands. Report of the Royal Commission on Forest Protection and Management. Part L St. Johns, NF: Department of Forest Resources and Lands; 1981. 114 p. Stedinger, J. Spruce budworm management models. Cambridge, MA: Harvard University; 1978. 351 p. Dissertation. Talerico, R.; Newton, C.; Valentine, H. Pest control decisions by decision-tree analysis. J. For. 80(1): 16-19; 1978. * Starred items are excellent examples of the application of strategic thinking and economic analysis to the budworm problem. 82 Chapter 6 Silviculture, Forest Management, and the Spruce Budworm . Barton M. Blum and David A. MacLean' TV'; ' Project Leader. USDA Forest Service. Northeastern Forest Experiment Station. Orono. Maine; and Research Scientist. Canadian Forestry Service. Maritimes Forest Research Centre. Fredericton. N.B. The prevention of a recurrence of the budworm is purely a question of forest management. Conditions must be developed that are least favorable to the enormous multiplication of this insect and least susceptible to injury so that future outbreaks can be rendered much less potent, and the losses reduced to a minimum. (Craighead 1924, p. 81). From the 1920’s to the present, management of the spruce-fir forest to alleviate the spruce budworm problem (fig. 6.1) has been a topic generating discussion, speculation, and research. The scale of management action required to effectively alter the spruce budworm/spruce-fir forest ecosystem is formidable in both time and space; managers must follow stands through a whole rotation and treat many stands over a large area. Because of these constraints, even the best suggestions of silvicultural treatments to reduce vulnerability have not been adequately tested. But most of the silvicultural techniques to reduce budworm damage are logical, and they often coincide with practices designed to achieve maximum yields. In this chapter, we summarize this topic, drawing upon many sources. We offer no apologies for not citing the work of many investigators, only grateful acknowledgments to all and the hope that we can condense their work into some meaningful, practical guidelines. Attitudes range from extreme pessimism to unjustified optimism regarding the potential for manipulating the forest resource to the detriment of the budworm and the benefit of people. Most budworm scientists agree, however, that (1) there definitely is a positive role for Figure 6.1 —Extcn.sive .spruce budworm damage in eastern Canada. 84 Vulnerability manipulating the forest resource in budworm management; (2) this role varies in detail from region to region, site to site, and among different severities of infestation; (3) bringing this role to fruition necessitates forest management of an intensity never before seen in the spruce-fir forest type; and (4) forest management and silviculture by themselves cannot be expected to eliminate the impact of the budworm on the resource. Implicit in this management scenario is a warning; we are dealing with an extremely complex system, and we must avoid the tendency to oversimplify. A problem with the management and silvicultural procedures we discuss in this chapter is that in no case can the results of these be quantified in terms of the expected reduction in vulnerability. Unfortunately, the state of our knowledge about the dynamic interaction between budworm and stands and between budworm and forests is such that we can make only qualitative statements. For real progress in management, procedures must be defined in terms of forest type, timing, location, area involved, and their projected results; we will discuss this concept later in this chapter. However, in the absence of quantified relationships between management and silvicultural actions and vulnerability, it makes sense to proceed at the level of qualitative relationships and the logic of the hr/ vulnerability relationship. This is what we attempt in this chapter. The usually recommended management and silvicultural goals are based on working hypotheses, not proven concepts. These hypotheses have not been tested experimentally. Thus, on an operational scale, our experience in actually shaping stands and forests toward desired goals has been limited. We hope that this chapter will encourage field managers to get involved in testing the fir/vulnerability hypotheses we will discuss. You are the ones closest to that great outdoors experiment. Try to reduce vulnerability with silvicultural approaches, watch development, and evaluate the individual (stand by stand) hypotheses. Your cooperation could be a major force in making progress toward broader understanding ot the spruce-fir/budworm ecosystem. The procedures discussed in this chapter are applicable across the eastern spruce-fir type from the Maritimes Region to the Great Lakes Region. Where important differences occur, we have attempted to discuss them in terms of forest characteristics (as mentioned in the introduction) rather than region, as they are seldom exclusively regional phenomena. When managers make changes in stand and forest characteristics through silviculture, a corresponding change may occur in the degree of vulnerability to budworm {see chapter 4). But the forest resource is only one cog in the wheel. Changing the forest through silviculture will not control the insect because other factors affect budworm survival, such as climate or natural enemy complexes. These factors can create conditions that enable budworm populations to override whatever limitations are imposed by the forest itself. 85 Long-Term Silvicultural Tactics Silvicultural tactics and regional management strategies should be aimed at reducing vulnerability in the future forest. Any long-term silvicultural tactic is, of course, directly affected by forest management constraints. Such constraints are imposed by factors of sustained yield regulation, present and future road network, availability of professional workers, protection costs, and other variables. All of these factors are in turn constrained by long-term markets and economics (see chapter 5). In discussing silvicultural tactics, we assume these limitations to be minimal, or at least within a range that permits a silvicultural program of some intensity to be implemented. Silvicultural decisions are affected by the specific characteristics of the stand in question—age, species composition, site, etc. Long-term silvicultural tactics are implemented over an entire rotation or longer. Effects of Species and Stand Types on Vulnerability Most silvicultural tactics are the byproduct of efforts to relate budworm-caused tree mortality to stand characteristics, both in a qualitative and quantitative manner. Of the many attempts to correlate vulnerability with stand characteristics, only one general association appears to be consistent—mature or overmature stands with a high proportion of balsam fir tend to be the most vulnerable. Beyond this, studies have not successfully related mortality to specific stand characteristics precisely enough for prediction purposes. Both the intensity and duration of outbreaks are extremely important in determining the likelihood of mortality. Also, budworm populations respond to biological and meteorological factors that are not related to the condition of the forest. Where extremely high populations occur, silvicultural techniques will partially alleviate the total impact of the infestation and will alter the timing and pattern of mortality. Although many stand characteristics besides species composition and age do not seem closely related to either growth loss or mortality due to budworm, factors such as stand structure, stand density, crown exposure, tree vigor, and proportion of nonhost species have demonstrated local importance. In short, any pontificating about the silvicultural “control” of budworm-caused tree mortality and growth loss is based on a combination of faith and logic plus scientific evidence and conclusions drawn from experience. One big plus is the fact that most of the silvicultural procedures that we will describe to reduce risk of budworm damage are the same silvicultural procedures pursued in an intensive silvicultural program for optimum growth and yield, even Vulnerability Host species Figure 6.2 —Relative vulnerability of the different budworm host tree species (Anonymous 1982). Key: bs = black spruce, rs = red spruce, ws = white spruce, bf = balsam fir. Average tree mortality level (percent) 100- Figure 6.3 —Average levels of mortality of balsam fir and spruce in mature and immature stands, from a wide variety of research studies (from MacLean 1980). 86 in the absence of a budworm threat. The one exception to this statement might be stand conversion to a nonhost species. Differences in vulnerability among the various host species are summarized in figures 6.2. 6.3. and 6.4. Balsam fir is the species most vulnerable to spruce budworm attack in the spruce-fir forest (see chapter 4 for additional details). White spruce, the most widespread spruce variety, is usually considered the second most vulnerable species. Though white spruce can support populations of the spruce budworm as high as those on fir, spruce damage is generally less severe. One theory attributes this phenomenon to the fact that white spruce produces more shoots than fir and these grow significantly larger than fir shoots, thus supplying more food for feeding larvae. Another theory is that white spruce is a better nutrition source, so that the budworm consumes fewer needles to get its required energy. Red spruce is the next most vulnerable species, followed by black spruce. Their relative resistance is due primarily to late-opening buds (on the average about 13 days after balsam fir and 9 days after white spruce) and the poor nutritional quality of old foliage and unopened buds for the support of emerging larvae. However, red spruce foliage can support emerging larvae to a greater degree than black spruce (fig. 6.5). Budworms also feed on eastern hemlock, eastern larch, and eastern white pine. In some local situations, damage to eastern hemlock can be significant. Most studies have consistently shown that vulnerability increases with increasing amounts of mature or overmature balsam fir. Additional trends detected in various studies indicate that 1. Vulnerability of spruce and fir tends to decrease as the proportion of nonhost species in the stand increases. This trend is apparently amplified if spruce or fir trees are Cumulative mortality, % number stems T Legend Baskerville 1960 Baskerville and MacLean 1979 Batzer 1973 Belyea 1952 Blais 1958 Macdonald 1962 McLintock 1955 Mott 1968 Time since start budworm outbreak, years Figure 6.4 —Cumulative percentage fir mortality in relation to time during various spruce budworm outbreaks (from MacLean 1980). 87 in a subordinate crown position relative to nonhost trees. Examples are understory and intermediate spruce-fir in an aspen (Populus spp.) stand, which occurs in the Lake States; a spruce-fir understory in a pioneer hardwood stand; or individual spruce-fir trees overtopped by large paper birch (Betula papyrifera Marsh.) or yellow birch (B. alleghaniensis Britton) in eastern Canada. 2. Vulnerability decreases with increasing tree and stand vigor, as demonstrated by growth rate and crown development, which, of course, is related to site quality and growing conditions. 3. Vulnerability tends to increase as stand density increases. This higher vulnerability may be related to lack Figure 6.5 —Young stand of black spruce untouched by budworm in the midst of an infestation in balsam fir. of vigor or poorly developed foliage in dense stands, or differences in larval dispersal dynamics. However, in a few recent cases where density has been intentionally reduced in spacing operations, budworm damage has been severe. 4. Vulnerability of individual spruce and fir trees increases when they are in a subordinate crown position relative to other host trees during a severe outbreak. Silvicultural Goals for Forest Management The relationships between stand characteristics and vulnerability that we have described can be translated into some general silvicultural goals. Boiled down, these goals include (1) maintaining a vigorous stand with rapid growth rates, (2) increasing the spruce and/or nonhost component in the stand, and (3) removing fir at an early age. If managers can achieve these goals, there should be a general reduction in stand vulnerability to budworm damage. Admittedly, at present we cannot quantify the reduction in vulnerability that would result; quantifying such relationships should be a key area of future budworm research. In a sense, achieving these goals readies the stand for the next outbreak. In reality, most of these goals are nothing new—even in the absence of budworm, it is good practice to maintain a vigorous, fast-growing stand, harvest fir on a short rotation (less than 50 years), and attempt to increase the proportion of spruce in the stand. In the absence of budworm damage, the end result of such stand manipulation is the production of high-value wood products or maintenance of a vigorous forest cover. But since we know that in the spruce-fir forest there is a high probability of a severe infestation occurring during a rotation, and that damage is likely to occur regardless of an intensive silvicultural program, we should ask what additional benefits might be derived from reducing vulnerability. With less tree mortality and growth loss, the need for direct control (spraying) during early stages of budworm infestation will decrease, and the time interval between direct control efforts will be longer. Having a sizable proportion of landholdings in a relatively invulnerable condition will also allow more time for shifting salvage operations to the most vulnerable stands as mortality commences. Also, the glut of salvaged material that occurs at the height of an infestation (fig. 6.6) will be somewhat reduced. Silvicultural Treatments to Meet Goals How, then, can managers actually accomplish this reduction of vulnerability? From a regional standpoint, the magnitude of the problem is almost overwhelming. In Maine alone, forest statistics from the early 1970’s for the spruce-fir type indicated that 48 percent of all trees above 1 inch (2.5 cm) in diameter were balsam fir, and only 20 percent were spruce. Of trees above 5 inches (12.5 cm) in Figure 6.6 —Salvage operations during an infestation can result in an oversupply of raw material. 89 diameter, 41 percent were fir and 27 percent spruce (Ferguson and Kingsley 1972). Clearly, altering the species composition on a regional basis to reduce budworm vulnerability would be a monumental job. (Its implications will be discussed further in a later section on regional strategies.) Nevertheless, silvicultural treatment of selected stands is a viable and important weapon in the integrated pest management arsenal. Given both sufficient time and intensity of treatment before a severe infestation, managers can achieve significant reductions in vulnerability. Certainly, any silvicultural treatment of stands should be considered in light of its long-term effects on vulnerability to budworm. Areas within the range of the budworm differ considerably, in the character of their forest resource, and in their marketing, economic, and social milieu. These differences affect the implementation of intensive silviculture. In addition, not all acres in a given ownership—particularly larger ownerships—will warrant such an effort. Site productivity, accessibility, and present stand condition are probably the limiting factors most common throughout the budworm’s range. The availability of up-to-date inventories, type maps, and site productivity information varies considerably. Such information sources are invaluable aids in identifying candidate stands for silvicultural treatments. If these data are unavailable, you must rely on the best Judgment of land managers familiar with the area. The greatest opportunity for manipulating species composition of existing stands occurs on high-quality, accessible sites. Fully mature or overmature stands having a good proportion of spruce or nonhost species probably require the least investment because marketable products can be removed, but sapling and pole stands offer the best opportunity because they have more stems to choose from, generally greater vigor, and somewhat less windthrow potential. While spruce-fir stands are amenable to either even-aged or uneven-aged management, even-aged management is the most common practice today. Applicable regeneration methods are clearcut harvesting in blocks, clearcut harvesting in strips, or shelterwood harvesting (table 6.1). During an active budworm infestation, stands to be regenerated under any system may require intensive suppression efforts to promote seed production, which is often lacking in heavily defoliated stands. A general Figure 6.7—Block clearcut harvest shortly after completion. 90 Table 6.1 —Summary of even-aged and uneven-aged forest management systems to reduce vulnerability to spruce budworm damage Even-aged management systems Clearcut harvesting in blocks Clearcut harvesting in strips Shelterwood harvesting Components of system Species conversion—natural conversion to less vulnerable species or site preparation and planting to nonhost or low-vulnerability species Thinning and partial cutting—heavy discrimination against fir where possible, to encourage increases in spruce content Uneven-aged management systems Selection harvesting description of these methods follows; consult the selected reference list at the end of this chapter for detailed prescriptions to be followed in a given region. Even-Aged Silvicultural Systems —Clearcut harvesting in blocks (fig. 6.7) or strips (fig. 6.8) is usually used for mature, overmature, or insect- and disease-ridden stands where partial harvesting could result in considerable mortality or damage to residual trees. Clearcutting is an efficient system of harvesting and is the best adapted to mechanical harvesting. If you plan to rely on natural regeneration to restock a clearcut area, success is critically dependent upon the presence of advance regeneration in the stand. There is usually no deliberate attempt to control initial species composition. In small clearcut areas, with inadequate advance regeneration, seed dispersal from adjacent stands may suffice, but many of these areas will require planting. Biologically, a clearcut harvest with advance regeneration present is a shelterwood, in the sense that the regeneration developed under a sheltering overstory. However, the occurrence of the regeneration is an accident of nature and not the result of a direct input by man to develop regeneration and manipulate seed source as would be the case with the shelterwood system of silviculture. Most importantly, all residual overstory trees of spruce budworm host species must be removed to prevent larval dispersal to the new regeneration. Figure 6.8 —Clearcut strip in spruce-tir forest. 91 In some areas, clearcut harvesting encourages undesirable vegetation that may inhibit the development of desirable species and may have to be treated with herbicides if normal growth is expected. Where advance regeneration is lacking, clearcut areas may require site preparation and planting, preferably to a nonhost species (fig. 6.9). Clearcut harvesting may be done in narrow strips or small patches, especially where advance regeneration is absent or where managers anticipate excessive losses due to drastic exposure or mechanical damage. This is often termed strip and patch shelterwood. Both methods leave nearby border trees that provide a seed source for regeneration and partial shade; this shelter and seed source distinguishes this method from ordinary clearcut harvesting. These same border trees are also a potential source of spruce budworm larvae that may disperse to young seedlings and cause damage. Harvesting in strips or patches also increases the species diversity of plants and animals and may encourage natural enemies of the spruce budworm. An example of the latter would be habitat enhancement for trap-nesting wasps that prey on budworm larvae.- The shelterwood system is applicable to spruce-fir stands that lack adequate advance regeneration, but where soils are sufficiently deep, sites are protected enough to reduce windthrow, and there are no insect or disease problems of immediate concern. With the shelterwood system, the overstory is gradually removed in two or three harvests, thus stimulating seed production and providing light and moisture conditions conducive to seedling development. Gradually opening the stand may improve windfirmness, and the partial shade will reduce the development of herbaceous growth such as raspberries (Rubus spp.). The shelterwood system allows some control over the species composition of developing regeneration, as long as desired species are present in the overstory for a source of seed. The system also provides good growing conditions for the residual overstory. If high populations of budworm are present in the overstory, however, direct suppression of the insect may be required through the regeneration period to prevent dispersal and damage to the developing regeneration and to aid seed production. Once all of the overstory is removed, budworm suppression should not be a problem. • Daniel T. Jennings, personal communication. Figure 6.9 —Crews planting a large clearcut in northern Maine. Stand Conversion —Converting a stand to nonhost species or less vulnerable ones is clearly desirable if trees other than balsam fir will adequately fill the landowner’s needs. If possible, white spruce should largely be replaced by black spruce in reforestation programs because white spruce is more vulnerable to damage. The economic and biological ramifications of stand conversion and creation of monocultures are many and vary considerably across the range of the spruce budworm. Throughout most of the spruce-fir region, researchers have made numerous advances in developing systems for artificial regeneration, including site preparation methods, planting techniques, improved planting stock, and techniques for controlling competing vegetation. While relatively expensive {see chapter 5), artificial regeneration of nonhost species on the best, most accessible sites will certainly decrease susceptibility and vulnerability to spruce budworm and improve long-term yield potential. But care must be taken that the species planted does not have major insect or disease problems of its own. 92 Uneven-Aged Silvicultural System —Uneven-aged silviculture, using the individual tree or group selection system, has been recommended in the past for reducing vulnerability to spruce budworm damage. Actually, this system would reduce vulnerability only if the fir were “selected” out, not if the stand were managed strictly by uneven-aged methods. Repeated light harvests create favorable conditions for the establishment of regeneration in stand openings. Experience indicates that uneven-aged silviculture can be an effective tool in altering species composition. However, this form of silviculture maintains a continuous, open, forest cover consisting of mature or near-mature trees that are highly vulnerable to budworm infestation. Once infested, the overstory serves as a reservoir of larvae that disperse downward, exposing younger age classes to damage. Thus, it is difficult to visualize the selection system as a particularly effective silvicultural tactic for reducing vulnerability. The selection system is more complicated than even-aged systems because of the mixture of age and size classes and the need to maintain this mixture. Harvesting must cover larger areas to meet a given allowable cut, harvested trees must be marked in advance, and the need for detailed recordkeeping is greater. But selection harvesting may be the only system allowable in some areas, such as streamside buffer strips and along roadsides where esthetics are an important consideration; and an all-aged approach is the only way owners of a small property can get a reasonably consistent return from their forest over time. Special protection approaches are needed to suit the management imperatives in these cases. Thinning or Partial Cutting —Once regeneration is well established, the key to reducing vulnerability in the developing stand is a program of frequent, relatively light partial harvests or thinnings. This will allow manipulation of species composition to the detriment of fir, particularly in fir-hardwood and fir-red spruce stands. On the best sites, a 10-year operating interval is probably the shortest that is practical, although the time period will vary depending on actual stand growth achieved, accessibility, and organizational constraints. If the regeneration process has been successful in maintaining or increasing nonhost or spruce seedlings 93 Salvage Operations throughout the area, a precommercial thinning when the stand reaches the sapling or small-pole stage can cause a dramatic change in species composition in the residual stand. Precommercial thinning also improves spacing and growing conditions around residual trees. Periodic thinnings or partial harvests should remove fir wherever possible. These harvests have a better chance of success in reducing vulnerability in mixed stands (fir-hardwoods) or fir-red spruce stands than in fir-white spruce stands. In most regions of Eastern North America, the latter type averages a ratio of 90 percent fir to 10 percent white spruce, so there is little spruce to work with. It is very difficult to encourage natural regeneration of white spruce. However, even a small proportion of spruce may be sufficient in absolute numbers to generate acceptable stocking, if it can be extricated from the fir competition. Where economically feasible, species control by precommercial thinning (“weeding,” “spacing”) can be a powerful tool. Besides removing fir, the primary goals of partial harvests should be to (1) provide adequate growing space for individual trees, (2) remove trees that may not survive to the next harvest, and (3) avoid creating large holes or openings in the canopy that may decrease windfirmness. In most cases, managers should first give priority to thinning from below (the removal of individual trees in subordinate crown positions) and then the spacing of the main crown canopy. Even pure balsam fir stands can be reduced in vulnerability if they are kept vigorous by thinning. Wind damage after partial cutting is a cause of considerable apprehension for many foresters and land managers in the spruce-fir region. Potential for wind damage varies considerably depending on site and soil characteristics, the amount of overstory removed in the partial harvest, and past management of the stand. To enhance windfirmness, harvests should be relatively light (perhaps no more than one-third of the basal area removed); however, this is a judgmental factor. If past management has kept the stand vigorous, well spaced, and fast growing, then improvements in windfirmness should follow naturally. Budworm defoliation and the possibility of subsequent rootlet mortality may be factors increasing the risk of wind damage. An uneven canopy resulting from budworm mortality or past harvesting practices may also increase the risk of wind damage. And, of course, the possibility of an overpowering storm, regardless of stand conditions, is always present. The primary objective of salvage operations is to harvest dead and dying trees while they can still be used, thereby reducing the economic consequences of the infestation. Integrated with chemical, biological, and long-term silvicultural protection measures, salvage should also reduce the impact of a severe outbreak on forest management goals such as sustained yield regulation and long-term silvicultural programs. The economic ramifications of salvage are discussed in chapter 5. The silvicultural tactics previously discussed are designed to reduce the overall vulnerability of spruce-fir stands to budworm damage, primarily by reducing the fir content. Short-term silvicultural tactics, on the other hand, are stopgap measures to be used in a salvage situation. These tactics address the manager’s need to react quickly to budworm impact, using appropriate silvicultural techniques where possible. It is very important that both protection and salvage activities be considered as integral parts of long-term management, especially in terms of maintaining a regulated age-class distribution. Otherwise, the need to salvage areas of dead or dying forests can result in loss of control over sustained-yield age class distribution. The procedures carried out in the woods are much the same for both short- and long-term silvicultural tactics. The main differences are that short-term tactics must be telescoped into a timespan bracketing the period in which most of the mortality occurs, as little as 7 to 10 years. Also, constraints exist with the harvesting and utilization of dead or deteriorating wood. On a regional basis and on large properties, salvaging dead trees on all areas that need it is practically impossible. Some combination of salvage, protection, or abandonment to the budworm is required to minimize total budworm impact. The decision to implement total salvage operations is affected by (1) the cost of harvesting the wood, (2) the present and future need and capacity for using the wood, (3) the protection options available, and (4) the risk of damage if the wood is allowed to stand unprotected. 94 Salvage Priorities The first step in implementing salvage operations is to determine which stands most need to be salvaged. Among the several systems that rate vulnerability of spruce-fir stands to budworm, details vary depending on how and where the systems were developed. Accuracy of almost all, however, depends on having an adequate forest inventory. The finer the species breakdown (particularly regarding the three spruces and balsam fir) and the higher the degree of accuracy, the better. Stand age or an estimate of maturity should be obtained where possible. Variables less precisely quantifiable (e.g., site productivity, stand isolation, diversity of stand characteristics such as species composition or age class over the landholding, tree condition, and past infestation patterns) may also be helpful in implementing a system of rating damage potential. Once the manager ranks stands according to their potential for incurring budworm damage, or damage already incurred, he or she must consider additional factors that may modify the decision to salvage. Accessibility, severity of past defoliation, harvesting resources available, treatment alternatives, available markets, and social or political constraints are but a few. Because salvage must be carried out before deterioration of dead trees is too severe, the timing of salvage operations is critical. Salvage is generally possible for up to about 5 years after mortality, although harvest yields decrease with time since death. It should be possible to make an attempt to salvage in an orderly fashion while implementing some basic silvicultural principles, albeit in haste. It is worth noting at this point that the longer a successful, long-term silvicultural program has been in place, the easier it should be to implement a sound salvage program (i.e., fewer vulnerable stands should require immediate salvage). Equally important is the need for an adequate detection and damage evaluation system (see chapters 3 and 4) to help determine which stands require salvage. Early detection of an impending infestation will allow some lead time for planning and implementing salvage procedures. Evaluation of damage already incurred in individual stands may modify priority ratings for salvage. Silvicultural Options Silvicultural options in a salvage situation are dictated by the present condition of the individual stands involved, assuming minimal harvesting constraints. It makes no sense, for instance, to salvage all mature fir from a spruce-fir stand, or to make an initial shelterwood harvest if it is obvious that the amount of vulnerable material removed will leave the residual stand susceptible to wind damage. The better alternative might be to clearcut and regenerate, or leave enough volume to reduce wind damage risk and then chemically protect the vulnerable spruce-fir left in the residual stand. Obviously, managers can choose from many scenarios. At the risk of oversimplification, we present one possible matrix of options in table 6.2. It cannot be overemphasized, however, that the mix of options actually put in place depends greatly on individual circumstances. Not the least of these are the ability to harvest and utilize the wood economically, and the technology to protect stands using chemical or biological controls with efficacy and precision. Although it is impossible to eliminate economic constraints from forest operations, silvicultural options should be weighed in terms of their long-term effects, and not be entirely the results of immediate economic constraints. 95 Table 6.2—Array of short-term silvicultural options available in a salvage situation Stand vulnerability rating Site quality Silviculture options Probable need for protection in the short term High Good Regenerate: 1) Block clearcut, natural regeneration Low 2) Clearcut, plant Nil 3) Shelterwood High Partial harvest, spruce and fir priority High Do nothing (abandon to budworm) High Poor Regenerate: 1) Block clearcut, natural regeneration Low Partial harvest High Do nothing Low Medium Good Regenerate: 1) Block clearcut, natural regeneration Low 2) Strip clearcut, natural regeneration Medium-low 3) Clearcut, plant Nil 4) Shelterwood Medium Partial harvest, spruce and fir priority Medium-low Do nothing Medium-low Poor Regenerate: 1) Block clearcut, natural regeneration Low 2) Strip clearcut, natural regeneration Medium-low 3) Shelterwood Medium-low Partial harvest, spruce and fir priority Medium-low Do nothing Low Low Good Regenerate: 1) Block clearcut, natural regeneration Low-nil 2) Strip clearcut, natural regeneration Low-nil 3) Clearcut, plant Nil 4) Shelterwood Low-nil Partial harvest Low-nil Do nothing Low-nil Poor Regenerate: 1) Block clearcut, natural regeneration Nil 2) Strip clearcut, natural regeneration Nil 3) Shelterwood Nil Partial harvest Nil Do nothing Nil 96 Long-Term Regional Management Strategies In general, the long-term silvicultural tactics already discussed are also valid for inclusion in a regional management strategy. Silviculture is carried out in a stand, while management concerns (among other things) the distribution of silvicultural treatments in a forest. Regional planning involves many stands, which cover large areas in different ownerships and political jurisdictions. Thus, the scale of treatments, the complications, and the regulatory requirements for actual implementation are increased manyfold. Because budworm populations are not affected by political or ownership boundaries, what is next door to or surrounding a silvicuturally treated stand can determine its ultimate fate. At the regional level, effective management strategies must be coordinated among different owners and regulatory jurisdictions, so as not to stop at boundaries. Perhaps the main difference between silvicultural tactics and regional management strategies is that at the regional level, area effects come into play. The spatial distribution of individual stand types and the distribution of age classes of stands become the most important factors that can be manipulated. Epidemic or outbreak dynamics of the spruce budworm population are also important on a regional scale because of budworm dispersal. The management strategy that should be followed for large properties or regions is to encourage between-stand diversity wherever possible, in terms of both age-class distribution and species composition. Having a variety of young and old, vulnerable and nonvulnerable, host and nonhost stands in any particular management area would not only lessen the overall impact of a budworm outbreak on wood supply from the area (since fewer stands would exist in the vulnerable condition) but would probably also decrease the losses in individual stands. This cannot be overemphasized: between-stand diversity is the key. What we are aiming at here is a patchwork of stands over the management area, with young stands and recent clearcuts located adjacent to mature and overmature stands, and nonhost or nonvulnerable stands located adjacent to vulnerable ones. This is accomplished through planning the location of harvesting. While this might appear relatively simple to attain, diversity is not simple: it requires a sustained, long-term regulatory effort that is coordinated among different ownerships and jurisdictions. This goal is often complicated by operational factors. Effects of Budworm Outbreak Dynamics on Strategies Aspects of the dynamics of budworm outbreaks—how and where outbreaks start, how population levels increase in different areas, what causes the collapse of outbreaks— obviously affect forest protection (spraying) strategy. Less obviously, they influence silvicultural and management strategies. Population dynamics of the spruce budworm has been extensively studied over the past 30 years, and one might suppose that the subject is well understood by now. However, recent and ongoing research in this area has altered some of the theories of how and why spruce budworm populations oscillate (increase and decrease). Some of the previously accepted causes or conventional wisdom now appears suspect, but more work is required to test these theories. The revised theories of budworm dynamics largely revolve around work done by Dr. Tom Royama of the Canadian Forestry Service in reanalyzing New Brunswick spruce budworm data, outbreak dynamics, and causes of budworm mortality and population dynamics. This is not the place to discuss Royama's analyses or conclusions in detail, but two points from his work have direct influence on treatment strategy: 1. Spruce budworm populations in different areas appear to oscillate in synchrony, regardless of level of damage to the forest. That is, the collapse of budworm outbreaks is not caused by spraying activities or by lack of food supply. This synchrony of oscillation, which apparently relates to the correlation of elimatic variables among sites, has been shown for the Province of New Brunswick (both sprayed and unsprayed areas) but requires further testing for other areas. 2. The cause of oscillation of budworm populations appears to be linked to an array of incompletely understood diseases and parasites affeeting the population. It is crucial to determine the actual cause of oscillation, and this is the topic of ongoing research. Population decline seems not to be universally regulated by weather, lack of food supply, or predators, although both climate and "area effeets” (forest type, geography, etc.) probably play a role influencing the efficacy of the disease/parasite array and may have major effects in specific instances. 97 If the Royania theory of population fluctuations is sound, there are important messages for silviculture. If budworm populations rise and fall independently of protection and food supply (i.e.. independent of the “forest”), then reducing vulnerability on the local scale takes on major importance in adapting management to the budworm. The message is that if in the long run budworm will come and go independently of what is done to the forest, the major effect of silviculture should be to buffer the stands against these periodic episodes. Results from ongoing research by Dr. Yvan Hardy of Laval University also promise to affect regional management strategies. He has been analyzing the properties of forest areas where the initial stages of the current budworm outbreak were first noted in the late 1960’s. Hardy has applied a theory of regional “zones of abundance” for budworm (based largely on climate and outbreak epidemiology) and hypothesized that differing durations of budworm outbreaks and degrees of damage occur in these zones. The main points made here are that budworm outbreak dynamics will affect silvicultural and management strategies, and that both protection and management strategies may well vary regionally in the future. Regional Management Strategies Manipulation of Age-Class Distribution—One strategy offers the most potential for reducing vulnerability on a regional basis; attaining a regulated, sustained-yield forest with an even age-class distribution (i.e., equal areas of the forest represented by the various age classes of stands). This will influence budworm dynamics because young stands suffer less damage from a given level of attack and offer less favorable egg-laying sites for budworm moths. On an areal basis, less damage will occur with a mixture of young and old (or nonvulnerable and vulnerable) age classes of stands. The spatial distribution of stands will also promote dispersal losses at the small-larval and (possibly) moth life stages of the insect. Although the goal of a regulated forest is entirely in line with the long-term, sustained-yield management strategy for most forested properties, many regions presently contain disproportionate areas of mature or overmature forest, the most vulnerable age class. In immature stands, both fir and spruce are less vulnerable and suffer lower average levels of mortality than in mature stands (fig. 6.3). Maximizing the spatial, between-stand diversity of different-aged stands will reduce the overall level of damage on a forestwide basis. Regional management to reduce vulnerability should actively pursue attainment of a regulated age-class distribution, even to the extent of allowing budworm to kill specific areas of forest (i.e., removing areas from an active protection program) and recycle them to younger age classes, if present levels of harvesting are insufficient to attain regulation. Stands recycled to younger age classes, whether by harvesting, budworm, or other means, should be spatially arranged to achieve maximum diversity of age classes, host-nonhost species mix, and vulnerability levels. Manipulation of Regional Species Composition—Significantly changing the species composition of forests is much harder than changing their age-class distribution because of the large areas involved. Although planting can theoretically change the species composition of forests, areas of millions of acres preclude any significant short-term changes. Even with intensive programs of site preparation and planting to nonhost or low-vulnerability species, managers have to leave many stands untreated, and these often regenerate into spruce-fir host types. In fact, clearcutting, fire protection, and repeated budworm outbreaks probably have all worked toward increasing the amount of balsam fir, the most vulnerable species, in our forests in recent years. How can budworm outbreaks assist in this direction, in many cases, especially if budworm kills balsam fir? The key is that “fir replaces fir.” Fir stands often have large amounts of advance fir regeneration, which develops into the succeeding stand after budworm kills the overstory. This process, with budworm outbreaks acting as the recycling agent, has been well documented for areas in New Brunswick and Cape Breton Island, but it is not clear how widespread the phenomenon is. 98 Manipulating species composition on a regional basis requires intensive efforts on large areas over a long period of time. Managers should adopt a twofold attack: 1. Ensure that site preparation and planting programs utilize nonhost species (if this is consistent with other management goals) and that both harvesting and planting are used to enhance overall forest (between-stand) diversity. 2. Discriminate heavily against balsam fir wherever possible, on both a whole-stand and a selection basis. Discrimination could entail preferential harvesting of fir rather than spruce stands, site preparation and planting of harvested fir stands rather than spruce-fir or nonhost stands, or cutting fir to a lower diameter limit. A general caution is in order regarding the species conversion strategy. It is a virtual certainty that some insect, disease, or other problem will develop for any forest type. Thus, it would be wise management not to rely entirely on any one particular type or monoculture, whether it is natural, vulnerable to budworm, or less vulnerable. In this regard, managing a forest is analogous to managing an investment portfolio—a diversified portfolio is much less risky over the long term than one invested in just a couple of securities. In terms of forestry and species conversion, smaller plantations distributed spatially are undoubtedly less risky than huge areas of the same species and age class. Other Strategy Elements—Besides manipulating the age-class distribution and species composition of stands, several other management options hold potential for the future, though they are probably not practical now. These include targeted protection and silvicultural treatments of particular geographic areas that may act as focal points for initiation of outbreaks, reservoir areas, or mass dispersal routes of budworm moths. These strategy elements are dependent upon a thorough understanding of spruce budworm population dynamics and outbreak epidemiology, and the ability to define the areas requiring treatment. At present, we can state only that these elements may hold potential. With the current progress being made in budworm population dynamics research, however, evaluation of such treatments should be possible in a few years. Two points deserve emphasis: 1. Management strategies to reduce vulnerability vary from one region to another, because of (a) regional differences in both budworm outbreak dynamics and damage, and (b) regional differences in the forest resource (both composition and usage). The budworm may react differently in different “zones of abundance”; and forest types, markets, and degree of usage vary in areas from the Lake States to Newfoundland. Therefore, regional strategies also differ. 2. An essential component of regional strategies is the ability to protect certain parts of the forest resource at specific times. The characteristics of the forest will determine the need for protection in terms of maintaining the required wood supply. That is, if large proportions of the forest are mature and vulnerable, and this constitutes the only available wood supply for the next two to three decades, there is no alternative but to protect. However, even in the absence of a continual, large-scale aerial spray program, the capacity to manage the pest in high-value silviculturally treated stands, plantations, seed production areas, stands with genetic breeding stock, etc., is essential. Also, managers must apply specific, targeted protection treatments to manipulate or maintain the age-class distribution of the forest. Otherwise, it is quite probable that future budworm outbreaks will reconvert the regulated, sustained-yield forest to a preponderance of one or two age classes. For example, the effect of a severe budworm outbreak on a regulated forest could well be to recycle all highly vulnerable stands aged 30 to 60-1- years to the 0- to 10-year-old age class. Protection of the intermediate age classes combined with harvesting of the older age classes could lessen this tendency. 99 The Problem with Silvicultural and Management Strategies—A Lack of Quantification As briefly mentioned near the start of this chapter, there is one problem with all of the silvicultural and management strategies to reduce vulnerability that we have discussed; at present, the results of the treatments cannot be quantified in terms of the expected reduction in vulnerability. In many cases, the treatments are also insufficiently defined with respect to type, timing, location, and amount. Yet there are clearcut differences in vulnerability due to species (fir, the three spruces, and nonhosts) and age classes of stands (mature v. immature). Thus, (1) removing fir, (2) increasing the amounts of less vulnerable (spruce) Figure 6.10 —Hypothesized relationships between vulnerability and stand and forest characteristics, ranked in approximate level of importance. Actual, quantified relationships between vulnerability and these characteristics must be developed before we can make real progress in defining management and silvicultural strategies for dealing with the spruce budworm. or nonvulnerable species, and (3) maintaining larger amounts of those age classes of stands least vulnerable in the forest cannot help but reduce vulnerability. Whether the reduction can be quantified or not, the logic of implementing these procedures to reduce future damage cannot be denied. On the other hand, quantifying the vulnerability reduction from different management or silvicultural strategies is essential to choose among various treatments, to determine the cost effectiveness of treatments, to accurately predict future yields from the forest for management planning, and to estimate levels of protection required for the future forest. The real issue here is what specific actions, taken to what specific levels, at what specific times, in what specific forest and budworm conditions, will render future outbreaks less potent by what specific amounts. Vulnerability itself must be quantified, and specifically A. Relationships between vulnerability and stand characteristics Vulnerability Vulnerability Vulnerability Stand age Vulnerability 100 Selected References related to factors such as species composition (percent fir. percent spruce spp., mixtures of fir-spruce, fir- hardwoods). stand structure (even-aged multistoried intimately mixed stands), "vigor” of individual trees and stands, growth rates, stand age (or maturity class or crown class), etc. Relationships as hypothesized in figure 6.10 must be developed, defining the axes, units, and relationships. Only by quantifying such relationships can we progress beyond the state that this subject has essentially been stalled at for over 50 years, of knowing that “Conditions must be developed ... so that future outbreaks can be rendered much less potent . . .” (see introduction to this chapter), but not explicitly defining these conditions. For progress in management, we need some usable quantitative relationships that can be tested in the real world in a real way. The need for quantifying work on vulnerability should be inescapably clear. B. Relationships between vulnerability and forest characteristics Vulnerability % of forest composed of stands in mature or overmature age classes Vulnerability % of forest composed of stands dominated by vulnerable species Anon. Guidelines for predicting tree mortality caused by the spruce budworm, and measures for reducing losses. Hull, PQ: Environment Canada, Canadian Forestry Service, Canada/United States Spruce Budworms Program; 1982. (Available from Canadian Forestry Service, Place Vincent Massey, 19th Floor, Hull, Quebec KIA 1G5. In French or English.) Baskerville, G. L. Spruce budworm: super silviculturist. For. Chron. 51(4): 138-140; 1975a. Baskerville, G. L. Spruce budworm: the answer is forest management: or is it? For. Chron. 51(4): 157-160; 1975/p. Baskerville, G. L., ed. Report of the task force for evaluation of budworm control alternatives. Fredericton, NB: Department of Natural Resources; 1976. 210 p. Batzer, Harold O.; Hastings, Arthur R. Rating spruce-fir stands for spruce budworm vulnerability in Minnesota. In: Hedden, R. L.; Barras, S. J.; Coster, J. E., tech, coords. Hazard-rating systems in forest insect pest management: symposium proceedings. Gen. Tech. Rep. WO-27. Washington, DC: U.S. Department of Agriculture, Forest Service, 1981: 105-108. Craighead, F. C. Studies on the spruce budworm (Cacoecia fumiferana Clem.). Part II. General bionomics and possibilities of prevention and control. Tech. Bull. 37 (N.S.) Ottawa, ON: Department of Agriculture; 1924: 28-91. Falk, Jonathan. Wind damage in spruce-fir stands— literature review with recommendations for harvesting methods. Misc. Rep. 225. Orono, ME: University of Maine at Orono, Life Sciences and Agriculture Experiment Station; 1980. 26 p. Ferguson, Roland H.; Kingsley, Neal P. The timber resource of Maine. Resour. Bull NE 26. Upper Darby, PA: U.S. Department of Agriculture, Forest Service; 1972. 129. p. 101 Flexner, J. Lindsey; Bassett, John R.; Montgomery, Bruce A.; Simmons, Gary A.; Witter, John A. Spruce-fir silviculture and the spruce budworm in the Lake States. Handb. 83-2. East Lansing, MI: Michigan Cooperative Pest Management Program; 1983. 30 p. Frank, Robert M.; Bjorkbom, John C. A silvicultural guide for spruce-fir in the Northeast. Gen. Tech. Rep. NE-6. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station; 1973. 29 p. Frank, Robert M.; Blum, Barton M. The selection system of silviculture in spruce-fir stands—procedures, early results, and comparisons with unmanaged stands. Res. Pap. NE-425. Broomall, PA: U. S. Department of Agriculture, Forest Service; 1978. 15 p. Gibbs, Carter B.; Blum, Barton M. Silviculture and the spruce budworm in Maine. Maine For. Rev. 8: 13-15; 1975. Hudak, J.; Raske, A. G., eds. Review of the spruce budworm outbreak in Newfoundland—its control and forest management inplications. Info. Rep. N-X-205. St. John’s, NF: Canadian Forestry Service; 1981. 280 p. MacLean, D. A. Vulnerability of fir-spruce stands during uncontrolled spruce budworm outbreaks: a review and discussion. For. Chron. 56(5): 213-221; 1980. MacLean, D. A. Vulnerability rating of forests in New Brunswick and Nova Scotia to budworm attack. Info. Rep. M-X-132. Fredericton, NB: Canadian Forestry Service; 1982. 21 p. McLintock, Thomas F. Silvicultural practices for control of spruce budworm. J. For. 45(9): 655-658; 1947. Montgomery, Bruce A.; Simmons, Gary A.; Witter, John A; Flexner, J. Lindsey. The spruce budworm handbook: a management guide for spruce-fir stands in the Lake States. Handbook 82-7. East Lansing, MI: Michigan Cooperative Forest Pest Management Program; 1982. 35 p. Montgomery, Bruce A.; Witter, John A.; Simmons, Gary A.; Rogan, Randall G. The spruce budworm manual for the Lake States. Tech. Man. 82-6. East Lansing, MI: Michigan Cooperative Forest Pest Management Program; 1982. 66 p. Morris, R. F., ed. The dynamics of epidemic spruce budworm populations. Mem. Entomol. Soc. Can. 31. Entomological Society of Canada; 1963. 332 p. Mott, D. Gordon. Spruce budworm protection management in Maine. Maine For. Rev. 13 (Summer): 26-33; 1980. Westveld, M. Forest management as a means of controlling spruce budworm. J. For. 44(11): 949-953; 1946. I 102 Chapter 7 '/a .-• • yvV^vi '■"fS! Microbial and Other Biological Control J. B. Dimond and O. N. Morris' ' Professor of Entomology, University of Maine, drono. Maine, ami Research Scientist, Agriculture Canada. Winnipee Man Nature of B.t. Society is looking for biological alternatives for suppressing forest pests and pest damage because of political, social, and environmental conflicts associated with use of chemical pesticides. This is particularly true in the case of spruce budworm because of the large scale of outbreaks and suppression projects. This chapter reviews the available biological control options. We will focus mainly on the bacterial insecticide Bacillus thiiringiensis, commonly known as B.t.—the only alternative that has been developed for operational use. We will briefly discuss the stages of development of other alternatives, e.g., viral diseases, parasites, nematodes, and sex pheromones. Bacillus thuringiensis is a naturally occurring bacterium that has been isolated from a number of insect species in several parts of the world. It was first found in Japan in 1901 in dying silkworm larvae. B.t. is actually a complex of varieties, with different ones associated with different host insects. Most present-day commercial formulations of B.t. use B. thuringiensis var. kurstaki, HD-1 isolate. B.t. becomes active when eaten by insects with an alkaline gut environment—a narrow range of pests. Most victims of B.t. are caterpillars (the immature forms of moths and butterflies), which have more alkaline conditions in the digestive tract than other insects. About 200 species of moths and butterflies are susceptible to B.t. but only in the larval stage. Most other insects are unaffected. A distinct advantage of using B.t., therefore, is that the natural enemies of the target pest, and most other nontarget organisms, are spared. k 0 . # ^ ' #• • Figure 7.1 —Photomicrograph of B.t. spray deposit on filter paper. Diamond-shaped bodies are the crystals. Spores are round or oval. (Photo by O. N. Norris, Canadian Forestry Service.) 104 Early Use of B.t. Against Spruce Budworm Natural epizootics of B.t. are rare, apparently because infected hosts produce relatively few spores and because sunlight readily destroys them. To be effective, therefore, the material must be introduced into the environment in large quantities, where it remains active for only a few days. There is no significant amount of carryover of the pathogen to subsequent generations. As B.t. cells mature, they produce spores—a resting stage of the organism, resistant to adverse conditions in the environment, except for sunlight. The spore stage is relatively easy to produce, handle, and store in large quantities. A toxic crystal is also produced with the spore (fig. 7.1). Some target insects appear most susceptible to infection by the germinating spores while others succumb rapidly to the toxic action of the crystal. Most insects, including the spruce budworm, can suffer from both spores and crystals; mixtures of the two are most effective. Commercial formulations of B.t. contain spores and crystals in about equal amounts. The mode of action of B.t. is more complex than that of most chemical insecticides. Insects that survive treatment with B.t. are debilitated. At the very least, B.t. causes some disruption of the digestive tract leading to reduced insect feeding. Such sublethally affected insects often develop more slowly and become undersized moths that lay fewer eggs and have poorer rates of survival. These effects explain why B.t. applications can satisfactorily protect foliage on treated trees without killing large numbers of caterpillars. Though dramatic reductions in populations will occur, particularly with higher dosages, a count of dead insects cannot reflect the total effect achieved with B.t. applications. The use of B.t. in spruce budworm control has been under development in eastern Canada since the 1950’s and since the 1960’s in the Eastern United States. Early tests were inconclusive: B.t. sometimes produced favorable results and sometimes not, but it rarely equaled chemical insecticides in effectiveness. Two problems existed in that period. Available formulations had been developed largely for ground applications in agriculture, and these did not perform well when applied from aircraft over forests. Also, available formulations were not very concentrated. The result was that in order to keep total spray volumes per acre within reasonable limits—1 to 2 gal/acre (10 to 20 1/ha) or less—only relatively light dosages of active B.t. could be applied. The rest of the spray mixture was water, byproducts of the commercial fermentation process producing the B.t., and additives to reduce evaporation and cause the spray to settle well. The amounts of actual B.t. applied at that time were one-third to one-half the amounts that can be applied now. During the 1970’s, new, concentrated formulations for aerial application have been developed by the producers of B.t. Current formulations provide a number of advantages and cost reductions. The cost of B.t. products was substantially reduced; shipping costs are also lower with concentrated products, and greater doses of B.t. in less total spray volume can be applied more economically. Modem formulations are also complete, requiring only the addition of water and a sticker, to reduce the erosive effects of rain. As a result of these developments, B.t. has come into operational use in the Eastern United States and Canada. Table 7.1 summarizes its use in this region in 1981. Between 88 and 100 percent of the sprayed areas were satisfactorily protected. Table 7.1 —Use of various B.t. products in 1981 in eastern Canada and Maine Products Acres treated (ha) Number of locations Dipel 4L (88) 74,300 (30,068) 18 Thuricide 24B 9,237 (3,738) 1 Thuricide 16B 74,443 (30,127) 33 Thuricide 32B 30,904 (12,507) 2 Futura 64B 2,316 (937) 1 105 Current B.t. Products B.t. has not replaced chemical insecticides, largely because of differences in costs; however, cost differences have narrowed in recent years. Table 7.2 compares costs in a recent spray project in Maine. There was a similar difference in costs in spraying small woodlots in New Brunswick in 1982; $5.87 (Canadian) per acre ($14.50/ha) with chemicals V. $13.37 (Canadian) per acre ($33.04/ha) for B.t. In Quebec, cost differentials between B.t. and insecticides have been less; the Quebec projects sprayed larger acreages with B.t. and achieved some economies of scale. The cost of spraying B.t., relative to chemicals, is expected to decline due to competition among producers, more efficient commercial products, and, particularly, reducing B.t. spray volumes per acre to levels as low as those used with chemicals. Table 7.2 —Cost breakdown per acre by major components for selected treatments, Maine 1982 spray project (from Maine Forest Service)' Sevin-4-oil Dipel 4L Thuricide 32LV Insecticide 2.75 U.S. dollars 5.57 4.50 Application 1.88 6.00 6.00 Mixing and loading .45 .45 .45 Monitoring and administration .32 .32 .32 5.40 12.34 11.27 ' Costs based on single applications using small, fixed-wing aircraft. Formulations of B.t. currently available in the United States and Canada for control of spruce budworm and other forest defoliators are listed in table 7.3. We should explain some of the terminology used with B.t. mixtures since it differs from that used with chemical insecticides. Weights or volumes are not used to express potency of B.t. mixtures as they are with chemicals. A pound or kilogram of one B.t. formulation may be of different potency from an equal weight of another because of the different proportions of spores, crystals, and inert fermentation byproducts that make up those weights. Therefore, potency is defined in international units (lU). An lU of any product is the amount which causes mortality equal to that of a standard laboratory strain of B.t. Because billions of lU are required to treat an acre or hectare, field dosages are expressed as BIU (billion international units) per acre or hectare. The abbreviation B, for BIU, is also used in trade names of many formulations {see tables 7.1, 7.3). A 32B designation indicates that the product contains 32 BIU per U.S. gallon. As we noted in the preceding section, modem formulations of B.t. are concentrated. In general, 32B and more concentrated formulations are common today, and we may see 64B and higher concentrates in the future. Scientists may isolate new varieties of B.t. that outperform today’s commercial varieties. B.t. formulations used in aerial spraying are normally liquids; where dilution is needed, they can be mixed with water. Some wettable powder formulations are also produced and can be used in ground spraying equipment. 106 How to Use B.t. Table 7.3 —B.t. products currently registered or expecting registration for control of spruce budworm in 1984 Trade name Type of formulation' Potency- Pattern’ Regis¬ tration'' Manufac¬ turer’ Bactospeine FC 35B A + G USA 1 Bactospeine WP 7.3B G USA 1 Bactospeine 50 FCW^ FC 50B A + G USA 1 Bactospeine 50 FCO'’ EC 50B A + G USA 1 Dipel 4F S 32B A + G USA 2 Dipel 88 s 32B A + G CAN 2 Dipel WP WP 7.3B G U + C 2 Dipel 6F s 48B A + G USA 2 Dipel 132 s 48B A + G CAN 2 Dipel 8F s 64B A + G USA 2 Dipel 176* s 64B A + G CAN 2 Futura FC 54.5B A + G U + C 1 Novabac-3 FC 32B A + G CAN 1 Thuricide 16B FC 16B A + G U + C 3 Thuricide 24B FC 24B A + G USA 3 Thuricide 32B FC 32B A + G CAN 3 Thuricide 32LV FC 32B A + G U + C 3 Thuricide 48FV FC 48B A + G U + C 3 ' FC = flowable concentrate. WP = wettable powder. S = emulsifiable suspension. ■ For liquids, potency is in BIU per U.S. gallon; for wettable powders, this is BIU per pound. ■ A = air, G = ground, A + G = both air and ground. ■* USA = United States, CAN = Canada, U + C = both countries. ’ 1 = Biochem Products, P.O. Box 264, Montchanin. DE 19710; 2 = Abbott Laboratories, CAPD, 14th St. and Sheridan Rd.. North Chicago. IL 60064; 3 = Zoecon Corp., Crop Protection Division, 425 Sherman Ave., Box 10975, Palo Alto, CA 94303. *’ Registration expected in 1984. Dosage Rates Operational usage of B.t. involves rates of 8 to 16 BlU/acre (20 to 40 BlU/ha), and we recommend the median dosage, 12 BlU/acre (30 BlU/ha) for most uses. If you want to use 8 BlU/acre to reduce costs and you’re using a water-based formulation, add the antievaporant sorbitol. The proper mix ratio is 5 parts B.t., 2 parts 70-percent sorbitol, 3 parts water. To obtain 12 BIU, use 0.5 gallon^ of a 24B concentrate or 0.25 gallon of a 48B concentrate. Because the best dosage of B.t. to use under different conditions is still a topic of research, users should check with a local forest pest control official or the manufacturer for current information. Spray Volumes B.t. formulations are normally diluted with water, and spray emission rates are usually 0.5 to 1 gal/acre (4.7 to 9.4 1/ha) in the East. Under the drier conditions of Western North America, spray emission rates may be double these. In Maine in 1982, operational spraying of B.t. at 12 BlU/acre (30 BlU/ha) was carried out at either 0.6 gal or 0.7 gal/acre (5.6 or 6.6 1/ha) with success. However, most recent tests indicate that 0.5 gal/acre gives adequate protection. Some formulations require a certain amount of dilution to produce a viscosity that will flow readily through pumping equipment and spray systems. Information of this sort will be found on the product label. This chart shows how to dilute 32B B.t. to obtain various spray emission rates: Spray emission Mix To obtain at rate of bT Water 12 BlU/acre 0.5 gal/acre 48 fl oz 16 fl oz 12 BlU/acre 1 gal/acre 48 fl oz 80 fl oz 30 BlU/ha 4.7 1/ha 3.5 1 1.2 1 Choosing a higher or lower spray emission level depends on several factors. If insect numbers are large (e.g., more than 25 budworm larvae per branch), you may choose the greater dilution and spray emission rate to achieve a greater density of spray droplets per unit area, i.e., better coverage. But larger spray volumes are more expensive to apply since an aircraft load will treat less acreage. For this reason, you may choose the lesser dilutions when insect numbers are moderate. Another factor to be considered is tree condition: you may want better coverage on trees in poorer condition. ‘ Throughout the book, “gallon” refers to U.S. gallons, 3.785 1. (An imperial gallon is 4.546 1.) 107 Effective swath width of the spray aircraft is another variable to consider here, and it interacts with dilution rate. Different aircraft have different ranges of swath widths in which they can operate effectively. In general, to achieve good coverage, choose a narrower swath width when using lower spray emission rates than when using high ones. Another general rule is that narrower swath widths should be used with water-based sprays, such as B.t., than with oil-based sprays because of the greater evaporation from water-based droplets. Some recommended swath widths for use of B.t. with common spray aircraft types are listed in table 7.4. Very recently, successful tests with undiluted sprays of B.t. concentrates (“neat” B.t.) have been carried out, using spray emission rates of 0.2 to 0.3 gal/acre (1.9 to 2.8 1/ha). These applications of neat B.t. have several advantages. You can treat much greater acreage with a single aircraft load, and you can avoid costs of dilution and mixing. Also, since diluted B.t. is inherently unstable, the use of neat B.t. sidesteps that problem. Undiluted B.t. was used operationally on substantial acreage in 1983 with good results. This method of applying B.t. is expected to become a standard procedure, particularly where application costs must be minimized. Spray Atomization and Nozzles Some difference of opinion exists on the optimum spray droplet size for applying B.t. One view holds that larger droplets, 300 microns, are preferred since they are more resistant to inactivation by sunlight. The other view is that small droplets, 100 microns or smaller, are required to achieve good penetration and impingement in the complex growth pattern of coniferous foliage. We support the second view and recommend small droplet sizes. Most operational and experimental applications of B.t. have been made with aircraft equipped with hydraulic booms and nozzles of either the hollow cone or flat fan type. Nozzle sizes will vary for aircraft type, speed, and pump pressures. To select the best equipment, discuss your situation with the manufacturer of the B.t. product you are using. There is growing consensus that rotary atomizer nozzles (spinning cages, spinning porous sleeves, spinning discs) are superior for applications of B.t. and worth their additional cost. These nozzle types produce small droplets of very uniform size. Rotary atomizer nozzles should be considered especially when lower spray emission rates will be used, and they are essential for success where undiluted B.t. is used at very low volumes. Table 7.4 —Swath widths appropriate for aerial application of B.t. to spruce-fir forests Aircraft type Swath width (Feet) (Meters) Bell 47 Helicopter 75-100 23-30 Hiller Helicopter 75-125 23-38 Bell Jet Ranger 100-150 30-46 Bell 205/212 Helicopter 150-250 46-76 Cessna Ag Truck 225^50 69-137 Rockwell Thrush, Grumman Ag Cat 225-450 69-137 Rockwell Turbo Thrush 225^50 69-137 McDonnell-Douglas C54 1000 + 305 + Sometimes you may want to monitor spray deposit in terms of spray droplet sizes and/or densities of droplets deposited on the target. For the former, white, glossy cards are placed on the ground in an open area under an aircraft swath. With most formulations, a dye must be added to the mixture to make the droplets visible. Some dyes may be toxic to B.t. organisms, so it is best to check with the manufacturer of the B.t. on suitable dyes and quantities to use. Droplet diameters can be measured under a microscope, but remember that the stain diameters, now in a single plane, will be about twice the diameter of the droplet when it was spherical. That is, the drop size actually emitted from the spray nozzle is about half that of the drop diameter on the card. Where only droplet densities need to be checked, you can expose petri plates of nutrient or trypticase-soy agar in openings in the spray blocks. These should be retrieved within 20 to 60 minutes of spray application and incubated at about 71.6° F (22° C) for 24 hours. Counts of bacterial colonies per unit area will reflect the densities of droplets that impinged on the plates. Densities of at least 20 to 25 droplets per cm- are usually sought in forest spraying. High densities of droplets are necessary for good protection of trees (table 7.5). Timing of Applications Laboratory tests have shown that more B.t. is required to kill larger, older larvae than smaller ones. However, the older larvae consume larger quantities of foliage and so ingest more of the applied B.t. The product of these two factors is that in the field, applications against third- through sixth- instar larvae can effectively reduce their numbers. The best timing is at the peak of the fourth instar, with a few larvae 108 Usage Patterns Table 7.5 —Relationship between ground level deposit of B.t. and percent protection of balsam fir foliage, eastern Canada and Maine, 1978-80 Spray droplets per cm- Total area treated Number of spray blocks Percent of treated area protected' 5-10 (Acres) 6,422 (Ha) 2,599 7 0 11-20 48,469 19,615 11 35 21-30 72,890 29,498 8 92 31-fO 20,259 8,199 4 100 41-50 17,122 6,929 4 100 51-87 13,689 5,540 2 100 ' Defoliation limited to 50 percent or less of current growth (from Grimble and Morris 1983). entering Lj and a few still in Spraying can commence somewhat earlier if the project is large and requires many days to complete. Do not delay application to the point that unacceptable damage to foliage has already occurred. In dense infestations, spraying can commence at the peak of the third instar. Generally, there will be a 10- to 14-day period between the peak of fourth-instar development and the time when larvae are no longer vulnerable. A second consideration in timing is the presence of a suitable target of foliage for the spray. After the second instar, budworms prefer to eat current-growth needles. Spray falling on old foliage is wasted. Therefore, spraying should be delayed until all buds have broken, shoots have elongated '/i to % inch (1 to 2 cm), and individual needles have started to flare. In most situations, this stage of foliage development usually corresponds with peak stage 4 of larval growth. Aircraft B.t. has been applied successfully with all types of aircraft commonly used in forest spraying, from small Bell 47 helicopters to large, four-engined aircraft such as the C54 (table 7.4). Most jurisdictions prefer to use the smaller aircraft and helicopters for B.t. applications; however, the Province of Quebec routinely uses large ones. Aircraft choice should be based on the size of the operations, proximity to airports, and similar considerations. For applying aqueous formulations of B.t., small aircraft may be better because less spray is lost to evaporation. ^ You may need to consult Federal, State, or university entomologists for help in determining these budworm life stages. Weather To use B.t., you need to pay more attention to weather conditions than is required for some chemical sprays. A major consideration is the effect of sunlight in degrading B.t. It generally remains effective on foliage for 3 to 7 days. The spray deposit must be eaten, and it is therefore important that weather favorable for feeding occur before the spray deposit degrades. Budworm larvae tend to feed little during periods of rain or cloudy, cool weather. Rain may also wash off the spray deposit, particularly if it has not completely dried on the treated foliage. If you must spray during unsettled weather, allow at least 1 to 4 hours for spray deposit to dry on the foliage, depending upon the type of sticker used. Densities of Spruce Budworm Several B.t. product labels recommend that B.t. not be used when budworm populations exceed 30 to 35 per 18-inch (45-cm) branch tip. This rule was developed when recommended rates for B.t. application were 8 BIU or less per acre. Now that higher dosages can be used, this limitation based on population may not be necessary. Nevertheless, specifications on labels must be followed, and tests against high budworm populations, which might justify label changes, have not been done. Poorer results are to be expected with any spray at very high budworm population densities. 109 Host Tree Species In the course of several years of a budworm outbreak, balsam fir will be the first host species to deteriorate and die. White spruce and red spruce should not show serious stress for 2 or 3 additional years. Hemlock may also suffer severe damage, particularly when mixed with the preferred hosts, fir and spruce. In nearly all tests and operational usages of B.t., efficacy has been far better on fir than on spruce. This is not a unique property of B.t.—the same discrepancy is ,>een with most chemical insecticides. Tree growth patterns provide more protection of larvae from all sprays on spruce than on fir or hemlock. Because spruce is somewhat less vulnerable to budworm feeding than fir, lower levels of control on spruce are often acceptable. Where high levels of protection on spruce are required, you can resort to split applications of a total of 12 BlU/acre (30 BlU/ha). The first of these should be applied at the peak of larval instar 4 followed by a second application when the persistent bud caps of spruce have fallen. Split applications with B.t. to control the budworm on spruce have not been tested extensively, so you should seek the latest information before proceeding. Vigor of Spruce Budworm Populations Although it has not been proven conclusively, there is some evidence that B.t. may work more effectively when spruce budworm populations are weakened by some additional factor. One such factor may be a microsporidian disease, of low virulence, which tends to increase in occurrence after a budworm outbreak has persisted in a region for several years. Recent testing of newer formulations and higher dosages of B.t. occurred in the later phases of the 1970’s budworm outbreak. Equally good results might not be obtained during the burgeoning, early phases of an outbreak. This is also the case with chemical insecticides, and some authorities suggest forgoing spraying of any kind during a peak year of an outbreak, when larval populations may exceed an average of 60 per branch. Under these conditions, little foliage is preserved by treatment, and without spraying you can achieve substantial natural reductions in budworm numbers through larval starvation. Trees should be protected by spraying in subsequent years so that their health is regained. 110 Additives and Mixing Modem formulations of B.t. are complete except for adding water for dilution and a sticker. Though formulations in the original state are stable for many months, the addition of water provides a medium in which other bacteria can grow; and diluted fomiulations will slowly degrade. Sufficient potency of the mix is expected to persist for 4 to 7 days, but in practice, spray managers like to mix the B.t. no more than 24 hours before applying it. If large amounts are mixed ahead of time, a delay of several days due to bad weather could result in some loss of potency. In large projects, tankers with triple tanks—one for B.t., one for water, and one for mixing—are used to ferry material to remote helipads and airports. Correct amounts of formulation and water can be metered into the mixing tank just before use. Users often ask whether chlorinated water can be used to dilute B.t. since chlorine is an antibacterial agent. This is not likely to be a problem. Upon addition of the B.t. to water, the chlorine content of the total mix is diluted to harmless levels. Where convenient, however, you should choose nonchlorinated water. The pH of the water should be between 5.5 and 7.5. Some formulations of B.t. contain a sticker and some do not. In practice, spray project managers add sticker in both cases. Extra cost is minimal. Some new classes of stickers (acrylics) are entering the market, and these appear superior to older ones. Check with the manufacturer of your formulation for recommendations on stickers. The sticker added usually makes only 1 or 2 percent of the total spray volume, and for proper mixing, the sticker should be thoroughly mixed with the water before adding B.t. There has been some research on adding small amounts of the enzyme chitinase to enhance activity of B.t., and this additive is used operationally in Quebec. Chitinase disrupts the integrity of the stomach wall of the insect, allowing the B.t. organisms to enter the body cavity more easily. Chitinase is a fairly cheap additive, but its value remains controversial. In most operations, it is not used. Mixtures of B.t. with small, sublethal quantities of chemical insecticides have also been tried with some success. We do not recommend them. With the new, concentrated formulations, you can simply increase the amount of B.t. rather than adding an enhancer. Many formulations of B.t. are quite viscous, particularly in the undiluted state. Heavy-duty pumps should be available for the mixing process. Thorough mixing in the mixing tank is usually accomplished by recirculation, and is an essential step. Because many B.t. formulations are abrasive, stainless steel fittings on pumps, tanks, and hoses are recommended over brass fittings. Ill Handling and Safety B.t. appears nearly totally safe to handle, except that irritation can occur if some is splashed into the eyes. Goggles should be worn, and eyewash bottles should be available during the mixing operation. Some B.t. formulations are sticky or oily, and some have an unpleasant odor. Loaders should wear gloves and coveralls, as much for cleanliness as for safety. Current B.t. formulations are not flammable and are not regulated as hazardous products in transport. While B.t. is very safe compared to many chemical insecticides, it is still considered an insecticide by Federal and local pesticide regulating agencies. Most of the same restrictions associated with conventional insecticides prevail, and the law requires that label directions and precautions be followed exactly. Read labels carefully and check with local pesticide regulating agencies for any special restrictions for your area. Ground Applications B.t. formulations can be applied with ground equipment as well as from the air. Ground application is appropriate for Christmas tree stands, nurseries, small plantations, seed orchards, and recreational sites such as campgrounds. The formulations designed for aerial application will also work well in air-blast sprayers. Some formulations will perform well in hydraulic sprayers, but wettable powders have been designed specifically for hydraulic use. Ground application is usually more effective than aerial application, probably because ground application puts more insecticide on the trees, resulting in better coverage. Using ground equipment may allow some reduction in dosage. For example, we expect as good results with 8 BlU/lOO gallons applied with ground equipment as with 12 BIU applied from the air. 112 Other Biological Control While B.t. is the only biological control for the spruce budworm that has reached operational status, many other approaches have been the subject of research. These controls range from other diseases of the budworm through parasitic insects and nematodes through use of sex pheromones. Probably the nuclear polyhedrosis virus (NPV) of spruce budworm will be the next biological tool made available to pest managers. The virus has the advantage of being even more specific to the budworm than is B.t., and NPV may persist in the population for several years after application. At present, it can be produced only in living budworms, the culture of which is prohibitively expensive except on an experimental scale. Inexpensive techniques for mass production are needed. In 1976, a study group in the Province of New Brunswick evaluated all of the new approaches to budworm control. Their report included a summary table that is reproduced here as table 7.6, revised to bring it up to date. While there are many interesting approaches, we can expect few new alternatives for biological control in the near future. Problems with mass production of biological organisms, stabilization of formulations, and high cost of production continue to retard development of alternative control methods. Table 7.6 —Summary of alternate biological control tactics Method Strategy for Use Status Limitations Potential 1. Native parasite enhancement Prevent outbreaks Minimum field trials Rearing Low for prevention—very low for outbreak control 2. Introduction of parasites Prevent outbreaks Laboratory Identification of candidates Low 3. Microsporidian parasites Prevent outbreaks, accelerate collapse Laboratory Spore production Low 4. Nematodes Prevent outbreaks Minimum field trials Mass production and application Low to moderate 5. Predator enhancement Prevent outbreaks Conceptual Basic information Low 6. Viruses Prevent outbreaks, accelerate collapse Field testing Virus production Moderately high if virus can be found and suitable application developed 7. Fungi Prevent outbreaks Field testing Application, human allergy Moderate 8. Host asynchrony Suppress outbreaks Laboratory Finding chemical Low 9. Pheromones Prevent outbreaks Field testing Getting “best” pheromone Low 10. Genetic control Prevent outbreaks Conceptual Induces sterility Low 113 Selected References Anon. Report of the task-force for evaluation of budworm control alternatives. Fredericton, NB: Cabinet Committee on Economic Development, Province of New Brunswick, Department of Natural Resources; 1976. 210 p. Barry, J. W.; Ekblad, R. B.; Markin, G. P.; Trostle, G. C. Methods for sampling and assessing deposits of insecticidal sprays released over forests. Tech. Bull. 1596. Washington, DC; U.S. Department of Agriculture; 1978. 162 p. Burges, H. D., ed. Microbial control of pests and plant diseases, 1970-1980. New York: Academic Press; 1981. 949 p. DeBoo, R. F.; Morris, O. N. Summary, conclusions and recommendations. In: Bacillus thuringiensis: Evaluation of commercial preparations of Bacillus thuringiensis with and without chitinase against spruce budworm. Info. Rep. CC-X-59. Ottawa, ON: Canadian Forestry Service, Chemical Control Research Institute; 1974. [This report contains several other articles of interest.] Dimond, J. B.; Spies, C. J. A comparison of B.t. alone with B.t. plus the additives chitinase and Orthene in control of eastern spruce budworm. Misc. Rep. 224. Orono, ME: Maine Agricultural Experiment Station; 1980. 15 p. Grimble, D. G.; Morris, O. N. Regional evaluation of B.t. for spruce budworm control. Agric. Info. Bull. 458. Washington, DC: U.S. Department of Agriculture, Forest Service; 1983. 8 p. Morris, O. N. Bacteria as pesticides; forestry applications. In: Kurstak, E., ed. Microbial and viral pesticides. New York: Marcel Dekker; 1983: 239-287. Morris, O. N. Entomopathogenic viruses; strategies for use in forest insect pest management. Can. Entomol. 112: 573-574; 1980. Morris, O. N.; Moore, A. Changes in spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae), biomass in stands treated with commercial Bacillus thuringiensis var. kurstaki. Can. Entomol. 115: 431- 434; 1983. Retnakaran, A.; Grant, G. G.; Ennis, T. J.; Fast, P. G.; Arif, B. M.; Tyrrell, D.; Wilson, G. Development of environmentally acceptable methods for controlling insect pests of forests. Info. Rep. FPM-X-62. Sault Ste. Marie, ON: Canadian Forestry Service, Forest Pest Management Institute; 1982. Smirnoff, W. A. Instructions for evaluating deposit of Bacillus thuringiensis formulas during aerial treatment. Info. Rep. LAU-X-54. Sainte-Foy, PQ: Canadian Forestry Service, Laurentian Forest Research Centre; 1982. 6 p. Smirnoff, W. A.; Juneau, A. Physical analysis of the dispersion of Bacillus thuringiensis against spruce budworm. Info. Rep. LAU-X-55. Sainte-Foy, PQ: Canadian Forestry Service, Laurentian Forest Research Centre; 1982. 18 p. Smirnoff, W. A.; Valero, J. R. Characteristics of a highly concentrated Bacillus thuringiensis formulation against spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae). Can. Entomol. 115; 443- 444; 1983. 114 Chapter 8 Chemical Control Patrick J. Shea and P. Chandra Nigam' i . It''**’ •- '^Vi. - X'fiV i ' Research Entomologist, USDA Forest Service, Pacific Southwest Forest and Range Experiment Station, Berkeley, Calit.; and Research Scientist, Canadian Forestry Service, Maritimes F-'orest Research Centre, Fredericton, N.B. Until the late 1920’s, effective insect protection in forestry protect it from spruce budworm. To our knowledge this was was not possible, much less practical. There were no cheap, one of the first aerial applications of an insecticide in potent insecticides and no practical application methods. In forestry. Apparently no further applications of this type took 1927, J. M. Swaine and E. Schreiner, the former an place until World War II (tables 8.1 and 8.2). But employee of the Dominion Forest Service and the latter of the commercial production of DDT and the availability of Oxford Paper Co., Maine, applied calcium arsenate from an aircraft stimulated remarkably successful research and airplane to a spruce-fir forest in Cape Breton, N.S., to development efforts on the control of agricultural insects. Table 8.1 —Summary of aerial spraying of chemical insecticides for spruce budworm suppression in Maine, 1954-82 (from USDA Forest Service 1979)' Year Insecticide Acres treated Ha treated 1954 DDT Thousand 21 Thousand 8.5 1958 DDT 302 122.2 1960 DDT 217 87.8 1961 DDT 53 21.4 1963 DDT 479 193.8 1964 DDT 58 23.5 1967 DDT 92 37.2 1970 Fenitrothion (Accothion) 210 85.0 1972 Mexacarbate (Zectran) 500 202.3 1973 Mexacarbate 450 182.1 1974 Mexacarbate 430 174.0 1975 Carbaryl (Sevin-4-Oil) 496 200.7 Fenitrothion (Sumithion) 1,499 606.6 Mexacarbate 238 96.3 1976 Carbaryl 3,460 1,400.2 Trichlorfon (Dylox 4) 40 16.2 1977 Carbaryl 808 327.0 Trichlorfon 55 22.3 Acephate (Orthene Forest Spray) 58 23.5 1978 Carbaryl 967 391.3 Trichlorfon 54 21.9 Acephate 96 38.9 1979 Carbaryl 2,543 1,029.1 Trichlorfon 97 39.3 Acephate 110 44.5 1980 Carbaryl 1,169 473.1 1981 Carbaryl 1,015 410.8 Acephate 31 12.5 1982 Carbaryl 686 277.6 Acephate 46 18.6 ' Microbial insecticides were also used (see chapter 7). Table 8.2 —Summary of aerial spraying of chemical insecticides for spruce budworm suppression in eastern Canada, 1944-82'- Year Insecticides Acres treated Ha treated 1944 DDT Thousand 0.01 Thousand 0.004 1945 DDT 64.7 26.2 1946 DDT 30.6 12.4 1951 DDT 2.47 1.0 1952 DDT 196.0 79.3 1953 DDT 1813.0 733.7 1954 DDT 1460.1 590.9 1955 DDT 2165.6 876.4 1956 DDT 2375.9 961.5 1957 DDT 6951.4 2813.1 1958 DDT 3360.1 1359.8 1959 DDT 2.0 0.8 1960 DDT 2650.1 1072.5 1961 DDT 2266.6 917.3 Phosphamidon 1.5 0.6 1962 DDT 1434.9 580.7 Phosphamidon 0.7 0.3 1963 DDT 646.4 261.6 Phosphamidon 22.2 9.0 1964 DDT 1819.9 736.5 Phosphamidon 161.8 65.5 1965 DDT 1689.7 683.8 Phosphamidon 897.6 363.2 1966 DDT 1755.6 710.5 Phosphamidon 220.2 89.1 1967 DDT 767.5 310.6 Phosphamidon 72.9 29.5 Fenitrothion 196.4 79.5 1968 DDT 208.1 84.2 Phosphamidon 236.7 95.8 Fenitrothion 577.5 233.7 ' These figures are approximate (compiled from reports of the Interdepartmental Committee on Forest Spraying Operations and annual forest and insect and disease survey reports; Nigam 1975). - Microbial insecticides w'ere also used (see chapter 7). 116 After the War, forest pest managers began successfully adapting agricultural innovations for their own use. Since then the planning and organization of forest insect spray projects has become enormously complex and difficult. In a brief chapter it is impossible to treat this subject in detail. Consequently, we are restricting the discussion to major topics related to the conduct of large-scale aerial operations with chemical insecticides, operations directed against epidemic populations of spruce budworms for the purpose of foliage protection. In addition, we refer you to other chapters in the handbook or to the relevant literature for technical information on topics mentioned in this chapter, such as deposit assessment. Year Insecticides Acres treated Ha treated Year Insecticides Acres treated Ha treated Thousand Thousand Thousand Thousand 1969 DDT 3.5 1.4 1976 Phosphamidon 493.7 199.8 Fenitrothion 3118.4 1261.9 Fenitrothion 14403.4 5829.0 Mexacarbate 11.9 4.8 Aminocarb 4984.7 2017.3 1970 Phosphamidon 306.0 123.8 Trichlorfon 263.9 106.8 Fenitrothion 4290.2 1736.2 Acephate 1.7 0.7 Aminocarb 6.7 2.7 1977 Phosphamidon 2417.1 978.2 Trichlorfon 4.2 1.7 Fenitrothion 4743.8 1919.8 1971 Fenitrothion 8162.7 3303.4 Aminocarb 4159.4 1683.3 Aminocarb 36.1 14.6 Trichlorfon 341.7 138.3 Mexacarbate 24.0 9.7 Acephate 4.2 1.7 1972 Phosphamidon 7.9 3.2 1978 Fenitrothion 3488.6 1411.8 Fenitrothion 3983.7 1612.2 Mexacarbate 127.3 51.5 Mexacarbate 173.7 70.3 Aminocarb 5267.7 2131.8 Aminocarb 75.4 30.5 Acephate 0.2 0.08 1973 Phosphamidon 2200.0 890.3 1979 Fenitrothion 391.4 158.4 Fenitrothion 11568.2 4681.6 Aminocarb 5332.9 2158.2 Mexacarbate 88.2 35.7 Acephate 4.7 1.9 Aminocarb 300.0 121.4 1980 Fenitrothion 3777.4 1528.7 Trichlorfon 1.0 0.4 Aminocarb 773.9 313.2 1974 Phosphamidon 3475.0 1406.3 Acephate 1.7 0.7 Fenitrothion 6604.2 2672.7 1981 Fenitrothion 5035.9 2038.0 Mexacarbate 1048.2 424.2 .Aminocarb 1961.2 793.7 Aminocarb 1200.0 485.6 1982 Fenitrothion 4779.7 1934.3 Trichlorfon 33.1 13.4 Aminocarb 2642.5 1069.4 Acephate 0.7 0.3 Acephate 0.1 0.04 1975 Phosphamidon 8206.4 3321.1 Fenitrothion 2339.2 946.7 Mexacarbate 587.9 237.9 Aminocarb 1448.5 586.2 Trichlorfon 313.3 126.8 Acephate 5.7 2.3 117 Why Chemical Insecticides? To achieve desirable foliage protection, an insecticide must be quick acting and toxic to the budworm. These are two necessary, but not sufficient, characteristics of an insecticide for foliage protection under epidemic conditions. Chemical insecticides registered for use against spruce budworm meet these two essential requirements. A curve that illustrates the start of a budworm epidemic, such as figure 8 . 1 , shows clearly that foliage protection results from substantial population reductions. Figure 8.1 (adapted from Simmons 1980) shows moth captures during the development of an epidemic. The right ordinate shows the level of a given percent reduction from the “peak.” For Number of moths captured Effect of given percent (x10) reduction in pest population 16 Years Figure 8.1 —Freehand curve fitted to light-trap captures of spruce budworm moths at Eustis, Maine, 1962-73. (Adapted from Simmons 1980.) example, a one-time 80-percent reduction in the peak leaves a population index of 28 moths, which in a little over 2 years will result in a “peak” population again. Larval population dynamics in the epidemic stage can be expected to show a far steeper rise in population over time. Moreover, the empirical data set illustrated has not peaked, and Simmons noted that defoliation in the area first occurred in 1974. In brief, most forest pest managers cannot accept epidemic population reductions less than 90 percent; otherwise the residual population may increase so fast that substantial defoliation will occur the following year and complete defoliation the year after. Quick action is necessary to protect current-year foliage. Budworm populations cannot be effectively treated until late Lj and preferably early L 4 . Prior to these stages the larvae are bud or needle miners and are not exposed to a contact insecticide. Table 8.3 (adapted from Roller and Leonard 1981) shows larval consumption of balsam fir foliage by instar and the effects of 90- and 70-percent population reductions on foliage conserved depending on the instar in which the population reduction occurred. It is clear that substantial foliage is saved if death occurs immediately after application. If population reduction is relatively poor, quick mortality is an even bigger advantage. The combination of modest population reductions and slow action is completely unacceptable for foliage protection. Chemical insecticides registered for spruce budworm are quick acting. Table 8.3 —Percent foliage consumption (grams of balsam fir per larva) by spruce budworm instars (adapted from Roller and Leonard 1981) Instar Foliage consumption Percent consumption Percent foliage saved with larval survival at 10% 30% L]-L 3 0.008 3 87.3 67.9 u 0.014 5.2 82.6 64.3 L 5 0.030 11.2 72.5 56.4 U 0.216 80.6 '36.3 28.2 Total 0.268 100 ' Assume mortality occurs mid-Lf,. 118 Federal and Provincial/State Responsibilities In the United States and Canada, Federal laws provide the machinery to accomplish regulation and control of pesticidal materials. In the United States, the law is known as the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and is administered by the U.S. Environmental Protection Agency (EPA). In Canada, the Eederal law is the Pest Control Products Act (PCPA), which is administered by the Canadian Department of Agriculture. Activities covered by these laws, and used to ensure the safety of pesticides, include the registration and reregistration process, the process of suspension and cancellation, the classification of pesticides, and the training and certification of personnel who apply pesticides. Appendix 3 lists other Federal laws relating to the aerial application of forest insecticides. The major statutes, the administering agency, and the principal features of each are covered. Local Jurisdictions, Provinces, States, municipalities, etc., also regulate the use of pesticides by law. Such laws are often more restrictive than Federal laws, reflecting local conditions. In jurisprudence, laws of a local jurisdiction prevail unless they can be shown to be in conflict with the intent and purpose of Federal law. In both countries, pesticide laws and regulations are vigorously enforced. They are also subject to amendment and regulatory changes as new information becomes available. Consequently, the forester or landowner contemplating the use of a registered pesticide must be thoroughly familiar with the current law affecting the proposed operation. Appendix 4 lists the Federal, Provincial, and State offices from which you can obtain current information on legal restrictions regarding the use of insecticides for all locations likely to experience severe budworm impact in Eastern North America. Classification of Chemical Insecticides For the purpose of this chapter, chemical insecticides are classified in three major groups: 1. Chlorinated hydrocarbons.—Perhaps the best- known chlorinated hydrocarbon insecticide is DDT. Most of these compounds have low acute toxicity to humans. However, they persist in the environment for relatively long periods of time and tend to accumulate in the fatty tissues of people and animals. Earlier, these pesticides were used against many forest pests, but they became notorious during the 1960’s after the publication of Rachel Carson’s book Silent Spring. Today, the chlorinated hydrocarbons are rarely used on the forests. 2. Organophosphates.—Organophosphate compounds are involved in more cases of occupational poisonings and deaths from pesticides than any other chemical group. The most familiar insecticides in this family (to budworm control operators) are acephate, fenitrothion, and trichlorfon. Organophosphate compounds do not persist in the environment and do not accumulate in the fatty tissues of people or animals. But in concentrates, most of them have high acute toxicity and must be handled with extreme caution. When applied to the soil, some organophosphates enter the plant roots and move throughout the plant to make the plant tissue poisonous. These are called systemic pesticides. 3. Carbamates.—Aminocarb and carbaryl are familiar carbamate insecticides. In general, the chemicals of this family are moderately persistent in the environment but do not accumulate in fat. The toxic hazard to humans and other warm-blooded animals is slight for carbamate insecticides used in operational budworm suppression. Carbamates, especially carbaryl, are used extensively in forestry to control such pests as gypsy moth and forest tent caterpillar, as well as spruce budworm. 119 Registered Chemical Insecticides Insecticides are also sometimes grouped according to the primary manner by which they enter or affect the insect: stomach poisons, contact poisons, or systemic insecticides. Insecticides vary in their mode of entry and effects on insects, and insecticide classification is therefore sometimes difficult. The effect of an insecticide is decided by its physical characteristics. Stomach poisons are those not sufficiently fat soluble or volatile to act as a contact or fumigant poison. They enter the insect via feeding, pass into the midgut, and from there are distributed throughout the insect. Their efficacy depends upon the stability of the chemical compound or its toxic metabolites on the foliage. Systemic insecticides are readily absorbed and distributed throughout the host plants. The insect feeds on contaminated foliage and thereby receives a toxic dose. Basically, systemic insecticides act as stomach poisons; but their efficacy depends on the plant delivering a biologically active dose to the insects feeding site without severely damaging itself. Contact insecticides are toxic when they come into contact with the body surface of insects and enter through the cuticle or respiratory system. Contact insecticides may also act as stomach poisons, except in cases where they are destroyed by digestion or fail to be absorbed into the insect’s system. The insecticides registered and available for use in the United States and Canada for aerial application against the spruce budworm are listed in tables 8.4 and 8.5. Most of the compounds are registered in both countries. However, only five (acephate, aminocarb, carbaryl, fenitrothion, and trichlorfon) have found much use in the past few years. The others have serious limitations (e.g., cost, environmental hazard, or relative effectiveness) that restrict their use. Since formulation and allowable rates of application vary significantly, the user should consult local pesticide regulation officials for recommendations. The registration labels (Agriculture Canada, EPA, or State) are always the final sources for information about allowable uses for insecticides. In both Canada and the United States, it is a violation of the law to use any registered pesticide in a manner inconsistent with label directions. Table 8.4 —Chemical insecticides registered for aerial application for spruce budworm control in the United States Common name Trade name and formulation EPA registration number Acephate Orthene Forest Spray 239-2443 Aminocarb Matacil 180 flowable' 3125-327 Carbaryl Sevin 80 S 264-316 Sevinmol 4 264-321 Sevin-4-Oil 264-323 Sevin XFR 264-333 Sevin SL 264-335 Sevin FR 264-345 Fenitrothion Sumithion 8E 39398-3 Sumithion Concentrate 476-2819 Malathion Cythion Ultralow Volume (ULV) Malathion UFV 241-208 Concentrate Malathion ULV 241-110 Concentrate 904-243 Mexacarbate Zectran DB 264-385 Trichlorfon Dylox 4 3125-210 ' Can be used in New Jersey. New York. Pennsylvania, and all New England States. 120 Table 8.5—Chemical insecticides registered for aerial application for spruce budworm control in Canada Common name Trade name and formulation' Use category- Agriculture Canada registration number Acephate Orthene Forest Spray FOR 14.226 (under tern- Concentrate—97% SP WLD porary regis- tration) Aminocarb Matacil 180-D EOR 14,186 (oil-soluble concentrate) WLD Matacil 180 Flowable FOR 17,418 Insecticide WLD Carbaryl Sevin-4-Oil EOR 11,115 Dimethoate Cygon 480-E ORE 14,767 WLD Cygon 4-E ORE 8.567 WED Pfizer Cygon 4-E ORE 9,382 WLD Fenitrothion Sumithion technical EOR 11,137 grade WLD Folithion liquid concen- EOR 10,776 trate WLD Novathion concentrate EOR 14,299 ORF WLD Trichlorfon Dylox 4.2 liquid solution EOR 14,307 WLD Dylox 420 liquid EOR 16,387 insecticide solution ORE WLD Danex 80% soluble EOR 9,827 powder ORE WLD Danex 80 SP ORF 15.319 Danex 80 SP ORF 16,887 WLD ' SP = suspension. WP = wettable powder. E = emulsion. - Use category'—Forestry (FOR) = total area treated over 1,235 acres (500 ha). Woodlands (WLD) = total area treated under 1.235 acres (500 ha). Ornamental (ORF) = total area treated under 2.471 acres (1 ha). Forestry and woodlands category pesticides may be sprayed by air. ground, or both depending on registration. However, all are classified as “restricted." and their use requires a Provincial government permit. Table 8.6 presents basic toxicity of commonly used insecticides to fish, birds, and mammals (Nigam 1975). For comparison, and interest, data on DDT are included. The decision to use any one of these products must be based partly on an assessment of its relative toxicity to different organisms in the environment. In comparing the LCjq or LDjo values,^ a simple guideline is “the larger the number, the safer the material.” Thus, in comparing acephate with DDT (acknowledging that the DDT fish data pertain to salmon and the acephate data to trout), acephate, with a fish LC 50 of 1,000 p/m, is 20,000 times safer than DDT, with a fish LC 50 of 0.05 p/m. The next column, however, shows that DDT is far less toxic to birds than is acephate. Acephate Marketed as Orthene, this product is a water-soluble systemic material. Its primary means of toxicity, however, is as a stomach poison. Among its advantages are relative safety to fish and mammals and ease of formulation in water. Disadvantages are that it is sometimes not effective against earlier budworm instars (L3-L4), it is toxic to bees, and the water-mixed spray is susceptible to evaporation when released from aircraft. Because acephate is a powder that must be handled in bags, rather than being pumped, it requires increased handling time. With proper application rates and timing, acephate is effective, usually for about 6 to 9 days. It has been used mainly in Ontario and Maine over small areas but has not yet gained acceptance in either New Brunswick or Quebec, due partly to its high cost. Aminocarb Marketed as Matacil, this insecticide is an oil-soluble formulation. It has been used extensively in Canada since 1973 and is most effective against budworm larvae in the third and fourth instars. Advantages of aminocarb are its effectiveness, relatively low cost, and ease of handling. Since it is an oil formulation, evaporation is not a problem. Carbaryl Marketed as Sevin, carbaryl has been used extensively as Sevin-4-Oil against the spruce budworm in the United States. It is registered but has not yet been used operationally in Canada. Carbaryl is effective for up to 28 days after spraying and is relatively inexpensive, but it is considered quite toxic to foraging bees and aquatic insects. Carbaryl shows low toxicity to fish, birds, and mammals. ^ LC,g and LD,,, values represent the “one-time" concentration or dosage, expressed in milligrams of active ingredient per kilogram of body weight, that will kill 50 percent of test animals. 121 Fenitrothion Marketed as Accothion, Sumithion, Folithion, and Novathion, this material has been used extensively in the spruce budworm operations in eastern Canada, especially in New Brunswick and Quebec. Applied as either a water emulsion or an oil solution, fenitrothion is effective for 10 to 14 days against the early (L 2 ) as well as the later (Lj-L^) instars of the spruce budworm. It is relatively cheap and has low toxicity to birds, fish, and mammals, if used correctly. Fenitrothion sometimes has a severe impact on nontarget insects and birds, especially when errors in application result in overdosage (e.g., double application). Trichiorfon Marketed as Dylox, trichiorfon has not been as commonly used as the preceding insecticides, largely because the recommended rates result in uneconomical, higher cost and because it is most effective against later instars (L^-L^) of the budworm, when the insect is more exposed to the spray. Most operators wish to remove the budworm threat early (while the insects are in the L, or L 4 stage), to preserve foliage on the trees. Dylox is water-soluble and, in water formulation, is subject to rapid degradation by rainfall. It was used operationally in Canada from 1974 to 1977, especially in New Brunswick around blueberry bogs because it is less toxic to bees than some other pesticides. Trichiorfon usually remains active for about 5 to 7 days after spraying. Table 8.6 —Toxicity of some chemical pesticides used against the spruce budworm in Canada and the United States (modified from Nigam 1975)' Toxicity to Mammalian toxicity in rats Registered fish (salmon) Toxicity to birds LD50 Common name Trade name application rate LC 50 p/m (48 hr) LD 50 (mg/kg) Oral Dermal (g a.i./ha) (mg/kg) DDT- DDT 20-2,280 0.05 2,240.0 87-500 1,931-3,263 Acephate Orthene 425-550 1000.00 (trout) 350.0 1,494 10,250 Aminocarb Matacil 55-90 1.30 22.5 30 275 Carbaryl Sevin 1,090 1.00 >2,179 307-986 >500->4,000 Fenitrothion Folithion Sumithion Novathion 150-275 1.4 1,190 250-670 200->3,000 Trichiorfon Dylox Dipterex 840-1,700 1.6 >5,000 450-569 > 2,000 ' To convert metric measurements, use these equivalents: 1 kg = 2.2046 lb 1 ha = 2.741 acres - In Canada, can be used only in an emergency situation and only under special restrictions. Use prohibited in the United States. DDT data are presented for comparison only. 122 Considerations for Planning and Organizing Aerial Operations Every operation differs in detail; however, there are some general principles of planning and organization that are worth stressing. First, it is essential that a spray or no-spray decision be made as soon as possible. In the case of budworm, go/no-go decisions should be made regarding an operation for the next field season in late August or early September, i.e., when information on population and defoliation condition first becomes available. Go decisions can be reversed anytime up to 3 or 4 weeks before the expected start of operations without adverse effects. But late go decisions waste precious time. Lack of time, budget, and trained staff, and senior management’s “concerns” and “advice” are the forest pest manager's principal problems. Once a go decision has been made, it is helpful to consider the total project as consisting of two components. Operations Planning and Field, with the forest pest manager coordinating and providing the machinery for the rapid exchange of usable information between the two groups. If the staff is essentially untrained, the forest pest manager’s first priority is to provide accelerated training in aerial insecticide operations against forest insects. Federal, State, and Provincial organizations and universities with forestry schools can provide materials and instructors. The manager with professional credentials and current contacts can quickly train and prepare inexperienced people for the job ahead. For experienced personnel, training consists of heightening safety consciousness, critiquing past operations to improve the efficiency of the pending one, and identifying unique conditions in the current situation that may affect operations. The functions of the Operations Planning group are planning, providing logistic support, and promoting good relations with the public. The functions of the Field group, up to the start of operations, are collection of information for transfer to Operations; intensive maintenance, repair, and replacement of owned equipment and facilities that are expected to be used; and public relations. When the operation starts, execution becomes the responsibility of the Field group under the direction of the forest pest manager. Appendix 5 is a checklist of what needs to be done or provided in a typical aerial spray operation, but pest managers will want to draft and continuously update a checklist of their own relevant to the project. This checklist provides the basis for organizing and preparing the operational plan, which will also require continuous updating. Previous training in time sequence analysis methods will be helpful for the Operations Planning group in developing the operational plan because such plans are essentially charts of chronological sequences of activities leading to deposits of insecticide on desired areas at the planned time. For illustrative purposes, table 8.7 shows a crude timeframe for major activities and the responsible group. The actual operation will almost certainly not proceed according to plan. The forest pest manager should expect this. It is impossible to anticipate all contingencies. What is important is to be able to make and communicate decisions changing the plan in its semi- and operational phases. The primary objective of the entire operation is to provide substantial host foliage protection on all the selected areas. This is accomplished by taking maximum advantage of favorable spray weather when the larvae are most exposed. The two factors that can be anticipated to result in late planning changes are the size of larval populations and the bud development of host species. Both are dependent on weather conditions, and the former may also be affected by imprecise prior information or a poor estimate of larval development. For example, population estimates based on hibernacula surveys (see chapter 3) can be profoundly affected by succeeding mortality estimates and level of dispersal (Blais 1979). Late population and bud development information can and should be used to change the timing of spray operations and to delete or add spray blocks. In addition, late biological information can affect decisions on the proposed use of split applications. Split applications were probably first intended to take advantage of the differences in foliage development of red spruce and balsam fir. Planned split applications offer the additional advantage of hedging against diverse weather conditions. That is, anticipating bad weather, the pest manager can cancel the application that would be affected. If the first application is cancelled, the concentration of the second can be increased (up to the label limit). However, if the second application is cancelled, the manager must accept the results of the first for which the dosage rate was reduced to accommodate the planned split. 123 Table 8.7 —Timing a major planning activity—Operations planning Activity Timeframe Mapping project From early fall, and continuing Location of project Start Location of host areas Start Development of hazard Early rating Hazard rate host area Early and continuing Selection of insecticide(s) Early Environmental assessment After selection of insecticide and continuing until due date Preliminary Selection of Mid and continuing suppression blocks Sensing public opinion in Begin after preliminary populated and selection of suppression semipopulated areas blocks Public relation plans As soon as “sensing” including delivery of indicates a need information fo affected communities Selecting required dose. Mid application volume, spray atomization Navigation procedure Mid Contracting Variable Field Population information Start and continuing Host development Late and then continuing information Equipment maintenance Start and continuing Preparation of operational Mid headquarters Sensing public reaction Mid and continuing Dry runs of support Mid activities, equipment checks Communication plan Mid Crew organization and siting Mid plan Successful split applications provide superior foliage protection. For balsam fir. the first application is timed as though it were a single application, i.e.. when the larvae are maximally exposed on the foliage, peak L 3 -L 4 . The second is timed for peak L 4 -L 3 . Since the second application is, in effect, against a residual population, a quick glance at foliage consumption (table 8.3) for L, and L^, shows why superior foliage protection is obtained with successful split applications of a quick-acting insecticide. Despite potential advantages, split applications are not always used by experienced budworm forest pest managers. Increased costs are obviously a factor, though there is not a doubling of costs as some maintain. More important, in large budworm outbreaks with multiple suppression blocks scheduled for treatment, is the need to maximize the use of available aircraft to provide the desired protection. Splits should definitely be considered (and are often used) for stands with high timber values, where a high degree of foliage protection is required, and for stands not likely to be harvested soon {see Dimond et al. 1984). Because successful split applications illustrate the utility of basic biological information on larval and bud development, we discuss timing in this context. Clearly, however, timing is especially critical for single applications. Biological considerations are important—a moderately successful early application will be reinforced by natural mortality factors, resulting in good foliage protection. A moderately successful late application will not effectively conserve current-year foliage, but the effect of population reduction on conserving next year’s foliage may be valuable, if the stands were in relatively good condition at the start. But the paramount consideration is the success of the entire project. In brief, logistics—what remains to be done and the time available to do it—are most important in deciding whether to spray early, late, or not at all. Finally, we must admit that most of what is known about timing of sprays refers to budworm development on balsam fir. A recent publication (Hansen and Dimond 1982) partially remedies this situation. Budworm development and feeding behavior on the spruces is different than on balsam fir (table 8 . 8 ). Unfortunately, we do not know if the differences are constant from year to year. Therefore, knowing the insect’s development and behavior on fir is not enough to enable us to confidently predict its development and behavior on the spruces. But, given that substantial numbers of L 3 and L 4 feed externally on red spruce buds, managers could probably provide better spruce protection with only a moderate sacrifice in fir, by spraying just a bit later than for a fir-only stand. 124 Table 8.8 —Approximate duration of, and spruce budworm instars involved in, three periods of larval feeding on five host species. Pupation occurred in the last week of June 1980 on all hosts (Hansen and Dimond 1982). Host Approximate duration Instars Balsam fir Needle mining 4/30-5/12 L2-L3 White spruce 4/30-5/16 L 2 -L 3 Red spruce 5/1 -5/20 L 2 -L 3 Black spruce 5/5 -5/20 L2-L3 Hemlock 5/1 -5/16 L 2 -L 3 Balsam fir Bud feeding 5/12-5/20 L 3 —L 4 White spruce 5/7 -5/20 L 3 —L 4 Red spruce 5/16-6/5 L 3 -L 5 Black spruce 5/20-6/5 L 3 -L 5 Hemlock 5/12-5/26 L 3 -L 4 Balsam fir Shoot feeding 5/21-Pupation L 4 L 5 White spruce 5/20-Pupation L 3 —L 6 Red spruce 6/5 -Pupation L 5 — Black spruce 6/5 -Pupation L 4 L 5 Hemlock 5/26-Pupation L 4 L 5 Two other “spray windows” for budworm have been considered. First, it is possible to track budworm moth flights by radar (Greenbank 1980). This fact creates a possibility of operations against adults, and the use of radar and the application of adulticides has been successful with some agricultural insects. But the prospects of such operations for forest insects are so shrouded in uncertainty, not to mention the unknown environmental impacts, that adulticides have never been seriously considered for operational use against budworm. Nevertheless, there is a tremendous advantage to be obtained from the successful use of an adulticide. This strategy strikes at fecundity, which ultimately drives the budworm outbreak. The second alternative spray window is the L 2 dispersal phase (Randall 1977). If managers could confidently spray during that phase, there would be a marked increase in foliage saved and a reduction in budworm populations. But not all experienced spruce budworm pest managers are convinced that research information on larval dispersal is adequate for operational use of this proposed window. We do know that larval dispersal is related to stocking levels and the amount of hardwood admixture (Jennings 1983 and Kemp’), suggesting that mixed-wood stands and thinned or opened stands might be very effectively treated in this window. The operational cycle is completed with postspray evaluation consisting of defoliation, pupal, and/or egg-mass surveys (see chapter 3). During an outbreak, these surveys provide the information to start the planning cycle for the following year. The defoliation survey tells how well the goals for foliage protection were met. Because egg-mass surveys reflect the production of immigrants as well as surviving residual moths, such surveys are chiefly useful for appraising the situation for the next field season. Additionally, a marked reduction in egg masses compared to the previous survey certainly suggests a very effective operation with a minimum of immigration. In reviewing the entire operational cycle, we can say with some confidence that if operational planning is done well, pest managers will have the flexibility to make effective tactical decisions that bring to bear their full knowledge of the biology of the insect and its host. If operational planning is not well done, managers will spend all their time dealing with emergencies, leaving none for processing information and making decisions. Even worse, knowing that changes should be made, managers may find themselves incapable of altering the course of the operation once begun. ’ Kemp, W. P. The significance of non-host and alternative host tree species on populations of larval spruce budworm, with emphasis on improving sampling techniques. Unpublished CANUSA report, available from USDA Forest Service, 370 Reed Rd., Broomall, PA 19008. 125 Aerial Spraying It is not possible in this chapter to discuss in detail all of the necessary equipment and actions needed to successfully and safely carry out an aerial spray project. Instead we will try to introduce the most important considerations and refer the reader to available literature for additional information. Aircraft Budworm control projects have utilized a variety of aircraft, ranging from small fixed-wing planes or small helicopters to large multiengine aircraft (Prebble 1975). Small aircraft, such as the Piper Pawnee, Stearman, Grumman AgCat, or Cessna AgWagon, are primarily useful for treating small or irregular areas and areas near water or human habitation. These planes normally operate at speeds of about 90 to 120 mi/h (145 to 193 km/h) and effectively cover spray swaths of about 75 to 150 ft (23 to 46 m) in width. They are generally used on blocks close to the operations airfield because their relatively slow speeds and small payload capabilities prohibit spraying at “long ferry" distances. Table 8.9 presents some characteristics of the principal types of aircraft used in recent budworm suppression projects. Following World War II, many large military aircraft became available at relatively low cost and were converted to forest spraying. These planes (e.g., Grumman Avenger [TBM], DC-6 and -7, and Lockheed PV-2) are faster, carry much larger payloads, and spray large blocks of forest effectively. Spray swaths with these planes usually are in the range of 400 to 500 ft (122 to 152 m) wide for the TBM and PV-2, and up to 2,500 ft (762 m) for DC-6 and -7. Because of their speed and reduced maneuverability, compared to smaller aircraft, these large planes cannot operate as close to the tree canopy as can the smaller aircraft. For example, an AgCat can release spray within 50 to 75 ft (15 to 23 m) of the treetops, whereas a TBM sprays at about 100 ft (30.5 m) above treetops and a Constellation at 150 ft (46 m) or more. Greater vertical distances between the spray plane and the tree foliage usually cause increased sideways drift of the spray materials Table 8.9—Characteristics of the principal types of aircraft used in forest insect control in Canada and the Eastern United States Aircraft Type Spraying speed Payload capacity Boeing Stearman Biplane (Milh) 90-100 (Km/h) 145-161 (U.S. gal) 125-150 (1) 473-568 DeHaviland Beaver Monoplane 90-100 145-161 150 568 Grumman Avenger Monoplane 150-170 241-274 700 2,650 Grumman AgCat Biplane 90-100 145-161 150 568 Piper Cub Monoplane 90-100 145-161 100 379 Piper Pawnee Monoplane 100-110 161-177 150 568 Cessna AgWagon Monoplane 120-130 193-209 200 757 Douglas DC-7B 4-Engine 230 370 4,000 15,142 Douglas DC-6B monoplane 4-Engine 200 322 3,600 13,627 Lockheed PV-2 monoplane 2-Engine 150 241 800 3,028 Lockheed Constellation 749 monoplane 4-Engine 205 330 3,600 13,627 Lockheed Constellation LI049 monoplane 4-Engine 215 346 4,400 16,656 Canadair CL-215 monoplane 2-Engine 150 241 1,450 5,489 Bell 47 monoplane Helicopter 60 97 50 189 Hiller UH12E Helicopter 60 97 50 189 Bell 205/212 Helicopter 100 161 150 568 Bell 206 Helicopter 80 129 90-100 341-379 126 and increased evaporation of water-based sprays. Table 7.4 (chapter 7) presents examples of swath widths for some commonly used small spray aircraft. Helicopters—slower yet more maneuverable than fixed-wing planes—are thus well suited to spray small, high-value, irregular, or environmentally sensitive areas. Helicopters can operate from primitive airstrips or even forest clearings but are not practical when distance to the spray block is great. The operating cost for helicopters is quite high; and even though newer, large helicopters are becoming more cost effective, it is still difficult for helicopters to compete economically with fixed-wing aircraft in large-scale spraying operations. Spray Nozzles and Deposits Conventional boom and nozzle arrangements and, more recently, rotating atomizers are used for atomizing pesticide sprays. In conventional nozzles, the formulation is atomized into drops by utilizing the pressure in the spray system and by encountering air resistance caused by the speed of the aircraft. Spray booms can be mounted under the wings of the airplanes, above the wings, or at the trailing edge of the wings (Randall 1976). Rotating atomizers are frequently used for low-volume applications (<0.5 gal/acre [4.7 1/ha]). The rotating atomizers (spinning discs or rotating cages of wire mesh) can be powered by electric current or driven by a windmill principle utilizing blades. Rotating atomizers powered by electric motors offer more control and versatility. The degree of spray droplet atomization affects spray behavior, evaporation, drift, convection, and pattern of deposition, all of which in turn affect the frequency and intensity of target coverage. Fine spray drops are affected more by meteorological factors than are coarse drops. Most of the time, these factors are unpredictable and beyond the operator’s control. Micrometeorological factors, including windspeed, horizontal and vertical air movements, temperature gradient profiles (stable, inversion, lapse), and relative humidity, affect the behavior and transport of spray drops suspended in the air and the pattern of dispersal, including the amount of active material actually deposited on target tree foliage. Spray atomization, with either tlat-spray or hollow-cone nozzles, can be varied by several mechanical factors used singly or in combination, as follows; 1. Direction of nozzle orifice in relation to the thrust line of the aircraft: nozzle orifice angled 45° forward will produce a fine atomization; pointed down, an intermediate atomization; and pointed to the rear, a coarse atomization. 2. Speed of aircraft: the faster the aircraft, the finer the atomization. 3. Size of nozzle orifice: the larger the orifice, the coarser the atomization. 4. Spray pressure; the higher the pressure, the finer the atomization. Several excellent manuals have been published which detail methods of characterizing spray droplets in field projects (Dumbauld and Rafferty 1977, Haliburton et al. 1975, Barry et al. 1978). Numerous and complex factors acting alone and in combination affect the emitted spray cloud, pattern of deposition, penetration of the forest canopy, and the amount and extent of drift outside the target area. Some of these factors are (1) specific properties of spray formulation (evaporation), (2) drop size, (3) swath deposit patterns produced by spray equipment and aerodynamics of an aircraft, (4) spraying height, (5) physiographic characteristics of forest area, and, above all, (6) meteorological factors. Spraying should be done at low wind velocities, preferably early in the morning because increasing ground temperature later in the day may result in convection and thermal air currents that can lift small particles and cause an increase in drift. Also, spraying should be avoided during a strong inversion because this condition might prevent deposition of the small drops. The greater the spraying height, the longer the spray drops will float in the air. During the suspension period, they are subject to such meteorological factors as wind and air movements, which result in more drift. If safety permits, the spraying height should be reduced when higher wind velocities and other less favorable meteorological conditions exist. Coarser spray atomization should be used in the presence of wind or upward air currents due to heat radiation, when layers of heavy, humid air are above the treetops, or when flying will take place over irregular and rough topography. 127 Evaluation of Efficacy Safety and Pesticide Use Evaluation of control operations is essential for future action and for determining success of the treatment. Sampling of spruce budworm populations, estimation of defoliation and tree vigor, and physical and chemical composition of spray droplets are the main factors for determining the effectiveness of the treatment. Various techniques used in eastern Canada for determination of spruce budworm populations and defoliation have been reviewed (Prebble 1975, Miller and Kettela 1975, Sanders 1980) and are summarized in chapter 3 of this book. Defoliation estimates are commonly made at the end of the feeding period, in treated and (for comparison) in adjacent untreated stands. The observations are visual estimates of foliage lost, usually in defoliation classes from sample branches. In large-scale projects, aerial surveys are supplemented by defoliation data obtained at ground points. Aerial observations are made as soon as feeding is complete (July or August). At that time, the shades of green, brownish-red, and gray, indicative of the extent to which foliage has been consumed or severed and dried out, can be interpreted by experienced observers in terms of broad defoliation categories. Safe use and proper management of insecticides, whether on a large- or small-scale project, is to everyone’s benefit. Adequate knowledge concerning the insecticide being used and prior planning will avoid potentially life-threatening accidents and protect project personnel, the public, and the environment. It cannot be overemphasized that each insecticide must be used in accordance with its label and the precautions printed on the label must be read and heeded. Safety manuals specific to insecticide use are available (Anon. 1975, Singer 1978) and well worth reading. Presented here are some minimum considerations to avoid problems; depending upon the size and nature of the project, other precautions may also be advisable. Personnel Safety Protection against overexposure of operational personnel to toxic materials depends upon (1) prevention of accidents, (2) use of protective clothing, and (3) adequate medical resources. Accident Prevention —All personnel involved in pesticide operations must be trained to observe the following guidelines: 1. Do not work alone, especially when handling a highly toxic pesticide. 2. Do not allow pilots to take part in mixing and loading operations, and make sure they stand well away. 3. Make sure that personnel who help with mixing or who maintain and clean equipment are aware of the hazards and follow safety procedures. 4. Keep all unprotected persons away from any equipment that may be contaminated. Consider all such equipment dangerous until properly decontaminated. 5. Insist that smoking, drinking, and eating are absolutely prohibited in every chemical handling area. 6. Make sure that water, soap, and towels are available at the loading site. 7. Be aware of the increased hazards of carelessness due to fatigue, especially in pilots. 8. Open, pour, and mix insecticides in a specific, well-ventilated area, where any spills can be cleaned up properly. Try to stand upwind of all pouring/mixing operations. 9. Open all pesticide containers carefully, and on a stable surface where they won’t tip or spill easily. 10. Use the proper tools to open containers. Use a knife to open paper and plastic bags, etc. (Don’t use a screwdriver on bags or a pickaxe on drums because of the risk of material spurting into the face and eyes.) Ripping open a bag usually causes an uneven tear, thus making spills more likely. 128 Protective Clothing —Protective clothing and devices should always be worn during handling, mixing, or applying pesticides. For water-based sprays, water-repellent clothing gives the best protection. However, in hot weather waterproof oilskins are impractical for loaders and are normally used only by flagmen, who run a greater risk of being accidentally sprayed. The next best protection is given by clothing of the “coverall” type, which is thick enough to retard penetration by pesticides. Full-length sleeves are necessary and must not be rolled up. Leather will absorb pesticides and is extremely hard to decontaminate; rubber or neoprene gloves and boots should be used. It is important that 1. Flagmen should wear waterproof hat, coat, and trousers. 2. Mixers and loaders should wear coveralls, rubber gloves, high rubber boots, and a full-length rubber apron, especially when handling concentrated or highly toxic materials. 3. Pilots should wear nonflammable coveralls and a hard helmet. 4. Clothes should be changed daily, and immediately if any contamination occurs. Always discard leaky gloves and thoroughly clean or discard contaminated clothing. 5. A respirator must be worn whenever there is any risk of dust or vapor being inhaled. 6. If a full-face respirator is not being worn (there is always a risk of damage to the eyes), be sure to wear goggles during mixing or loading operations. They should fit snugly but comfortably and should be of the nonfogging type. Medical Resources —It is entirely possible to handle all pesticides safely, and with no ill effects; but because of the hazards associated with this work, it is necessary to 1. Arrange for medical supervision, on a continuing basis. The medical problems associated with most pesticide hazards are special ones. If possible, managers should engage a physician who has special interest in this branch of medicine. 2. Prearrange for emergency treatment, in every locality. If an accident or overexposure occurs, time is of the essence. 3. Learn to recognize the typical signs and symptoms of pesticide poisoning. If any worker feels ill during pesticide application, or shortly after, he or she should seek medical attention at once. 4. Know that a very serious risk is taken if a victim of pesticide poisoning is allowed to drive home unattended. It is simply not possible to judge ultimate severity by initial symptoms: a severe poisoning may seem quite mild at the outset. Once poisoning is suspected, someone should stay with the patient until he or she gets medical treatment. Transportation and Storage Great care must be taken in the transport of pesticides. It is essential to take all possible steps to prevent damage to containers; and to ensure that no leaks develop, that no container is punctured or ruptured, and that no lids or caps are loosened. Containers should be tied down, so that none can roll or fall about due to vehicle movement. It is particularly important to ensure that no container can fall off the vehicle. Open containers must never be transported. Partly used containers must be securely resealed before movement. After transportation, all pesticide containers should be inspected for damage and leaks, and the vehicle should be carefully examined for contamination. Extreme care is necessary in the transportation of empty containers or unwanted pesticides to an approved disposal site. Avoid contamination of the truck. Trucks transporting pesticides should carry a sign “Warning—Pesticides” at the tailgate. This sign should include the name of the pesticide, if possible, for information in case of accident. Pesticide stocks should be stored in a specially signed (e.g.. “Danger—Pesticide Storage,” or wording locally required) building that is reserved for this purpose and can be securely locked. Because only minimum quantities should be held in storage, planners need to make realistic estimates of the total amounts required. At the beginning of a day's work, only the amount of pesticide needed for that day should be withdrawn from storage. After the day’s operation, both unused and empty chemical containers must be returned to the storage building. Empty containers and spilled or residual material stored in waste cans must be held in the pesticide storage building until final disposal. The following precautions must be observed in connection with the storage of any pesticide materials: 1. Always store pesticides in rooms away from food, animal feed, or water. 2. Store all pesticides in the original labeled container. 129 Future Use of Insecticides 3. Check all containers frequently for leaks, tears, or loose lids. 4. Records should be maintained of all stored pesticides. 5. Local fire departments should be notified of the kinds of pesticides stored in buildings. Decontamination and Pesticide Disposal In order to keep spillage and waste to a minimum, a clean and well-equipped loading/mixing area is essential. All spills should be cleaned up at once. Suitable receptacles (e.g., open-head steel drums) should be conspicuously painted and used for the collection of spilled materials and empty chemical containers. These waste bins should be emptied daily, or kept in the pesticides storage building overnight. Spilled dry materials should be swept up into plastic bags, which are then tied and labeled before placement in the waste bin. Spilled liquids should be absorbed by coarse clay or sawdust, which is then swept up into plastic bags for disposal. In the case of organophosphate compounds, lime should be spread over the spill and left for several hours before collection. Avoid hosing down spills: the chemical may enter bodies of water or streams, with resultant hazard to water supply, fish, and wildlife. In the event of an accident, decontamination procedures may be required on a large scale. An accident area must immediately be barred to onlookers, and traffic must not be allowed to pass over contaminated surfaces. In the case of spills on public roads or on other areas used by the public, local police must be informed. Federal, Provincial or State, and municipal regulations must be consulted before disposing of waste insecticides or used containers. Once again, the insecticide label will show specific instructions. Personnel should rinse all empty liquid containers several times and empty the rinse water each time into the mixing tank. After rinsing, the container should be punctured so that it is not used for any other purpose. Used containers can be disposed of at an approved dump site or returned to the manufacturer or distributor for disposal. Excess unmixed insecticide can be returned to the manufacturer or stored under appropriate conditions for future use. Disposal of excess insecticide already mixed can be accomplished in several ways, but because of variations in Federal and State regulations, we recommend that local or regional Federal offices be consulted (see appendix 4). In recent years, much field and laboratory research on new chemical insecticides has been conducted. The objective of this research has been to develop effective and more environmentally acceptable alternatives to present-day broad-spectrum insecticides; that is, to kill the pest insect while protecting nontarget organisms such as people, birds, and fish. Two types of compounds, juvenile hormones and insect growth regulators, have shown some promise. Both types attempt to interrupt physiological processes that are critical to insect growth and development. Juvenile-hormone-type compounds interfere with normal metamorphosis, the process whereby insect larvae transform to pupae or pupae to adults. Timing and the internal supply of juvenile hormone are both important factors if an insect is to develop normally. Interruption of either factor can result in an individual remaining a larva or prematurely transforming into an adult, with lethal results. There are, as yet, no juvenile hormones commercially available for spruce budworm control. The second type of compound, insect growth regulators, acts by interrupting the formation of chitin (insect exoskeleton), especially in the larval stages. The cuticle (skin) of insect larvae that have fed upon growth regulators becomes very fragile and eventually punctures, releasing body fluids. Many candidate growth regulators have been subjected to laboratory and field research by scientists in both Canada and the United States. Some are already commercially available for other insect pests, but none are presently registered for use against spruce budworm in either of our countries. At the same time, a number of more conventional chemical compounds have been tested against spruce budworm in the laboratory (Nigam 1975, 1981). Some of them were abandoned after the initial testing, but a few were field tested or were proposed for field evaluation. In 1980, for example, about 11 new compounds were introduced for laboratory evaluations, along with new formulations of fenitrothion, aminocarb, and carbaryl. 130 Selected References In 1981 a task force was established by the Canadian Council of Resource and Environment Ministers (CCREM), composed of forestry representatives from every Province and each Federal agency involved in the review and registration of pesticides. The task force was directed to identify the obstacles to registration of new insecticides. A reciprocal registration agreement between Canada and the United States was established in 1979, in order to make use of available registration data from both countries. Under this agreement, aminocarb was registered with both countries on the basis of data generated through CANUSA. To expedite the registration of forest insecticides in both countries, the CANUSA Program stimulated the formulation of a joint United States-Canadian committee that includes representatives of EPA, Agriculture Canada, the Canadian Forestry Service, and the US DA Forest Service. The committee reviews administrative agency procedures and makes recommendations on data equivalency. It has already demonstrated its usefulness, and its operations will likely be continued. There is little doubt that insecticides will continue to play an important role in management of spruce-budworm-infested stands for the foreseeable future in both the United States and Canada. Only aerial treatments with chemical pesticides or with B.t. [see chapter 7) have been effective in limiting tree mortality due to spruce bud worm infestations. Alternative methods of protection against budworm damage are still in the research stage and are not yet available for operational use. Forests will be more intensively managed in the future and may need even greater protection from economically important forest pests to assure that trees live long enough to benefit from silvicultural treatments. An interdisciplinary approach must be used in the future to integrate knowledge from supporting disciplines in developing improved pest management systems. In the meantime, the use of chemical pesticides on current forest crops allows management options to be kept open. Anon. Aerial application of pesticides safety manual. Third ed., reviewed 1975. Ottawa, ON; Health and Welfare Canada, Environmental Health Directorate; 1975. 160 p. Barry, J. W.; Ekblad, R. B.; Markin, G. P.; Trostle, G. C. Methods for sampling and assessing deposits of insecticidal sprays released over forest. Tech. Bull. 1596. Washington, DC: U.S. Department of Agriculture; 1978. 162 p. Blais, J. R. Comparison of spruce budworm overwintering populations with emerged populations (peak Lo in the lower St. Lawrence region of Quebec, 1978. Can. For. Serv. Bi-month. Res. Notes 35(b); 33-34; 1979. Carrow, J. R.; Nicholson, S. A.; Campbell, R. A. Aerial spraying for forest management—an operational manual. Ottawa, ON: Ministry of Natural Resources, Province of Ontario; 1981. 44 p. Dimond, J. B.; Seymour, R. S.; Mott, D. G. Planning insecticide application and timber harvesting in a spruce budworm epidemic. Agric. Handb. 618. Washington, DC; U.S. Department of Agriculture, Forest Service; 1984. Dumbauld, R. K.; Rafferty, J. E. Field manual for characterizing spray from small aircraft. Missoula, MT; U.S. Department of Agriculture, Forest Service, Equipment Development Center; 1977. 68 p. Greenbank, D. O.; Schaeffer, G. W.; Rainey, R. C. Spruce budworm (Lepidoptera; Tortricidae) moth flight and dispersal: new understanding from canopy observations, radar and aircraft. Memoirs Entomol. Soc. Can. 110; 1-49; 1980. Haliburton, W.; Hopewell, W. W.; Yule, W. N. Deposit assessment chemical insecticides. In: Prebble, M. L., ed. Aerial control of forest insects in Canada. Cat. No. F023-19-1975. Ottawa, ON: Environment Canada, Canadian Forestry Service; 1975: 59-67. Hansen, R. W.; Dimond, J. B. The feeding biology of spruce budworm on several hosts with reference to timing of insecticidal sprays. Life Sci. Agric. Exp. Stn. Misc. Rep. 266. Orono, ME: University of Maine; 1982. 19 p. 131 Jennings, D. T.; Houseweart, M. W.; Dimond, J. B. Dispersal losses of early-instar spruce budworm larvae in strip clearcut and dense spruce-fir forests in Maine. Environ. Entomol. 12(6): 1787-1792; 1983. Roller, C. N.; Leonard, D. E. Comparison of energy budgets for spruce budworm, Choristoneura fiimiferana (Clemens) on balsam fir and white spruce. Oecologia 49: 14-20; 1981. Miller, C. A.; Kettela, E. G. Aerial control operations against the spruce budworm in New Brunswick, 1952-1973. In; Prebble, M. L., ed. Aerial control of forest insects in Canada. Cat. No. F023-19-1975. Ottawa, ON: Environment Canada, Canadian Forestry Service; 1975: 94-112. Nigam, P. C. Chemical insecticides. In: Prebble, M. L., ed. Aerial control of forest insects in Canada. Cat. No. F023-19-1975. Ottawa, ON; Environment Canada, Canadian Forestry Service; 1975: 8-24. Nigam, P. C. New chemical insecticides. In: Hudak, J.; Raske, A. G., eds. Review of the spruce budworm outbreak in Newfoundland—its control and forest management implications. Info. Rep. N-X-205. St. Johns, NF: Canadian Forestry Service; 1981: 127-128. Prebble, M. L., ed. Aerial control of forest insects in Canada. Cat. No. F023-19-1975. Ottawa, ON: Environment Canada; Canadian Forestry Service; 1975. 330 p. Randall, A. P.; Zylstra, B. F.; McFarlane, J. W. The effects of fenitrothion and aminocarb on second instar spruce budworm, Choristoneura fumiferana (Clem.) in Quebec. Rep. FPM-X-5. Sault Ste. Marie, ON: Canadian Forestry Service; 1977. 24 p. Randall, A. P. Insecticides, formulations, and aerial applications technology for spruce budworm control. In; Proceedings of a symposium on the spruce budworm; November 1974; Alexandria, VA. Misc. Publ. 1327. Washington, DC; U.S. Department of Agriculture, Forest Service; 1976: 77-90. Sanders, C. J. A summary of current techniques used for sampling spruce budworm populations and estimating defoliation in eastern Canada. Rep. O-X-306. Sault Ste. Marie, ON: Environment Canada, Canadian Forestry Service, Great Lakes Forest Research Centre; 1980. 33 p. Simmons, G. A. Use of light trap data to predict outbreaks of the spruce budworm. Info. Rep. 80-6. East Lansing, MI; Michigan State University, Department of Entomology; 1980. 13 p. Singer, J. Pesticide safety: guidelines for personnel protection. FPM 83-1. Washington, DC; U.S. Department of Agriculture, Forest Service; 1982. 45 p. U.S. Department of Agriculture, Forest Service. Cooperative spruce budworm suppression project, Maine, 1979. Final environmental statement. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Area, State and Private Forestry; 1979. 104 p. U.S. Department of Agriculture, Forest Service. Proposed cooperative spruce budworm integrated pest management program, Maine 1981. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Area, State and Private Forestry, Environmental Assessment Department; 1981. 21 p. 132 Chapter 9 Spruce Budworm Planning—L' Environmental Imp Joan Garner Trial and Peter D. Kingsbury' ' Assistant Scientist, Department of Entomology. University of Maine. Orono. and .Maine Cooperative Fisheries Research Unit; and Environmental Impact Project Leader. Forest Pest Management Institute. Canadian f-orestry Service. Sault Ste. Marie. Ont. Forest management manipulates components and processes to increase yields of lumber and fiber, alter streamflow regimes, or manage wildlife habitat; but these changes cannot be achieved without environmental impacts. Environmental impacts are changes—damaging or beneficial—in the components and processes of ecosystems. With care, forest managers can minimize adverse environmental impacts by selecting management actions that (1) cause the least damage, and (2) do not seriously compromise production of forest products. This chapter explains the types of environmental impacts that are associated with spruce budworm management and demonstrates that pests can be managed in several ways, each with different impacts. Spruce budworm control programs and forest management during severe infestations reduce spruce budworm populations, maintain tree vigor, and gradually change forest composition. Killing budworm or cutting trees affects the whole ecosystem because components are interrelated or linked. Additionally, an insecticide may kill nontarget organisms and disrupt energy flow. Science has identified a wide range of potential impacts resulting from spraying chemical and biological insecticides and changing the characteristics of forest stands. Pest control may benefit or damage fish and wildlife. You can identify and predict impacts on fish and wildlife if you (1) know the biology and ecology of the organisms, (2) understand how these organisms are linked in the ecosystem, and (3) examine records of impacts from similar projects. Some impacts are more easily predicted than others. For example, insecticide spraying will kill other insects in the forest besides budworm. Environmentally responsible forest management includes evaluating the impacts of alternative management strategies. We constructed a matrix that lists possible impacts of chemical and biological insecticide applications, silviculture, and abandonment/no action (table 9.1). The lists include impacts that are predicted using ecosystem models and the results of Canadian and United States monitoring- and toxicity studies. This data base was also used to construct a matrix of impacts associated with different insecticides (table 9.2). Using the table requires a basic understanding of the ecosystems affected and the components usually studied. ’ Reports on environmental monitoring may be obtained from agencies listed as selected sources. Table 9.1 —Potential effects of spruce budworm strategies on nontarget ecosystem components and processes Strategy Direct toxic effects Secondary effects Physical or chemical effects on habitat Insecticide Chemical Mortality, reduced growth, physiological dysfunction, altered behavior, reduced species diversity (invertebrates and vertebrates) Disrupt food chains, alter animal community structure and interactions, reduce survival Although most residue disappears quickly, some may persist for extended periods (<3 years) Biological Mortality, altered behavior, disease (insects) Alter animal community structure and interactions Spores in environment Silviculture None predicted Disrupt inorganic nutrient cycles, alter plant and animal community structure and interactions, disrupt food chains Increased erosion, changed structure of forest No action No human-caused ecosystem perturbations Disrupt food chains, alter plant and animal community structures and interactions Changed structure of forest 134 Table 9.2—The impacts of insecticides on aquatic and terrestrial ecosystem components. If impacts were observed at different than registered rates for spruce budworm, those rates are in parentheses. Compound name. country of registration. Forestry data base (years application rate generated) Aquatic invertebrates Fish Forest invertebrates acephate Modest eastern and Little apparent effect Limited acetylcholin- Moderate to severe Canada extensive western on stream benthos. esterase (AChE) de- effects on ants. 0.4 to 0.5 Ib/acre North American data Occasional increases pression in suckers. honeybees and wild (0.43 to 0.56 kg/ha) U.S. 0.5 Ib/acre (0.56 kg/ha) (1970's) in drift. Low toxicity to fish. pollinators at 1 to 2 Ib/acre (1.12 to 2.24 kg/ha) aminocarb Extensive Canadian No detectable effects Little adverse impact Some effect on Canada and modest eastern on stream benthos. reported. Nonylphe- foraging honeybees 0.08 Ib/acre U.S. data (after Occasional slight in¬ nol in some formula¬ and wild pollinators. (0.09 kg/ha) U.S. 0.15 Ib/acre (0.17 kg/ha) 1975) creases in drift. tions increases toxicity. Kills foliage-dwell¬ ing spiders; popula¬ tions recover quickly. carbaryl Extensive eastern Large, consistent in¬ AChE depression Moderate to severe Canada and western U.S. creases in drift effects on ants, bees. 0.5 to 1.1 Ib/acre (0.6 to 1.23 kg'ha) U.S. 1 lb acre (1.12 kg/ha) (maximum) data (after 1975) accompanied by se¬ vere and persistent depression of ben¬ thos, particularly mayflies and stone- tlies wild pollinators, spiders at 0.4 to 2 Ib/acre (0.45 to 2.24 kg/ha). Reduced fruit set at 0.75 Ib/acre (0.84 kg/ha). fenitrothion Extensive Canadian Occasional, large AChE depression Moderate to severe Canada and modest eastern increases in drift. effects on honeybees 0.13 to 0.25 Ib/acre U.S. data (after sometimes accom¬ and wild pollinators (0.15 to 0.28 kg/ha) U.S. 0.2 lb acre (0.21 kg/ha) (maximum) 1965) panied by temporary reductions of benthos at 0.2 to 0.25 Ib/acre (0.22 to 0.28 kg/ha), resulting in reduced fruit set. Forest vertebrates Breeding populations of songbirds and small mammals not affected at ^2 Ib/acre 2.24 kg/ha). Songbird AChE depression and occasional poisoning observed at 1 to 2 Ib/acre (1.12 to 2.24 kg/ha). Breeding populations of songbirds and small mammals not affected at 0.15 Ib/acre (0.17 kg/ha). Limited song¬ bird AChE depression at 0.06 to 0.09 Ib/acre (0.07 to 0.10 kg/ha). Little or no effect on songbirds or small mammals. Limited AChE depression in songbirds at 2 Ib/acre (2.24 kg/ha). No effect on breeding songbirds and small- mammal populations at 0.2 to 0.25 Ib/acre (0.22 to 0.28 kg/ha). Poisoning and mor¬ tality in swath over¬ laps (e.g., 0.4 to 0.5 Ib/acre [0.45 to 0.56 kg/haj). Songbird AChE depression at 0.2 to 0.25 Ib/acre (0.22 to 0.28 kg/ha). Continued 135 Table 9.2 —Continued Compound name, country of registration, application rate Forestry data base (years generated) Aquatic invertebrates Fish Forest invertebrates Forest vertebrates mexacarbate U.S. 0.15 Ib/acre (0.17 kg/ha) Modest U.S. data (before 1974) Occasional, modest increases in drift. No effect on benthos. No effect reported No data from moni¬ toring. Highly toxic to honeybees. No effect on breeding songbird or small- mammal populations. AChE depression in songbirds. trichlorfon Canada 0.75 Ib/acre (0.84 kg/ha) U.S. 1 Ib/acre (1.12 kg/ha) Modest North Amer¬ ican data (early 1970's) Occasional, modest increases in drift. No effect on benthos. No effect reported Used without effect on insect-pollinated crops No effect on breeding songbird or small- mammal populations. Moderate AChE de¬ pression in songbirds and mice. Bacillus thuringiensis Canada 8 to 12 BlU/acre (20 to 30 BlU/ha) U.S. 12 to 18 BlU/acre (30 to 45 BlU/ha) Substantial North American data (after 1970) No known impact No known impact Affects some non¬ target Lepidoptera No known impact 136 Aquatic Ecosystem Components Terrestrial Ecosystem Components Aquatic insects are often affected by pesticide applications in small forest streams that are important habitat for trout or salmon. These fish feed on aquatic insects that drift downstream, and sampling procedures attempt to measure the abundance of these food items. Drift nets are placed to catch insects drifting due to lethal or sublethal insecticide poisoning. The standing crop of aquatic insects present within a portion of stream bottom (benthos) is measured before and after insecticide application to determine if potential fish food supply has been affected. These studies have found that the most significant impact in the aquatic system is on certain aquatic insects. The direct impact of an insecticide on fish is ususally assessed with measurements of fish mortality, population density, growth and condition, acetylcholinesterase (AChE), and feeding. The acetylcholinesterase level is a measure of exposure to AChE-inhibiting organophosphate and carbamate insecticides. Short-term increases in fish feeding and growth are reported for all insecticides that knock terrestrial insects (including budworm) into streams. Feeding also increases if an insecticide causes increased drift of aquatic insects. The loss of aquatic insects has an adverse impact on the system, whereas the addition of terrestrial food is of short-term benefit to fish. Terrestrial arthropods are affected by forest insecticides. Activity of wild insect pollinators regulates the amount of fruit produced by insect-pollinated plants. In sprayed and unsprayed areas, pollinator activity is measured using census, collecting, and caging techniques, and is correlated with fruit set in May and June. Losses of terrestrial insects may affect behavior of songbirds. Observations of foraging birds, censuses of singing males, breeding territory maps, and mist net collections document changes in behavior and density. Small mammals and other terrestrial vertebrates are trapped, observed, or tracked to study effects of insecticides. The direct impacts of insecticides on birds and mammals are assessed by estimating populations before and after spray and measuring growth, reproductive condition, and AChE. Generally. 20-percent inhibition indicates exposure and 50-percent indicates poisoning that may result in altered behavior or mortality. Environmental impacts depend not only on management strategy and insecticide but also on application rate, formulation, spray timing, and block layout. For example, the impact of carbaryl depends on whether the maximum allowable rate is applied, if it is formulated in water or oil, if there are one or two applications, and whether the spray falls directly in water. The impact of any insecticide on the aquatic ecosystem is greatest if streams and lakes are directly sprayed. Fenitrothion applied on a warm morning is likely to kill more pollinators than if applied on cool days or in the evening. Overlapping spray swaths during fenitrothion applications frequently cause lethal and sublethal poisoning of birds. Tables 9.2 and 9.3 are generalized lists of the impacts of currently used insecticides, formulations, timings, block layouts, and application methods. Table 9.3 considers the potential for impacts in nontarget areas and does not necessarily address specific effects on individual species. We recommend that aquatic and wildlife biologists be included in planning to ensure that specific information on endangered species, game and nongame species, and critical habitats will be available as needed. 137 Table 9.3 —Assessing the impacts of alternative spray project planning decisions Decision Environmental considerations Decision Environmental considerations Timing of spray Try to avoid spraying when animals of Swath width With swaths of all sizes there are within day or season concern are most active. chances for overlap; however, narrow swaths may increase the chances of Frequency of spray As few applications as possible reduce significant overlap. between years the chances of chronic toxicity and allow recovery of impacted Application rate Low concentrations are likely to be populations. less damaging to the environment. Sequence of If two classes of insecticides are to be Formulation Adjuvants may be toxic (e.g.. insecticides used, use reversible AChE inhibitors nonylphenol). The distribution and before nonreversible inhibitors (i.e.. disappearance of insecticide in carbamate before organophosphate). environmental substrates (water, foliage) and the quality and quantity of Application A targeting system that ensures only deposit are different for oil and water budworm-susceptible stands are sprayed reduces the range of environmental impacts. formulations. Block layout Size Large blocks increase the probability of contamination of complete watersheds and require many unsprayed buffers for streams. Buffers Buffer size should be directly proportional to the importance of ensuring no insecticide contamination occurs. Each State and Province has policies or regulations that establish buffer size for various nontarget areas. Insecticide labels may also define required buffers. Lines Spray swaths perpendicular to buffers increase the chances for spraying in a buffer area. 138 Evaluation System Example Assessment With the information provided in tables 9.1-9.3, you can easily include an assessment of environmental impacts in spruce budworm management planning. The following steps provide an evaluation system that fits into the 1PM decision process (fig. 2.1). We assume that you have already identified the management strategies that will effectively fulfill forest management objectives, and therefore, need only consider the environmental impacts of these actions. Steps in the Process 1. Set environmental objectives and integrate these objectives with economic and social objectives. 2. Use table 9.1 to determine which management strategy will best fulfill your environmental objectives. 3. If the action is a chemical or biological insecticide program, use table 9.2 to select an insecticide or combination of insecticides. 4. Finally, using table 9.3 and the advice of biologists, determine the timing, sequence of insecticides, block layouts, and application methods that will cause the least impact. The manager decides that an insecticide spray program is required. 1. He or she selects these environmental objectives: • Avoid spraying near eagle nests. • Avoid contamination of streams and lakes. • Keep trees alive in deer yards. • Avoid killing pollinators near blueberry fields. • Minimize overall environmental impact. 2. These objectives may be accomplished with usual budget constraints in which the slightly higher costs are acceptable. Implementing Objectives Neither carbaryl nor fenitrothion will be sprayed near commercial blueberry fields; B.t., trichlorfon, or aminocarb are acceptable. B.t. will be sprayed on deer yards near streams. With the aid of wildlife biologists, field crews will locate eagle nests. Based on the biologists’ advice, managers will establish around each nest site unsprayed buffers that ensure the adults are not disturbed. Unsprayed buffers will be established on all lakes and streams except streams with adjacent deer yards, where B.t. will be sprayed. Because pollinators are active on warm mornings, spraying will be scheduled, when possible, for days predicted to remain cool. Early season days would be best for the blocks near blueberry fields. Small, well-targeted spray blocks will be defined and the best aerial application navigational system will be used. Where possible, spray swaths will be parallel to buffer areas. The evaluation system we suggest is a modification of existing environmental assessment methodologies. However, unlike most methods, the system provides the data needed to predict and compare impacts. With this information and that in previous chapters, you have all the elements necessary to choose spruce budworm management strategies that cause the least environmental damage without compromising forest management goals. 139 Selected References Selected Sources Adamus, P. R. Techniques for monitoring the environmental impact of insecticides on aquatic ecosystems. Agric. Handb. 613. Washington, DC: U.S. Department of Agriculture, Forest Service; 1983. 64 p. Bart, J.; Hunter, L. Ecological impacts of forest insecticides: an annotated bibliography. Ithaca, NY: New York Co-operative Wildlife Research Unit; 1978. 128 p. Fisher, D. W.; Davies, G. S. An approach to assessing environmental impacts. J. Environ. Manage. 1(3); 207-227; 1973. Jain, R. K.; Urban, L. V.; Stacey, G. S. Environmental impact analysis: a new dimension in decision making. New York: Van Nostrand Reinhold; 1977. 330 p. Kingsbury, P. D. Environmental impact assessment of insecticides used in Canadian forests. In; Garner, W. Y.; Harvey, J., Jr., eds. Chemical and biological controls in forestry. Am. Chem. Soc. Sympos. Ser. 238. Washington, DC: American Chemical Society; 1984: 365-376. May, T. A. Insecticide impacts on non-target terrestrial biota and their relevance to forest pest management. Tech. Note 89. Orono, ME: University of Maine, College of Forest Resources; [in press]. Oliver!, S. F. Assessment of the environmental impacts of spruce budworm suppression operations in Maine and eastern Canada. Trans. N.E. Fish and Wildlife Conf. 40; [in press]. Trial, J. G. Environmental monitoring of spruce budworm suppression programs in the Eastern United States and Canada: an annotated bibliography. Orono, ME: Maine Agricultural Experiment Station; ]in press]. Environment New Brunswick (E.M.O.F.I.C.O.) P.O. Box 6000 Fredericton, N.B. E3B 5H1 Forest Pest Management Institute Canadian Forestry Service P.O. Box 490 Sauk Ste. Marie, Ont. P6A 5M7 Maine Department of Conservation Forest Service State House, Station 22 Augusta, ME 04333 Newfoundland and Uabrador, Department of Consumer Affairs and Environment P.O. Box 4750 St. Johns, Newf. AlC 5T7 Nova Scotia Department of Lands and Forests P.O. Box 68 Truro, N.S. B2N 5B8 Ontario Ministry of Natural Resources Pest Control Section Maple, Ont. LOJ lEO Quebec Ministere de I’Energie et des Ressources Service d'Entomologie et de Pathologie 175 Rue St. Jean Sainte-Foy, Que. GIR 1N4 140 Appendix 1—Projection Methods Gary A. Simmons, Wilf Cuff, Bruce A. Montgomery, and J. Michael Hardman This appendix discusses a group of tools that can be of help with the myriad considerations a decisionmaker must face. One development that has complemented the 1PM- based approach is the construction of mathematical models to try to predict future events based on existing information. Among other objectives, these models aim to predict (1) budworm populations, (2) forest growth, (3) risk to tree mortality and/or growth loss, and (4) the outcomes of a variety of management actions. Models often provide economic evaluation information in addition to other analysis and evaluation criteria. Before we list the kinds of models currently available to decisionmakers, perhaps it would be useful to discuss briefly the idea, and forms, of mathematical models. Mathematical models are representations of existing processes. An example of a simple model is the following, which estimates budworm larval numbers 1 year hence: logNn ^ I = 0.98 + 0.76 log Nn + 0.18 (T.^^x - 66.5) where Nn ^ 1 = large-larval density next year, being year n -4 1 Tmax = mean maximum daily temperature during the period of large-larval development (°F) This single-equation model is extremely simple; there also exist mathematical models made up of many interacting equations. For most models nowadays, computers are used to produce a time trace of the dependent variable(s) of the model (e.g., log N^+i above) to compare with observed behavior of the variable over time. In table 1 of this appendix, we list specific models the decisionmaker can choose from, the area of decisionmaking they pertain to, the geographic region they were designed for, and other pertinent information that may help in determining when and if they could be used. The simplest and thus often the easiest understood models are those consisting of only one equation, and dedicated to a single phenomenon. For example, the larval population model we illustrated previously is simple and straightforward. The tree mortality hazard-rating model of Webb, the tree mortality model of Batzer and Hastings, and the vulnerability model of MacLean are slightly more complex, but still easily understood and used. The forest growth models are often more complex. Where these models consist of a number of equations, computers are used to evaluate them, i.e., to look at the behavior of the dependent variables over time. Good projections of forest growth are now available, based on previous scientific study of growth in the region or area of interest. The most complex models are those that we refer to as strategic analysis models. These models project tree growth and mortality and budworm density, and incorporate evaluations (economic and otherwise) of various management options. Because they incorporate many equations, these models are the most complex of those we list. Although they have had a patchy history, they hold promise for structuring biological and socioeconomic considerations for long-term planning and policymaking. We are unable to provide you with scientifically based judgments on which models are “the best” to be applied to your situation. Specific circumstances will dictate whether existing models are adequate as they exist or adequate with modification, or if entirely new models should be constructed. To help you with these judgments, the remainder of our discussion will explain the criteria that we feel you must consider when deciding whether or not to use these tools in your decisionmaking process. Purpose This is perhaps the first step in selecting models. If the purpose governing construction of a model is the same as your purpose in applying it. then all the better. If not, it may be difficult (or impossible) to modify the existing model for the purpose at hand. Don't let this discourage you; existing technology is often the only technology that can be applied, given the timelag involved in producing new, suitable technology. 142 Assumptions Most models are based on empirical data or otherwise accepted tact. For some models, portions are made without factual information because such information is nonexistent; this is common in strategic analysis models. We do the same every day when we make decisions based on incomplete information. In the case of models, however, you must be comfortable with the assumptions that have been made. If not, you probably will not trust decisions based on projections made with that model. Area Applicability Most models that have been constructed are either explicitly designed for a specific geographic area or are based on data from a specific region, giving them “locality bias.” How important these geographic biases are depends, in part, on the purposes the user has in mind. Generally, the more area-specific you wish your decisions to be, the more area-specific your model should be. Of course, you may be able to adapt a model constructed for another area to be appropriate to conditions in your area. Time and Space Dimensions Models are generally designed to provide information or predictions for a specified time period and to represent a specified unit of land area. For example, hazard-rating models are usually designed to predict mortality risks during the next growing season for a specific stand of trees. Thus, the time and space dimensions of models used should provide you with information that meets your time and land-area requirements. Validation When empirically based models are constructed, they are usually based on one set of data or a limited number of sets. Often, to see how well a model will perform in another situation, modellers compare the predictions of the model to a set of data independent in time, space, or both from the data originally used to develop the model. If there are no differences or if differences are minor, the model is said to have been “validated” with one independent data set. The necessity and utility of validation are sometimes misunderstood. A model that can accurately reproduce an independent data set will often create confidence in the user. But then it the model is asked to generate predictions outside the model’s domain (i.e., where no previous data had been obtained), then the predictions are open to question. Further, independent data sets are not always available to use in a validation exercise. And in the case of models consisting of many equations, it may be possible to validate only a subset of the equations but impossible to validate the entire model. One of the reasons for constructing models at all is to explore areas where no previous data or experience has been obtained! What we are saying is that the importance of validation depends on the use to which a model will be put. If it is constructed to “explore possibilities,” validating the model is not essential (although still desirable); if it will be used to precisely predict an event, validation is essential. Input Data Requirements Some (dynamic) models require specific initial conditions to make them start off correctly. Such information is commonly termed “input.” Such information can be easy, difficult, or impossible to provide. When selecting a model, you should be able to provide the necessary input in the form the model requires. Output Data Generated Models will provide you with projections of dependent variables over time and related information useful in decisionmaking. Such information is commonly termed “output.” When selecting a model for use, make sure the output contains the types of information you desire. 143 Selected References for Appendix 1 Availability and Compatibility of Software Computers are often used to get desired output from models. More specifically, computer programs (software) are written to evaluate the model of particular interest, to get the output. Software is usually written in a specific "high-level” language, which is translated into a pedantic “low-level” machine language by another program in the computer. This allows the user-written software to take the form of simple, intuitively meaningful expressions that are easily understood. It is not necessary to be familiar with the internal workings of computers. Two of the more common high-level languages that software is written in are FORTRAN (short for FORmula TRANslation) and BASIC (short for Beginner’s All-purpose Symbolic Instructional Code). Other general-purpose high-level languages, such as PASCAL, may also be found, as well as a variety of special-purpose “simulation languages.” Thus, the language that the model is “implemented” in should be a factor to consider; the computer you are using may not have the language and, if not, you will have to reimplement the model. This may require more effort than you wish to give to the task. Unfortunately, not only is the correct language important but so is the specific make of computer. For example, a program written in FORTRAN for use in an IBM computer system may have to be modified to run on a CDC 6500 computer system even though both systems support FORTRAN. Thus, while computers can help a lot to look at the behavior of a specific model, they do exact a price that the user must pay. Specialized Analytic Tools In some instances models are implemented so they have, or can produce, information in specialized ways helpful in decisionmaking. For example, some model implementations produce useful graphics. The convenience of such tools for decisionmakers should not be underestimated. In summary, mathematical models are abstractions of existing processes. Models provide a set of tools to help with projections (usually over time) and analysis of information for decisionmaking. They are usually constructed with specific purpose(s) in mind and perform best when used for those purposes. Models are helpful in that they allow a decisionmaker to explore possible consequences of decisions being considered for application. Models can be powerful tools for the decisionmaker; however, they cannot substitute for decisionmakers with their analytical and intuitive powers. Baskerville, G.; Kleinschmidt, S. A dynamic model of growth in defoliated fir stands. Can. J. For. Res. 11: 206-214; 1981. Batzer, H.; Hastings, H. Rating spruce-fir stands for spruce budworm vulnerability in Minnesota. In: Hedden, R. L.; Barras, S.; Coster, J. E., tech, coords. Hazard-rating systems in forest insect pest management: symposium proceedings. Gen. Tech. Rep. WO-27. Washington, DC: U.S. Department of Agriculture, Forest Service; 1981: 105-108. Blais, J. R.; Archambault, L. Rating vulnerability of balsam fir to spruce budworm attack in Quebec. Info. Rep. LAU-X-51. Sainte-Foy, PQ: Canadian Forestry Service, Laurentian Forest Research Centre; 1982. 19 p. Brand, G. J. GROW—a computer subroutine that projects the growth of trees in Lake States forests. Res. Rep. NC-207. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station; 1981. 11 p. Davis, W.; Shortle, W.; Shigo, A. Potential hazard rating system for fir stands infested with budworm using cambial electrical resistance. Can. J. For. Res. 10: 541-544; 1980. Ford, R. P. Spruce budworm in a white spruce plantation. St. Paul, MN: U.S. Department of Agriculture, Forest Service, Northeastern Area, State and Private Forestry, Forest Insect and Disease Management Evaluation Service; 1980. 4 p. Gage, S. H.; Sawyer, A. J. A simulation model for eastern spruce budworm populations in a balsam fir stand. Proc. [10th annual] Conf. Model. Simulat. 10: 1103-1109; 1979. Hall, T. H. Toward a framework for forest management decisionmaking in New Brunswick. TRl 78. Fredericton, NB: New Brunswick Department of Natural Resources; 1978. 3 p. Hardy, Y. J.; Dorais, L. G. Cartographie du risque de retrouver de la mortalite dans les forets de sapin baumier attaquees par la tordeuse des bourgeons de Tepinette. Can. J. For. Res. 6: 262-267; 1976. 144 Jones, D. D. The budworm site model. In: Norton, G. A.; Holling, C. S., eds. Pest management. Oxford, EN; Pergamon Press; 1979; 91-155. Kemp, W. P.; Nyrop, J. P.; Simmons, G. A. Simulation of the effects of stand factors on spruce budworm (Lepidoptera: Tortricidae) larval redistribution. Great Lakes Entomol. 13(2): 81-91; 1980. Ker, M. F.; VanRaalte, G. D. Tree biomass equations for Abies balsamea in northwestern New Brunswick. Can. J. For. Res. 11; 13-17; 1981. Kleinschmidt, S.; Baskerville, G. L.; Solomon, D. W. Foliage weight distribution in the upper crown of balsam fir. Res. Pap. NE-455. Broomall, PA; U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station; 1980. 8 p. Ludwig, D.; Jones, D. D.; Holling, C. S. Qualitative analysis of insect outbreak systems: the spruce budworm and forest. J. Anim. Ecol. 47: 315-322; 1978. MacLean, D. A. Vulnerability rating of forests in New Brunswick and Nova Scotia to budworm attack. Info. Rep. MX-132. Fredericton, NB; Canadian Forestry Service, Maritimes Forest Research Centre; 1982. 21 p. Marty, Robert. A guide to economic evaluation of spruce budworm management opportunities in the East. Agric. Handb. 627. Washington, DC; U.S. Department of Agriculture, Forest Service; [in press). Meating, J.; Lawrence, H.; Howse, G.; Carrow, J. The 1981 spuce budworm situation in Ontario. Info. Rep. O-X-343. Sault Ste. Marie, ON: Canadian Forestry Service, Great Lakes Forest Research Centre; 1982. 92 p. Morris, R. F., ed. The dynamics of epidemic spruce budworm populations. Mem. Entomol. Soc. Can. 31: 1-332; 1963. Mosher, D. G.; Murray, R. L.; Heyd, R. L.; Simmons, G. A.; McKeague, M. A.; Nyrop, J. P.; Wilson, L. F. 1980 Michigan Forest Pest Report. Ann. Rep. 80-1. East Lansing, MI; Michigan Cooperative Forest Pest Management Program; 1980. 33 p. Nadeau, J. P. Economic feasibility of controlling the current spruce budworm outbreak in Quebec. Quebec Mem. 33E. Quebec, PQ; Quebec Department of Lands and Forests; 1977. 38 p. Regniere, J. A process-oriented model of spruce budworm phenology (Lepidoptera; Tortricidae). Can. Entomol. 114: 811-825; 1982. Renlund, D. W. Forest pest conditions in Wisconsin. Ann. Rep. 1979. Madison, WI; Wisconsin Department of Natural Resources; 1980. 35 p. Royama, T. Fundamental concepts and methodology for the analysis of animal population dynamics, with particular reference to univoltine species. Ecol. Monogr. 51: 473-493; 1981. Seymour, R. S.; Mott, D. G.; Kleinschmidt, S. M. Future impacts of spruce budworm management—a dynamic simulation of the Maine forest 1980-2020. Orono, ME; University of Maine, Green Woods Project; 1980. 88 p. [draft.] Stedinger, J. R. Analysis of spray policies with the Maine budworm forest simulation model. Tech. Note 69. Orono, ME; University of Maine; 1977. 17 p. Trial, H.; Devine, M. Spruce budworm in Maine: biological condition in 1980 and expected infestation conditions for 1981. Tech. Rep. 17. Augusta, ME: Maine Forest Service; 1981. Ung, C. H. A dynamic programming approach for optimizing logging and spraying against spruce budworm. [Paper presented at CANUSA meeting, Toronto, Ont., Nov. 1, 1979.] Sainte-Foy, PQ; Canadian Forestry Service, Laurentian Forest Research Centre; 1981. 19 p. Watt, K. E. F. The use of mathematics and computers to determine optimal strategy and tactics for a given insect pest control problem. Can. Entomol. 96; 202-220; 1964. Webb, F. E.; Cameron, D. G.; Macdonald, D. R. Studies of aerial spraying against the spruce budworm in New Brunswick. V. Techniques for large-scale egg and defoliation ground surveys 1953-55. Interim Rep. 1955-8. Fredericton, NB; Canada Department of Agriculture, Forest Biology Division, Forest Biology Laboratory; 1956. 24 p. 145 Table 1 —Models available for use in decisionmaking for spruce budworm/spruce-fir forest management Modelling the influence of the spruce hudworm on the forest Specific purpose Output generated Geographic area of applicability Time and space dimensions Expected damage Mortality: “heavy” cate¬ gory expected to result in mortality Minnesota Next year on a forest manage¬ ment unit basis Influence of budworm on forest growth (balsam fir) Differences in growth (stand volume in mV ha/yr) between stands with and without budworm North-central Maine and New Brunswick Stands 30-70 years old, 30 years, 1-year increments Expected damage Basal area of dead balsam fir Minnesota For trees > 4 inches d.b.h. and after 5 yr defoliation on a per-stand basis Mortality risk “Vulnerabil¬ ity”: low, moderate, high (and very high by MacLean) New Bruns¬ wick and Nova Scotia (MacLean); Quebec (Blais and Archam- bault) Next year on a forest manage¬ ment unit basis Health and vigor (not a model per se) Mean electri¬ cal resistance per stand in microohms Northeastern United States Short- or long¬ term projec¬ tion on a forest management unit basis Tree growth (white spruce) Tree condition and % ex¬ pected defolia¬ tion Great Lakes region Next year on a forest man¬ agement basis 146 Unique features Major assumptions Input data required Validation considerations Software Reference Can be used on a map Egg-mass den¬ sity; current defoliation (aerial sketch map) Informal validation (in use for many years) Does not re¬ quire a computer Mike Albers, Minn. Dept, of Natural Re¬ sources, Grand Rapids, pers. comm. Relates defoliation to biomass of foliage Light penetra¬ tion from de¬ foliation will positively affect growth. Stand volume; number stems/ ha; % defolia¬ tion; foliage distribution; photo¬ synthetic capacity Informal validation (plausible output) FORTRAN available from authors Baskerville and Klein- schmidt (1981) In tabular form Based on empirical data Original basal area of balsam fir; basal area and % non¬ hosts per acre Formal valida¬ tion Does not re¬ quire a computer Batzer and Hastings (1981) Can be used within compu¬ terized stand inventory data system Budworm will affect stands based on cli¬ mate, com¬ position and stand density. Volume of spruce and fir (mVha); % fir >60 yr old; volume of black and red spruce (mV ha), if fir- white spruce volume > 27 mVha; climate Formal valida¬ tion Does not re¬ quire a computer Blais and Archambault (1982), Mac- Lean (1982) Could be added to ex¬ isting mortal¬ ity risk-rating data Use Shigo- meter to sam¬ ple resistance in stands. Not a com¬ puter model Davis et al. (1980) Current defoliation (4 categories); egg-mass den¬ sity including parasitism; tree crown condition (live, top-kill, or dead); basal area of spruce; species composition Does not re¬ quire a computer Ford (1980) 147 Table 1 —Continued Modelling the influence of the spruce hudworm on the forest Specific purpose Output generated Geographic area of applicability Time and space dimensions Mortality risk A map show¬ ing levels of mortality risk; nil, low, weak, intermediate, and extreme Quebec Next year on a forest man¬ agement unit basis To estimate volume incre¬ ment reduction as a function of defoliation % reduction of volume in¬ crement and cumulative growth loss (mVha) Northwestern Maine Eir-spruce stands (40 to 70 yr old) for a 5-year period Expected damage Infestation (hudworm and damage); nil, light, moder¬ ate, severe Ontario Next year on a forest man¬ agement unit basis Expected damage Mortality; “heavy” cate¬ gory expected to result in mortality Michigan Next year on a county basis Expected damage Defoliation; light, mod¬ erate, mod¬ erate-heavy, heavy-severe Wisconsin Next year on a forest man¬ agement unit basis Mortality risk “Hazard-rating index”; low moderate, high, and extreme Maine Next year on a forest man¬ agement unit basis 148 Unique features Major assumptions Input data required Validation considerations Software Reference Map Past 4 years of defoliation; egg-mass density Informal validation (in use for many years) Does not re¬ quire a computer Hardy and Dorais (1976) Looks at growth loss due to non- fatal defo¬ liation 1) No backfeeding occurred 2) Annual vol¬ ume growth and new foliage pro¬ duction is con¬ sistent and “normal.” Defoliation es¬ timate (meas¬ ured by weight of ovendry age classes/predic¬ ted normal weight), total volume inside bark for each of past 20 yr Kleinschmidt et al. (1980) Can be used on a map Egg-mass den¬ sity; current defoliation; % of spruce and fir respective¬ ly; cumulative damage Informal validation (in use for many years) Does not re¬ quire a computer Meating et al. (1982) Can be used on a map Aerial sketch map of heavy, moderate, and light Informal validation (in use for many years) Does not require a computer Mosher et al. (1980) Can be used on a map Egg-mass den¬ sity; current defoliation (aerial sketch map); top-kill and tree mor¬ tality Informal validation (in use for many years) Does not require a computer Renlund (1980) Can be used on a map Egg-mass den¬ sity; current defoliation %; previous defo¬ liation (2 yr); tree vigor rating Informal validation (in use for many years) Does not require a computer, but mapping routine is available from Maine Eorest Service, Old Town Trial and De- vine (1981) 149 Table 1 —Continued Modelling the influence of the spruce budworm on the forest Specific Output Geographic area Time and space purpose generated of applicability dimensions Mortality risk Hazard rating: very low, low, moderate, high, and very high New Brunswick Next year on a forest man¬ agement unit basis Modelling forest growth Simulate Tree list with Lake States Unlimited growth and updated (Minn., mortality for diameters, Mich., Wise.) any tree size status codes, or species tree factors. mixture and crown ratio codes Wood supply/ forest pro¬ ductivity Merchantable Very general Short- or volume (mV long-term ha) projections on a “forest unit” basis Predict Ovendry Northwestern Current ovendry weight in kg New Bruns¬ condition weight of of different wick (Green biomass of balsam fir and white spruce trees tree compo¬ nents (wood, bark, branches, foliage, roots) for each tree species River area) 150 Unique Major Input data Validation features assumptions required considerations Software Reference Can be used on _ Egg-mass den- Informal Does not re- Webb et al. a map sity; current validation (in quire a (1956) defoliation %\ use for many computer past defolia¬ tion %; foliage recovery years) Calculates 2 _ Number of 1) Model Computer Brand(1981) types of years to project based on program avail- mortality— the stand, num- 1,500 per- able from stochastic and ber of trees. manent plots author deterministic d.b.h. array. 2) Tests based species, status on predicted code, number and actual of trees per mean di- acre the tree ameters, num- represents. ber of trees/ crown ratio, acre, and BA/ site index. acre for 2 data mortality code sets: a) selected properties from the calibration database; b) an independent data base Stresses Development Yield curve; Model is FORTRAN Hall (1978) industry- patterns in age-class dis- completely available from standard “forest units” tribution; oper- general if New Bruns- units is known. ability and har- input is wick Dept. vesting rules; specified of Natural area in “forest units” correctly Resources Many Empirical D.b.h., crown Comparisons Does not Ker and Van independent regression width, crown of the sum of require a Raalte (1981) variables analysis length, total predicted computer height component weights to the predicted sum of the same components using data from 64 plots 151 Table 1 —Continued Modelling population dynamics Specific purpose Output generated Geographic area of applicability Time and space dimensions Document and Budworm lar- Based mostly Within and simulate some val density on New between years of the detailed (no./10 ftO, % Brunswick (year by year) biological pro- defoliation, data for a single cesses of the available stand of bal- spruce bud- worm sys¬ tem—popula¬ tion density and tree mor¬ tality foliage (ft7 acre), % para¬ sitism, bud- worms con¬ sumed by birds (no./acre), density of birds, ave. temperature during larval and pupal periods, pre¬ cipitation dur¬ ing larval and pupal periods sam fir Simulate the % mortality of Boreal forest Current year effects of larvae (range of bud- in an indi- stand factors on survival of first and second instars worm hosts) vidual stand 152 Unique Major Input data Validation features assumptions required considerations Software Reference Can be used Does not Initial forest Sensitivity FORTRAN Gage and with a plotter account for age (15-105 analysis computer pro- Sawyer (1979) adult migra- yr), years of gram tion into stand simulation, in¬ itial budworm density (no./ acre), daily or annual simula¬ tion, weather selection; ran¬ dom, con¬ stant, or in¬ put, position in random weather series, plot re¬ quest Computer plots 1) Host spe¬ Openness of — FORTRAN Kemp et al cies are ran¬ the stand. computer pro¬ (1980) domly distri¬ nonhost pro¬ gram buted through¬ portion, total out a stand. larvae avail¬ 2) Probability able, stand of a larva hit¬ density, pro¬ ting an open portion of area is pro¬ cloud cover. portional to parasitism rate available open area. 3) 20% of larvae inter¬ cepted by non¬ hosts reach forest floor and die. 4) Probability of interception is the same for hosts and nonhosts. 153 Table 1 —Continued Modelling population dynamics Specific purpose Output generated Geographic area of applicability Time and space dimensions Predict the Number of Green River Next year in population large larvae and Kedgwick individual density of per 10 ft- of watersheds in stands large larvae (instars 3-6) foliage northwestern New Bruns¬ wick Develop Survival rates Northwestern With the same framework for for each age New Bruns¬ generation for analyzing and interval within wick a stand modelling the survival rates of budworm life stages and reproductive potential and to isolate mor¬ tality factors the generation Analysis of Survival rates Northwestern Within same generation for each age New Bruns¬ generation for survival in interval in wick a stand sprayed v. un¬ separate mod¬ sprayed areas, els for each of isolate mortal¬ 4 types of ity factors treatment To simulate Development Data from Day-to-day and predict status or phy¬ Ontario but no development budworm phe¬ siological age apparent from pre¬ nology of budworm limitation emergence of (i.e., life second instar stage status at to end of arbitrary inter¬ moth emerg¬ vals) ence within a crown, tree, or stand 154 Unique Major Input data Validation features assumptions required considerations Software Reference Key factor Important With severe . Does not re- Morris analysis changes in defoliation: quire a com- (1963), p. 120 population large-larval puter density may density and be essentially weather (ave. determined by maximum dai- a few key fac- ly tempera- tors; no lags ture). Without in population severe defolia- growth tion: parasi¬ tism log n/n, and a.m. temperature. All models Each model is Number small Multiple re¬ Does not re¬ Morris are relatively purely indica¬ larvae; ave. gression quire a com¬ (1963), p. 105 simple. tive and d.b.h.; analyses and puter empirical; cumulative proportion of relatively defoliation; variance ex¬ small number survival from plained of plots and parasitism; years number large larvae/10 fE foliage; phe¬ nology; tem¬ perature; humidity; fecundity; de¬ foliation his¬ tory; forest in¬ solation index Assess the im¬ mediate effects on the generation treated and the delayed effects on subsequent generations Similar to Morris (1963), p. 105 29 sets of data were used to test the model of survival of sprayed gen¬ eration, but none of the other 3 models were tested. Does not re¬ quire a com¬ puter Morris (1963), p. 170-173 Process- oriented as opposed to heat- accumulation methods Temperature (daily mini¬ mum/max¬ imum), expo¬ sure of crown level Comparison of simulation result with observed phe¬ nology Computer pro¬ gram Regniere (1982) 155 Table 1 —Continued Modelling population dynamics Specific purpose Output generated Geographic area of applicability Time and space dimensions To identify Annual flue- New Bruns- Inter- and major eco¬ logical factors and their roles in budworm population dynamics tuation (log rate of change) in budworm population density for given life stages from one generation to the next wick intragenera- tional changes for a given locality Strategic analysis models To simulate Average tree New Bruns- Yearly time budworm out- size, tree’s wick steps in a stand breaks (quali- energy re- tatively and serve, and quantitatively) budworm and to describe density the outbreak/ decline cycle during the budworm/ balsam fir in¬ teraction 156 Unique Major Input data Validation features assumptions required considerations Software Reference Modeled in The endoge- Log rate of Simulation Does not re- Royama the form of a nous compo- survival from based on Mor- quire a com- (1981) second-order nent is deter- the egg to the ris (1963), p. puter density-depen- mined not adult stage 120 data dent process only by den- and the appa- that considers sity in the rent log repro- both most recent ductive rate endogenous generation but per adult and exoge- also by den- (function of nous compo- sity in the moth dis- nents preceding few persal); a func- generations. tion of local climatic con¬ ditions Analytical The major Carrying — Does not re¬ Ludwig et al model approx¬ limiting fac¬ capacity, quire a (1978) imation of tors of bud- growth rate. computer model by worm density budworm and Jones(1979) are food sup¬ branch densi¬ ply and the ties, consump¬ effects of tion rate, ave. predators and tree size, and parasites. energy re¬ serves (or none if qualitative analysis only) 157 Table 1 —Continued Strategic analysis models Specific purpose Output generated Geographic area of applicability Time and space dimensions Resource Density of New Bruns- Yearly for as management budworm wick long as de- policy design eggs, small larvae, large larvae, pupae, and adults; surface area of branches; foliage; bud- worm control policy; and forest man¬ agement policy sired, covers two-thirds of New Bruns¬ wick in terms of 264 regions To simulate a Annually cal- Maine (>90% Annually for wide range of culates forest of the spruce- the period management inventory fir resource in 1959-2020 strategies and stocking level. Maine) for individual their impact net and gross; land areas on Maine’s age-class; separated by wood supply growth rates; management and forest budworm- strategy. structure and caused tree forest type composition mortality and tree decline of older stands; regenerated areas cut over or depleted; targeted har¬ vesting on par¬ ticular areas or forest species; annual sal¬ vages and har¬ vests and species (spruce or fir) levels 158 Unique Major Input data Validation features assumptions required considerations Software Reference Second try at Based on con- Initial bud- Informal FORTRAN Jones (1979) long-term. sensus of worm age- computer pro- large-scale modelling class density. gram budworm- team forest struc- based strategic ture and initial model age distribu¬ tion, amount of new and old foliage per susceptible branch Allows various 1) Mortality 1) Proportions Clock turned Computer Seymour et al. sections of the occurs only on of total forest back and re- program (1981) unprotected the unpro- area divided suits compared lands to be in tected areas into with actual different and last 6 a) lands pro- data from stages of years. tected and inventories, foliage deple- 2)Simulated unprotected surveys, and tion and dif- area includes from budworm yield function ferent outbreak only Maine’s outbreaks intensity private hold- b) Softwood ings >500 and mixed- acres in the wood types “Protection with fir and District.” spruce by age- 3) % stocking. class in each species type composition, 2) Timing of and age-class budworm distributions attack, the pro- are reliable. tection re- sponse, and the lag period before mortal¬ ity occurs 3) Proportion of spruce-fir regeneration 4) Annual cut at minimum harvest age and proportion of harvest per species, age- class, pro¬ tected V. unprotected areas 159 Table 1 —Continued Strategic analysis models Specific purpose Estimate con¬ trol benefits v. control costs Output generated 1) Fir harvest volume with¬ out control 2) Spruce harvest volume with¬ out control 3) Fir harvest volume saved by control 4) Spruce harvest volume saved by control 5) Discounted value of treat¬ ment costs 6) Value of volume saved at harvest 7) Discounted value of con¬ trol 8) Net present value of con¬ trol 9) The rate of return to con¬ trol 10) The breakeven % Geographic area of applicability Public or pri¬ vate lands managed for timber Time and space dimensions Within one rotation for individual stands or con¬ trol blocks 160 Unique features Major assumptions Input data required Validation considerations Software Reference Adapted for use on a pro¬ grammable calculator 1) Number of yr until har¬ vest 2) Full- — Programmable calculator pro¬ gram Marty (in press) stocking har¬ vest volume 3) Proportion of stand in fir 4) Proportion of stand in spruce 5) Proportion of fir volume that will be lost without control 6) The acceptable or guiding rate of return on control invest¬ ments 7) Anticipated stumpage price for fir 8) Anticipated stumpage price for spruce 9) Income af¬ ter taxes 10) Cost after taxes 11) Number of yr to each treatment 12) Cost of each antici¬ pated treat¬ ment 161 Table 1 —Continued Strategic analysis models Specific purpose Evaluate eco¬ nomic feasi¬ bility of dif¬ ferent bud- worm control policies Output generated Comparison of total net present values saved (timber) and control costs Geographic area of applicability Quebec Time and space dimensions 40 yr Pro¬ vince-wide To evaluate Spray fre- Maine Yearly on a the effective¬ quency or 36-mi- site ness of dif¬ average pro¬ ferent spray portion of the policies forest sprayed each year, average egg density, and average de¬ foliation rate 162 Unique Major Input data Validation features assumptions required considerations Software Reference Compares 1) Outbreaks Forest type, — — Nadeau different eco- last for 10 yr. growth, net or (1977) nomic criteria 2) 30 yr pass gross allow- (benefit/cost. before next able cut. incremental outbreak. choice of in- rate of return. 3) Outbreak secticide, use net present progresses of wood, ap- value) or from west to plication cost. analytical east. stumpage techniques 4) The extent values, values of current of final pro- damage is ducts, indirect known. benefits 5) Cost of generated by spraying will forestry, mini- increase at a mum discount rate of 3%/yr. 6) The assumed rate of tree mortal¬ ity due to de¬ foliation is realistic. rate Proportion of Sensitivity Computer pro¬ Stedinger area covered analysis (a gram (1977) by spruce-fir. one¬ age distribu¬ dimensional tion in 5-year compression age-classes of the two- over the site, dimensional spray policy Maine model) 163 Table 1 —Continued Strategic analysis models Specific Output Geographic area Time and space purpose generated of applicability dimensions Simulate spraying/log¬ ging combina¬ tions The amount Quebec of insecticide that must be sprayed, and the area to be harvested Year-to-year for 30 yr on one manage¬ ment unit (as defined by the Quebec Dept, of Lands and Forests) Simulate the Population de¬ effect of nsity of weather. spruce bud- population worm, the density, and parasites, and various the incidence strategies on of diseased reproduc¬ and dead tion, disper¬ pests; area cri¬ sal, and tically defoli¬ mortality in ated; the prop¬ a pest ortion of trees population dead; and financial losses New Bruns- 4- x 4-mi wick squares in a total area of 10,000 mi- for 35 yr at 1-yr intervals 164 Unique features Optimization model First attempt at a long-term large-scale budworm- based strategic model Major assumptions Input data Validation required considerations Software Reference 1) Natural Proportion of mortality only age structure affects >10- into 3 harvest yr-old trees. classes, har¬ 2) Logging vesting limits, and spraying initial bud- are the only 2 worm egg- decision vari¬ mass density. ables. climate, defol¬ 3) Spatial iation level variations in stand condi¬ tions were not considered. 4) Can log only trees >60 yr old Computer pro- Ung (1981) gram Population dynamics based on Mor¬ ris (1963, p. 120); forest is an evenly spaced stand of balsam fir 20 cm d.b.h. Large amount of input data required (17) Some runs were initial¬ ized in year 1925 for com¬ parison with actual events FORTRAN computer pro¬ gram Watt (1964) 165 Appendix 2—Incorporating IPM in Forest Management Gary A. Simmons, Wilf Cuff, Bruce A. Montgomery, and J. Michael Hardman In assessing the wood supply, forest managers often call for minimizing destructive effects of pests. IPM can help with such policy-level decisions even though IPM would put aside the idea of minimization in preference to reduction of pest populations below the level of economic injury. From an ecosystem perspective the latter criterion is the better, and in the long run also better from an industrial perspective. Integrated pest management can help at both planning and operational levels. The identification of these two levels is, in part, arbitrary to serve as a convenience on which we organize our discussion of decision processes. By planning level, we refer to those activities that are identified and organized to give substance to policy, an example of such a policy directive being that “there will be a protection program.” By operational level, we refer to those procedures involved in carrying out the activities identified at the planning level and any changes in activities necessitated by experience. Planning is a process that is conducted relatively infrequently (less often than annually) and whose function it is to set the scene for the yearly operational procedures. The results of the planning level are procedures for implementation; the results of the operational level are those actions actually carried out in the field. We envision the first step that is required by someone wishing to apply 1PM to a specific fbrest-pest problem as the recognition of the decision process in use by the forest industry/management agency. The stress that we lay on the decision process is not standard IPM practice. We introduce it here because we believe that IPM as defined largely for agricultural application is not adequate for the practice of forestry. The slow rate of forest maturation encourages a long-term orientation to forest management, including pest management of forest insects; and the relatively large size of forest “farms,” or management units, makes it economically feasible to conduct long-term plans. Thus, we see the standard definition of IPM as most appropriate to our operational levehrThis level is usually conducted on an annual basis, relies on annual monitoring of pest levels, and uses an approximate economic injury level with its tree hazard index. But the “planning” level is somewhat different. The economic injury level is very loosely defined; and pest monitoring is involved, but not with the same degree of constancy as at the operational level. Assessment and integration of control tactics are retained in planning. We believe that enough IPM ideas are valuable to long-term planning that it makes sense to talk about IPM-based forest management planning as well as operations. Emphasis on the decision processes in use by the forest industry/management agency is our attempt to place contributions of IPM-based pest management into the perspective of the user. Unless this step is accomplished, IPM tools will run the risk of being ignored in planning. Of course, by formalizing decision processes (examples in appendix 2, figs. 1 and 2, and chapter 2, fig. 2.1), we run the risk of confusing the decisionmakers. Decision flow diagrams such as we use in this chapter do correspond to what is done in decisionmaking, but the process is only rarely formalized to this degree. Our aim is not to try to make the decisionmakers more explicit in their deliberations but rather to allow the existing scientific tools to be placed relative to the decisionmaker’s conventions— and hence more readily usable in the planning process. Even at the operational level, the size of forest management units implies an organizational structure of sufficient magnitude that pest management must find a niche in existing decision structures, or run the risk of being ignored. While each organization can be expected to have its own decision structures (even though they may not be formally described), similarities as well as differences will be found among decision processes likely to arise in forest management. Surely goals must always be defined, whether explicitly as policy directives (e.g., mount a protection program) or as a consequence of contemplated programs. Decision processes (programs) set up to respond to the goals will usually require that the magnitude of the resource be estimated and pest damage be predicted by some means. Having already decided on the most likely future, managers should investigate if the pest population will exceed the economic injury level. If not, nothing beyond routine monitoring procedures need be considered. If it will, decisionmakers should evaluate options based on costs V. benefits, ecological impacts, and other related criteria {see chapters 5 and 9). The most suitable option(s) will then be selected and implemented. The results of the action(s) will be evaluated and modifications added as necessary. 166 Planning Planning can be done before or during a budworm outbreak. In appendix 2, figure 1, we present a decision process useful in attempts to devise actions that lessen the impact of budworm outbreaks when they occur. Figure 1 will be discussed first in general terms and then by example. In the decision process of figure 1, the decisionmaker would first review the management plans in place (e.g., ignore budworm). Next comes a consideration of the management actions that are currently feasible. We caution the reader not to mistakenly relate only those forest-directed techniques with the planning level; all forest-directed, bud worm-directed, and no-action techniques apply to varying degrees of both planning and operational levels. The decisionmaker next predicts the status of the forest and spruce budworm populations (using, for example, tools listed in chapters 6-8) to determine if the currently used management actions, within existing management plans, have effects on the forest/budworm ecosystem that are suitable given the management objectives in place. Strictly speaking, the IPM criterion for having met management objectives is reducing pest damage below the economic injury level. But in forestry practice, a looser definition is not uncommon: “Will things continue to go well under the current management actions?” might well be the question considered. If things seem acceptable, then after a given time, the process may be repeated. If, however, the future outlook does not seem acceptable, then it is necessary as part of the ongoing planning exercise to identify the management options; evaluate their environmental, social, and economic consequences; select one or a set of alternatives for incorporating the plan; and eventually implement actions in the field. All these steps must be done as well as possible within the time constraints of the planning exercise. Then if the process is repeated, it will likely be after a period of years. Figure 1 —Flow diagram of a decision process that might be appropriate for planning activities or prevention of budworm damage over the long term. Given this decision process, ways must be found to satisfy each of the tasks implied by the boxes in the figure. It is the role of the decisionmaker to choose from the available techniques the ones to be used at each stage of the decision process. The techniques may be subjective or rational; if rational, they may stem from scientific considerations or from other rational processes. On the other hand, the role of the professional scientist is to contribute scientific knowledge to any (or all) of the stages involved in the decision process. Entomologists may, for example, help to predict the influences of specific budworm outbreaks, to discern if those influences will negatively affect management goals, to identify management options that could mitigate undesirable effects on the management objectives, and to evaluate possible options based on economic, environmental, and sociological consequences. (It should be added that scientists—as people as well as professionals—can also use nonscientific, including subjective, techniques to help in the decision proccess.) Example Let us take an example of the decision process given in the figure. Suppose a management block contains three spruce-fir stands and each has good road accessibility. Each stand contains about 60 percent balsam fir, 30 percent spruce, and about 10 percent mixed hardwoods (see appendix 2, table 1 for more details). A review of management plans is now being conducted. At present, the management plan does not address budworm management; hence the management plan is not to deal with budworm effects before scheduled harvesting, when stand age reaches 70 years. This plan specifies “no action,” even though a wide range of possible actions is available. A budworm/forest prognosis based on experience and hazard rating (a function of stand age and composition) suggests that older, slower growing stands will support budworm populations and sustain tree mortality. The 60-year-old stand is primed for trouble. An existing model trusted by the planning team indicates that if an outbreak occurs, about 70 percent of the balsam fir will be killed in such older stands. This means that mortality of 50 ft7acre (11.5 mVha) basal area and about 13.4 cords/acre (84.4 mVha) could occur under the current management plan. In addition, common sense suggests that harboring a budworm population in the older stand will provide a source of budworms to spill over into younger stands and at least halve the annual growth increment. This prognosis certainly calls into question the wisdom of the current “no-action” management plan. Identifying available management options becomes a necessity. Table 1 —Example data used to illustrate planning activities Stand Area in acres (ha) Mean age Site Index in ft (m) Basal area in ft-/acre (m7ha) Current yield in cords/acre (mVha) Growth increment in cords/acre/yr (mVha/yr) 1 430 70 100 23 1.5 (174) 38 (21) (23) (145) (9.4) 2 320 50 120 32 0.4 (130) 60 (15) (28) (202) (2.5) 3 530 55 110 (214) 20 (17) (25) NA NA Here is a list of available options for such mortality risk. Each includes asumptions on the outbreak behavior in the stands and estimates of anticipated net value of harvest under each option, in standardized current dollars. 1. Do nothing until scheduled harvesting; assume no outbreak will occur in any stand; $91,000. 2. Immediately market and harvest the current 60-year-old stand; assume no outbreak in stands 1 and 3; $61,000. 3. Do a balsam-fir-only cut in the 60-year-old stand; assume no outbreak in any of the stands before scheduled harvesting; $74,000. 4. Wait until an outbreak begins and then salvage the 60-year-old stand; assume no outbreak in stands 1 and 3; $80,000. 5. Conduct partial cuts within the 60-year-old stand to break up the continuity and provide a checkerboard of older and younger forest; assume no outbreak in any of the stands before scheduled harvesting; $76,000. 6. Spray all stands with chemical insecticides as hazard assessment suggests; assume outbreaks will occur at least once in the next 50 years; $75,000. Without trying to estimate the probabilities of outbreak behavior in any stand, one can make some progress toward deciding which option to implement. For example, from an entomologist’s perspective option 1, although apparently providing the highest monetary return at harvest under the outbreak assumption, is the least desirable because entomologists are very sensitive to the difficulty of predicting outbreak behavior. Option 2 is the most 168 desirable entomologically in that it removes the high-risk stand but is the least desirable economically. Options 3 and 5 seem to provide good protection from outbreaks and give an acceptable return. But after cuts are made, residual stands are subject to windthrow, the effects of which have not been taken into account. Option 4 is good economically, but the unknown influence of the old stand on budworm populations that could infest adjacent stands makes this option questionable. In addition, it is assumed that a market can be found at the time it is needed. Option 6 will provide adequate forest protection but runs the risk of public controversy. The ultimate ecological consequence of each option is similar in that within 50 years the whole management block will be harvested. There will be some short-term differences in the influences on various wildlife populations. Sociologically, the visual impact of option 2 will be the greatest, with an immediate clearcut versus a delayed clearcut or a partial cut. Based on such preliminary considerations, decisionmakers would usually assign probabilities to each assumed “state of nature,” as given in the option list above and maximize expected return to help in their choice of option. Given this array of information, informal and formal analytical techniques, and his or her biases, the decisionmaker would make a choice and implement the actions of the decision. Once action is taken, the management block is reconsidered when results of the action are clear. Eventually management plans are once again reviewed, and the process just described is repeated. Operations Despite our best efforts to avoid serious spruce budworm problems, outbreaks will occur. When this happens, quick action may be required. The decision process of the previous section, with its emphasis on management for lessening future damage, will probably be too slow to respond to impending tree mortality from an outbreak. A decision process that seems more appropriately done on an annual basis is shown in appendix 2, figure 2. Figure 2 —Flow diagram of a decision process that might be appropriate for operational activities or response to budworm population and forest impact in the short term. Surveillance and monitoring of forest conditions and spruce budworm abundance is the foundation of the IPM-based response to budworm populations and forest impacts. If on the basis of a budworm/forest prognosis such information indicates that the budworm will affect management objectives, then a management response (“option” in appendix 2, figure 2) may be considered. Each option is evaluated and compared with other alternatives based on environmental, social, and economic consequences. Once an option is selected and implemented, the short-term results are evaluated. Surveillance and monitoring are usually conducted annually, while the additional actions are incorporated only when management objectives appear threatened. Now let’s consider an example of the application of this decision process. The example that follows approximates what one can find in all eastern Canadian Provinces and in the State of Maine. Example Each year aerial observers fly over the entire Province/State during July, when signs of defoliation are easy to spot. During this period, foliage of dying trees takes on a reddish-brown coloration. All areas displaying defoliation are mapped. Based on the intensity of coloration (i.e., light, moderate, or severe), observers record the area’s defoliation history. Beginning in August and continuing through mid-September, ground crews conduct egg-mass sampling. This is done uniformly throughout some regions but not in others. At each egg-sampling location, crews obtain additional information to be used in a hazard-rating system. Thus, for each of many locations (e.g., 1,750 in New Brunswick in 1982), a tree-mortality risk assessment is provided to give an indication of potential tree deterioration under continued budworm attack. Generally areas of susceptible forest exhibiting medium and greater hazard are considered for possible management actions. In some jurisdictions, merchantable volume is also taken into consideration. Late fall and early winter sampling of larvae is used to define more precisely the boundaries of areas selected for any management action. In this example the budworm/forest prognosis of appendix 2, figure 2 is the hazard-rating system, and management objective is low hazard (risk). Where management objectives are affected, the array of options for a particular locality can vary depending upon specific circumstances such as primary uses of the area, harvesting schedules, road access, impacts on nontimber values, and the like. But the following options represent a typical array of actions: spray with pesticides, abandon, harvest and regenerate, salvage, conduct a fir-only cut (or a similar partial cut), or some combination. (The following steps are theoretically correct but in practice have not received much attention, as usually only “spray” or “abandon” have been the options implemented. But times have changed.) The next step would be to conduct an economic evaluation of each option or combination of options considered feasible and appropriate. In addition to economic criteria, environmental and social concerns would be considered with each option. Spraying a particular wildlife area might ignite public opinion and result in litigation that stops all spraying. Once a decision is made for taking a particular management action, then the action is implemented, and the results of that action are evaluated. Sometimes this evaluation is an informal procedure where managers casually look at results some months later; sometimes it is more formal: evaluation data are obtained in the form of insect numbers, stand mortality, and the like. Again, specific circumstances dictate the extent to which an evaluation is conducted. Combining Planning and Operational Activities Up to this point we have left the impression that decisions and actions could be applied to only two discrete situations—when longer term preventive planning activities were being undertaken or when short-term response operational activities were dictated. Actually, these situations represent two extremes on a continuum of decisions and actions that are needed in the management of spruce-fir. In many instances, especially in the Northeastern United States and in southeastern Canada, managers are confronted with dealing with outbreaks and impending tree mortality and at the same time are attempting to plan longer term actions to lessen the impact of the budworm in the future. In these instances, the two decision processes we discussed earlier are combined. When this is done, the process ends up looking like figure 2.1 in chapter 2. The only additional details are that some of the boxes have both short-term and long-term aspects. 170 Appendix 3—Principal laws governing handling and application of forest insecticides United States Act Principal provisions Agency Cooperative Forest Management Act of 1950 (64 Stat. 473, as amended; 16 U.S.C. 568c, 568d) Authorizes Federal officials to provide technical assistance to forest landowners, and public agencies for forest protection and other management needs U.S. Department of Agriculture Environmental Quality Improvement Act of 1970 (84 Stat. 114. as amended; 42 U.S.C. 4371-4374) Establishes office of Environmental Quality and Council of Environmental Quality (CEQ) to advise and assist the President on policies and programs of Federal Government affecting environmental quality Office of the President Forest Pest Control Act of 1947 (61 Stat. 177, as amended; 16 U.S.C. 594-1 to 594-5) Authorizes forest insect surveys, and control operations, and appropriations for such purposes U.S. Department of Agriculture National Environmental Policy Act of 1969 (83 Stat. 852, as amended; 42 U.S.C. 434, 4331-4335, 4341-4347) Requires preparation of environmental documentation for proposed actions by Federal agencies or supported by Federal government Office of the President Forest and Range Renewable Resources Planning Act of 1974 (84 Stat. 476, as amended; 16 U.S.C. 1600-1614) Requires Secretary of Agriculture to report to Congress use of pesticides on National Forests U.S. Department of Agriculture Federal Insecticide, Fungicide, and Rodenticide Act of 1978 Requires registration of toxic materials transported between States; stipulates procedures for registration, suspension, cancellation and reregistration U.S. Environmental Protection Agency Canada British North America Act, Canadian Constitution (1982) Assigns responsibility for natural resources, including protection, to Provinces Agriculture Canada Pest Control Products Act (R.S.C. 1970, C. P-10) Controls purchase and use of pesticides, requires registration of pesticides, establishes classes and standards for pesticides, restricts use according to classification Agriculture Canada Environmental Contaminant Act (S.C. 1974-75-76, C-72) Provides Federal officer authority to regulate use of environ¬ mental contaminants in situations not covered by existing law Environment Canada Fisheries Act (R.S.C. 1970, C.F.-14) Protects fish habitat Fisheries and Oceans Canada Migratory Bird Convention Act (R.S.C. 1970, C.J.-12) In habitats used by migratory birds, prohibits deposit of materials that are toxic to them Environment Canada Transportation of Dangerous Goods Act (S.C. 1980, C-36) Regulates transportation of toxic materials Transport Canada Food and Drugs Act Provides for tolerance levels of pesticides on foods entering into commerce Department of National Health and Welfare 171 Appendix 4 —Federal, State, and Provincial offices for current information on insecticides for spruce budworm suppression Eastern United States Federal Offices Area Director Northeastern Area, State and Private Forestry USDA Forest Service 370 Reed Road Broomall, PA 19008 Field Representative Forest Pest Management Northeastern Area, State and Private Forestry USDA Forest Service Concord-Mast Roads, Box 640 Durham, NH 03824 Field Representative Forest Pest Management Northeastern Area, State and Private Forestry USDA Forest Service 1992 Folwell Avenue St. Paul, MN 55108 State Offices Director Bureau of Forestry State House Station #22 Augusta, ME 04333 Director Division of Forests and Lands Box 856, 105 Loudon Road Concord, NH 03301 Director Division of Lands and Forests Department of Environmental Conservation 50 Wolf Road Albany, NY 12233 Director Department of Forests, Parks and Recreation Division of Forestry Heritage 11, 79 River Street Montpelier, VT 05602 State Forester Forest Management Division Michigan Department of Natural Resources Steven T. Mason Building Box 30028 Lansing, MI 48909 Director Division of Forestry Centennial Building 658 Cedar Street, Box 44 St. Paul, MN 55155 Chief State Forester Department of Natural Resources P.O. Box 7921 Madison, WI 53707 172 Canada Federal Offices Director General Research and Technical Services Canadian Forestry Service 19th Floor, Place Vincent Massey Ottawa. Ont. KIA 1G5 Provincial Offices Ontario Director Forest Pest Management Institute Canadian Forestry Service Director Forest Resources Branch Ministry of Natural Resources Whitney Block, Queens Park Toronto, Ont. M7A 1W3 Quebec P.O. Box 490 Sault Ste. Marie, Ont. P6A 5M7 Directeur Service d'Entomologie et de Pathologic Direction de la conservation Ministere de I’Energie et des Ressources 175 rue St. Jean Quebec, P.Q. GIR 1N4 New Brunswick Director Eorest Management New Brunswick Department of Natural Resources P.O. Box 6000 Fredericton. N.B. E3B 5H1 Newfoundland Director Forest Protection Department of Forest Resources and Lands Building 810, Pleasantville St. Johns. Newf. AlA 1P9 Nova Scotia Director Reforestation and Silviculture Nova Scotia Department of Lands and Forests P.O. Box 68 Bently Building 523 Prince Street Truro, N.S. B2N 5B8 Prince Edward Island Director Forestry Branch Department of Energy and Forestry P.O. Box 2000 Charlottetown, P.E.I. CIA 7N8 173 Appendix 5—Aerial spraying-checklist (Items for consideration—not all will be required for each operation. Adapted from Cairow et al. 1981.) Soliciting bids and contracting for aerial application 1. Contractor must satisfy all Federal and State or Provincial regulations. 2. Include the following information in contract: Total number of acres or ha to be sprayed Number and size of spray blocks Requirements for spray volume (per unit area) and atomization required Map (1:500,000) showing all spray blocks and airstrips Aircraft capacity (unit area per hour capability) Starting date, application period Stand down (no spray) payments Ferrying distance for aircraft (airport to spray block) Estimated average spraying time per day Items to be supplied by contractor Items to be supplied by contractee Delivery system specifications Location of pilots’ and ground crews’ accommodation, responsibilities for cost Aircraft to be calibrated prior to arrival Pilot to have forestry spraying experience Method and timing of payment to contractor Notification of public 1. Notify local authorities. Federal aviation authorities, landowners, public news media, etc. Field preparation 1. Chemicals Pesticide ordered Diluent or additives ordered if necessary Insecticide potency checked after delivery Materials delivered to site Field storage, handling and loading facilities prepared 2. Project maps 1; 15,000 to record treatments and progress 1:50,000 topographic Recent aerial photos (1:15,000) for each pilot Spray block boundaries shown on maps, photos Swaths marked Spray block corners marked Key features highlighted (navigational or danger) 3. Airstrip Meets specifications Sides brushed out Surface graded and packed Stones removed and holes filled Aircraft fuel ordered Aircraft fuel delivered to site Aircraft traffic patterns Search and rescue plans Aircraft safety plans, emergency equipment, etc. 4. Water for mixing Check pH and/or clarity of water supply Pumps with backup units Intake hoses Foot valves Float to keep foot valve off bottom Outlet hose to reach mixing tank or water truck Pail to prime pump Inlet strainer Gas for pump Pump maintenance kit 5. Water or alternative material for wetting runway Dribble bar if water truck is being used “Y” valve in water supply line Appropriate nozzle for spraying/wetting runway surface Adequate hose to cover runway and turnabout area near mixing area 6. Washing facilities for mixing crew Clean water Soap Dishpan or bucket Clean water storage drum, fitted with valve Stand for water drum 7. Radios Walkie talkies for balloon men, observers Appropriate FM radio and antenna to install in aircraft Radio for weather monitor Mixing site radio to communicate to block Mixing site radio to communicate to aircraft Radios for men on road for traffic control 174 8. Mixing/loading equipment Mixing tanks Jacks and blocks for leveling mixing tanks Appropriate hitch and truck for mixing unit transport Mixing/loading pump (ca. 150 gal/min [570 1/min] capacity) Gas for pumps Backup loading pumps Pump maintenance kits Inlet hoses Outlet hoses, chemical-resistant material Dry break coupling for aircraft inlet 12 volt drum transfer pump Jumper cables 12 volt battery Charger or DC generator (motor vehicle) Barrel loader (truck mounted) Barrel sling for loader Hoses, couplings, valves, and tees for recirculation and repairs Soft paper towels to clean aircraft windshield Aerial spraying record Stopwatch Calibrated containers (different sizes) Calibrated drum to check flowmeter (at least 50 gal [190 1]) Flowmeter Inline strainer 50 mesh screen for strainer (2) Standpipe (drum sucker) Drum rinser Sample bottles for insecticide Dyes Scales for weighing powder dye 9. Safety equipment Notification of local hospital Arrangement with local physician For mixing crew Neoprene or rubber safety boots Neoprene or rubber gloves, elbow length Full rain suits and disposable coveralls Hard hats with chin straps Respirators, full face or half face Safety goggles Refills for respirators First aid kits For balloon men Disposable coveralls Hard hats with chin straps Goggles Respirators, half face Safety boots Walkie talkies —common frequencies —communication with aircraft —communication with mix site —shoulder strap, remote microphone —spare batteries, antennae Sturdy packsacks Helium supply for balloon markers “D” size helium cylinders —yoke —handle or wrench to operate valve —check pressure in used tank; tank fills 3 balloons Monofilament fishing line Large reel or winder Balloons Diagram of block spray plan flight lines Strobe lights For camp Fire extinguishers First aid kits Posted emergency procedures Traffic barricades on road/airstrip 10. Equipment for monitoring crew (weather, deposit of insecticides) Trucks Radio for weather monitor to contact mix site/guidance aircraft Deposit cards and holders with carrying case Psychrometer Water for psychrometer, rain or distilled if possible Wind gage Weather record forms Watch Rain gage Signs to post sprayed areas 175 Appendix 6—Acknowledgments The technical coordinators for this manual wish to acknowledge the very significant contributions of a number of '‘silent” reviewers whose corrections in the manuscript preparation stage have added greatly to the readability and subject-matter coverage of the text. Chapter authors have cited these individuals in particular: Chapter 1: Daniel T. Jennings, USDA Forest Service. Northeastern Forest Experiment Station, Orono. Maine; and Dan Kucera, USDA Forest Service, Northeastern Area, State and Private Forestry, Broomall, Pa. Chapter 2; Marcia McKeague, Woodlands Division, Great Northern Paper Co., Millinocket, Maine; Dan Mosher and Ron Murray, Michigan Department of Natural Resources. Lansing and Roscommon, Mich., respectively; Louis L. Wilson, USDA Lorest Service, East Lansing, Mich.; George Bird, Stuart Gage, and Dean Haynes. Department of Entomology, Michigan State University; Robert Campbell, USDA Lorest Service, CANUSA-West, Corvallis, Oreg.; William Waters, University of California. Berkeley; and Penny M. Ives, CSIRO Division of Plant Industri, Narrabri, N.S.W., Australia. Chapter 3; Ron Kelly, Vermont Department of Forests, Parks, and Recreation, Morrisville, Vt.; Jerry Williams, International Paper Co., Augusta. Maine; Marcia McKeague, Woodlands Division. Great Northern Paper Co., Millinocket, Maine; and Dan Mosher, Michigan Department of Natural Resources, Lansing. Chapter 4: J. Hudak, W. J. Meades, and A. G. Raske, Newfoundland Forest Research Centre; C. H. A. Little, D. A. MacLean, L. P. Magasi, and H. Peine, Maritimes Forest Research Centre; J. T. Basham, G. M. Howse, B. J. Stocks, Great Lakes Forest Research Centre; and H. O. Schooley, Petawawa National Forestry Institute, all for their contributions of updated written material on various topics related to this chapter’s contents. For their technical reviews, the chapter authors acknowledge the help of J. L. Flexner, A. M. Lynch, and C. E. Olson, Jr., The University of Michigan, R. P. Ford, USDA Forest Service, Northeastern Area, State and Private Forestry, St. Paul, Minn.; and D. A. MacLean, Maritimes Forest Research Centre, Fredericton, N.B. Chapter 5: R. P. Ford, USDA Forest Service, State and Private Forestry, St. Paul, Minn.; Dan Schmitt and Dave Gansner, USDA Forest Service, Northeastern Forest Experiment Station, Broomall, Pa.; Tom Rumpf, Maine Forest Service, Augusta; Wilf Cuff, Canadian Forestry Service, Maritimes Forest Research Centre, Fredericton, N.B.; and Ted Howard, University of New Hampshire, Durham. Chapter 7; H. J. Irving, Forest Protection, Ltd., Fredericton, N.B.; Michel Pelletier, Ministry of Energy and Resources, Quebec, P.Q.; and Thomas D. Smith. Department of Lands and Forests, Truro, N.S., for providing information on the use of B.t. in particular regions. For technical reviews of the chapter, thanks are extended to William R. Beck, Technical Representative, Sandoz, Inc.; Robert Cibulski, Product Development, Abbott Laboratories; Jesus Cota, USDA Forest Service, Northeastern Area, State and Private Forestry, Morgantown, W.V.; Franklin B. Lewis, USDA Forest Service, Northeastern Forest Experiment Station, Hamden, Conn.; John Lublinkhof, Biochem Products; and Thomas Rumpf, Maine Forest Service, Augusta. Chapter 8; Jack Armstrong, Canadian Forestry Service, Ottawa; Charles L. Hatch, USDA Forest Service, Northeastern Area, State and Private Forestry, Broomall, Pa.; and Henry Trial, Maine Forest Service, Old Town. Chapter 9: For reviews of early drafts of the chapter, the authors thank Steven F. Oliver!, Maine Forest Service; John B. Dimond, University of Maine at Orono; and Jon G. Stanley, Maine Cooperative Fisheries Research Unit, Orono. CANUSA Program Management sought technical review of the book as a whole from four prominent experts on budworm; Fred B. Knight, Dwight B. Demeritt Professor of Forest Resources, University of Maine at Orono; Charles A. Miller, Canadian Forestry Service, retired; Paul Flink, Bureau of Forestry, Michigan Department of Natural Resources, Lansing; and Jesus Cota, USDA Forest Service, Northeastern Area, State and Private Forestry, Morgantown, WV. These people put in many hours under severe time constraints during the summer of 1983, and the technical coordinators of this manual gratefully acknowledge their help. Douglas C. Ferguson and William L. Murphy, of USDA's Insect Identification and Beneficial Insect Introduction Institute (Agricultural Research Service), Beltsville, Md.. verified all common and scientific names of insects in this volume. 176 Index Abandonment. 94 Of attacked stands, 71 Impacts of, 134 Abbott’s formula, 32 Abies balsamea (L.) Mill., v, 2 Accessibility Silvicultural management and, 90 Of small holdings, 80 Accothion. 122 Acephate, 119-121 Acetylcholinesterase, 137 AChE, 137 Acleris variana (Fernald), 9 Actia interrupta (Curran), 9 Adult, spruce budworm, 5, 7 Adulticides, 125 Aerial photography, 74 Aerial spraying. Aircraft for, 126 First, 116 Navigation systems for, 139 Planning and execution checklist, 174 Swath overlap, 137 Aerial surveys, 34, 54 Cost of, 74 Agar, 108 Age of stands, 13 Excessive, 68 Age-class, Distribution, 45, 73, 94, 98 Diversity, 97 Structure, modifying harvest schedules, 74 Aggregating chemicals, 41 Agriculture Canada, 119, 131 Air currents, in budworm dispersion, 6, 7 Airbases, 73 Aircraft, In aerial sketch mapping, 34 In aerial surveys, 54 Nozzles for, 108 Payloads of, 126 Spray heights, 126 Swath width, 108 Airspeed, For application of insecticides, 126 In sketch mapping, 34 Alkali consumption, during pulping of budworm-killed timber, 43 Altitude, For insecticide spraying, 126 In sketch mapping, 34 Aminocarb, 119-120, 121, 139 New formulas of, 130 Antievaporants, iov Bacillus thuringiensis. 107 Ants, 8 Apanteles fumiferanae (Viereck), 8 Aplomya caesar (Aldrich), 8 April, 6 Aquatic insects, 134 ff. Armillaria fungi, 41 Aspen, 49, 58, 72, 88 Atlantic salmon, 137 Atomization, of insecticide sprays, 126-127 Audience, for this manual, v Auger’s bud classification system, 30 August, 6, 7 Automated egg-mass counter, 25 Avian predation, on spruce budworm, 7-8 BASIC, 144 Bacillus thuringiensis, 104 ff., 139 Activity in insect gut, 104 Aircraft to apply, 108-109 Budworm density and, 109 Carryover, 105 Chitinase for, 111 And Christmas trees, 112 Commercial formulations, 105-106 Cost of, 73, 106 Dilution of, 107 Dosage rates, 107 Droplet density and size, 108 Dyes used with, 108 Early use of, 105 Efficacy by tree species, 110 Formulations From kurstaki, 104 Now available, 106 Ground applications of, 1125 HD-1, 104 Laws regulating, 111-113 Metal fittings with, 111 Mixed with insecticides, 111 Mode of action, 105 Natural occurrence of, 104-105 Neat, 107-108 For nurseries, 112 Origin of, 104—105 Persistence, 105 Plantations and, 112 Potency terminology, 106 Bacillus ihuringiensis-lContinued ), Rain and, 109 Safety of, 111-112 Species susceptible to, 104 Split applications of, 110 Spores, 105 Spray emission rates, 107 Spray window, 109 Stability of, 111 Stickers for, 105, 109, 111 Sunlight and, 109 Tankers, 111 Time for mixing, 111 Timing, By foliage development, 108-109 By foliage development, 109 Larval stage to kill, 108-109 Toxic crystal, 105 Undiluted, 107-108 Viscosity of, 111 Water and, 105, 111 Weather considerations, 109 Wettable powder formulations, 106 Backfeeding, 7, 42 Bacteria, 8 Balsam fir, v, 2 Budbreak in, 87 Component in Maine, 89 Defoliation estimates by, Fettes method, 32-33 Discrimination against, 98-99 Flower production, 40-41 Growth loss in, 38-39 Mixed stands with, 94 Mortality, 42, 109 In Maine, 52-53 Need for quick harvest of, 43 Proportional increases of, 49 Shoestring rot in, 41-42 And stand vulnerability, 86 Timing of sprays, 124 Vulnerability, 87 Reduction of, 94 Balsam fir bark beetle, 42 Bark beetles, 41-42 Basal area. And mortality determination, 56 Mortality estimations and, 58 Of spruce-fir, v Removed, 94 Baskets, in larval sampling, 31 Benefit-cost evaluation, 166 ff. Benthos, 137 Betula alleghaniensis Britton, 88 Betula papyrifera Marsh., 88 Bias, in estimating budworm populations, 32 Binoculars, 33-34 Biologists, wildlife, 139 Biology, of budworm/spruce-fir forest, 13 Birch, 88 Bird habitat, 8 Birds, 7-8, 46, 49 Habitat for, 49 Insecticide, Impacts on, 137 Toxicity to, 121 Overlap of spray swaths and, 137 Predation by, 7-8 BIU, defined, 106 Black light, 23 Black spruce, 2, 7, 53 Budbreak in, 87 Mortality, 42 Replacing white spruce, 92-93 Vulnerability of, 87 Blocks, selection for spraying, 73 Blowdown, 68, 69 Blueberries, Fields of, 139 Insecticides and, 122 Booms, 126 ff. Hydraulic, 108 Boreal forest, 2, 44 Borrowing money, 76 Branch(es), Ocular examination of, 33-34 Sampling requirements, 27 Brass, 111 Brightness loss in pulping, 43 Brook trout, 137 Budbreak, 7, 87, 108-109 Bud development index. Auger’s, 30 Bud mining, 6 Buffer areas, 139 Buffer strips, 72 Harvesting, 80 Selection harvesting and, 93 Butt cull, 42 Butt rots, 41, 68 Calcium arsenate, 116 Cambial electrical resistance, 58 178 Cambium, 58 Cameras, Aerial, 54 Film for remote sensing, 54 For remote sensing, 54 For stand ratings, 57 Canada Department of Agriculture, 119 Canada/United States Spruce Budworms Program (CANUSA), V, vi, 13 Canadian Council of Resource and Environment Ministers, 131 Canadian Forestry Service, v, 97 Canopy, 52 CANUSA, see Canada/United States Spruce Budworms Program. Cape Breton Island, 56 Aerial surveys of, 54—55 Fir replaces fir in, 98-99 First chemical control site, 116 Carbamate insecticides, 119 And AChE, 137 Carbaryl, 119-121, 139 Impact of, 137 New formulations of, 130 Carbohydrates, 41 Carson, Rachel, 119 Caustic soda, 27, 30, 32, 119 Cessna AgWagon, 126 Check plots, 32 Chemical control, for budworm, 116 ff. Chemicals, aggregating, 41 Chickadee, 7 Chipper, 43 Chitin, 130 Chitinase, for Bacillus thuringiensis, 111 Chlorinated hydrocarbon insecticides, 119 Choristoneura fumiferana (Clemens), v, 2 Christmas trees. Bacillus thuringiensis for, 112 Clearcutting, 69, 72, 90-92 Climate, v, 6, 7 And budworm population dynamics, 97 And budworm vulnerability 85 Cloquet Valley State Eorest, 53 Clothing, protective, 129 Collapse, of budworm outbreaks, 7, 14 Coloration, Of budworm-killed foliage, 54 As sign of tree death, 42 Of spruce budworm life stages, 3, 5 Color photography, in remote sensing, 34 Combined Forest Pest Program, 13 Computer(s), Languages, 144 Eor modelling, 144, 146-165 Modelling, to compare management strategies, 76 For remote sensing analysis, 54-55 Software for models, 144 Cone, Damage, 40-41 Mortality, 38, 40-41 Constellation, 126 Contact poisons, 119-120 Control, for spruce budworm. Biological, 104 ff. Chemical, 116 ff. Microbial, 104 ff. Silvicultural, 86-87 Cost-benefit evaluation, 166 ff. Covered funnel traps, 23-24 Craighead, F. C., 84 Cuticle, 130 Cuts, fir-only, 72 Cutting, To lower diameter limits, 98 On small holdings, 80 Cytoplasmic polyhedrosis virus, 8 DC-6, 126 DC-7, 126 DDT, 116, 119 Toxicity to fish, birds, mammals, 120 Damage, defined, 38 Damage assessment, 38 ff. Cost of, 74 And salvage, 95 Debarking, 43 Decay, in stems, 42 Decisionmaking, 18-19 Example, 168-170 Elow chart of, 17 Operations level of, 16 Planning level of, 16 Process, 14-15 Tools, 144 Decision trees, 77 Deer, 49 Deer yards, 139 179 Defoliation, Amount required to kill trees, 42 Canadian. 52-53 Categories, 34 Effect on regenerating trees, 49 Estimates, 54. 128 By binoculars, 33-34 And fungal invasion, 41-42 Impact of, on stands, 49 Intensity, 34 Mapping, 34, 54, 170 Photographic assessment of, 54 Prediction, by overwintering larvae, 27-28 Recreation and, 52 Reduces seed production, 40 Species’ reaction to, 42 ff. Surveys, ground, 32 Tree’s response to, 41 Detection, and salvage, 95 Diameter, of stems, 38-39, 40 Diameter at breast height (d.b.h.), 39 Dichlorvos, 24 Digital data, in remote sensing, 54-55 Dioryctria reniculleloides Mutuura & Monroe, 8, 9 Discoloration, fungal, 42 Discount rates, 76 Discounts, for timber, 71, 72 Diseases, And budworm population dynamics, 97 Of spruce budworm, 8-9 Microsporidian, 110 Dispersal, Of budworm adults, 7 Of budworm larvae, 6 Of egg-carrying females, 14 Routes of, 99 Dominion Forest Service, 116 Douglas-fir Tussock Moth Program, 13 Drainage, 58 Drift, of insecticides, 127 Drift nets, 137 Dylox, 122 Eagles, 139 Eastern blackheaded budworm, 9 Eastern hemlock, 2, 87 Eastern larch, 87 Eastern larch beetle, 41, 52 Eastern white pine, 87 Eclosion, 6 Economic injury level, 12 Economic pest, defined, 67 Economic(s), 66 ff. As a dictator of policy, 15 Estimating losses, 52 Impact of spruce budworm, 52 In integrated pest management, 12 As management constraint, 97 Models related to, 142 ff. Of the spruce-fir region, 15 Zero value of dead fir in, 71 Ecosystem, Impact of pesticides on, 134 ff. Interaction of components, 46 As management unit, 12 Spruce-fir, 84 Spruce-fir/budworm, 85 Units, as site classifiers, 46 Egg-laying, sites favorable for, 98 Egg-mass sampling, 25 ff. Adjusted for bias by workers, 32 Timing of, 25 Egg-mass surveys, 74, 125 Electrical resistance, in trees, 58 Elevation, 46 Emergence, of spruce budworm larvae, 3,5,6 Endemic population phase, v Endothenia albolineana (Kearfott), 9 Energy chips, 72 Engineering, in integrated pest management, 12 Entomophthora egressa MacLeod & Tyrrell, 9 Entomopoxvirus, 8 Environmental assessment, sample situation, 139 Environmental impacts, of pesticides, 134 ff. Environmental monitoring, as a management expense, 74 Ephialtes Ontario (Cresson), 8 Epidemic, spruce budworm, 13 Population phase, v, 7 Collapse, 8 Epidemiology, of budworm outbreaks, 7 Epizootics, of viruses, 8-9 Erosion, 72 Erynia radicans (Bref.) Humber, Ben-Ze, Ev and Kenneth, 9 Esthetics, affected by spruce budworm, 52 Estimating, Defoliation, 32-33, 54, 128 Larval numbers, 144 ff. Tree mortality, 58 Evaluation, of control activities, 18 Evaporation, of water-based insecticides, 127 180 Evening grosbeak, 7 Extraction of larvae from hibernacula, 27 Eye irritation, from Bacillus tlmringiensis, 111 Eye protection, 129 False-color films, 54 Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), 119 Fenitrothion, 119-120, 122, 139 New formulas of, 130 And pollinators, 137 Fettes method, 32-33 Fiber loss due to beetles, 42 Film, for remote sensing, 54 Fir, 7-8, 9, 94 Component in Maine, 89 Cuts of, 72 Dead, as a free good, 71 Discriminating against, 98-99 Green, required by mills, 71 Growth loss studies in, 48 Fife cycle, 45 Fifespan of, 73 Market demand for, 67 Reducing component of, 72 Reducing proportion of, 73 Removal, 89 Replaces fir, 49, 98 Shoestring rot in, 41-42 Shoots, 87 And stand vulnerability, 86 Substituting, 74 Volume, and hazard rating, 58 Volume loss, 44-45 Vulnerability, v. spruce, 68-69, 110 Fire, 18, 49-50 And abandonment, 71 Fish, pesticides and, 134 ff. Flagmen, clothing for, 129 Flies, 46 Flight, of budworm, 7 Flowering, in conifers, 40-41 Foliage, Area, how to determine, 25 Discoloration, and aerial surveys, 34 Nutritive quality of, 87 Old, 87 Quality, 7 Saved, by percent, 32 Folithion, 122 Forbs, 49 Forest, Boreal, 2, 44 Fire, 49-50 Growth models, 58, 150-151 Inventories, 14, 16, 74 Fake States, 2, 67 Management, 12 Maritimes, v, 2 Rotation, 84, 86 Succession, 49 Sustained-yield, 98 Forest tent caterpillar, carbamate insecticides for, 119 FORTRAN, 144 Free good, 71 Frost, 46 Fulure, 23 Fungi, 8, 41-42 Armillaria, 41 Heart wood, 40 Sap-rotting, 42 Shoestring root rot, 41 Stem invasion by, 42 Gaspe Peninsula, 41, 67 Genotype, 41 Glypta fumiferanae (Viereck), 8 Golden crowned kinglet, 7 Government, Management concerns of, 67 Role of, 15 Granulosis virus, 8 Great Lakes forest, v, 2 Green River Project, v Griselda radicami Walsingham, 9 Gross regional product, 15 Ground, Applications of Bacillus thuringiensis, 112 Plots, Fixed-area, 56 Prism-point sample, 56 Surveys, for defoliation, 32 181 Growth, Forest, modelling, 60 Loss, 38-41 Fungi and, 42 Of height, 48 As optical illusion, 68 Recovery from, 48 Of volume, 48^9 Radial, 52 Rate, 13, 16 And vulnerability, 87-88 Reduction, 68 Growth-cut ratio, 69 Grumman AgCat, 126 Grumman Avenger, 126 Gypsy moth, carbamate insecticides for, 119 Gypsy Moth Program, 13 Hardy, Yvan, 98 Harvest, Accelerated, 74 Models for scheduling, 74 Ranking stands for, 57 Regulation of, 18 Rotation desirable, 89 Harvesting, 90 Based on foliage discoloration, 34 From best sites, 69 Clearcut, 92 Light, 92-93 Mechanical, 42 On small holdings, 80 Partial, 72, 94 To reduce danger of budworm attack, 16 In uneven-aged stands, 93 Versus abandonment, 71 Hatching, of larvae, 6 Hazard-rating systems, 56-57 Ground-collected data for, 56-57 Remote-sensing data for, 57 Models for, 19 Heartwood fungi, 40^1 Height-growth loss, 38-39 Helicopters, 108-109, 126 Hemlock, see Eastern hemlock. Herbicides, 92 Hexane, 27 Hibemacula, 6, 27 Surveys of, 123 High-site lands, 71 Hormones, 41 Horses, in salvaging, 80 Host species, for budworm, 49 Foliage development in, 123 Nutritive quality of, 87 Proportion of, 74 Range of, v, 2 Hydrocarbon, chlorinated, as insecticide, 119 Ice age, 13 Impact, Of insects, 38 Salvage to reduce, 94 Industry, management concerns of, 67 Infrared photography, in remote sensing, 34, 74 Inflation, 69 Insect growth regulators, 130 Insecticide(s), 104 ff., 116ff. For budworm control, 116 ff. Chemical, Cost of, 73 Efficacy by species, 110 Current information sources, 172-173 Decisionmaking, 122 ff. Desirable features of, 118 Environmental impacts of, 134 ff. Evaluation of, 139 Foliage protection from, 118 Future use of, 130-131 Impacts of, 134—139 Labels on, 120, 128 Mixed with Bacillus thuhngiensis, 111 Mode of action, 120 Oil-based, 121 Organophosphate, 119-120 Persistence of, 119-120 Quickness of action of, 118 Registered for budworm, 120 Safety for handling, 128 ff. Split applications of, 123 Insects, aquatic, 134 ff. Instar, 3, 5 How to identify, 30 Integrated pest management, 12 ff., 134, 166 ff. Definition of, 12 Elements of, 12-13 And evaluation of pesticides, 139 ff. General principles of, 12 Incorporated into forest management, 166 ff, Objectives of, 12, 166 ff. Operations level, 169-170 182 Integrated pest management—(Cc^/zm/nec/), Philosophy of, 19 Planning, 167-170 Silviculture in, 89-90 Interest, real, 76 International Units (lU), 106 Inventory, Forest, 95 Insufficient detail of, 74 Silviculture and, 90 Invertebrate predators of spruce budworm, 8 Itoplectis conquisitor (Say), 8 July, 6, 7 Egg-mass sampling in, 25 June, 6, 7 Fruit set in, 137 Juvenile hormones, 130 Kraft paper yields, 43 Kromekote cards, 108 LQo, 121 LD50, 121 Labels, on insecticides, 120, 128 Lacewings, 8 Ladybird beetles, 8 Lakes, 67 Lake States, 67 Egg-mass density in, 25-26 Egg-mass sampling in, 25-26 Fir and aspen mixture in, 72 Fire risk in, 71 Forest, 2, 67 Mixed stands in, 87-88 No-action response to budworm in, 16 Tree mortality in, 53 Land managers, 67 Landowners, Management concerns of, 67 Treatment choices by, 67 Landsat, 54—55 Larix laricina (Du Roi) K. Koch, 2 Larvae, 3-7 Associates of, 9 Early-instar, 6 Feeding behavior of, 6-7 Food supply of, 87 Lary die—(Continued), Identifying instars of, 30 Instars to aim for, 108-109 Late-instar, 6-7 Population dynamics of, 118 Protected by tree growth patterns, 110 Sampling of, 74 Surveys of, 27 Larval dispersal, into regeneration, 91 Larval sampling, 74 Large, 28 Lateral buds, 41 Latitude, 46 Laval University, 98 Lichens, 6 Light, Budworms attracted to, 23 Reaction to, by budworm larvae, 6 And seedling development, 92 Light traps, 23 Lime, 130 Loaders, clothing for, 129 Lockheed PV-2, 126 Logging, cost of, 72 Losses, valuing, 75 Low-site lands, 71 Lypha setifacies (West), 8 Maine, v, 2, 15, 67 Acephate used in, 121 Bacillus thuringiensis used in, 105 Economic analysis for, 76 ff. Egg-mass sampling in, 25 Fir component in, 89 Foliage protection assessment, 32-33 Flazard-rating system in, 57 Impact of defoliation on stand volume in, 48 Larval surveys in, 27 Light traps in, 23 Spray costs in, 73 Spruce budworm populations in, 54 Washington County, 54 Mammals, insecticide impacts on, 137 Management, Coordination among owners, 95, 97 Even-aged, 90 Of property already infested, 66 ff. Preventive, 66 Silvicultural, 84, 86-87 Uneven-aged, 90 183 Management practices, economics and, 66 ff. Management strategies, How to judge, 76 To protect future growth potential, 76 Mapping, Defoliation, 34, 54, 166 ff. Infestation levels, 56 Sketch, 34 Maps, forest type, silviculture and, 90 Maritimes region, 16, 67, 166 ff. Economic analysis for, 76 ff. Egg-mass sampling in, 25 Eorest, v, 2 Green fir required in, 71 Larval surveys in, 27-28 Markets, for budworm-killed timber, 73-74 Masked shrew, 49 Mass attack, by spruce budworm, 41 Matacil, 121 Mathematical models, of budworm population processes, 14 Mathematics, In integrated pest management, 12-13 Models utilizing, 146-165 May, 6 Fruit set in, 137 McKenzie River, 2 Mechanical harvesting, 42 Medical handling of pesticide emergencies, 129 Merchantable age of stands, 16 Merchantable volume, 68 Metabolites, 41 Metamorphosis, interruption of, 130 Meteorus trachynotus (Viereck), 8 Meterology, in integrated pest management, 12 Methylene blue, 27 Michigan, v Estimating fir mortality in, 58 Plot size in, 56 Spruce budworm outbreaks in, 53 Upper Peninsula of, 53 Microorganisms, as disease vectors, 8 Microscope, 108 Microsporidian(s), 8-9 Diseases of budworm, 110 Mills, 69, 71 Capacity of, 74 Converted to hardwoods, 74 Financial survival of, 73 Subsidizing, 16 Minnesota, v Branch sampling requirement in, 27 Cloquet Valley State Forest, 53 Estimating fir mortality in, 58 Spruce budworm outbreaks in, 53 Mist nets, 137 Mites, 8 Mixers, clothing for, 129 Model(s), 146-165 To compare management strategies, 76 Evaluating and comparing, 144-165 Forest growth, 60, 150-151 Harvest-scheduling, 74—75 Hazard-rating, 19, 146-165 Input, 143 Locality bias in, 143 Output, 143 Strategic analysis, 158-165 Tree mortality hazard rating, 146-158 Validation of, 143 For vulnerability, 142 Money, borrowing to finance forest management, 76 Monitoring spruce budworm populations, 14, 15, 16, 18 Monocultures, 92-93, 99 Moose, 49 Mortality, Of budworm larvae, 6-8 Of cones, 40-41 Cumulative, 56 Determination, basal area and, 56 Estimation, 57-58 Fir, related to vigor, 58 In the Lake States, 53 Normal, 68 Of roots, 41 Of seedlings and saplings, 42, 49 Of seeds, 40-41 And site conditions, 45-46 Of trees, 41, 42 ff., 44-45, 49 And outbreak duration, 46 And stand characteristics, 86 Natural control, of spruce budworm, 14 Natural enemies. In integrated pest management, 12 And silviculture, 85 And species diversity, 92 Of spruce budworm, 7-8, 46 Needle mining, 6 184 Needles, 41 ff. Flaring. 109 Nematodes, 113 Nets, Drift, 137 Mist, 137 New Brunswick, vi, 15-16 Acephate not used in, 121 Bacillus tlmringiensis costs in, 106 Branch sampling requirements, 27 Egg-mass sampling in, 25 Fenitrothion used in, 122 Fir replaces fir in, 99 Impact of defoliation on stand volume in, 48 Population dynamics studies in, 97 Studies of budworm controls, 113 Tree height growth loss in, 48 New England, 67 New Hampshire, v Spruce budworm outbreaks in, 53 New York, v, 67 Newfoundland, vi, 2 Egg-mass sampling in, 25 Larval surveys in, 27 Nitrogen, 41 Nonphotographic sensors, 54 Nontarget organisms, pesticides and, 134 Nosema fumiferanae (Thompson), 9 Nova Scotia, vi, 15-16 Bark beetle attacks in, 41 Tree growth reduction in, 38-39 Novathion, 122 Nozzles, 126 ff. For spray aircraft, 108 Nuclear polyhedrosis virus, 8, 113 Nurseries, Bacillus tlmringiensis for, 112 Nutrient translocation, in conifers, 39 Nutritive quality of host species, 87 Ocular examination, of branches, 33-34 Omotoma fumiferanae (Tothill), 8 Ontario, v Acephate used in, 121 Branch sampling requirements in, 27 Egg-mass sampling in, 25 Infestations related to egg masses, 25-26 Organophosphates, And AChE, 137 In insecticides, 119-120 Spills, cleanup of, 130 Orthene, 121 Oscillation, of budworm populations, 97 Outbreak(s), 6-8 Cycle, 13-14 Duration and mortality, 86 Historical, 52 Intensity of, and mortality. 86 Probability, 14 Unpredictability of, 14 Overstocking, 68 In small, private holdings, 80 Overwintering, of budworm larvae, 6 Oxford Paper Company, 116 Paper birch, 88 Parasites, 8 Alternate host requirements, 8 And budworm population dynamics, 97 Introduced, 8 Releases of, 80 PASCAL, 144 Pellets, 72 Persistence, Of carbamates, 119-120 Of organophosphates, 119-120 Pest, economic, defined, 67 Pest control, in integrated pest management, 12 Pest Control Products Act, 119 Pesticide(s), Areas where banned, 80 Containers for, 129 Current information sources, 172-173 Disposal of, 130 ff. Environmental impacts of, 134 ff. Evaluation of. 139 Impacts of, 134—139 In integrated pest management, 12 Laws regulating, 118-119, 171 Persistence of, 119-120 Registration of, 118-119, 130 Residues of, 12 Resistance to, 12 Safety and, 128 ff. Split applications of, 123 Storage of, 129 Systemic, 120 Transporting, 129 ff. pH, of water for Bacillus tlmringiensis, 111 Phaeogenes maculicornis hariolus (Cresson), 8 Pherocon ICP traps, 23 185 Pheromone, 7, 41, 113 Trapping, 80 Traps, 23 Photo-interpretation, 57 Photo-positivity, of spruce budworm larvae, 6 Photography, Aerial, 54, 74 Color V. black and white, 54 Scale of, 54 Season for, 54 Damage assessment using, 57 Estimating future damage using, 57 Infrared, 54 In remote sensing, 34 Time of day in, 54 Photosynthesis, 41 Phryxe pecosensis (Townsend), 8 Physiology, in integrated pest management, 12 Picea glauca (Moench) Voss, v, 2 Picea mariana (Mill.) B.S.P., 2 Picea rubens Sarg., v, 2 Picture elements, in nonphotographic remote sensing, 54 Pilots, clothing for, 129 Pine, white, 2 Pinus strobus L., 2 Piper Pawnee, 126 Pixels, 54 Planning, aerial spray operations, 123 ff. Plantations, Bacillus thuringiensis for, 112 Planting, 91-92 For species manipulation, 99 Techniques, 92 Plot, Fixed-area, 56 Line, 56 Size in Michigan, 56 Pole pruner, 25, 27, 28, 31 Poletimber, Stands, 90 Thinning, 94 Policymaking, 15 Pollinators, 137, 139 Polyponis abietimis Dicks ex Fr., 42 Population, of spruce budworm. Controls, 7-8 Dynamics, model for, 60 Prediction, overwintering larvae and, 27-28 Populus spp., 88 Precommercial treatment of stands, 68-69 Predators, 7-8 Prices, shadow, 75 Prince Edward Island, vi Prism-point sample plots, 56 PROGNOSIS model, 60 Projection tables, 14 Protection, For high-value properties, 80 Targeted, 99-100 Protozoa, 8, 9 Pulp, Degradation of, 42 Yield from budworm-killed timber, 42 Pulping characteristics of budworm-killed timber, 43 Pupae, 5 Pupation, 7 Quebec, vi, 15, 67 Acephate not used in, 121 Bacillus thuringiensis costs in, 106 Branch sampling requirements in, 27 Chitinase in Bacillus thuringiensis used in. 111 Egg-mass sampling in, 25 Fenitrothion used in, 122 Helicopters used in, 109 Insecticide costs in, 106 Larval surveys in, 27 Spray decisions in, 31 Spruce beetle attacks in, 41 Rabbit, 49 Radar, for tracking budworm flights, 125 Radial growth, 52 Radial increment reduction, 38-39 Radiation, in nonphotographic remote sensing, 54 Rain, And Bacillus thuringiensis, 105, 109 And trichlorfon, 122 Raspberries, 92 Rating stands for spruce budworm hazard, 19, 56-57 Rating systems, 56-57 Recreation, effect of spruce budworm on, 52 Red spruce, v, 2, 7, 13, 53, 94 Budbreak in, 87 Mortality of, 42, 110 Vulnerability of, 87 “Redstriped needleworm,” 9 186 Regeneration, Advance, 92 Artificial, 72, 92-93 Border trees for, 92 Caused by spruce budworm, 14 Of fir stands and bird habitat, 8 Methods, 90 Natural, 91 Of white spruce, 94 Seed production and, 91 Registration, of pesticides, reciprocal, 131 Remote sensing, 34 Nonphotographic, 54—55 Optical-mechanical detectors for, 54 Photographic, 54 Reservoir, of budworms, 93, 99 Resin, 41 Respirator, 129 Response actions to decisions, 16 Return on investment, from small property, 93 Risk-rating system, 56 Roads, 12, 72 As management constraints, 86 Root(s), Girdling by fungi, 42 Mortality, 41 Rot, 41^2 Rotation, 84 And silvicultural management, 86 Royama, T., 7, 97 Riibus spp., 92 Safety, of personnel handling insecticides, 120 ff. Sales, Preparation of, 72 Of timber, 67 Salmon, Atlantic, 137 Salvage, 18, 71-72 Determining what to, 33, 80 Objective of, 94 Options matrix, 95 Ranking stands for, 57 For small, private holdings, 34 Timing after mortality, 95 Total, 94 Sampling, Branches, 27, 32-33 Egg-mass, 166 ff. Extensive v. intensive, 25 Large larvae, 27-28 Sampling—, Prespray and postspray, 32 Repeatability of, 35 Sequential, of balsam fir, 26 Sap rot, 42^3 Sap stain, 43 Sapling(s), Mortality, 42 Stands, 90 Thinning of, 94 Saprophytes, 9 Sapwood, deterioration due to fungi, 42 Satellite(s), 56 For aerial photography, 54 Imagery, 34 Sawyer beetles, 42 Scale, of aerial photographs, 54 Scanners, airborne multispectral, 54 Schreiner, E., 116 Seed(s), Mortality, 38, 40-41 Orchards, Bacillus thuringiensis for, 112 Production, 80 And regeneration, 91 Seedling mortality, 42 Sensors, photographic, 54 September, egg-mass sampling in, 25 Sequential sampling, of balsam fir, 26 Sevin, 121 Shadow prices, 75 Shelterwood, 91 Cuts, 72 Harvesting, 90 “Strip and patch,” 92 Shigometer, 58 Shoestring root rot, 41-42 Shoots, Elongating, 108-109 Spruce V. fir, 87 Shrew, masked, 49 Shrubs, 49 Signage, for pesticide warnings, 129 Silent Spring, 119 Silvicultural management. In integrated pest management, 12 Outcome of, 86-87 187 Silviculture, In budworm management, 84 ff. For high-value properties, 80 Goals of. 89 Identifying stands for, 90 Impacts of. 134—137 Options in salvage situations, 95 Shelterwood system of, 91 Uneven-aged, 92-93 Site(s), Classification systems, 46 For egg-laying, 98 High-quality, 90 Preparation, 91-93 Quality, Species manipulation for, 90 And vulnerability, 87-88 Which to treat, 69 Sketch mapping, 34 Sociology, in integrated pest management, 12 Software for models, 144 Soil, V, 92 Fungi in, 42 Organophosphates in, 119 Solitary vireo, 7 Songbirds, 49, 137 Sorbitol, 107 Southern Pine Beetle Program, 13 Spacecraft, in aerial surveys, 54 Spacing trees, by thinning, 94 Species, Competition, with budworm, 9 Composition, v, 2, 13, 74 Altering, 93, 98 In Maine forests, 88 Manipulation of, 90, 93, 98-99 Mortality estimation and, 58 Nonhost, 86 Of stands, 45 And vulnerability, 87-88 Control by thinning, 94 Conversion, 86-87, 92, 98-99 Diversity, 92 Encouraging nonhost, 98-99 Manipulation, 88-89 Spiders, 8, 46 Spills, of pesticides, 130 Split applications, 123 Spores, of Bacillus thuringiensis, 104-105 Spray, Bans, 80 Blocks, 139 Determining what to, 56-57 Efficacy evaluation of, 32 Planning, 57 Programs, 18 History of, 67 Swaths, 139 Overlap of, 137 Windows, 125 Sprayers, hydraulic, 112 Spraying, 18 Aerial, Equipment for, 126 ff. Evaluation of, 127 ff. Planning, 122 ff. Windspeed in, 128 Bacillus thuringiensis, ground, 106 Economics in favor of, 71 Factors affecting success of, 127 Ground, using Bacillus thuringiensis, 106 Minimum timespan of, 73 Morning, 139 Nozzles for, 108 Postspray evaluation of, 125 Reduced, 89 Spruce budworm adults, 125 Strategy, 97 Timing by host species, 124 Sprouting, as means of regeneration, 72 Spruce, 2, 7 Black, 2, 7 Seed production, 40-41 V. White, 92 Budbreak in, 87 Bud caps of, 110 Component in Maine, 89 Damage on, 87 Growth loss in, 38-39 Increasing proportion of, 72, 89 Life cycle, 45 Lifespan of, 74 Lumber downgraded, 43 Mortality, 42, 109-110 In Maine, 53 Red, V, 2, 7, 13, 94 Vulnerability of, 87 Shoestring rot in, 42 Shoots, 87 188 Spruce—(Continued). Volume, and hazard rating, 58 Volume loss, 44 White, V, 2, 94 As food source, 87 Vulnerability, 87 Spruce beetle, 41, 52 Spruce bud moth, 9 Spruce budworm, Adults, 5, 7 And bud development, 28 Associates, 9, 52 Biology, 2 ff. Chemical controls for, 116 ff. Cone and seed damage by, 40-41 Control treatments. Efficacy of, 32 Outcome of, 134 Damage assessment. Aerial surveys for, 54 Ground checks for, 54 Defenses against, 41 Defoliation caused by, 52-53 In Canada, 52 Estimation, 54 ff. In the United States, 53 Defoliation surveys for, ground, 32-34 Density, equation for, 25 Detection, 22 Cost of, 35 Surveys, 22 Development, on host species, 124 Diseases of, 8-9 Dispersal, Larval, 89 Phase, 125 Economic impact of, 52, 68 ff. Effects, On flowering, 40-41 On recreation, 52 Eggs, 3, 5, 6 Egg-mass counter, automated, 25 Egg-mass sampling, 166 ff. At outbreak levels, 25-27 Endemic populations of, 13 Epidemics, v, 7, 13-14 Estimating population trends, 22 Eecundity, 9 Feeding habits, weather and, 109 Females, behavior of, 7 Food supply, 87 Spruce budworm—(Continued), Growth curve, 68 Harvesting timber killed by, 69, 71 Hosts, 2 Identifying larval instars of, 30-31 Impact, 44-45 On stands, 44 ff. On trees, 38^5 Infestation levels, mapping of, 56 Insecticide control of, 104 ff., 116 ff. Larvae, 3, 5, 6 Dispersal of, 87-88 Feeding behavior of, 6-7 Food supply for, 86-87 Models for estimating, 146-165 Population dynamics of, in epidemics. Sampling of, 118 Stages of, to kill, 108-109, 118 Surveys of, 27-28 Life cycle, 2 ff. Longevity, 7 Males, behavior of, 7 Management, Objectives, 167 Practices, economics and, 66 ff. Strategies, 80-81, 86 Mass attack, 41 Mating success, 7 Microsporidian diseases of, 110 Migration, 23 Models available for, 146-165 Monitoring, 14, 16, 18 Mortality, Factors in, 13 In the Lake States, 53 Natural, formula to estimate, 32 Natural control, 14 Natural enemies of, 7-8 And silviculture, 85 Natural mortality, formula to estimate, 32 Outbreak collapse, 14 Outbreak dynamics, and silviculture, 98 Outbreak probability, 14 Outbreaks, 6, 7, 13-14 In Canada, 52 History of, 52 In New England, 53 Parasites, 8 Pheromone, 23-24 spruce budv'.orm —(C oiuiniiecl). Population, Collapse, 97 Controls, 7-8 Dynamics, models for, 60 Prediction, 142 ff. Sampling, 22 Oscillation of, 7, 97 Predators, invertebrate, 8 Predicting outbreaks, 23 Projection tables, 14 And pulping characteristics of wood, 43 Pupae, 5, 7 Surveys of, 32 Range, 2, 13 Rate of development, 30-31 Regeneration caused by, 14 Regional impacts of, 52 ff. Reservoirs of, 93, 99 Response options to, 69 Sampling, Large-larval, 28 ff. Prespray and postspray, 32 Silvicultural management of, 84 ff. And species composition of stands, 45, 49 Species mortality from, 109-110 Spray, Efficacy evaluation, 32 Programs, 18 Stands vulnerable to, 68 Survey(s), 23 ff. Aerial sketch mapping for, 34 Costs of, 35 Detection, 22 Ground, 32 Of outbreak populations, 25 ff. Overwintering larval, 27-28 Susceptible forest, 2, 7 As a thinning agent, 14 Treatment plots, 32 Tree growth patterns and, 110 Vulnerability, Of overstocked stands, 73-74 Silviculture and, 85 ff. Wood loss due to, 52 Spruce coneworm, 8, 9 Spruce-fir forest, v, 2 ff. Spruce needleminer, 9 Stainless steel, 111 Staminate flowers, of balsam fir, 6 Stand Prognosis Model, 60 Stand(s), 15 Abandonment, 71 Age, 44 ff., 94-95 Excessive, 68 Characteristics, and vulnerability to budworm, 86 Condition, 74 Conversion to nonhost spp., 86-87, 92-93 Density, 7, 86-87 And vulnerability, 87-88 Diversity between, 97 High-risk, 97 Likelihood of being attacked, 16 Managing for diversity of, 98-99 Merchantable age of, 16, 18 Overmature, 86 Overstocked, thinning of, 73-74 Rating for spruce budworm hazard, 57 Salvage, 94—95 Size, as a factor in budworm outbreaks, 46 Spatial distribution of, 97 Structure, 7, 86-87 Uneven-aged, 93 Unmanageable, 18 Vigor, 68-69 And vulnerability, 87-88 Stearman, 126 Stem(s), Changes after budworm invasion, 42 Diameter, 38-39 Growth of, 46 Moisture content of, 42 SXxcktxs, fox Bacillus thuringiensis, 105, 111 Stocking, V, 7 Excessive, 68 Minimum seedling level, 49 Reducing fir component of, 72 Stomach poisons, 120, 121 Stone groundwood process, 43 Strategy, for budworm management, 67 Streams, 72, 139 Buffer strips for, 93 Stress, Tree, 41 ff. Water, 41 Strip cutting, 90 ff. Stumpage prices, 69 In valuing losses, 75 Subsidizing mills, 16 Succession, forest, 49 Sulfite, 43 Sumithion, 122 190 Sunlight, and Bacillus tlmringiensis, 105, 109 Supervised classification, 55 Surveys, Defoliation, 32 Light traps for, 23 For outbreak populations, 25 Pheromone traps for, 23-24 Pupal, 32 For sparse populations, 23 Survival, tree, after budworm attack, 32 Susceptibility, 56 And artifical regeneration, 92-93 Sustained yield, 94, 98 Swaine, J. M., 116 Swath width, of aircraft, 108, 126 Synchronicity, Of budworm and host development, 7 Of flowering and larval emergence, 40-41 Synchrony, 7, 97 Synetaeris temdfemur (Walley), 8 Systemic insecticides, 120 Tamarack, 2 Tankers, ior Bacillus tlmringiensis, 111 Targeted protection, 99-100 Taxes, 16, 75 Impact on decisionmaking, 67 Thermal inversion, 127 Thinning, 93-94 From below, 94 Precommercial, 73-74 By spruce budworm, 14 Young stands, 74 Timber, Annual flow of, 69 Real price of, 75 Sales, 67 Unsalvageable, 75 Tools, for handling pesticides, 129 Top-kill, 38-39 Topography, 46 Tortricids, 28 Toxicity, Of acephate, 121 Of carbamates, 119 Of chlorinated hydrocarbons, 119 Of pesticides, 134-137 To fish, birds, mammals, 120 Training, for pesticide application personnel, 123 Transpiration, 41 Transportation costs for wood, 42 Traps, Covered funnel, 23-24 Light, 23 Pherocon ICP, 23 Pheromone, 23-24 Population sampling, 22 Treatment(s), Anticipatory, 73-74 Block selection, 73 Cost of, 73 Plots, 32 Precommercial, 68 Silvicultural, Results unquantified, 99-101 Targeted, 99-100 Tree(s), Electrical resistance in, 58 Mortality, 38, 41-42, 45^6 Hazard rating for, 19, 166 ff. In the Lake States, 53 Normal, 68 And outbreak duration, 46 Predicting, 142 ff. Vigor and, 58 Nutritive quality of, 87 Radial growth in, 38-39, 52 Size, desirable, 69 Spacing by thinning, 94 Stress, 41 ff. Water, 41 Vigor, 86-88 Reductions in, 41 Trichlorfon, 119-120, 122, 139 Trichogramma minutum (Riley), 8 Trout, brook, 137 Tsuga canadensis (L.) Carr, 2 Type maps, 90 Unemployment, 15 Ungulates, 49 U.S. Department of Agriculture, Forest Service, 131 Combined Forest Pest Program, 13 U.S. Environmental Protection Agency, 119, 131 Validation of models, 143 Value, of standing timber, 75 Vapona, 24 Vectors, microorganisms as, 8-9 191 Vermont, v, vi Spruce budworm outbreaks in, 53 Vigor, Of stands, 68 Tree mortality related to, 58 Virginia, v Viruses, 8 Visual examination of branches, 33-34 Volume, Decline, 68 Loss in budworm-attacked trees, 48 Vulnerability, 56-57 And artificial regeneration, 92-93 Of host-tree species, 87-88, 1 10 Indexes, 56 Model to predict, 146-165 Need for quantification, 100-101 Of overstocked stands, 74 Rating systems, in Canada, 58 Reducing, By age-class manipulation, 98 By fir reduction, 72 By silviculture, 84 ff. By thinning, 94 And stand characteristics, 88-89 Uneven-aged silviculture and, 92-93 Waferboard, 43, 72 Plants, 74 Warblers, 7 Wasps, 46, 92 Water, Chlorinated, 111 Stress, 41, 46 Watersheds, and sketch mapping, 34 Weasel, 49 Weather, 6, 7, 8, 9, 46 And Bacillus thuringiensis, 109 And budworm populations, 86 And dispersal of budworm, 14 Factors affecting spray success, 127 In integrated pest management, 12 And insecticide application, 123, 128 Weeding out undesirable species, 94 Weevils, 42 Western spruce budworm, 60 West-to-east outbreak patterns, 14 Wettable powders, 112 White pine, 2 White spruce, v, 2, 94 Black spruce to replace, 92-93 Budbreak in, 87-88 Management, 90 Mortality of, 42, 110 Vulnerability of, 86-87 White-throated sparrow, 7 Wilderness, 80 Wildfire, 18, 48, 49-50 Wildlife, 48, 49-50 Area, ramifications of spraying in, 166 ff, Biologists, 139 Pesticides and, 134 ff. Wind, 6, 7 Damage, 94 Windfirmness, 94 Improving, 92 Windspeed, in spray operations, 128 Windthrow, 68, 69, 72. 95 After fire, 52 Potential, 90 Wisconsin, vi Branch sampling requirements, 29 Spruce budworm outbreaks in, 53 Wood, Dead, when not to salvage, 71 Degradation, 42 Fungal deterioration of, 42 Losses due to spruce budworm, 52 New markets for, 72 Yellow birch, 88 “Yellow spruce budworm,” 9 Yield, Projections, 60 Sustained, 94, 98 Zeiraphera fortunana Kearfott, 9 Zero value. Of dead fir, 71 Of standing timber, 75 Zones of abundance theory of budworm outbreaks, 7, 98, 99 192 N United States Department of ^ Agriculture Forest Service Cooperative State Research Service Agriculture Handbook No. 621 Spruce Budworms Handbook Guidelines for the Operational Use of Bacillus thuringiensis Against the Spruce Budworm In 1977, the United States Department of Agriculture and the Canada Depart¬ ment of the Environment agreed to cooperate in an expanded and acceler¬ ated research and development effort, the Canada/United States Spruce Bud- worms Program (CANUSA), aimed at the spruce budworm in the East and the western spruce budworm in the West. The objective of CANUSA was to design and evaluate strategies for controlling the spruce budworms and managing budworm-susceptible for¬ ests, to help forest managers attain their objectives in an economically and environmentally acceptable man¬ ner. The work reported in this publi¬ cation was wholly or partially funded by the Program. This manual is one in a series on the spruce budworm. canu/a Canada United States Spruce Budworms Program June 1984 2 Contents Introduction. 5 Assessing Defoliation . 6 Aerial Application of B.t. 8 Commercial Products. 8 Dosage . 9 Volume.11 Additives.11 Sticker.11 Tracer Dye.11 Water .11 Pumps.11 Mixing Sequence.11 Storing Tank Mixes.11 Aircraft.12 Nozzles.12 Calibrating Aircraft.15 Assessing Droplets ...20 Density and Size .20 Weather Conditions.21 Bud and Larval Development .... 22 Assessing Bud Development.22 Assessing Larval Development.24 Recommended Spray Schedule .. .25 Summary .25 Literature Cited.26 3 Guidelines for the Operational Use of Bacillus thuringiensis Against the Spruce Budworm by Oswald N. Morris, John B. Dimond, and Franklin B. Lewis* Introduction The bacterium Bacillus sotto was first isolated in 1902 from dying silkworms in Japan. Later, it was identified as a variety of B. thuringiensis Berliner, a disease-causing agent characterized by rapid paralysis of the gut soon after ingestion by the insect (Burgess 1981). B. thuringiensis (B.t.) occurs naturally in numerous species of agri¬ cultural and forest insects (Morris 1982a) and is the basis of several commercial insect-control products available in North America and Europe. Preparations of B.t. contain spores— the dormant and resistant form of the bacteria—and a toxic crystal (delta endotoxin) that is activated when in¬ gested and damages the gut of suscep¬ tible lepidopterous insects. This results in cessation of feeding, various non- lethal physiological effects, bacterial invasion into the blood cavity, and eventual death of the larva. The com¬ mercial formulations used in North America are toxic almost exclusively to moth and butterfly larvae and gen¬ erally are accepted as environmentally safe. These formulations can be used in integrated pest management pro¬ grams not only in commercial forests but also in watershed areas, wildlife preserves, buffer zones, urban areas, and near reservoirs. The first aerial applications of B.t. against the spruce budworm (Choris- toneura fumiferana Clem.) were in New Brunswick in 1960. The technol¬ ogy improved steadily until 1978, when the first Canada-U.S. guidelines for operational use of B.t. were for¬ mulated (Morris 1980). Accelerated field research during the past 4 years dictated the need for up- to-date guidelines. This publication summarizes the current technology re¬ lating to the suppression of spruce budworm by aerial applications of B.t. This technology is based on the con¬ sensus of a committee of scientists ac¬ tively involved in research relating to the management of spruce budworm in Canada and the United States. 'Oswald N. Morris is with Agriculture Canada. Winnipeg, Man. John B. Dimond is with the University of Maine at Orono. Franklin B. Lewis is with the USDA Forest Service, Northeastern Forest Experiment Station, Flamden, Conn. 5 Assessing Defoliation The aim of any program to control the spruce budworm is to minimize defol¬ iation. Treatments with B.t. achieve this aim by reducing both the density of larval populations and feeding and growth rates of surviving budworm. The success of an operational spray, however, is a matter of personal judg¬ ment by the land manager. In the past, retaining at least 50 percent of the current-year’s foliar growth has been considered acceptable by most operators. One method of estimating success is by visually observing the effects of treatments from the air (figs. 1 and 2). Figure I—Aerial view of an untreated spruce-fir cates severe defoliation or needle damage on stand in Matawa, Ontario, that is heavily infested current-year growth, (Photo by O. N. Morris, with budworm. The reddish-brown color indi- Canadian Forestry Service.) Figure 2—Aerial view of a spruce-fir stand treated with Bacillus ihuringlensis, situated 3,300 ft (1,000 m) from the untreated plots (fig. 1). Foliage protection is indicated by the green tops and upper branches. (Photo by O. N. Morris, Canadian Forestry Service.) 6 Another method is using binoculars to view the treated stands from the ground. This method is appropriate for stand evaluation regardless of insect numbers. Spruce and fir trees are ranked according to the amount of de¬ foliation visible within the crown: 1. No defoliation: no observable feeding damage, 0 to 20 percent of to¬ tal foliage missing. 2. Light to moderate defoliation: 21 to 50 percent defoliation with no observable top-kill. 3. Heavy defoliation: 51 percent or more defoliation with no observable top-kill. 4. Severe defoliation: 51 percent or more defoliation with obvious top- kill. Postspray assessment of defoliation also can be made by the Fettes method (Fettes 1950) (fig. 3), which 0 0+ 10 1020 20+ 30 30-t- 40 40+ 50 50+ 60 0 1 2 3 4 5 6 60+ 70 70 + 80 80+ 90 90+ 99 100 100 + 7 8 9 10 11 12 Example: Def. cat. Freq. Class midpoints 6 4 X 55 = 220 7 18 X 65 = 1170 8 2 X 75 = 150 9 1 X 85 = 85 25 1625 1625 divided by 25 = 65 65% Avg. defoliation Figure 3—The Fettes method for estimating'defoliation. 7 Aerial Application of B.t. is used widely in both experimental and operational trials. The method consists of; 1. Collecting small branches from the midcrown of sample trees. 2. Removing a predetermined number of current (new growth) shoots from each branch (usually 25, all taken from one side of the branch, starting at the tip). 3. Visually comparing the ap¬ pearance of each current shoot to a se¬ ries of diagrams (fig. 3) and assigning a defoliation category number to each shoot (0 through 12) depending on the relative proportion of needles missing from the shoot. Missing needles are presumed to be eaten by budworm lar¬ vae. For a general estimate of defolia¬ tion, categories 11 and 12 are pooled as 100-percent defoliation. 4. Computing defoliation for a sample of shoots. The frequencies are weighted by the class midpoint values, summed, and divided by the total number of shoots in the sample (fig. 3). Commercial Products A number of commercial products of B.t. are available in North America for use against the spruce budworm. All the products listed in table 1 are registered for aerial and ground appli¬ cation and are based on the bacterial strain B. thuringiensis kurstaki, also known as HD-1. They are all free of the broad-spectrum bacterial toxin known as beta-exotoxin, which may be found in other strains of insect pathogenic bacteria. The following are products- of B.t. (HD-1 isolate) for which registration has been requested: Concentration Product of B.t. 3 BlU/gal BIUIl Thuricide 64LV'* 64 16.9 Dipel 176^ 64 16.9 -The use of trade, firm, or corporation names in this publication is for the information and conve¬ nience of the reader. Such use does not constitute an official endorsement or approval by the U.S. Department of Agriculture, Agriculture Canada, or the University of Maine of any product or service to the exclusion of others that may be suitable. ■’BIU stands for billion international units, a stan¬ dard measurement for B.t. in both countries. Throughout this handbook, “gallon" (= 3.785 1) refers to U.S. gallons. ■'Aerial application only. Pending registration in the United States only. •“’Aerial application only. This product is re¬ stricted to forestry use only. 8 c .2 u 'a, o, cd 'O c 3 O u, Oij ■a c 3 3 -o WJ QJ 3 o 3 ■3 a: o ■o 3 X) O o 3 u a. aj c/3 ri u •— u. i 3 .3 C O ^5 • — J2 3 U "O o Co S cq =S g 'sO vO irj :::d ^ c: g m ^ to OC 00 (N (N rn rn xi X) -o X X X X X X <•<<;< GJ O c c Cl-0.C1-Q.Q-D- 5 Q Q Q 5 5 5 £ cd (U ^ Q- 2 3 X CQ X ■o X - > > CQ J J (N (N 00 m (n Tt (U TD X (U TD GJ T3 3 3 X X U Pm rn I o cd X > O Z 9 C - commercial; R - restricted. In the United States, the Environmental Protection Agency lists all these pesticides as general use or unclassified. -Not registered in Canada at presstime. ■’In Canada, registered for small-woodlot use only. ■*Not registered in the United States. ■'’In the United States, this product is registered for agricultural uses only. Although the actual potencies of com¬ mercial products must by law closely approximate that indicated on the pes¬ ticide label, it is recommended that; whenever possible, an independent evaluation of the potencies of drum samples be made before use. Poten¬ cies varying markedly from those in¬ dicated on B.t. labels have been detected in the past; prior knowledge of actual potency will allow the opera¬ tor to compensate for any significant variations from label potency claims. Based on the experience to date, we recommend that for currently regis¬ tered products (table I), a dosage rate of 12 BlU/acre (30 BlU/ha) be used. Dosage The recommended dosage for spruce budworm control on the labels of reg¬ istered products ranges from 8 to 12 BlU/acre (20 to 30 BlU/ha), though results have been less consistent in re¬ ducing populations and protecting fo¬ liage when the lowest rate noted above has been used. The chart shows the relationship between dose rate of B.t. and effectiveness against spruce budworm for 118 spray trials on 304,491 acres (123,276 ha) of balsam fir forests in Canada and the United States during 1979-82 (Morris 1980, 1981, 1982b; Maine Forest Service 1982 field data); Dose rate Area treated Protection achieved* BlU/ucre BlUlha Acres Hu Perceiii 8 20 201 M3 84,147 75 12 30 91,622 37,094 97 16 40 5,026 2,035 100 10 ^Portion of treated area reported by operator> as acceptably protected. Volume Field data indicate that application of B.t. in 0.25 to 1 gallon/acre (2.37 to 9.4 1/ha) docs not significantly change the efficacy of the product in reducing budworm populations or protecting fo¬ liage. Therefore, lower volumes (0.25 to 0.5 gallon/acre, 2.37 to 4.7 1/ha) are recommended provided that the volume chosen contains the recom¬ mended dose rate (12 BlU/acre [30 BlU/ha]). For large-scale treatments (several thousand acres) where large aircraft, e.g., DC-6’s, are used, 0.25 gallon/acre (2.37 1/ha) is recommended. Additives Sticker —A sticker is recommended for all currently used B.t. formulations at concentrations suggested by manu¬ facturers of the B.t. At present, there is insufficient information on the ef¬ fectiveness of various stickers and their compatibility with various B.t. formulations to make recommenda¬ tions for their use. Each formulation may require its own type of sticker. In Canada, these stickers are subject to registration requirements. Tracer Dye —Dyes arc not recom¬ mended for operational application; however, if a dye is needed to record spray deposit, the recommendation of the B.t. manufacturer should be followed. Water —The water'diluent used in the tank mixes should have a pH of 5.5 to 7.5. The pH can be readily checked with pH-sensitivc paper. Chlorinated water should not be used as a diluent in tank mixes. Pumps —Heavy-duty pumps are rec¬ ommended for mixing all formulations except Futura, which requires a membrane-type pump. Mixing Sequence —Unless otherwise specified by the B.t. manufacturer, the mixing sequence is water, then sticker (and an antievaporant if necessary), then tracer dye (if required), then B.t. The B.t. should be added while the water mixture is being agitated, to en¬ sure proper suspension. Storing Tank Mixes —Undiluted for¬ mulations are stable below 90° F (32° C). To maintain the insecticidal activity of diluted formulations, do not store tank mixes longer than the time specified by the manufacturer. Follow the manufacturer’s recommendations for storage temperature. Aircraft Small and large fixed-wing aircraft and helicopters have been used to ap¬ ply B.t. The type of aircraft is dic¬ tated by the specific requirements of the operation. Aircraft used and block sizes treated include: AgCat: 63 to 15,000 acres (25 to 6,000 ha); Paw¬ nee: 35 to 1,000 acres (14 to 400 ha); Thrush: 100 to 30,000 acres (40 to 12,000 ha); AgTruck: 100 to 15,000 acres (40 to 6,000 ha); Stearman: 100 to 7,500 acres (40 to 3,000 ha); Lock¬ heed Constellation: 2,500 to 52,500 acres (1,000 to 21,000 ha); Bell 205 and 212 helicopters: 125,000 to 200,000 acres (5,000 to 80,000 ha); Bell 47: 5 to 1,000 acres (2 to 400 ha). Nozzles B.t. has been applied with a variety of nozzles, e.g., open, rotary, and con¬ ventional boom with flat fan or hollow cone. Stainless steel nozzles are rec¬ ommended over brass because the abrasive properties of some B.t. for¬ mulations can increase the orifice di¬ ameter of nozzles of soft metal. For large aircraft (e.g., DC-6, DC-4, and Super Constellation), an open nozzle is recommended. Micronairs (rotary atomizers) are preferred for applica¬ tions of highly concentrated and undi¬ luted sprays. Aircraft and nozzles commonly used in applying B.t. over forests are listed in table 2. Table 2 —Aircraft and nozzles used in the application of B.t. against the spruce budworm in the Eastern United States and Canada, 1979-82 Number of applications Aircraft Nozzle 1979-82 Product Used Grumman AgCat Tee Jet 8004 28 Thuricide 16B, 32LV, 48LV Tee Jet 8006 21 Dipel 88 Micronair AU 3000 7 Novabac-3, Bactospeine FC Piper Pawnee Tee Jet 8004 1 Thuricide 16B Flat fan 3 Thuricide 24B, 32LV Micronair (restrictor size #14) 3 Novabac-3, 45B; Dipel 88, Dipel 32B Thrush Tee Jet 8006 3 Thuricide 16B, 24B, 32LV, 48B Tee Jet 8004 4 Dipel 4L, 6L; Bactospeine FC Micronair AU 3000 2 Novabac-3 Mini Micronair AU 5000 2 Thuricide 32LV 12 Table 2—cont’d Number of applications Aircraft Nozzle 1979-82 Product Used Cessna AgTruck Tee Jet 8004, 8006 7 Thuricide 16B, 24BA, 24BC, 48B; Bactospeine FC Micronair AU 3000 6 Novabac 45B; Dipel 88, 6L Pawnee PA 25- Micronair AU 3000 4 Thuricide I6B, 24B; Dipel 235 88 Cessna 185 Micronair AU 3000 10 Thuricide 32LV, Dipel 88 Cessna Ag- Wagon Micronair AU 3000 1 Dipel 88 Lockheed Con- Open 9 Thuricide 32B; Novabac-3; stellation Dipel ABG, 88; Futura DC-4 Open 1 Futura Bell 206 helicop- Tee Jet 8004 1 Bactospeine FC ter Bell G5 helicop- Tee Jet 8003 3 Thuricide 16B, 32LV ter Bell 205 helicop- Tee Jet 8006 17 Thuricide 16B, 24B, ter 32LV; Bactospeine FC; Dipel 4L Bell 204 helicop- Tee Jet 8004, 8006 10 Thuricide 16B, 24B; Dipel ter 4L; Thuricide 32LV; Bac¬ tospeine Bell 212 helicop- Tee Jet 8004 9 Thuricide 16B, 32LV; Di- ter pel 4L; Bactospeine FC Bell 47 helicop- Micronair AU 3000 1 Thuricide 16B, 32LV ter Tee Jet 7 Thuricide 16B, 32LV Hughes 500 heli¬ copter Tee Jet 8004 1 Dipel 88 Bell Jet Ranger Tee Jet 8003 1 Bactospeine FC; Novabac-3 Hiller Tee Jet 8003 1 Bactospeine FC 13 The following swath widths are effec¬ tive in applying B.t. to spruce-fir forests: Aircraft AgTruck Thrush, AgCat, Air Tractor Turbo Thrush C 54 Bell 47 Hiller Bell Jet Ranger Bell 205 and 212 Bell 206 Bell G5 Pawnee PA 25-235, Cessna 185 Lockheed Constellation Swath Width Feel Meiers 225 to 450 70 to 140 225 to 450 70 to 140 225 to 450 70 to 140 1,000 + 308 + 75 to 100 23 to 31 75 to 100 23 to 31 100 to 150 31 to 46 150 to 250 46 to 78 100 31 125 39 50 to 108 15 to 33 500 152 For additional information on nozzles, operators are advised to contact their Federal, State, or Provincial authori¬ ties for recommendations. 14 Calibrating Aircraft Proper calibration of aircraft before spraying, especially for flow rate and required swath width, cannot be over¬ emphasized. Calibration procedures are described by Randall (1975), Dumbauld and Rafferty (1977), and Barry et al. (1978). The lower the volume being applied, the more im¬ portant it is to calibrate accurately. The aircraft should be calibrated for each tank mix of each commercial product (not for water). If, however, the relative flow rates of the formula¬ tion are known, then calibration by water can be adjusted accordingly. For Dipel, Abbott Laboratories suggests an effective swath width^ of 150 to 200 ft (45 to 60 m) for small fixed- wing aircraft (Grumman AgCat, Thrush Commander, Air Tractor, Cessna AgWagon, Piper Pawnee) flying 50 to 75 ft (15 to 22 m) above trees at 90 to 110 mi/h (144 to 176 km/h) on an in-wind flight path and equipped with open nozzles (8003 to 8006) or rotary atomizers (Micron- air AU 3000 or AU 5000). For small helicopters (Bell 47G), swath width should be 50 to 100 ft (15 to 30 m) at 50 mi/h (80 km/h). For large helicop¬ ters (Bell 205 and 211, Jet Ranger, Hiller) traveling at 70 to 90 mi/h (44 to 56 km/h), a swath width of 150 to 250 ft (45 to 75 m) is effective with open nozzles (8003 to 8006). Undi¬ luted Dipel 4L applied from a Thrush Commander equipped with Micronair nozzles (35-degree pitch) provided an effective swath width of more than 240 ft (73 m). Spray characteristics determined by the Maine Forest Ser¬ vice for Dipel, Thuricide, and Bacto- speine are summarized in tables 3 and 4. ^Effective swath width is that span in which the amount of spray materials deposited equals or exceeds a specified amount considered to be effective. 15 Table 3—Spray characteristics of Dipel formulations >5 ^ C r- r3 o > C £ 2 Os I— ^ in a^ ^ ^ ^ ON m ro — — o m ON ON X; E 3 z o, o •o m sO ^ cxD o m (N O ON o in in (n m m m 00 sO nO ^ in in o in o in o o o in + 'n O + o o + "n O + 'n o + 'n O r; ^ D NO ON 2 CN D '*5 c D NO (N D NO ON D NO ON D NO ON CQ _c 3 _c 3 _C 5 3 o 3 .S 3 .E 3 _c 3 .E 3 .E oo (N r-l nj rsi oo (N 04 (N > o < < u- 17 Table 4 —Spray characteristics of Thuricide and Bactospeine formulations >2 •a c E •- I ° z ^ -o ."2 '5 Cm UJ o o o o r-* o o o o o o ON ON ON 00 00 o rn o k. On) — ~ (N S 'o ‘lI pa so Ol -a ON ^ O ^ VD oo m o m oo NO m oo ON oo -It r-- oo ^ r- m — O O OO NO — O — 'it ON O 00 o m CJ o o o OJ o CJ CJ CJ CJ Un u. w Un u. Lm t-l k. o o O o o CJ CJ 3 CJ CJ «s CJ C3 C3 JZ CC TD C3 N N N N N N "n H “n N CJ N o o o o o o o o o n o NO NO o o NO • — ON ON NO nD so 00 OO ON NO c NO c c c C C c c c c 3 c • • • • D D D D D D D D D D D CQ oa CQ CQ CQ QQ CQ CQ CQ CQ CQ OO rj OO (N OO m (N (N (^1 (N o o o o o o o o o o o o o O 00 OO 00 OO OO 00 00 p3 C O m in in m m m o o o o o o o o o o o o in m in in D D D D < < < < o 03 c/5 (U -o c c3 C O U 18 AU 5000 35 12 BIU (undiluted) 300 8004 12 BIU (undiluted) 127 Volume Effective swath Number of median ^ijth droplets/cm- diameter >5 3 o o Z c c o z CQ H Tt O ON 00 o O (N rf r-- ^ lO ^ ^ o vD (N O O OO sO t^ so O t^ CJ C3 C3 "TD 3 OJ 'n 3 o O ■5 c -5 c rt- \o NO C 3 3 c c 3 • * .« -S_^ 2 MM S 5 CQ DQ CQ ru r't In 1977, the United States Department of Agriculture and the Canada Depart¬ ment of the Environment agreed to cooperate in an expanded and acceler¬ ated research and development effort, the Canada/United States Spruce Bud- worms Program (CANUSA), aimed at the spruce budworm in the East and the western spruce budworm in the West. The objective of CANUSA was to design and evaluate strategies for controlling the spruce budworms and managing budworm-susceptible for¬ ests, to help forest managers attain their objectives in an economically and environmentally acceptable man¬ ner. The work reported in this publi¬ cation was partially funded by the Program. This manual is one in a se¬ ries on the western spruce budworm. canu/a Canada United States Spruce Budworms Program December 1984 Contents Introduction . 5 Keys to Larvae of Western Spruce Budworm and Associates . 8 Key to Small Lepidopterous Larvae in Opening Buds and New Shoots of Douglas-fir and True Firs. 9 Geometridae . 9 Tortricidae, Gelechiidae, Pyralidae, and Noctuidae . 10 Key to Larger Lepidopterous Larvae on New Foliage of Douglas-fir and True Firs . 14 Geometridae . 14 Tortricidae, Gelechiidae, Plutellidae, Pyralidae, and Noctuidae . 15 Biological Notes on Species and Groups . 19 Western Spruce Budworm . 19 Achytonix epipaschia (Grote). 22 Acleris gloverana (Walsingham) . 23 Anomogyna mustelina (J. B. Smith) . 25 Archips sp. 25 Argyrotaenia spp. 26 Chionodes spp. 29 Choristoneura retiniana (^SLhmgYi'dm) . 31 Choristoneura n. sp. 32 Coleotechnites spp. 32 Diaryctria spp. 33 Egira simplex (Walker) . 36 Enypia griseata Grossbeck . 38 Epinotia radicana (Heinrich).•.. 39 Eupithecia spp. 41 Lambdina fiscellaria lugubrosa (Hulst). 42 Melanolophia imitata (Walker) . 43 Nematocampa limbata (Haworth) . 44 Nepytia phantasmaria (Strecker). 45 Orgyia pseudotsugata (McDunnough) . 46 Stenoporpia sp. 48 Syngrapha spp. 48 Telphusa sedulitella (Busck) . Ypsolopha spp. Zeiraphera spp. Role of Associates in the Habitat . 54 Host Preference . 54 Life History ..■. 55 Feeding Sites . 58 Abundance . 59 Additional Research Needed . 60 Acknowledgments . 60 Literature Cited . 61 Lepidoptera Associated introduction With Western Spruce Budworm by Robert E. Stevens, V. M. Carolin, and George P. Markin^ 'Robert Stevens: Entomologist, Colorado State University, Ft. Collins, Colo. V. M. Carolin: consulting entomologist in Portland. Oreg. George Markin: Entomologist. USDA Forest Ser¬ vice. Pacific Southwest Forest and Range Experi¬ ment Station, Hilo. Hawaii. Field workers doing surveys, control operations, and research on western spruce budworm often encounter other kinds of foliage-feeding larvae, some of which closely resemble western spruce budworm. Workers must be able to distinguish between the differ¬ ent species and groups. Western spruce budworm is character¬ ized here, along with its common Lepidoptera associates (table 1); keys are included for separating smaller and larger larvae of common species. The keys are designed for practical separa¬ tion of species; no attempt has been made to reflect taxonomic conventions or phylogeny. Lindquist (1982) covers some of the same material for the spruce budworm in Eastern North America. Notes on the biology of the species and groups covered are given, and larvae and adults of associates are illustrated. Sawfly larvae (Hymenoptera) are also found in and on the foliage of bud¬ worm hosts, but these larvae are usu¬ ally less common and, except for the web-spinners in the family Pamphili- idae, easy to identify. Larvae of Lepi¬ doptera and foliage-feeding Hymenoptera can be separated by characters that can be seen with a hand lens. The most important is the 5 Table 1 —Lepidoptera associates of western spruce budworm Family Species, species group Distribution Hosts' Gelechiidae Chionodes abella Busck Southwest — Chionodes spp. Pacific region,^ Rocky Mtns. Abies, Pseudotsuga Coleotechnites spp. Westwide Abies, Pseudotsuga Telphusa sedulitella (Busck) Pacific region Abies Geometridae Enypia griseata Grossbeck Southwest Abies, Pseudotsuga Enypia sp. nr. griseata Pacific region Pseudotsuga Eupithecia annulata (Hulst) Pacific region, Rocky Mtns. Pseudotsuga E. catalinata McDunnough Southwest Pseudotsuga Lambdina fiscellaria lugubrosa (Hulst) Pacific region, Rocky Mtns. Abies, Pseudotsuga Melanolophia imitata (Walker) Pacific region. Rocky Mtns. Abies, Pseudotsuga Nematocampa limbata (Haworth) Pacific region. Rocky Mtns. Abies, Pseudotsuga Nepytia phantasmaria (Strecker) Pacific region Abies, Pseudotsuga Stenoporpia sp. Pacific region Pseudotsuga Lymantriidae Orgyia pseudotsugata (McDunnough) Westwide Abies, Pseudotsuga Noctuidae Achytonix epipaschia (Grote) Westwide Abies, Pseudotsuga Anomogyna mustelina (J. B. Smith) Pacific region Abies, Pseudotsuga Egira simplex (Walker) Westwide Pseudotsuga Feralia deceptiva McDunnough Pacific region Pseudotsuga Syngrapha spp. Pacific region. Southwest Abies, Pseudotsuga 'Only those reported in association with western spruce budworm. ^Used here to include the area west of the Rocky Mountains between British Columbia and northern California. 6 Table 1 —Continued Family Species, species group Distribution Hosts' Plutellidae Ypsolopha nella (Busck) Southwest Abies Ypsolopha sp. prob. cervella (Walsingham) Pacific region Pseudotsuga Pyralidae Dioryctria spp. Westwide Abies, Pseudotsuga Tortricidae Acleris gloverana (Walsingham) Westwide Abies, Pseudotsuga Archips sp. Pacific region Pseudotsuga Argyrotaenia dorsalana (Dyar) Westwide Abies, Pseudotsuga A. klotsi Obraztsov Southwest Abies, Pseudotsuga A. provana (Kearfott) Westwide Abies, Pseudotsuga Choristoneura retiniana (Walsingham) Pacific region Abies Choristoneura n. sp. Pacific region Abies, Pseudotsuga Clepsis persicana (Fitch) Westwide Pseudotsuga Epinotia radicana (Heinrich) Westwide Abies, Pseudotsuga Zeiraphera spp. Westwide Abies, Pseudotsuga number of abdominal prolegs—a maximum of five pairs in caterpillars and seven to nine pairs in the sawflies (fig. 1). Larval characters used in the keys are also shown in figure 1. The roles of associates in budworm habitat are compared—where, when, and how these species live and, par¬ ticularly, how they obtain their food. Differences in host preference, life history, feeding sites, and natural ene¬ mies result in a unique role being played by each associate. The kind Figure 1—A. Typical lepidopterous larva; B. hymenopterous larva of sawtly genus Neodiprion: C. features of lepidopterous head capsule. a LEGEND a abdomen 1 labrum ad adfrontals pa pleural area ap abdominal proleg ps prothoracic shield as anal shield s seta c clypeus sa setal area d dorsum t thorax h head tl thoracic leg la intersegmental area V venter 1 7 Keys to Larvae of Western Spruce Budworm and Associates and amount of damage caused to the tree, interaction with the western spruce budworm, and the reaction of the host are important factors in con¬ sidering impact on the habitat, and particularly in proper assessment of budworm-caused impact on the forest. Basic information on the role of bud¬ worm associates in the habitat is lim¬ ited; what information is available is summarized here, and suggestions for further work are included. Some of the groups included pose dif¬ ficult taxonomic problems. As more detailed studies of life history and habits are carried out, these taxonomic problems will gradually be unraveled. These keys are revisions of Carolin and Stevens (1979 and 1981). Large and small larvae are discussed sepa¬ rately because many larvae change in appearance as they pass through suc¬ cessive instars. Feeding habitat also changes with maturity: the smaller lar¬ vae feed inside buds, and larger larvae usually feed openly on developing needles. In the keys, patterns of lines and stripes are frequently used as identify¬ ing characters (fig. 2). Two cautions to keep in mind when using the keys are: • Although all the common associated species have been included in the keys, other species may sometimes develop high populations and be¬ come local budworm “associates.” • Insects, like other organisms, vary individually and may have slightly different color patterns than' de¬ scribed and illustrated. We have sometimes included several photo¬ graphs of a single species to show this variability. With experience you will learn to recognize it and find the keys easier to use. Figure 2 —Examples of longitudinal dorsal mark¬ ings: A. central stripe (Zeiraphera hesperkinaY. B. irregular lines (Dioryclria renicidelloides): C. regular lines (Egirci simplex). 8 Key to Small^ Lepidopterous Larvae in Opening Buds and on New Shoots of Douglas-fir and True Firs A. Larvae with 2 pairs of prolegs, moving with an inching or looping motion based on use of anal prolegs . Section I. Geometridae B. Larvae with 5 pairs of prolegs, moving at a constant pace, but often wig¬ gling violently when disturbed . . Section 11. Tortricidae, Gelechiidae, Pyralidae, and Noctuidae Section I. Geometridae 1. Dorsum banded dark brown and white on first 5 abdominal segments; head dark brown to black; body 4 to 7 mm long . ... 1 St instar Lambdina fiscellaria lugubrosa 1. Dorsum either unicolorous, or with longitudinal lines; head brown, green. or reddish.2 2. Dorsum light to dark green, with one pair of longitudinal whitish lines ..3 2. Dorsum other than green; unicolorous or with dark lines.5 3. Head pale yellow-brown; dorsum light bluish-green and lines whitish yel¬ low; pleural area with similar lines and also a very thin line; larvae on new shoots 10 to 12 mm long and often larger . Enypia sp. 3. Head green; dorsum apple green to dark green and lines white; pleural area with a yellow line or stripe; larvae on new foliage up to 8 to 10 mm long before moving to old foliage .4 4. Head green with no markings . Melanolophia imitata 4. Head green with 10 black dots . Nepytia phantasmaria 5. Pair of long, knobbed projections on dorsum of 2d abdominal segment; head and dorsum brown. Nematocampa limbata 5. No body projections; head reddish or brown; dorsum yellow, yellowish brown, or orange red .6 6 . Dorsum orange red, with 3 longitudinal purple lines; head pale orange-red; body 9 to 12 mm long. Eupithecia anmdata 6 . Dorsum without longitudinal lines; head light to dark brown .7 -Up to about 12 mm long. 9 7. Head medium to dark brown; dorsum yellowish brown to pinkish brown, and each segment with 4 dark dots; pleural area with 3 dark-brown lines; body 6 to 15 mm long . . 2d and 3d instars Lambdina fiscellaria lugubrosa 7. Head light brown; dorsum yellow to reddish brown, without conspicuous dots .8 8 . Dorsum bright yellow; pleural area light brown; body 6 to 9 mm long; feeds under bud sheath on Douglas-fir . Eupithecia anmdata 8 . Dorsum orange-red-brown, with yellow plueral area and venter; body 10 mm long and longer; open feeder. Stenoporpia sp. Section II. Tortricidae,’ Gelechiidae, Pyralidae, and Noctuidae 1. Dorsum marked with longitudinal lines; setal bases conspicuous only in Achytonix and Egira (Noctuidae) . 17 I. Dorsum unicolorous; setal bases often a lighter or darker color, causing a slightly spotted or spiny appearance. 2 2. Dorsum yellow green, bright green, or olive green. 15 2. Dorsum dirty white to brown, but sometimes with a greenish tint in Egira simplex. Choristoneura retiniana, and Epinotia radicana . 3 3. Head and prothoracic shield yellow, yellow brown, light brown, or chest¬ nut brown . 13 3. Head dark brown to black; prothoracic shield brown to black; anal shield conspicuous, light brown to black . 4 4. Dorsum orange brown or olive brown. 5 4. Dorsum yellow, dirty white to light brown, or cinnamon brown ... 7 ■includes Olethreutidae as a subfamily. Oiethreu- tinae, per revised ■■ Check list of the Lepidoptera of America north of Mexico (Hodges et ai. 1983). 10 5. Prothoracic shield light to medium brown; anal shield light brown; body orange brown, 5 to 7 mm long (3d instar) or light olive-brown, 6 to 10 mm long (early 4th instar) . Choristoneura occidentalis 5. Prothoracic shield, setal areas, and anal shield dark brown to black.6 6 . Dorsum dark olive-brown with yellowish brown in intersegmental areas; setal areas raised; anal shield orbicular, dark brown; body 4 to 5 mm long . Achytonix epipaschia 6 . Dorsum light orange-brown, sometimes with greenish tinge; setal areas not raised; anal shield black, occupying most of segment; body 4 to 7 mm long ... Egira simplex 7. Dorsum pale yellow to lemon yellow . 10 7. Dorsum dirty white (pale gray) or cinnamon brown .8 8. Dorsum pale to dirty white; head wider than long; spots of scleroti- zation on penultimate abdominal segment .9 8 . Dorsum cinnamon brown; head as wide as long; head and prothora¬ cic shield black; setal bases pale; anal shield large, pale ivory; no penultimate sclerotization; body 6 to 12 mm long . .4th instar Choristoneura occidentalis 9. Head dark brown; prothoracic shield chestnut brown; setal bases dark; anal shield large, dark brown; body 6 to 8 mm long; on Douglas-fir . . intermediate instar Zeiraphera hesperiana 9. Head and prothoracic shield light brown, both darker posteriorly; setal bases inconspicuous; anal shield light brown; body 7 to 9 mm long; on true firs. last 2 instars Zeiraphera pacifica 10. Prothoracic shield and thoracic legs dark brown to black; setal areas inconspicuous. 12 10. Prothoracic shield and thoracic legs medium brown; setal areas visible. 11 11 11. Anal shield dark brown, orbicular; body form slender, 3 to 5 mm long .... . Epinotia radicana shield outlined on edges by dots of sclerotization; body form moder- stout, 3 to 5 mm long . 3d instar Choristoneura retiniana Head, prothoracic shield, prespiracular sclerotization, and outside of thoracic legs jet black; anal shield medium brown, orbicular; body 3 to 8 mm long . Acleris gloverana Head black, prothoracic shield and prespiracular sclerotization dark brown; thoracic legs annulated dark brown and white; anal shield represented by a few dots of sclerotization; body 5 to 8 mm long. 4th instar Choristoneura retiniana 13. Head and prothoracic shield chestnut brown; head narrower than body; dorsum pinkish brown, yellowish brown, or cinnamon brown; setal bases prominent; anal shield semicircular, pale chestnut-brown and occupying most of segment; body slender, 5 to 7 mm long . Coleotechnites sp. 13. Head and prothoracic shield yellow to yellow brown; dorsum yellow brown to yellow green; setal bases and anal shield inconspicuous.14 14. Head as wide as body, wider than long, yellow brown to pale chestnut-brown; anal segment long, yellow, with small shield; body 6 to 8 mm long . Epinotia radicana 14. Head narrower than body, longer than wide; anal segment of moder¬ ate length, with shield inconspicuous; body 4 to 7 mm long. . Argyrotaenia dorsalana 15. Head green with yellow-brown tinging around labrum and adfrontals; thorax, thoracic legs, and abdomen emerald green; anal shield represented by a few dots of sclerotization; body 8 to 12 mm long. . Argyrotaenia provana 15. Head unicolorous, light brown to black; dorsum pale yellow-green; legs light brown; anal shield orbicular; body 8 to 10 mm long . 16 16. Head, prothoracic shield, and anal shield yellow brown to pale chestnut-brown, with fine, black markings in center rear of prothora¬ cic shield; anal shield orbicular. Argyrotaenia dorsalana 16. Head and thoracic legs dark brown to black; prothoracic shield paler; anal shield inconspicuous . Acleris gloverana 11. Anal ately 12 . 12 . 12 17. Dorsum reddish brown or brownish gray, with 8 to 10 interrupted, white longitudinal lines; a large, white eyespot around lateral seta on 8th abdom¬ inal segment . Diotyctria reniciilelloides 17. Dorsum yellow, greenish brown, or pale brown; longitudinal lines either dark, or, if white, few in number . 18 18. Dorsum with white longitudinal lines or stripes .21 18. Dorsum with dark longitudinal lines or stripes . 19 19. Dorsum yellow with 3 orange-brown longitudinal lines; head almost as wide as body and light brown; prothoracic shield light brown; body stout, 8 to 10 mm long . Epinotia radicana 19. Dorsum pale brown or gray; head narrower than body; head and prothora¬ cic shield light chestnut-brown; body slender, up to 8 or 9 mm long ... 20 20. Dorsum pale brown, with 3 to 5 reddish-purple longitudinal lines.... ...•. Chionodes spp. 20. Dorsum very pale-yellow or pale-gray, with 7 to 9 fine, brown-to- lavender longitudinal lines . Telphusa sp. (probably sedulitella) 21. Dorsum pale olive-green, with a narrow, central, white line; head jet black; prothoracic and anal shields dark brown; setal areas dark brown; body 5 to 7 mm long . .. Achytonix epipaschia 21. Dorsum green or greenish brown with 3 rather broad, white longitudinal lines; prothoracic shield, anal shield, and setal areas either conspicuous or inconspicuous .... 22 22. Dorsum greenish brown; head, prothoracic shield, and setal areas black; anal shield dark brown; body 8 to 10 mm long. . Egira simplex 22. Dorsum apple green; head pale yellow-green; prothoracic and anal shields not visible—body striping covering them; body 7 to 10 mm long ... Achytonix epipaschia 13 Key to Larger'* Lepidopterous Larvae on New Foliage of Douglas-fir and True Firs A. Larvae with 2 pairs of abdominal prolegs, moving with an inching or loop¬ ing motion based on use of anal prolegs . Section 1. Geometridae B. Larvae with 5 pairs of abdominal prolegs, moving at a constant pace, but often wiggling violently when disturbed. ... .Section II. Tortricidae, Gelechiidae, Plutellidae, Pyralidae, and Noctuidae Section L Geometridae 1. Dorsum unicolorous or color blotchy, without lines .5 1. Dorsum with longitudinal lines or stripes .2 2. Dorsum orange red, with 3 longitudinal purple lines; head pale orange-red; body 12 to 15 mm long . Eiipithecia annulata 2. Dorsum green, with 1 pair of whitish longitudinal lines; head green or brown; body 12 to 37 mm long.3 3. Head green to pale yellow-brown; dorsum light bluish-green with wide, whitish-yellow lines; pleural area with 1 wide and 1 narrow, whitish-yellow line; body up to 25 mm long . Enypia spp. 3. Head green; dorsum apple green to dark green with white lines; pleural area with a single whitish line or stripe .4 4. Head green with no markings; body up to 37 mm long; feeds mostly on old foliage . Melanolophia imitata 4. Head green with 10 black dots; body up to 28 mm long; feeds on both new and old foliage. Nepytia phantasmaria 5. Pairs of long, flexible, knobbed projections on dorsum of 2d and 3d ab¬ dominal segments; pairs of short knobs on 1st and 8th abdominal segments; head brown; body with blotches of dull brown or greenish brown; body up to 20 mm long . Nematocarnpa limbata 5. No body projections; head light brown or mottled with brown; dorsum or¬ ange brown in toto or in intersegmental areas .6 6 . Head light brown, unicolorous; dorsum orange red brown; pleural area with yellow stripe; body up to 30 mm long; on both new and old foliage . Stenoporpia sp. ■^Twelve millimeters or more in length. 14 6 . Head with brown mottling; dorsum brownish or greenish, with orange brown in intersegmental areas; network of lines in pleural area; on old foliage. 7 7. Head with brown streaking as well as mottling, and 4 black dots visible above; dorsum pale orange-brown or pale green; body 12 to 20 mm long .. .4th instar Lambdina fiscellaria liigubrosa 7. Head with brown mottling and 10 black dots visible above; dorsum light yellow-brown to gray-brown, with orange brown on prothorax as well as in intersegmental areas; body 18 to 30 mm long . .5th instar Lambdina fiscellaria lugubrosa Section II. Tortricidae, Gelechiidae, Plutellidae, Pyralidae, and Noctuidae 1. Dorsum with prominent longitudinal lines or stripes . 11 1. Dorsum unicolorous or rarely with very fine lines . 2 2. Head, prothoracic shield, and remainder of body emerald green; pro- thoracic shield collarlike; setal areas and anal shield inconspicuous; body form slender, 12 to 18 mm long . Argyrotaenia provana 2. Head and prothoracic shield brownish or black; body form stout or moderately stout, except for Argyrotaenia dorsalana . 3 3. Head and prothoracic shield yellow brown, light brown, or chestnut brown; outside of thoracic legs brownish or either tipped or annulated with black; setal areas conspicuous (in Acleris changing to inconspicuous during 5th instar) . 5 3. Head, prothoracic shield, and outside of thoracic legs jet black; setal areas inconspicuous . 4 4. Body yellow green to green; prothoracic shield sometimes pale in front; body form flattish, 10 to 14 mm long . . 4th instar Acleris gloverana 4. Body lemon yellow; prothoracic shield solid black; body form terete and stout, 12 to 16 mm long . Archips sp. 5. Head pale brown to chestnut brown with no dark markings above; prothor¬ acic shield a shade of light brown or greenish . 7 15 5. Head chestnut brown with 2 dark triangles on each side, dorsally; prothor- acic shield dark brown to black.6 6. Dorsum olive brown to dark brown, with prominent, ivory setal areas; pleural areas and venter pale yellow to light tan; body 10 to 16 mm long .5th instar Choristoneiira occidentalis 6. Dorsum lime green with olive tinge, with pale-yellow setal areas; pleural areas and venter usually greenish but sometimes yellowish; body 9 to 14 mm long. . 5th instar Choristoneiira retiniana ( = viridis) 7. Head mostly light brown but with greenish color around labrum and dark streak on lower head; prothoracic shield indistinct, concolorous with body; body pale green with small, yellowish setal areas and with yellow inter- segmental areas; body slender, 10 to 14 mm long . . Argyrotaenia dorsalana 7. Head without greenish color; prothoracic shield distinct; body form stout .8 8. Dorsum reddish brown or olive brown, with large, ivory .setal areas and large, ivory anal shield; head and prothoracic shield orange brown to chestnut brown. 10 8. Dorsum grass green, with small or moderately large, pale setal areas; head usually a light brown; prothoracic shield a lighter shade of brown than head .9 9. Prothoracic shield pale brown to transparent, with a thick black line at base of shield; head yellow brown, becoming chestnut brown; setal areas pale but conspicuous at start of stadium, later becoming inconspicuous; anal shield orbicular, concolorous with green anal segment; body 12 to 16 mm long. 5th instar Acleris gloverana 9. Prothoracic shield pale yellow-brown with 2 black dots at base on each side of split in shield; head light tan; setal areas pale yellow and conspicu¬ ous; anal shield oblong-orbicular, pale yellow; body 16 to 22 mm long_ . 6th instar Choristoneiira retiniana ( = viridis) 10. Setal areas oblong; anal shield oblong-orbicular, ivory to pale yel¬ low; body 17 to 28 mm long . .6th instar Choristoneiira occidentalis 10. Setal areas round; anal shield round, ivory to light brown; dorsum occasionally with 2 very fine white lines; colors brighter than in occidentalis; body 12 to 18 mm long . . last 2 instars Choristoneiira n. sp. 16 11. Dorsum various shades of yellow, orange, red, or brown, marked with ei¬ ther lines or stripes . 16 11. Dorsum various shades of green, sometimes with brownish tint, with ei¬ ther lines or stripes . 12 12. Dorsum with 3 narrow to wide white longitudinal lines. 13 12. Dorsum with 3 wide, brown longitudinal lines; head brown; prothor- acic shield green; body 12 to 18 mm long. Argyrotaenia klotsi 13. Head black, globose, and wider than body; prothoracic shield very pale; body light green to olive; setal areas large and black . 15 13. Head green to brown, no wider than body; prothoracic shield either invisi¬ ble or pale brown; body apple green; setal areas small and black . 14 14. Head green, narrower than body; body bright green, sometimes with bluish tinge; setal areas inconspicuous; longitudinal lines extended over prothorax and anal segment; body 10 to 17 nim long . . penultimate instar Achytonix epipaschia 14. Head brown, as wide as body; body pale green; setal areas conspicu¬ ous; central longitudinal line extended over prothoracic shield, and all 3 lines extended over brown anal segment; body 18 to 22 mm long. last instar Achytonix epipaschia 15. Anal shield very pale; dorsum olive, with setal areas scarcely raised; body 10 to 14 mm long . intermediate instar Egira simplex 15. Anal shield dark brown, occupying whole segment; dorsum mottled green, setal areas large and raised; body 15 to 30 mm long. . last 2 instars Egira simplex 16. LaVge, white eyespot around lateral seta on 8th abdominal segment; 2 irregular (undulating) white lines running through dorsocentral tae; head and prothoracic shield light brown .20 16. No eyespot on 8th abdominal segment; longitudinal lines or stripes with even margins; head and prothoracic shield light brown to chest¬ nut brown . 17 17. Body form stout; head wider than long; head and prothoracic shield orange brown to chestnut brown, the latter usually margined at the rear with a black line; dorsum pale yellow to orange yellow, with a broad, central olive-brown or chocolate-brown stripe; body 12 to 15 mm. . last instar Zeiraphera hesperiana 17 17. Body form slender; head no wider than long; head and prothoracic shield pale brown to chestnut brown; dorsum with either narrow or wide longitu¬ dinal lines . 18 18. Dorsum purplish, with 2 narrow and 1 broad, yellowish-green longi¬ tudinal lines on either side of the dorsal midline; setae and setal bases black and conspicuous; venter light greenish-white; body 9 to 14 mm long; larvae web ends of new needles together and feed in¬ side enclosure. Ypsolopha nello 18. Dorsum yellow or brown; setae and setal bases inconspicuous; venter same color as dorsum .. 19 19. Body pale yellow to bright yellow; dorsum with 3 orange-red or orange- brown, narrow to wide lines; body 9 to 14 mm long . .last instar Epinotia radicana^ 19. Body pale brown; dorsum with 3 wide, red-lavender lines; body 12 to 14 mm long.unidentified species Gelechiidae 20. Dorsum pinkish brown or reddish brown; an irregular white line in pleural area; body 10 to 15 mm long . .penultimate instar Dioryctria spp. 20. Dorsum pale orange to orange red; 1 irregular, chocolate-brown stripe on each side of dorsum; body 16 to 20 mm long . . last instar Dioryctria spp. ^Epinotia radicana later enters a 3- to 4-week nonfeeding period in which it loses its markings and coloration, becoming a whitish nondescript larva. It hides among foliage debris, where it pu¬ pates late in summer. 18 Biological Notes on Species and Groups The following information on life his¬ tories and synoptic features is pro¬ vided to help identify associate species or groups. The western spruce bud- worm is presented first as a basis for comparison; the associate genera are listed in alphabetical order, without regard to taxonomic position. Many budworm associates are well- known forest insects; information on their life histories and habits is given by Furniss and Carolin (1977). The available information is summarized here for insects that are less well known. Western Spruce Budworm (Choristoneura occidentalis Freeman) Biology —Oviposition occurs usually in late July or early August; eggs are deposited, overlapping, in masses on needles of host conifers. The newly hatched larva crawls under bark scales and among lichens, spins a silken hi- bernaculum, molts into the second in¬ star, and overwinters. In spring, the larva may mine needles, enter stami- nate flowers, or go directly to opening buds. In attacking opening buds, the larva spins a small web outside the bud before chewing its way inside; most early feeding is by third and fourth instars. As the shoots elongate, the larva spins a web between the needles, which becomes especially conspicuous during the sixth (last) in¬ star. The large larva is easily dis¬ turbed, dropping from its web when disturbed by wind and other factors, and many larvae drop to the lower branches and to the undergrowth. The larva pupates in a web when feeding is completed. The pupal period is 10 to 14 days. Synoptic Features First Instar —The larva is about 2 mm long and light green, with a light- brown head and prothoracic shield. It does not feed, and does not increase in size. Second Instar —During its spring feeding, the larva ranges from 2 to 4 mm long, is yellow orange with tiny, dark setal areas, and has a dark brown, squarish head and a lighter brown prothoracic shield. Its anal shield is barely discernible as a few dots of sclerotization. 19 Third Instar —The larva ranges from 4 to 7 mm long and has an orange- brown body. Its head is brown black with lighter adfrontals, a black mark on each side of the upper head, and a pale clypeus. Its prothoracic shield is brown with a central liplike undulation at its rear margin. The anal shield, barely visible, is pale brown with 12 to 16 dots of sclerotization. Fourth Instar —The larva is 6 to 10 mm long and light brown to cinnamon brown, with small, ivory-colored setal areas. Its head, including the clypeus, is brown-black. The prothoracic shield is brown-black and has a straight rear margin. The anal shield is easily visi¬ ble as ivory-colored dots in the shape of an anchor. Fifth Instar —The larva (fig. 3) is 10 to 16 mm long and two toned. Its up¬ per body is olive brown with conspic¬ uous ivory-colored setal areas; its lower sides are light tan to pale or¬ ange. Its head is reddish brown or oc¬ casionally light chestnut brown, with two black triangles on each side of the upper head. The prothoracic shield is black and has a partial longitudinal split centrally located, at its base. The anal shield is orbicular and ivory col¬ ored, with uniformly distributed brown dots. Sixth Instar —The larva (fig. 4) is 17 to 28 mm long and two toned; its up¬ per body is olive brown or occasion¬ ally light reddish brown and rarely yellowish brown, with large, conspic¬ uous ivory-colored setal areas. Its lower sides are pale yellow or pale or¬ ange. Its head and prothoracic shield are yellow brown to light chestnut brown with variable, small black markings; the prothoracic shield is di¬ vided by a median longitudinal line or split. The anal shield is large, orbicu¬ lar, and ivory colored. Adults have highly variable markings; one form is shown in figure 5. Figure 3—Fifth instar Choristoneura occiden- talis, 15 mm long. Figure 4—Sixth instar Choristoneura occiden- talis. 17 to 28 mm long. Figure 5 —Choristoneura occidentalis adult, wingspread 22 to 28 mm. 20 21 Achytonix epipaschia (Grote) (Crumb 1956) A. epipaschia is an occasional bud- worm associate throughout the West¬ ern United States. Biology—Moths are in flight during late July in the Pacific Northwest; ovi- position habits are not known. The small larva overwinters in a shelter spun in the foliage. Larvae in the spring are about 5 mm long and are found inside opening buds. Subse¬ quent feeding pattern is similar to that of western spruce budworm, but the insect pupates about a week earlier. Synoptic Features—The small larva closely resembles that of western spruce budworm, except that setal areas are black and raised, three very fine lines occur on the dorsum, and the anal shield is dark brown. Sueces- sive changes of body color as the larva molts are very pale olive green, apple green, and bright bluish green, with the white lines beeoming more conspicuous. Figure 6 shows colora¬ tion and markings of the fully devel¬ oped larva. The adult (fig. 7) is a medium-large (wingspread about 35 mm) gray moth with distinctive boomerang-shaped markings on the forewings. Figure 6 —Achytonix epipaschia larva. 18 to 22 mm long. Figure 7— Achytonix epipaschia adult, wing- spread about 35 mm. 7 22 Acleris gloverana (Walsingham), western blackheaded budworm An important defoliator in its own right on the Pacific coast, A. gloverana is a common associate over much of the range of western" spruce budworm. It has recently been found in the Southwestern United States (Stevens and others 1983). The adults of A. gloverana present a variety of color and marking patterns but the forewings always have raised patches of scales. Three typical forms are shown in figures 8, 9, and 10. 8 Biology—On the west coast, black¬ headed budworm adults fly 2 to 3 weeks after western spruce budworm. Oviposition is protracted; eggs are laid singly on needles, and the insect over¬ winters in this stage. The larva forms a silken tube in the opening buds, be¬ tween and in alinement with the new needles. In late instars, it makes a shelter among damaged needles, where pupation occurs. Figure 8 —Acleris gloverana adult, wingspread about 18 mm. Figure 9 —Acleris gloverana adult, wingspread about 18 mm. Figure 10 —Acleris gloverana adult, wingspread about 18 mm. 10 23 Synoptic Features—The early instars have black heads and prothoracic shields, and lemon-yellow bodies (fig. 11). At the start of the last instar, the setal areas are prominent, although pale, and the body is a subdued yellow-green color; at this time, the larva resembles the Modoc budworm. Soon after, the setal areas fade, and the combination of chestnut-brown head, pale prothoracic shield, and grass-green body make the larva dis¬ tinctive (fig. 12). Figure 11—Early instai Acleris gloverana. length 10 mm. Figure 12—Fully developed Acleris gloverana larva, length 12 to 16 mm. 24 Anomogyna mustelina (J. B. Smith) (Crumb 1956) A. mustelina is a rare budworm asso¬ ciate in the Pacific Northwest, and is unknown elsewhere. Biology—Overwintering occurs as an advanced instar. In spring, larvae are found in opening buds. They continue to feed on the new foliage for 2 to 3 weeks, then pupate. The pupal period lasts about 4 weeks. Otherwise, little is known about this species. Synoptic Features—The larva is 25 to 30 mm long during its spring feed¬ ing. It has a pale-gray to pale-brown head and anal shield, and a yellow- brown thorax and abdomen with copi¬ ous markings. Dorsal markings in¬ clude small, reddish-brown dots and dashes running longitudinally and three thin, whitish-yellow longitudinal lines. The color of the anterior half of each segment is lighter than the poste¬ rior half, and sometimes the dorsum is suffused with pink. The pleural area is marked with a distinctive broad, whitish-yellow stripe; the venter is a pale olive green, suffused with pinkish brown. Archips sp. An unidentified species of Archips was reared on several occasions from the foliage of Douglas-fir in the Pa¬ cific Northwest. Little is known about its life history and habits, except that the larva builds a silken tube or shel¬ ter from which it feeds. Fully devel¬ oped larvae (length about 25 mm) have dark brown to black head cap¬ sules and prothoracic shields, with the remainder of the body yellow to grass green. 25 Argyrotaenia spp. Three species of Argyrotaenia, A. dorsalana, A. provana, and A. klotsi, are recognized budworm associates. A. klotsi is known only from the Southwestern United States; the others are distributed throughout the West. Argyrotaenia dorsalana (Dyar) (Powell 1964a) Biology —The life history of A. dor¬ salana is similar to that of western spruce budworm. Eggs are laid on the needles in small masses, and the hatching larvae overwinter on the branches. In spring, the larvae feed in opening buds as does western spruce budworm, mostly gouging the centers of the new needles. Later, they feed in a more exposed position than the western spruce budworm, often with the silken tube they use for shelter completely outside the feeding area. Pupation, in the foliage, oceurs slightly earlier than that of western spruce budworm. Synoptic Features —Eggs are laid in masses in the same locations as those of western spruce budworm. Eggs of A. dorsalana, however, are smaller and their chorion has a finer texture; also, the egg masses have an orange- pink tint. The yellow-green body and pale yellow-brown head and prothora- cic shield separate the early instars from all associates except other Argyrotaenia species. In late instars, appearance is somewhat variable, but the head is usually light tan, the pro- thoracic shield yellow to yellow green, and the body light olive green or pea green (fig. 13). The adults (figs. 14 and 15) are generally yellow- 26 14 ish, with highly variable amounts of brown markings on the fore wings. Adult size varies considerably; ones we have reared have wingspreads from 16 to 24 mm. Argyrotaenia provana (Kearfott) (Powell 1964a) Biology —Life history information on A. provana is sketchy. Presumably the life history is similar to that of A. dorsalana, but events occur slightly later. After feeding, the larva enters a quiescent period for about 2 weeks before it pupates. Synoptic Features —The earliest in¬ stars are unknown. Later, at a body length of 8 to 12 mm, the entire body of the larva—including the head, pro- thoracic shield, and anal shield—is emerald green. In the next instar, two narrow, yellowish, longitudinal stripes are superimposed on the dorsum, and a similar yellowish stripe on the pleural area, with the remainder of the body emerald green. In the last instar, the stripes are lost and the body color becomes subdued to a grass green. The full-grown larva is slightly larger than that of A. dorsalana. The adult (fig. 16) has gray-black forewings, with distinctive white patches, and has a wingspread of about 20 mm. Figure 13— Argyrotaenia dorsalana larva, length 15 to 17 mm. Figure 14— Argyrotaenia dorsalana adult, wing- spread 16 to 24 mm. Figure 15— Argyrotaenia dorsalana adult, wing- spread 16 to 24 mm. 15 16 Figure 16— Argyrotaenia provana adult, wing- spread about 20 mm. 27 Argyrotaenia klotsi Obraztsov (Obraztsov 1961) Biology —The biology of this species is unknown but is likely similar to that of A. dorsalana and A. provana. Synoptic Features —Small larvae are not known. Fully developed larvae (fig. 17) have brown head capsules with mottled black markings. Thoracic and abdominal segments are yellow green; broad brown dorsal and subdor¬ sal lines run from the second thoracic to the penultimate abdominal segment. The adult (fig. 18), like that of A. provana, has gray-black fore wings, but ornamented with yellow rather than white. It is about the same size as A. provana. Figure 17 —Argyrotaenia klotsi larva, length about 16 mm. Figure 18 —Argyrotaenia klotsi adult, wing- spread about 20 mm. 28 Chionodes spp. At least three species of Chionodes are known associates of western spruce budworm. Of these, only C. abella Busck (fig. 19) is a described species (Busck 1903). It is found rarely in the Southwest, and its life history and habits are unknown. One undescribed species is known only from collections in southern Oregon. The other (fig. 20) is common in the Northwest, and as far east as Montana. All are small moths, with wingspreads of about 12 mm. Biology—These notes refer to the common undescribed species in the Northwest. Oviposition and overwin¬ tering habits are unknown. Larvae do not appear until the new shoots are well developed, which may suggest that early feeding is mainly in needles and staminate flowers. Fully devel¬ oped larvae are present in shoots at the same time as full-grown western spruce budworm. Adults emerge in late summer. Figure 19 —Chionodes ahellci adult, wingspread about 12 mm. Figure 20 —Chionodes sp. adult, wingspread about 12 mm. 29 21 Synoptic Features—Larvae of the Northwestern species vary little be¬ tween instars. The head and prothora- cic shield are light chestnut brown, and the dorsum is marked with many alternating reddish-brown and white lines (fig. 21). The larva, slender in form, is extremely active when dis¬ turbed. The larva of C. abella (fig. 22) is uni¬ formly brown, with the head and anal segments having a somewhat rosy cast. Thoracic legs and the posterior dorsal part of the first thoracic seg¬ ment are black. Figure 21 —Chionodes sp. larva, length about 10 mm. Figure 22 —Chionodes abella larva, length about 10 mm. 30 Choristoneura retiniana (Walsingham) (= C. viridis Freeman), Modoc bud worm C. retiniana is common in California and southern Oregon; scattered popu¬ lations are also found within other parts of the range of western spruce budworm.^ Biology —White fir is the principal host. Oviposition and overwintering habits are similar to those of western spruce budworm, but overwintering sites appear to be mainly on foliated parts of branches. In spring, some needle-mining occurs. The feeding habit in opening buds and elongating shoots is similar to that of western spruce budworm. In high populations, larvae appear to drop on silken threads to a greater extent than do those of western spruce budworm. Synoptic Features —Small larvae feeding in opening buds are yellow. In the third instar, the head and prothora- cic shield are a medium brown; body length is 3 to 5 mm. In the fourth in¬ star, the head and prothoracic shield are dark brown to black, and body length is 5 to 8 mm. Larger larvae feeding on elongating shoots are greenish. In the fifth instar, the body is usually yellow-lime but may be much darker. The head is brown with dark triangles as in the western spruce budworm, the prothoracic shield '’Poweli. J. A.; DeBenedictis, J. A. Taxonomic relationships and pheromone isolation among western spruce budworm populations. CANUSA West llnal report; 1982. 41 p. [Available from USDA Forest Service. Pacific Northwest Forest and Range Experiment Station. P.O. Box 3890, Portland. OR 97208.] black, and setal areas pale yellow and conspicuous. In the sixth and extra in¬ stars, the body is grass green. The head is light tan, the prothoracic shield yellow brown, setal areas pale yellow and elliptical (smaller than those of western spruce budworm), and the anal shield pale yellow brown and oblong-circular. Length at matu¬ rity is around 20 mm. The yellow, bud-feeding larvae are sometimes confused with those of Acleris gloverana. In casual observa¬ tion, large larvae can be confused with various green-bodied associates. 31 Choristoneura n. sp. This rare species from the Pacific Northwest has likely been lumped with the western spruce budworm dur¬ ing field examination of foliage. Lar¬ vae collected from the southern Willamette Valley of Oregon and the eastern Cascades of Washington in the 1950’s and 1960’s were reared to adults that were identified by a spe¬ cialist at the U.S. National Museum. Biology—Oviposition and overwinter¬ ing habits are probably similar to those of western spruce budworm, but the larva may feed before overwinter¬ ing. When found in opening buds, the larva is somewhat larger than that of western spruce budworm, but their subsequent feeding habits appear iden¬ tical. The new species ceases feeding and pupates about 2 weeks earlier than western spruce budworm, however. Synoptic Features—When the larva is 8 to 10 mm long, the head is or¬ ange brown, the prothoracic shield light brown and margined on the sides and rear by a broad black line; the anal plate is large, ivory-colored, and circular. The dorsum is reddish brown, with prominent roundish ivory-colored setal areas and two pale longitudinal lines, and the pleural area bears a broad yellow stripe. Later, when the larva is 12 to 15 mm long, the head and anal plate become light chestnut brown, and the pale lines dis¬ appear. The very dark adult is much smaller than that of western spruce budworm. Coleotechnites spp. At least two undescribed species of Coleotechnites are budworm associ¬ ates. Biology—Few details are known of the life history or the habits of these species, but they are probably similar to those of the closely related C. pi- ceaella (Kearfott), an associate of Choristoneura fumiferana in the East¬ ern United States. Coleotechnites pi- ceaella lays eggs between old bud scales and in similar protected loca¬ tions late in summer. The small larva of this and the common Northwestern species mines needles and overwinters in a needle or a mass of mined nee¬ dles. In spring, as buds open, the larva spins a silken tube from the twig to the base of the bud, and feeds* from the tube into the bud. Synoptic Features—The larva (fig. 23) varies in color from pinkish brown to yellowish brown; the head, collar¬ like prothoracic shield, and anal plate are light brown. Setal bases are small, but dark and conspicuous. The larva is very active. At maturity it is 7 to 8 mm long. Adults (fig. 24) are small, fragile moths with heavily fringed wings; wingspread is about 10 mm. 32 Dioryctria spp. (Mutuura & Munroe 1973) The spruce coneworm, Dioryctria ren- iculelloides Mutuura & Munroe, has long been recognized as a western spruce budworm associate, at times being about as numerous as budworms themselves. Recently, D. pseudotsu- getla Munroe has been identified as another associate of western spruce budworm (Stevens and others 1983). The two species are difficult to distin¬ guish in the larval and adult stages, so we choose here to consider them a single entity. Other as yet undescribed species may also be involved. The following sections on life history and synoptic features were prepared for D. reniculelloides, but probably serve reasonably well for D. pseudotsugella. Biology—Eggs are laid on the bark of limbs. After hatching, the small larva overwinters in some of the same places as the western spruce bud¬ worm. In spring, it sometimes mines needles. Normally it feeds in opening buds much as does the western spruce budworm, and as the shoot elongates, feeding and webbing are also similar. Pupation is slightly later than that of the western spruce budworm in the Pacific Northwest, and 7 to 10 days earlier than western spruce budworm in the northern Rocky Mountains. Synoptic Features—During needle¬ mining and bud-feeding, the larva re¬ sembles the western spruce budworm in form, but the body is reddish brown to almost black with 8 to 10 interrupted longitudinal white lines and a distinctive white “eyespot” on each side of the eighth abdominal seg¬ ment. The frass, expelled into the 23 24 Figure 23 —Coleotechnhes sp. larva, length about 8 mm. Figure 24 —Coleotechnites sp. adult, wingspread about 10 mm. 33 webbing during bud-mining, is yel¬ lowish and a good clue to the identity of the hidden miner. In later instars, the brightly colored dorsum and undu¬ lating subdorsal lines make the larva easy to distinguish, at least to genus. Figure 25 shows a typical larva; fig¬ ures 26 and 27 show variations. The pupae are dark brown to black; the moths (figs. 28 and 29) have gray forewings (wingspread about 20 to 25 mm) with distinctive whitish trans¬ verse bands and are not likely to be confused with other budworm associates. Figure 25— Dioryctria sp. larva, length 18 to 24 mm. Figure 26— Dioryctria sp. larva, length 18 to 24 mm. Figure 27 —Dioryctria sp. larva, length 18 to 24 mm. Figure 28 — Dioryctria reniculelloides adult, wingspread 20 to 25 mm. Figure 29— Dioryctria pseudotsugella adult, wingspread 20 to 25 mm. 25 34 27 35 Egira simplex (Walker) (Hardy 1962) E. simplex (fig. 30) is a large noctuid that is widely distributed throughout the West, and is an occasional bud- worm associate. It is found in older literature under the name Xylomyges simplex. Biology—In early spring, the adult deposits groups of eggs on foliage of both conifers and hardwoods. On Douglas-fir, the young larva pene¬ trates the opening bud and feeds much like the western spruce budworm; as the shoot elongates, the larva feeds from an external silken shelter much like that of western spruce budworm. It pupates 1 to 2 weeks later than the western spruce budworm and overwin¬ ters in that stage. Synoptic Features—In its early feed¬ ing, the small larva (4 to 6 mm long) resembles the western spruce bud¬ worm in its orange-brown coloration and dark-brown head. The last ab¬ dominal segment is almost completely black, however, and the setal areas are black. In subsequent instars, the dorsum is marked with three white or whitish-yellow lines on a light olive- green background and, later, on a brighter green background. The head, prothoracic shield, setal bases, and anal shield remain dark brown or black (fig. 31). At maturity, the larva is 30 to 35 mm long, strikingly large and stocky. Life stages, including each instar, are described in detail by Hardy (1962). Figure 30— Egira simplex adult, wingspread 40 mm. 36 Figure 31—Early-instar Egira simplex larva, 15 mm long. 37 Enypia griseata Grossbeck (Evans 1960) E. griseata has been reared as a bud- worm associate from the Southwestern United States, and adults identified as ""Enypia sp. nr. griseata" have been reared from the Pacific Northwest. Other species of Enypia are known from Douglas-fir and true firs (Evans 1960) and may also appear as western spruce budworm associates. The fol¬ lowing material relates to E. griseata. Biology —The pearly eggs are laid singly or in twos on needles. The larva overwinters, usually in the fourth instar. Pupation is in the fo¬ liage. Adults may be found throughout the summer. Synoptic Features —The head and prothoracic shield of the small larva are pale green-brown; the body is gen¬ erally gray-green, with several green¬ ish longitudinal lines. The fully developed larva (fig. 32) is green, with two pairs of conspicuous, near¬ white lines; the head is pale russet- green, with darker epicranial mark¬ ings. Length is 20 to 25 mm. The adult (fig. 33) is a large, generally gray moth, with a wingspread of about 35 mm. The wings of the com¬ monly reared species in the Pacific Northwest have a dusting of whitish scales superimposed on the gray. Evans (1960) includes photographs of the adults of many species. Figure 32 —Enypia griseata larva, 20 to 25 mm long. Figure 33 —Enypia griseata adult, wingspread about 35 mm. 32 33 38 Epinotia radicana (Heinrich), spruce tip moth (Blais 1961, Powell 1964b, Brown 1983) Figure 34 —Epinotia radicana larva, 9 to 12 mm long. E. radicana, known until recently as Griselda radicana, is transcontinental and an associate of both the western and the eastern spruce bud worms. Biology —Eggs are laid singly at the base of needles. They overwinter and hatch in the spring; the small larvae enter the opening buds, feeding mainly at the top. The larvae cease feeding about the same time as, or slightly later than, the western spruce budworm, then go into a quiescent pe¬ riod for 3 to 4 weeks in dead needles and other debris before pupating. Emergence is in late summer. Synoptic Features —Early instars are pale yellow. The first instar is slender, but in later stages (figs. 34 and 35) the larvae grow stouter, and pinkish to red-brown longitudinal lines appear. In early feeding, the bud cap is tied with silk, like a hat, to the opening bud. During the quiescent period be¬ fore pupation, the larva becomes whi¬ tish and unmarked. The adult (fig. 36) is small (wingspread about 12 to 16 mm) with gray forewings having dis¬ tinctive rusty-colored basal sections. 39 36 Figure 35 —Epinoiia radicana larva, 9 to 12 mm long. Figure 36 —Epinotia radicana adult, wingspread 12 to 16 mm. 40 Eupithecia spp. (MacKay 1951, McDunnough 1949, Ross and Evans 1956) Many members of the genus Eupithecia feed on foliage of conifers. E. annulata (Hulst) is common in the Pacific Northwest and the northern Rockies, and E. catalinata McDunnough has been reared from the Southwestern United States. The following material pertains to E. annulata. Biology —Oviposition occurs in early spring, but the sites are unknown. The small larva feeds on the new needles of opening buds under cover of the bud scales. As it grows, the larva continues to feed on the new needles, gouging out rectangular patches near the middle of a needle. It pupates in early summer, with a few crinkly strands of silk holding the tail end of the pupa. The pupa overwinters. Synoptic Features —When about 6 mm long, the larva has a yellow body, with the head, pleural areas, and anal shield brown. The prothora- cic shield is light brown and paler in the center. The fully developed larva (fig. 37), about 22 mm long, has a pale brown head; the dorsum is red¬ dish or yellowish brown with three longitudinal lines; the pleural area may have a yellowish stripe. The adult of E. annulata (fig. 38) is an in¬ distinctly marked moth, with a wing- spread of 20 to 24 mm. E. catalinata is similar in size and is similarly marked. Figure 37 —Eupithecia annulata larva, about 22 mm long. Figure 38 —Eupithecia annulata adult, wing- spread 20 to 24 mm. 41 Lambdina fiscellaria lugubrosa (Hulst), western hemlock looper Biology —Single eggs are laid in early fall on lichens, moss, and roughened bark. Eggs overwinter and hatch in spring. Newly emerged larvae feed on needles of opening buds and later in¬ stars feed on old needles. Pupation occurs both on and off the tree in var¬ ious kinds of natural debris. Synoptic Features —Eggs are spheri¬ cal and grayish. The first instar has a distinctive black head, and each of the first five abdominal segments has a transverse whitish-yellow band fol¬ lowed by a dark-brown band. In sub¬ sequent instars, the head gradually becomes paler but with dark streaking and mottling and round black dots; the dorsum is pale brown or pale green, with the setal bases appearing as four dark dots on each segment. A maze of white and dark lines occurs in the pleural area. In the last instar (fig. 39), the head is whitish, with light- brown mottling and eight large dots; the dorsum ranges from a very light yellowish brown or pinkish brown to a light gray. A white subdorsal stripe is subtended by a broken black line, with the maze of fine lines below. The mature larva is 25 to 30 mm long. The adult (fig. 40) is tan, with a wingspread of about 35 mm. Figure 39 —Lambdina fiscellaria lugubrosa larva, 18 to 30 mm long. Figure 40 —Lambdina fiscellaria lugubrosa adult, wingspread about 35 mm. 40 42 Melanolophia imitata (Walker), greenstriped forest looper (Evans 1962) The greenstriped forest looper, com¬ mon along the Pacific coast, feeds on a variety of conifers. Biology —In early spring, the adult deposits small, barrel-shaped eggs on tree limbs and boles. After the eggs hatch, larvae move to the foliage and feed on both new and old needles, with 1-year-old foliage preferred. In September, the mature larva drops to the ground, pupates in the duff, and overwinters. Synoptic Features —In all stages, the larva has a green head with no mark¬ ings, and a green body; the dorsum is marked with a pair of whitish longitu¬ dinal lines. The last instar (fig. 41) is apple green, 30 to 37 mm long, with the white dorsal lines prominent and a fainter yellow stripe in the pleural area. Although commonly a coastal species, it has recently been found in beatings of Douglas-fir in the northern Rocky Mountains (Volker 1978). The adults (fig. 42) vary in wingspread from 20 to over 35 mm. Figure 41 —Melanolophia imitata larva, 30 to 37 mm long. Figure 42 — Melanolophia imitata adult, wing- spread 20 to 35 mm. 43 Nematocampa limbata (Haworth), filament bearer The filament bearer, a transcontinental species, is an occasional budworm as¬ sociate in the Pacific Northwest and the northern Rockies. In the older lit¬ erature this insect is listed as Nemato¬ campa filamentaria. Biology —In northern Idaho in 1976, Markin (unpublished) found develop¬ ment of N. limbata lagging signifi¬ cantly behind that of western spruce budworm; early instars were seen in late June, and the larvae finished feeding in late July. Adults appeared in early to mid-August. Eggs failed to Figure 43 —Nematocampa limbata larva. 20 mm long. Figure 44 —Nematocampa limbata adult, wing spread about 20 mm. hatch by fall; the species apparently overwinters in this stage. Early instars fed mostly on new foliage, but later stages fed more or less indiscrimi¬ nately, cleaning up needles unclaimed by western spruce budworms. Synoptic Features —The knobbed dorsal projections on the fully devel¬ oped larva (fig. 43) readily identify the species. The larva is up to 20 mm long; and the medium-sized adult (fig. 44) is tan and has a wingspread of about 20 mm. 44 Nepytia phantasmaria (Strecker), phantom hemlock looper (Wickman and Hunt 1969) This species has been associated with low populations of western spruce budworm on Douglas-fir in the Willamette Valley of Oregon. Its usual host in coastal Oregon and Brit¬ ish Columbia is western hemlock, but it has also caused serious damage to white fir in northern California. Biology—In late September and Octo¬ ber, the eggs are laid singly or in small clusters on the underside of con¬ ifer needles; they overwinter and hatch about the time buds are opening. The small larva feeds at first on new nee¬ dles, then moves to old needles during its third or fourth instar. It molts into a fifth instar and continues to feed un¬ til early September; then, it attaches itself by a few silken strands to nee¬ dles and pupates. Synoptic Features—First and second instars are pale green with two faint white longitudinal stripes on the dor¬ sum. Third and fourth instars have green heads with black dots; the body is green with two white dorsal stripes. The appearance changes little in the fifth and final instar (fig. 45), when it reaches a length of 25 to 35 mm. The adult (fig. 46) has a wingspread of about 25 mm. 45 46 Figure 45 —Nepytia phantasmaria larva, 25 to 35 mm long. Figure 46 —Nepytia phantasmaria adult, wing- spread 25 to 30 mm. 45 Orgyia pseudotsugata (McDunnough), Douglas-fir tussock moth (Brookes and others 1978) The Douglas-fir tussock moth ranks with western spruce budworm as one of the most important forest defolia¬ tors in Western North America, and is a potential budworm associate. Biology —Eggs masses overwinter and eggs hatch in May and June; young larvae usually feed on newly expand¬ ing foliage of Douglas-fir and true firs. Later instars feed on both old and new foliage; then, most pupate in stout cocoons on foliage where they have been feeding. Females are wing¬ less and mate on their cocoons. 46 48 Synoptic Features—This is one of the few western spruce budworm lar¬ val associates that are hairy, and thus readily distinguishable. The tussock moth has a variety of hairy projections in the different instars (figs. 47 and 48). The instars are described in detail by Beckwith (1978). Figure 47 —Early instar Orgy la pseudoisugaia, about 15 mm long. Figure 48 —Fifth instar Orgyia pseudoisugaia. about 25 mm long. 47 Stenoporpia sp. An undetermined species of the looper genus Stenoporpia has been reared from Douglas-fir in the Pacific North¬ west. The fully developed larva (about 30 mm long) has a light-brown head, orange-red-brown dorsum, and yel¬ lowish pleural and ventral areas. Syngrapha spp., false loopers (Eichlin and Cunningham 1978, McGuffin 1954) Moths of this genus are occasionally reared as associates of western spruce budworm, but they are relatively un¬ known to most forest entomologists. We have reared S. angulidens (J. B. Smith) occasionally in the Southwest; 5. celsa (Hy. Edwards) is well known from the Pacific region. Biology —The eggs are laid singly, and members of the genus overwinter as small larvae. Synoptic Features —Full-grown lar¬ vae are green, with a white or dark green stripe in the pleural area, and up to 25 mm long; they have only three pairs of abdominal prolegs. The adults (figs. 49 and 50) are medium-sized (wingspread 25 to 30 mm), heavy¬ bodied, distinctively marked moths. 48 49 Figure 49 —Syngraplui angididens adult, wing- spread 25 to 30 mm. Figure 50 —Syngrapha celsa adult, wingspread 25 to 30 mm. 49 51 Telphusa sedulitella (Busck) T. sedulitella is a relatively rare asso¬ ciate of western spruce budworm in the Pacific Northwest. Biology —In spring, the larva is found in an intermediate stage, feeding in opening buds of grand fir. It continues its feeding in elongating shoots and pupates 1 to 2 weeks before western spruce budworm. Emergence is in early July. Synoptic Features —When first found in opening buds, the slender larva has a yellowish chestnut-brown head, pro- thoracic shield, and anal shield, and a pale dorsum marked with five, brown, longitudinal lines. In the next instar, the lines become lavender brown. In the final instar, the head and prothora- cic shield are chestnut brown, the pro- thoracic shield tinged with black at the rear, and the dorsum pale yellow and now marked with seven, reddish- brown, longitudinal lines. A similar line occurs below the lateral midline, and the venter is pale yellow. The mature larva is 9 to 10 mm long. The adult (fig. 51) is a small, slender moth with narrow dark-brown wings marked with silver. Ypsolopha spp. Y. nella (Busck) is a common associ¬ ate of western spruce budworm on white fir in the central Rockies and the Southwestern United States (Stevens and others 1983), and a spe¬ cies identified as Ypsolopha prob. cer- vella (Walsingham) has been reared from Douglas-fir in the Pacific North¬ west. The following material refers to Y. nella. Biology —Relatively little is known of the life history of this species. Larvae appear in late spring to early summer and pupate in the foliage, about the same time as the budworm. Synoptic Features —Larvae and adults are both highly distinctive, as are the larval feeding characteristics. Color varies considerably within and between instars, but all stages have conspicuous black setae borne on black setal bases (fig. 52). Back¬ ground colors on the dorsum range from gray to green to purple; all in¬ stars have a series of longitudinal dor¬ sal lines. The adults have wingspreads of about 20 mm; their abdomens and hindwings are gray. The forewings are narrow, brown, and often ornamented with a darker longitudinal line. Fig¬ ures 53 and 54 show typical markings. Larvae web the outer ends of the nee¬ dles together into a tent, within which they feed. As the needles elongate, the tent becomes more globular than spindle-shaped, and is a readily seen indicator of Ypsolopha. Figure 51 —Telphusa sedulitella adult, wing- spread about 10 mm. 50 53 54 Figure 52 —Ypsolopha nella larva. 9 to 14 mm long. Figure 53 —Ypsolopha nella adult, wingspread 20 mm. Figure 54 —Ypsolopha nella adult, wingspread 20 mm. 51 Zeiraphera spp. Z. hesperiana Mutuura & Freeman has long been considered an associate of western spruce budworm in the Pa¬ cific Northwest and the northern Rockies (Carolin 1980, Markin 1982), and adults identified as Z. hesperiana have recently been reared from the Southwestern United States (Stevens and others 1983). Z. pacifica Freeman also appears to be a common associate in Idaho. Biology—Eggs of Z. hesperiana are laid singly on bare portions of limbs during midsummer, and overwinter. In spring, eggs hatch, and the young lar¬ vae feed completely concealed in the opening buds. Early feeding encircles the base of the new shoot. As the shoot develops, the larva and the ef¬ fects of its feeding gradually become visible. In the Northwest, the larva drops to the ground to pupate in the litter about the time the larvae of western spruce budworm are entering the last instar. The life history of Z. pacifica has not been intensively studied; presumably, it is similar to Z. hesperiana. Damage caused by Z. pacifica is noted by Condrashoff (1966). Synoptic Features—Eggs are small, yellow, and spiny surfaced. The larva of Z. hesperiana resembles the west¬ ern spruce budworm slightly when small, but the body is dirty whitish- brown or pale yellow. The setal bases are conspicuously black, and three small sclerotized areas occur on the dorsum of the penultimate segment. Later, the larva becomes brownish yellow, and in the last two stages has a broad brown dorsal stripe (fig. 55). The larva is generally sluggish. Adult Zeiraphera moths are distinctively marked and readily separable from any other common budworm associ¬ ates by the presence of a prominent saddle-like, white to brownish-white patch located on the forewings when the moth is at rest. Adults identified as Z. hesperiana (fig. 56) are generally larger than those of Z. pacifica (fig. 57) (wing- spreads 15 to 20 mm vs. 10 to 12 mm), but the species appear similar otherwise. In Idaho, sympatric popu¬ lations of what appear to be both spe¬ cies tend to be host-specific— Z. hesperiana on Douglas-fir, Z. pacifica on true fir. In Idaho, at least, larvae are separable; Z. pacifica is smaller, flattened dorsoventrally, and has a uniformly pale, off-white thorax abdomen. Both have tan head and capsules. Figure 55 —Zeiraphera hesperiana larva. 12 to 15 mm long. Figure 56 —Zeiraphera hesperiana adult, wing- spread 15 to 20 mm. Figure 57 —Zeiraphera pacifica adult, wing- spread 12 to 15 mm. 52 53 Role of Associates in the Habitat Although the role of individual bud- worm associates in the habitat is fairly well known, the interaction among them is not. A synthesis of available information is presented below. Host Preference Studies in Oregon and Washington by Carolin (1980) showed that most of the defoliators associated with western spruce budworm on Douglas-fir were also found on grand fir and with the Modoc budworm on white fir. In northeast Oregon, sampling of paired Douglas-fir and grand fir trees showed: no preference between the two tree species by Argyrotaenia dorsalana and Dioryctria sp., proba¬ bly reniculelloides', a strong preference for Douglas-fir by Epinotia radicana and Zeiraphera hesperiana; and, a strong preference for grand fir by Acleris gloverana, Chionodes- Telphusa species, and a then-unidenti¬ fied Zeiraphera species, possibly Z. pacifica. In similar studies in the eastern Washington Cascades, a pref¬ erence for grand fir by the Chionodes- Telphusa complex was again shown; populations of other associates were too low for comparison. Surveys in northeast Oregon in 1956 revealed a spot infestation by Acleris gloverana on subalpine fir, with light but visible defoliation (Whiteside 1957), suggest¬ ing a general affinity of this species for true firs in areas away from the insect’s usual coastal habitat. 54 Life History Indications of host preference by other associates are strictly observational. In an outbreak in northern Idaho and western Montana during 1937, the western hemlock looper showed a preference for true firs, but several in¬ termixed species, including Douglas- fir, were also fed upon (Evenden 1938). Two noctuids, Achytonix epipaschia and Egira simplex, listed by Carolin (1980) as sporadic on Douglas-fir and rare on grand fir, caused noticeable defoliation in 1964 on Douglas-fir on 8,400 acres (3 360 ha) in western Oregon (Orr and others 1965). After an analytical review of records, Beckwith (1978) concluded that apparent host preference by the Douglas-fir tussock moth between Douglas-fir and grand fir was incon¬ sistent, differing among forest areas. The amount of damage associates may add to that caused by western spruce budworm is affected by the timing of larval feeding and larval development relative to bud-opening and shoot de¬ velopment and to feeding site. Abun¬ dance is also a factor; Markin (1982) describes an insecticide field test against western spruce budworm on Douglas-fir in southeast Idaho in which associates constituted 52 per¬ cent of all larvae found on foliage samples. A few associates have life histories similar to that of western spruce bud¬ worm. At least one and possibly two Dioryctria species fit the budworm pattern closely, but with variations shown in relative time of pupation. Three species of Argyrotaenia have life histories similar to that of western spruce budworm, with pupation rang¬ ing from slightly before to slightly af¬ ter that of the budworm. One noctuid, Achytonix epipaschia, also has a simi¬ lar life history, but with slightly ear¬ lier pupation. All other associates for which we have life history information differ in phenology from that of west¬ ern spruce budworm in one or more respects. Simplified comparisons be¬ tween the phenology of western spruce budworm and selected associ¬ ated species are made in table 2. 55 Table 2—Synopsis of life histories of some lepidopterous associates, compared with western spruce budworm Species Oviposition Eclosion Start of feeding Pupation Choristoneura occidentalis Mid to late summer Mid to late summer Spring Midsummer Achytonix epipaschia Midsummer Mid to late summer Spring Midsummer Acleris Late summer Spring Spring Late summer gloverana Argyrotaenia spp. Mid to late summer Mid to late summer Spring Midsummer Chionodes sp. Spring Late summer Summer Spring' A Chionodes 7 7 Spring Midsummer other spp. Coleotechnites sp., nr. Mid to late summer Late summer Late summer Late spring' piceaella Dioryctria spp. Mid to late summer Mid to late summer Spring Midsummer Egira simplex Spring Spring Spring Mid to late summer Eupithecia Spring Spring Spring Early summer annulata Epinotia Late summer Spring Spring Late summer^ radicana Lambdina Early fall Spring Spring Late summer fiscellaria lugubrosa Melanolophia Spring Spring Spring Late summer imitate Nematocampa limbata Mid to late summer Spring (?) Late spring Midsummer Nepytia Early fall Spring Spring Late summer phantasmaria 'Of the following year. ^Larva undergoes a 3- to 4-week nonfeeding period before pupating. 56 Table 2 —Continued Species Oviposition Eclosion Start of feeding Pupation Orgyia pseudotsugata Late summer Spring Spring Late summer Syngrapha Midsummer Midsummer Late summer Early summer' spp. Telphusa Mid to late Mid to late 7 Midsummer sedulitella summer summer Zeiraphera hesperiana Midsummer Spring Spring Early summer 'Of the following year. Despite differences in life histories, most associates feed in buds as early instars, like the western spruce bud- worm. A few associates in buds are advanced instars, however; they have obviously fed in the previous fall, on trees either host or nonhost for west¬ ern spruce budworm, and wintered as larvae. During bud-feeding, two noc- tuids, Syngrapha sp. nr. celsa and Anomogyna miistelina, and the loop- ers, Stenoporpia sp., and one or more species of Enypia are larvae 20 to 25 mm long. Their feeding is concluded in about 2 weeks. The common spe¬ cies of Ypsolopha in the Southwest, and a rare species in the Pacific Northwest, are first found on new growth as intermediate instars. The larvae of Coleotechnites sp. nr. piceaella, a small gelechiid, are mainly in their last stages at the time of budfeeding, and pupate in about 2 weeks. With the possible exception of Ypsolopha nella, these species have little impact on the production of new foliage. Of early instars in opening buds, only Zeiraphera hesperiana, the Zeiraphera on true firs, and Eiipithecia annulata (and possibly E. catalinata) cease feeding noticeably earlier than western spruce budworm. The Zeiraphera lar¬ vae cease feeding about the time west¬ ern spruce budworm is entering its last larval stage, dropping to the ground to pupate; E. annulata pupates shortly thereafter. Because of its frequent abundance, Z. hesperiana may have a significant impact on production of new foliage, but would not be re¬ corded in late larval samples for west¬ ern spruce budworm. Three loopers of sporadic occurrence, Lambdina fiscellaria lugubrosa, Melanolophia imitata, and Nepytia phantasmaria, are found in freshly flushed buds but feed late into the growing season and more on old than new needle growth. Acleris gloverana also feeds later, pu¬ pating about the time western spruce budworm is laying eggs. 57 Feeding Sites Variation in bud-feeding sites of asso- eiates provides a potential for serious bud damage, particularly if this feed¬ ing adds to that of western spruce budworm. A few associates, such as Achytonix epipaschia and Egira sim¬ plex, feed much as does western spruce budworm. Others usually oc¬ cupy a different part of the bud. Zeiraphera hesperiana tunnels around the base of the bud, rarely touching the shoot axis. Dioryctria spp. tend to bore directly into the center of the bud and damage the shoot axis; western spruce budworm is located in this area too, but usually has a meandering mine near the shoot axis. Epinotia radicana usually is at the tip of the opening bud, webbing the bud cap to the tip. Acleris gloverana and Ypsolopha spp. build tubes made of needles. Argyrotaenia spp. usually feed only part way into the bud, keep¬ ing their bodies in an external silken tube. The various loopers are mostly external feeders and can be character¬ ized as needle-gougers. Competition between associates and western spruce budworm and among associates is probably ameliorated by the variation in feeding sites. Sample counts for western spruce budworm and associates in Oregon and Wash¬ ington (Carolin 1980) show that (1) when little previous bud damage has occurred, both western spruce bud¬ worm and associates can be abundant; and (2) when previous bud damage has reduced the food supply, abun¬ dance of associates is sharply reduced. The preponderance of associates over western spruce budworm described by Markin (1982) may demonstrate the effect of little previous damage to buds. Some direct competition be¬ tween western spruce budworm and associates is evident. Dioryctria reniculelloides larvae are known to prey on western spruce budworm pu¬ pae (McKnight 1971), and mature lar¬ vae of Epinotia radicana have been observed feeding on fresh western spruce budworm pupae (Carolin, un¬ published). Other instances of preda¬ tion no doubt go unobserved, and are indicated only by dead western spruce budworm found inside the buds. No predation among the various associates is known to us, but it probably occurs to a minor extent. 58 Abundance In unsprayed infestations of western spruce budworm in Oregon and Washington during 1955-58, associ¬ ates feeding in opening buds of Doug- las-fir constituted 3 to 28 percent of the total larval population on samples at the different plots (Carolin 1980). During insecticide tests against west¬ ern spruce budworm on Douglas-fir in southeast Idaho in 1976, associates found on all samples for all sampling intervals represented 52 percent of all larvae recorded (Markin 1982). In similar tests in western Montana in 1981, associates made up 27 percent of all larvae found (Markin, unpub¬ lished). In Oregon and Washington infesta¬ tions, Carolin (1980) listed six species as being relatively abundant; Acleris gloverana, Argyrotaenia dorsalana, Coleotechnites sp. nr. piceaella. Dioryctria reniculelloides, Epinotia radicana, and Zeiraphera hesperiana. In unsprayed Douglas-fir plots, Z. hesperiana was the most abundant species, with up to 206 larvae per 100 15-inch (37.5-cm) twigs. Epinotia radicana was next in abundance, with up to 131 larvae per 100 twigs, and D. reniculelloides, although low in density at three plots, reached 158 lar¬ vae per 100 twigs at a fourth plot. Acleris gloverana attained a density of 30 larvae per 100 twigs on Douglas-fir plots, and over 100 larvae per 100 twigs at a subalpine fir plot sprayed several years before. In southeast Idaho, of the total defo¬ liator population, associates were represented as follows; D. reniculelloides, 18 percent; Z. hesperiana, 17 percent; Nematocampa limbata, 8 percent; E. radicana 2 per¬ cent; A gloverana, 1 percent; and unidentified larvae, 7 percent (Markin 1982). Both D. reniculelloides and Z. hesperiana occurred at densities as high as 6 larvae per 100 buds, and N. limbata as high as 2.6 larvae per 100 buds at one of the sampling intervals. In the western Montana tests (Markin, unpublished), D. reniculelloides repre¬ sented 16 percent, A. gloverana 1 per¬ cent, E. radicana 5 percent, and Z. hesperiana 1 percent of all larvae found. Because these records were obtained in different years, no valid comparison can be made between forest regions represented. These associates have been shown to oscillate in density over a period of years (Carolin 1980), but Zeiraphera hesperiana, Dioryctria reniculelloides, Epinotia radicana, and Argyrotaenia dorsalana are clearly among the major associates of western spruce budworm. 59 Additional Research Needed Acknowledgments Although some facts about budworm associates are known, clearly much remains to be learned. For some areas, even such basic information as the composition of the associate com¬ plex is unknown. Data on life histo¬ ries and habits are sketchy for many of the associates. We urge entomolo¬ gists to collect and rear associates and to make their findings known. Only in this way will these important informa¬ tion gaps be filled. The authors are indebted to many of their colleagues for help in developing this handbook. Field observations and associated insects were provided by W. E. Waters, W. J. A. Volney, W. Schaupp, M. Stelzer, R. Beckwith, L. Stipe, and C. Stein. G. P. Markin took most of the larval photographs; several were taken by D. A. Leather- man and W. C. Guy. Most of the adult photos were provided by D. C. Ferguson and R. W. Hodges from specimens in the U.S. National Mu¬ seum. W. A. Murphy, of the USDA’s Insect Identification and Beneficial In¬ sect Introduction Institute, verified the taxonomic names. 60 Literature Cited Beckwith, Roy C. Biology of the insect. In: Brookes, Martha H.; Stark, R. W.; Campbell, Robert W., eds. The Douglas- fir tussock moth; a synthesis. Tech. Bull. 1585. Washington, DC: U.S. Department of Agriculture, Forest Service, Science and Education Agency, Douglas-fir Tussock Moth Research and Development Program; 1978 ; 25-30. Blais, J. R. Notes on the biology of Gri- selda radicana (Wlshm.) (Lepidoptera: Olethreutidae). The Canadian Entomolo¬ gist. 93(8): 648-653; 1961 . Brookes, Martha H.; Stark, R. W.; Campbell, Robert W., eds. The Douglas- fir tussock moth: a synthesis. Tech. Bull. 1585. Washington, DC; U.S. Department of Agriculture, Forest Service, Science and Education Agency, Douglas-fir Tussock Moth Research and Development Program; 1978 . 331 p. Brown, Richard L. Taxonomic and mor¬ phological investigations of Olethreutinae: Rhopobota, Griselda, Melissopus, and Cy- dia. (Lepidoptera; Tortricidae). Entomogra- phy. 2: 97-120; 1983 . Busck, August. Notes on the Cerostoma group of Yponomeutidae, with descriptions of new North American species. Journal of the New York Entomological Society. 11; 45-59; 1903 . Carolin, V. M. Larval densities and trends of insect species associated with spruce budworms in buds and shoots in Oregon and Washington. Res. Pap. PNW-273. Portland, OR: U.S. Department of Agricul¬ ture, Forest Service, Pacific Northwest Forest and Range Experiment Station; 1980 . 18 p. Carolin, V. M., Jr.; Stevens, Robert E. Key to small lepidopterous larvae in open¬ ing buds and new shoots of Douglas-fir and true firs. Res. Note RM-365. Fort Col¬ lins, CO; U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station; 1979 . 4 p. Carolin, V. M., Jr.; Stevens, Robert E. Key to large lepidopterous larvae on new foliage of Douglas-fir and true firs. Res. Note RM-401. Fort Collins, CO; U.S. De¬ partment of Agriculture, Forest Service, Rocky Mountain Forest and Range Experi¬ ment Station; 1981 . 4 p. Condrashoff, S. F. Larval descriptions of Zeiraphera pacifica Freeman and Epinotia hopkinsana (Kearfott) (Lepidoptera: Oleth¬ reutidae). The Canadian Entomologist. 98(7):703-706; 1966 . Crumb, S. E. The larvae of the Phalaeni- dae. Tech. Bull. 1135. Washington, DC: U.S. Department of Agriculture; 1956 , 356 p. Eichlin, T. D.; Cunningham, H. B. The Plusiinae (Lepidoptera: Noctuidae) of America north of Mexico, emphasizing genitalic and larval morphology. Tech. Bull. 1567. Washington, DC; U.S. Depart¬ ment of Agriculture; 1978 . 122 p. Evans, David. A revision of the genus En- ypia (Lepidoptera: Geometridae). Annals of the Entomological Society of America. 53: 560-574; 1960 . Evans, David. Descriptions and life his¬ tory of Melanolophia imitata (Walker) (Lepidoptera: Geometridae). The Canadian Entomologist. 94(6): 594-605; 1962 . 61 Evenden, James C. Ellopia infestations within the Inland Empire, 1937. Coeur d’Alene, ID; U.S. Department of Agricul¬ ture, Bureau of Entomology and Plant Quarantine, Eorest Insect Investigations Laboratory; 1938 ; report. 9 p. Furniss, R. L.; Carolin, V. M. Western forest insects. Misc. Publ. 1339. Washing¬ ton, DC: U.S. Department of Agriculture; 1977 . 654 p. Hardy, George A. Notes on life histories of one butterfly and three moths from Van¬ couver Island (Lepidoptera; Lycaenidae, Phalaenidae, and Geometridae). Entomo¬ logical Society of British Columbia Pro¬ ceedings. 59: 35-38; 1962 . Hodges, Ronald W., et al. Check list of the Lepidoptera of America north of Mex¬ ico. London: E. W. Classey Ltd.; Wedge Entomological Eoundation; 1983 284 p. Lindquist, O. H. Keys to lepidopterous larvae associated with the spruce budworm in Northeastern North America. Sault Ste. Marie, ON: Canadian Eorestry Service, Department of the Environment, Great Lakes Eorest Research Centre; 1982. 18 p. MacKay, Margaret R. Species of Eupi- thecia reared in the Eorest Insect Survey in British Columbia (Lepidoptera: Geometri¬ dae). The Canadian Entomologist. 83(4): 77-91; 1951 . Markin, George P. Abundance and life cycles of Lepidoptera associated with an outbreak of western spruce budworm Chor- istoneura occidentalis (Lepidoptera; Tortri- cidae) in southeastern Idaho. Journal of the Kansas Entomological Society. 55(2): 365- 372; 1982 . McDunnough, James H. Revision of the North American species of the genus Eitpi- thecia (Lepidoptera, Geometridae). Bulletin of the American Museum of Natural His¬ tory. 93(8): 533-728; 1949 . McGuffin, W. C. Descriptions of larvae of forest insects: Syngrapha, Autographa (Lepidoptera: Phalaenidae). The Canadian Entomologist. 86(1); 36-39; 1954 . McKnight, M. E. Natural mortality of the western spruce budworm, Choristoneura occidentalis in Colorado. Res. Pap. RM- 81. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Moun¬ tain Forest and Range Experiment Station; 1971 . 12 p. Mutuura, Akira; Munroe, Eugene. American species of Dioryctria (Lepidop¬ tera: Pyralidae): 4. The Schuetzeella group and the taxonomic status of the spruce cone moth. The Canadian Entomologist. 105; 653-668; 1973 . 62 Obraztsov, N. S. Descriptions of and notes on North and Central American spe¬ cies of Argyrotaenia, with the description of a new genus (Lepidoptera, Tortricidae). Am. Mus. Novit. 2048. New York: Amer¬ ican Museum of Natural History; 1961. 42 p. Orr, P. W.; Pettinger, L. F.; Doiph, R. E. Forest insect conditions in the Pa¬ cific Northwest during 1964. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region; 1965. 90 p. Powell, J. A. Biological and taxonomic studies on tortricine moths, with reference to the species in California. Univ. Calif. Publ. Entomol. 32. Berkeley, CA: Univer¬ sity of California; 1964a. 317 p. Powell, Jerry A. A review of Griselda, with descriptions of a related new genus and two species. Pan-Pacific Entomologist. 40(2); 85-97; 1964b. Ross, D. A.; Evans, D. Annotated list of forest insects of British Columbia: Part 3— Eupithecia spp. (Geometridae). Entomo¬ logical Society of British Columbia Pro¬ ceedings. 52: 36-38; 1956. Stevens, Robert E.; Carolin, V. M.; Stein, Catherine. Lepidoptera associated with western spruce budworm in the Southwestern United States. Journal of the Lepidopterists’ Society. 37(2); 129-139; 1983. Volker, Kurt Carl. Ecology of parasites and predators of the Douglas-fir tussock moth in the Pacific Northwest. Moscow, ID: University of Idaho; 1978. 92 p. Ph.D. dissertation. Whiteside, J. M. Forest insect conditions in the Pacific Northwest—1956. Portland, OR: U.S. Department of Agriculture, For¬ est Service, Pacific Northwest Forest and Range Experiment Station; 1957. 40 p. Wickman, Boyd E.; Hunt, Richard H. Biology of the phantom hemlock looper on Douglas-fir in California. Journal of Eco¬ nomic Entomology. 62(5): 1046-1050; 1969. 63 • ■ " y f? f /, -*» 'ft 'jfv ■ T. u •' ' ■ ■• ■ 9>J‘' ^ * >• if .>^4 ‘ftf } • . ^ > -pM « |< ’ ,4 ' . < t ■ * . « .■ ',.,!l/'..' ,• v^v t • (i ^ ^ z *• * /r ' ./T — fj >; . • -v . j . • ■ r f •» I * ■• t ik ^ ^ -j'- i*s* . r' j I- *• ( ‘ 'ji . '"v 1 iK *'■; I'i .-'^r™ ^ *». 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'r■■ ♦4'^ 'J'* ' ■ J, ,y<' ' ■-; , t y .Ii r ^ ^ United States kjj) Department of ^ Agriculture Forest Service Cooperative State Research Service Agriculture Handbook No. 623 Spruce Budworms Handbook UNIVERSITY Of ILLINOIS PGRICULTORE LIBRARY How To Distinguish Between Old and New Egg Masses of the Western Spruce Budworm Contents In 1977, the United States Department of Agriculture and the Canada Depart¬ ment of the Environment agreed to cooperate in an expanded and accela- rated research and development effort, the Canada/United States Spruce Bud- worms Program (CANUSA), aimed at the Spruce budworm in the East and the western spruce budworm in the West. The objective of CANUSA was to de¬ sign and evaluate forests, to help forest managers attain their objectives in an economically and environmentally ac¬ ceptable manner. The work reported in this publication was funded by the Pro¬ gram. This manual is one in a series on the western spruce budworm. Introduction. ^ Handling Branches. 3 Examining Branches. 4 What To Look For. 4 Literature Cited. 7 4 canu/a Canada United States Spruce Budworms Program May 1984 [ow To Distinguish Between Old I nd New Egg Masses of the Western i pruce Budworm y Daniel B. Twardus* and V. M. Carolin^ introduction ampling egg masses of western spruce jdworm (Choristoneura occidentalis reeman) is an accepted method of itimating population density and redicting population trend (Buffam nd Carolin 1966, Carolin and Coulter 972, McKnight and others 1970). One . ritical aspect of the sampling is : istinguishing between newly deposited lew) egg masses and those from revious years (old). n spruce budworm (C. fumiferana Clemens]), Morris (1955) observed nat sampling error can be introduced ly the mistaken inclusion of old egg nasses as new; retention of egg masses in foliage from one year to the next was is high as 20 percent. Buffam and •Carolin (1966) reported that many vestem spruce budworm egg masses ire retained, especially in drier areas. This observation led to their levelopment of population-trend prediction based on old and new jgg-mass ratios. Estimates of budworm population density should be based on sampling the ipurrent year’s egg masses only and should exclude the egg masses deposited during previous years. To do his consistently, foliage collectors and examiners must be trained to follow :ertain precautions and guidelines. ' Entomologist, U.S. Department of Agriculture, Forest Service, Pacific Northwest Region, P.O. Box 3623, FPM, Portland, Oreg. 97208. ^ Consulting Entomologist, Portland, Oreg. Handling Branches Branches must be handled properly before and during examination; • Do not let clipped branches touch bare ground. Road dust can make new and old egg masses practically indistinguishable. • Attach basket to the pole pruner so clipped branches do not fall through the crown or onto the ground. • Transport branches carefully, preferably in heavy paper sacks or cardboard boxes. Plastic bags are not appropriate because they do not allow moisture to escape. • Pack containers loosely to prevent damage to the egg masses. Egg masses are easily crushed or rubbed off the needles. • Store branches for no mor'* than 3 to 5 days prior to examination. • Always store in a refrigerator or cool place (at temperatures less than 50° F, 10° C) to prevent drying and molding. Mold can hide the distinguishing characters and prevent identification. 3 Figure 1—Unhatched, greenish, western spruce budworm egg mass. Examining Branches Initial foliage examination to find egg masses is best done in a well-lighted area using desk-top magnifiers. Egg masses can be found more easily under ultraviolet light because they fluoresce, but ultraviolet does not help distinguish new from old egg masses. To distinguish new from old egg masses, experienced egg-mass examiners commonly use a dissecting microscope that magnifies 7 to 10 times, with a black or dark stage. The dark background provides contrast against the white egg mass. Egg masses collected soon after deposition are green, unhatched (fig. 1), and readily distinguished without magnification. Figure 2—Newly hatched western spruce budworm egg masses, showing variation in color,! fullness, and condition. What To Look For The principal characteristics of hatched new (fig. 2) and old egg masses are listed (table 1) in order of their value for identification. To identify new and old egg masses: • Separate current from previous years’ foliage while the needles bearing egg masses are being plucked from the branch. Because new egg masses can be deposited on old as well as current needles, this separation will not identify all new masses but you will know, at least, that those on current needles are new. Use of this characteristic assumes, however, that you are certain about the age of the foliage. • Look for unhatched eggs and the remains of a yolk ring. The yolk ring in new egg masses will appear as specks of orange, yellow, or sometimes Figure 3—Range of egg-mass characteristics likely to be encountered (left to right): green, unhatched egg mass; partially hatched; new, parasitized; newly hatched; and egg mass from the previous year. green. Any tinge of green in the egg mass indicates a freshly deposited egg mass. • Check for dead larvae in the egg mass. In a new egg mass, the larval remains are green or yellow. In an old egg mass, they are brown to black. From here on, separation of new and old egg masses becomes increasingly subjective. Thus, handling and transporting the branches carefully is essential. In particular, avoid crushing the new egg masses, which destroys the characters that distinguish new from old. • Look at the fullness of the whole mass. A new one, although hatched, is more upright and full than an old one that has had time to collapse (fig. 3). • Examine egg-mass surface. A new egg mass is somewhat transparent and has a slight lustre; old ones are dull, often gray to cream colored. Mold may cause a surface stain on the egg mass. Magnification and good light help to show differences in the surface. Again, proper handling of the branches is vital; if they become dusty from lying on the ground or are stored for more than a few days before being examined, differences in surface appearance are not reliable. • Look under the egg mass for signs of staining. Bacteria acting upon Table 1—Characters that distinguish new and old egg masses of western spruce budworm Character New egg masses Old egg masses Location on branch On current and older needles On older needles only Unhatched eggs and yolk ring Green to yellow Eggs brownish, yolk ring bleached white Dead larvae in eggs Head capsules dark brown, bodies green to yellow orange Head capsules light brown, bodies brown to black (larvae rarely present) Surface Pearly white to somewhat transparent; clean, but may have superficial dust Dull or discolored, grayish white or cream colored Fullness of egg mass Usually upright Partially to totally collapsed with shrinkage at edges Needle staining beneath egg mass Never stained Occasionally, yellowish stain beneath the egg mass the adhesive secreted with the eggs sometimes—but not always—produce a stained area on the needle beneath an old egg mass. New egg masses never have such stains, unless the foliage has been stored for excessive periods. An experienced observer should make the actual determinations. Collecting needles that bear old egg masses before new egg masses are deposited can provide excellent training for inexperienced observers. Attention to the characters described will eliminate some of the subjectivity in distinguishing between new and old egg masses. Because no absolute distinguishing criteria are known, we recommend using all of the characters together, not one at a time. 6 literature Cited Buffam, P.; Carolin, V. M. Determining trends in western spruce budworm egg populations. Journal of Economic Entomology. 59(6): 1442-1444; 1966. Carolin, V. M.; Coulter, W. K. Sampling populations of western spruce budworm and predicting defoliation on Douglas-fir in eastern Oregon. Res. Pap. PNW-149. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station; 1972. 38 p. McKnight, M. E.; Chansler, J. F.; Cahill, D. B.; Flake, H. W., Jr. Sequential plan for western budworm egg mass surveys in the central and southern Rocky Mountains. Res. Note RM-174. Ft. Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station; 1970. 8 p. Morris, R. F. The development of sampling techniques for forest insect defoliators, with particular reference to the spruce budworm. Canadian Journal of Zoology. 33(4): 225- 294; 1955. 4 \ I i ^ United States , ijij Department of Agriculture Forest Service Cooperative State Research Service UNIVERSITY Of ILLINOIS Spruce Budworms Handbook sSno 624 Ground-Spray Techniques To Reduce Damage From Western Spruce Budworm Contents In 1977, the United States Department of Agriculture and the Canada Depart¬ ment of the Environment agreed to cooperate in an expanded and accela- rated research and development elfort, the Canada/United States Spruce Bud- worms Program (CANUSA), aimed at the spruce budworm in the East and the western spruce budworm in the West. The objective of CANUSA was to de¬ sign and evaluate forests, to help forest managers attain their objectives in an economically and environmentally ac¬ ceptable manner. The work reported in this publication was funded by the Pro¬ gram. This manual is one in a series on the western spruce budworm. Introduction. 3 Insecticides, Mixing, and Safety Precautions . 3 Selecting Spray Equipment. 4 Timing and Application. 5 Literature Cited. 7