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De ‘ 3) Bas oS 49 ree Re Bass HSN Ses eae aS : SH SAY Noss Raa Bais od ae a 3 BER S > 5 ee iS S2o2> ) 5 S Saas ass 4 a5 as i ac5 ise S55 eats oe ES aS Ses au S i i sd EB ae Sas eae ares ie < Sree a i Sat aaa exes ates Bk Fates 2 . asy ies 5 >: baer Sia SLs 3 3 St sy Sone Sasa 35 ee BS Scie) Sates aaa zee essere 4 2 Siena 32 74g Neaatae ASRS: eset as eae Reeve! ees ee Meidteas Steinert enone i S COO OER Soe NS SOO RECS aaa as Paveoree ie ae Sree A Rae eS Reece RRR Paka ean Se Vet A ties We ee etna % ‘ eee Leet atone PETER IIS S oo VN el io i i a j 2 y NA | Htate College of Agriculture At Cornell Anibersitp Sthaca, N. D. Librarp Cornell University Library Entomology(Miscellaneous publications] U.S. DEPARTMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY—BULLETIN NO. 58, Part II. L. O. HOWARD, Entomologist and Chief of Bureau. 4h 33 SOME INSECTS INJURIOUS TO FORESTS. THE WESTERN PINE-DESTROYING BARKBEETLE. BY J. L. WEBB, Special Field Agent, Forest Insect Investigations. Issuep Avaust 18, 1906. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1906. LETTER OF TRANSMITTAL. U.S. DeparRTMENT OF AGRICULTURE, Bureau oF ENntTomotoey, Washington, D. C., May 28, 1906. Sir: I have the honor to transmit herewith the manuscript of a contribution, by Mr. J. L. Webb, on the Western Pine-destroying Barkbeetle. It has special reference to the results of investigations by Mr. Webb in central Idaho in 1905, but relates also to the results of other investigations and to available information on the insect and methods of combating it. JI recommend its publication as Part IT of Bulletin No. 58 of this Bureau. The figures and plates are neces- sary for the illustration of the text. Respectfully, L. O. Howarp, Chief of Bureau. Hon. James WILson, Secretary of Agriculture. III CONTENTS. Tnitroduction:..3.455 20542. aynkacemocce aa Seon cee ye ee ee Death of the pine caused by the western pine-destroying barkbeetle.............. Character of the insect and its work... -... 22.2... 2.2222 ee ee ee eee ee ee eee Dist PibUbION esse sit einem ess Sialic iad eget ee hee haere tye fui Extent of damage and losses.........-..-...-------- 2-22-22 eee ee ee ee eee eee Possibilities of preventing losses......... 2.22222 20 02sec e eee ee cece cece ee eeees Early history of the species.......-...-. 20-2222 eee eee ee ee ce eee eee Observations by Hopkins, 1899-1904............-0---- 220-222-222 ee eee eee eee Observations by H. E. Burke, 1904. ..-.-...-.-- 2212-22-22 eee ee ee ee ee eee eee Observations by the writer, 1905.........--.-. 22-22-2222 ee ee eee ee ee ee ee eee Life history and habits of the insect...........-...-2------2---2-------+--- LIDEIMA BION: Sree bceane Aes ot. seat hal eevee soe SSR oceans First generation....... 2.0... -2222ecccecececececececeeececeeeeeeees Secolid Peneration wc iacsuss cio. seciatace sein ecse vs)stesaae cee sees e aes Methods of combating the insect......-.-..----.---------- +--+ ++ ee eee eee eee First recommendations. -.-.........-.-------- 2-0-2 - eee ee eee eee eee eee Storm-felled and lightning-struck trees...........---------.-------- 22 -e eee Publications relating to the western pine-destroying ‘parkbeetle........ sjecieias Saws ILLUSTRATIONS. PLATES. Pirate II. Work of the western pine-destroying barkbeetle in bark, removed from killed tree; also faint marks on surface of wood....--.--...-.-.----- III. Work of the western eens barkbeetle, removed from killed tree... Slender be fokepoe eters ial dat ste vars averaturstebarst od Ghoweedavoremei cusp? TEXT FIGURES. Fic. 7. The western pine-destroying barkbeetle (Dendroctonus brevicomis): adult male and female and details........-...-. 22 cele eee ee eee eee eee 8. The western pine-destroying barkbeetle (Dendroctonus brevicomis): galleries in'the inper bark... 5.200 ceecen someon ees seammesnccncs te esinieeece 9. The western pine-destroying barkbeetle (Dendroctonus brevicomis): larva. 10. The western pine-destroying barkbeetle (Dendroctonus brevicomis): pupa... 11. The western pine-destroying barkbeetle (Dendroctonus brevicomis): pitch tubes on bark of tree..... 2.2... e ee ee eee ce ee ee ee eee eee ecee 12. The western pine-destroying barkbeetle (Dendroctonus brevicomis): hiber- nating or transformation cell, exit burrow, exit holes, pitch tubes....... VI Page, 18 18 18 19 20 25 26 U.S. D. A.,B. E. Bul. 58, Part IT. F.1.1., August 18, 1906. SOME INSECTS INJURIOUS TO FORESTS. THE WESTERN PINE-DESTROYING BARKBEETLE. (Dendroctonus brevicomis Lec.)a@ By J. L. Wess, Special Field Agent, Forest Insect Investigations. INTRODUCTION. The object of this paper is to give available information on this insect and methods of combating it, with special reference to the results of investigations by the writer during the summer of 1905 in central Idaho. The need of the investigations was suggested in a letter dated August 10, 1904, from Mr. Gifford Pinchot, forester of the U. S. Department of Agriculture, to Dr. L. O. Howard, chief of the Bureau of Entomology, as follows: Tlearn from the Payette Lumber and Manufacturing Company, one of the Weyerhaeusers, whose land lies on the Payette River north of Boise, that the pine in their holdings is said to be dying from the attacks of insects. If it were possible for you to assign Doctor Hopkins, or one of his assistants, to make examination of this region, unless it has already been done, Ishould greatly appreciate it, and I should likewise appreciate your sending to Mr. Edgar M. Hoover, general manager of that company at Boise, any information you may have bearing on this subject. In response to this request the matter was referred by Doctor Howard to Dr. A. D. Hopkins, in charge of forest insect investigations, for attention, and Mr. H. E. Burke, an assistant, was instructed to make preliminary investigations in October of the same year. In May, 1905, the writer was assigned to this work, with instructions from Doc- tor Hopkins to make a detailed study of the forest insects of the region, with special reference to determining the following points: (1) The relation of the several species of insects to the dying of the trees; (2) the number of species involved, the relation of each to primary and secondary attack, and the life histories of the primary and secondary enemies; (3) the extent of the infested area, the percentage of timber killed each year during the past two or three years within given areas, the approximate losses, etc.; (4) the relation of logging operations to a Order'Coleoptera, family Scolytide. 17 18 SOME INSECTS INJURIOUS TO FORESTS. depredations by insects in adjoining forests, and the relation of time of felling timber in regular logging operations to attack by Dendroc- tonus and other bark and wood boring insects. Accordingly, investigations were begun by the writer on May 17, 1905, with headquarters at Centerville, Idaho, and continued until October 10, 1905. DEATH OF THE PINE CAUSED BY THE WESTERN PINE- DESTROYING BARKBEETLE. Observations by the writer served to confirm the conclusion of Mr. Burke that the primary enemy was a barkbeetle identified by Doctor Hopkins as the western pine-destroying barkbeetle (Dendroctonus brevicomis Lec.). CHARACTER OF THE INSECT AND ITS WORK. The adult insect is a stout, brownish-winged beetle (fig. 7) from one-eighth to three-sixteenths inch in length, which attacks the living trees in swarms, and burrows into the living bark, through the inner layer of which- each female excavates wind- ing galleries (fig. 8 and Pls. TI, IIT) in which to deposit eggs. These galleries serve to cut off the natural movement of the sap and com- pletely girdle and kill the tree. In the vicinity Fic. 7—The western pine-destroying barkbeetle (Dendroctonus of Centerville, Idaho, brevicomis): a, adult female; db, ¢, d, details of punctuation; e, the eggs, deposited dur- adult male. Natural size at left (original). ing June July or Au- Oo ? ? gust, in little niches in the sides of the galleries, hatch within 4 or 5 days into small whitish larve (fig. 9), which mine at right angles from the primary gallery through, the outer layers of the inner bark until they have completed their growth, which requires from about 20 to 30 days. They then bore into the outer corky bark (fig. 12, a) where they excavate little cells in which to transform, first to the pupa (fig. 10) and later to the adult. When the broods of the first genera- tion have thus developed—in about 60 or 70 days—they bore out through the bark and fly to other trees to repeat the process and con- tinue their depredations. The presence of this destructive insect in a forest is indicated (1) by dead and dying trees scattered about or in clumps or large patches. (The dying ones, with fading yellowish and reddish foliage, are called Bul, 58, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE II. WoRrRK OF THE WESTERN PINE-DESTROYING BARKBEETLE IN BARK, REMOVED FROM KILLED TREE; ALSO FAINT MARKS ON SURFACE OF Woop. (ORIGINAL.) Bul, 58, Bureau of Entomology, U.S. Dept of Agriculture. PLATE III. WORK OF THE WESTERN PINE-DESTROYING BARKBEETLE, REMOVED FROM KILLED TREE. (ORIGiNAL.) THE WESTERN PINE-DESTROYING BARKBEETLE. 19 “sorrel tops,” and the dead ones, with reddish-brown foliage, are called ‘‘red tops,” or, if with bare branches or broken tops, are known as “black tops” or “broken tops;’’¢ (2) by small masses of resin (pitch tubes, figs. 11 and 12, c) in the crevices of the bark of recently attacked living trees, as well as in those of the dying and dead "| ones; and (3) the i | presence of the (| | iY species is deter- ‘i | | mined by remov- Fig. 8.—The western pine-destroying barkbeetle (Dendroctonus brevi- comis): Galleries in the inner bark. (Original.) VAP 011TH 1 nil | y | . \ i f || ; 1 * || | | bs | kh A, |——————} ing the bark from the dying and dead trees and finding the characteristic galleries (fig. 8 and Pls. II, III). It must be remembered, however, that there are many different kinds of insects, some of them closely resembling the destructive species, always found in dying pine trees. Therefore, for the general observer to be positive in the matter, specimens of insects and work should be sent to the Bureau of Entomology for authentic identifi- cation. . DISTRIBUTION. The insect is found in southern Idaho throughout, and its range extends to the northern part of the State. It is recorded from Cali- fornia, Oregon, and eastern and western Washington, and, according to Doctor Hopkins, a variety occurs in Arizona and New Mexico and attacks the western yellow pine (Pinus ponderosa) and the sugar pine (Pinus lambertiana). EXTENT OF DAMAGE AND LOSSES. With our present knowledge of the destructive work of this insect, it is evident that a vast amount of timber has been killed by it during the past ten years within the range of its distribution. It is estimated that each year for the past two or three years, from 2 to 5 per cent of the matured standing bull pine timber within the section investigated in the summer of 1905 has died as the result of its ravages. POSSIBILITIES OF PREVENTING LOSSES. With our additional knowledge of the life history and habits of the beetle, we are able to suggest practical methods of controlling it and of preventing a large percentage of the losses heretofore caused by its depredations. : a See Bul. 56, Bur. Ent., U. S. Dept. Agric. The Black Hills Beetle. 20 SOME INSECTS INJURIOUS TO FORESTS. EARLY HISTORY OF THE SPECIES. LeConte, in 1876, described the species under the name Dendroc- tonus brevicomis from a single specimen collected in middle California. Dietz, 1890, considered D. brevicomis the same as the southeastern species, D. frontalis Zimm. Hopkins, 1899, concluded that it was distinct from D. frontalis, and therefore that the old name should be retained. It appears that previous to 1899 nothing had been recorded in regard tothe habits and life histony of this insect, and that, therefore, the earliest records were made in 1899 by Hopkins, who found it associated with dying sugar pine and western yel- low pine at McCloud, Cal., on April 21, 1899, and the next day at Grants Pass, Oregon, with several hundred pine trees which had evidently died from its attack. On May 20, also, at Buckeye (near Spo- kane), Wash., many trees were found Fic. 9.—The western pine-destroying - a . A barkbeetle (Dendroctonus brevicomis) : which were dying, or had died, as evl- Larva, Line below represents natural qdenced by the abundance of the insects length (original). : ee and the extent of their work, and onJune 6, at Cedar Mountain, Idaho, Doctor Hopkins found it in the bark of pine trees which had been defoliated the previous year by the cater- pillars of the pine butterfly (Neophasia menapia Feld.). He found also that this beetle was quite intimately associated with the destruc- tion of a large amount of timber only partly defoliated by the cater- pillars. Under his discussion of the principal scolytid enemies of the forests in the Northwest, Doctor Hopkins refers to this species as follows:* — Dendroctonus brevicomis Lec. was found to be a most destructive enemy of the yellow pine (Pinus ponderosa) in northern California, southern and eastern Oregon, northeastern Washington, and western Idaho. A large amount of some of the finest timber in all of these localities had died within the past seven or eight years, evidently as a direct result of attacks by this bark beetle —1t was also found to attack and prevent the recovery of trees injured by defoliating insects and other causes. Its habits and the character of its galleries appear to be identical with those of Dendroctonus frontalis, which is noted for its destruction of vast quantities of pine and spruce timber in West Virginia and adjoining States between 1890 and 1893. It is killmg the western yellow pine just as D. fronialis commenced to kill the eastern yellow pine (Pinus echinata) before it spread to all the other pines and spruce. Therefore, just as D. frontalis has proven to be the most destructive enemy of eastern conifers, the western representative of this species will doubtless prove to be, under similarly favorable conditions, equally as destructive to Nhe western forests in which the conifers predominate. ‘ Among the most important features observed regarding the habits of this beetle was the fact that it is attracted to trees girdled by settlers and farmers in the process of clearing land, and that in the bark of such trees it breeds and multiplies in sufficient numbers to enable it @ Bul. 21, n.s., Div. Ent., U.S. Dore, A; 190nn THE WESTERN PINE-DESTROYING BARKBEETLE. 21 to attack and kill the timber in adjoining healthy forests. Indeed, my observation leads me to conclude that a considerable number of girdled pine trees may easily form a nucleus for a destructive invasion by it. In the same bulletin, under the head of “The western yellow pine,” he says: It has in Dendroctonus brevicomis a most pernicious enemy, which penetrates and exca- vates winding galleries through the living bark of the finest trees, thus speedily causing their death. Very many trees have died and are dying from this cause, and the dead ones are contributing to the spread of forest fires. Specimens of the insect and its work occupied a prominent place in the exhaustive exhibit of insect enemies of forests and forest products at the Louisiana Purchase Exposition at St. Louis, in 1904, and the Lewis and Clark Centennial Exposition at Portland, Oregon, in 1905, and were referred to in the catalogues of the exhibits by the Bureau of Entomology.* OBSERVATIONS BY HOPKINS, 1899-1904. The following summary relating to this species, prepared by Doctor Hopkins from his field notes, includes many facts which have not been published and which have a direct bearing on the life history and habits of the species in different sections of the country where it is found: McCloud, Cal., April 21, 1899.—Work and dead adults were dis- covered in a sugar pine log, evidently from a tree which was dying when felled; also dead parent adults in primary galleries, and larvee and pup abundant in outer bark of large dying western yellow pine with the characteristic appearance of eastern pines when dying from the attack of the destructive pine barkbeetle, D. frontalis. A few imma- ture adults were found in the outer bark, and evidence that some had emerged. This evidence was in the form of apparent exit holes in the bark, which may have been ventilating holes from main galleries, for with our present knowledge it is not likely that any adults could have emerged so early. ‘ Grants Pass, Oregon, 1899.—On April 24 numerous dying western yellow pine trees were found here scattered through the forest where a severe windstorm had blown down much large timber on Septem- ber 24,1895. Young adults, larvee, and pups were found in the outer bark of the standing trees which had evidently been attacked and had commenced to die the previous fall. April 25, numerous trees were observed which died the fall before and others which were not yet dead. One group of 30 young trees about 2 miles north.of town were dying at the top, the leaves turning yellow and brown. All trees, without exception, were either infested or had been infested with D. brevicomis, and every indication pointed to this species as primarily to a Buls. 48 and 53, Bur. Ent., U. S. Dept. Agric. 22 SOME INSECTS INJURIOUS TO FORESTS. blame for the trouble. There were many trees which had been dead for from 3 to 10 years, and in the bark of those dying within the past 4 years traces of the characteristic galleries of D. brevicomis were found. No large bodies of timber had died, but the dead and dying trees were scattered all through the forest. A few examples of adults were found mining in living bark of a dying tree, where they had evidently passed the winter, since none of the broods had sufficiently matured to emerge. April 26, eight large trees—five western yellow pine and three sugar pine—which had evi- dently died in 1897, were observed in the Slate Creek Valley. The western yellow pine exhibited abundant work of Dendroctonus brevicomis, and the sugar pine the work of both this and a larger species of the same genus (D. monticolz). Buckeye, Wash. (near Spokane), May 22.—A small western yellow pine tree, evidently killed by the in- Fic. 10.—The western pine-destroying bark- sects, was found. None of the brood ventral view; same, dorsal view. ver. bad emerged, having died in the bark, tical line in center represents natural possibly from the effects of unfavor- engihi fonginal): able climatic conditions. In another tree killed by this species at this place, young living adults were found.” Cedar Mountain, Idaho (near Moscow), June 4.—The bark of western yellow pine trees defoliated by pine butterfly larvee was found to be infested by larvee and pupx of D. brevicomis. Dead parent adults, also, were found in the primary galleries. Marvposa County, Cal., June 9, 1904.—Fragments of dead adults were found in primary galleries in bark of a large western yellow pine tree, evidently killed by this species. Yosemite Valley, California, June 13, 1904.—Western yellow pine trees cut between September 20 and 24, 1903, were found to be thickly infested with larvee of this species from eggs evidently de- posited in September or October, OBSERVATIONS BY H. E. BURKE, 1904. From October 20 to 26, 1904, Mr. Burke found the work of this species on western yellow pine quite abundant in the region of Smiths Ferry, Idaho. Under date of October 26 he records observations regarding this barkbeetle in a western yellow pine tree 3 feet in diam- eter felled some time during that summer; the foliage and bark were living, but red borings on the bark showed where insects had entered. Adults of the Dendroctonus Were priests oi rarcurn cece we THE WESTERN PINE-DESTROYING BARKBEETLE. 23 in the living inner bark, two adults to a gallery. Eggs occurred singly in niches on the sides. He estimated that as a result of the work by this insect near Smiths Ferry 30 per cent of standing timber was dead and 5 per cent was dying. This was at the worst point of infestation, but scattered dying timber was found all over Boise and Payette basins. The same con- dition extended into the Bitter Root Forest Reserve. OBSERVATIONS BY THE WRITER, 1905. The investigations by the writer during the summer of 1905, so far as they related to this species, were mainly for the purpose of deter- mining the principal facts in its life history and habits in the vicinity of Centerville and Smiths Ferry, Idaho, The results may be sum- marized as follows: LIFE HISTORY AND HABITS OF THE INSECT. HIBERNATION. While it is probable, as observed by Hopkins at Grants Pass, Oregon, that a few parent adults which enter the bark in the fall may pass the winter in that stage, it appears that it is in the young to matured larval stages that the insect normally passes the winter, each individual in a separate mine or cell in the outer corky bark of the tree in which it developed the previous summer and fall. The ear- liest observations at Centerville were made on May 18, when larve, pup, and young adults were found. Some of the larve were small, but the majority of them were mature and ready to change to pupe. The pup and adults had evidently transformed from larve since the beginning of activity in the spring. The latest date on which larve of the hibernating broods were found was June 13. Pupz were found as late as July 3, and adults July 7. Itis therefore evident that the majority of the over-wintering broods develop to the adult stage by about the middle of June, but broods from eggs deposited late in the fall may not develop until nearly the middle of August. Adults begin to emerge in the latter part of May and continue to do so through June and July and into August. Thus the period of activity of the hibernating broods at Centerville is probably from the first warm days in April and May until about the last of July—approximately 90 days—the majority, however, coming out in June and in early July. FIRST GENERATION. The first generation at Centerville begins with the first eggs depos- ited, apparently about the last of June, by the adults developed from hibernating larve and pupx. These eggs hatch in about 4 days after deposition. The principal egg-laying period for this generation is evidently between the latter part of June and the first part of August. 24 SOME INSECTS INJURIOUS TO KORESTS. It would appear that the length of time spent in the larval state is from 31 to 35 days. Sometimes, however, a few individuals of this first generation, either from retarded development or other causes, do not go through their transformations with the rest of the broods, but remain as larve all through the fall and winter, evidently chang- ing to pupe in the following spring. The length of time spent in the pupal stage is approximately 15 days. Pupe of this generation were observed in different broods from August 14 to September 6. The first adults, evidently of this generation, were observed in the bark August 14. The length of time spent in the bark after reaching this stage appears to be from 7 to 14 days. It is difficult to tell just when the emergences cease, as the last individuals of the brood come out scatteringly. Thus, on October 10 a few adults were still found in the bark. As this was the last observation, it is not known whether adults emerged later in the fall or whether they passed the winter in the bark before emerging; but the latter was probably the case. In one tree under observation eggs were deposited July 6 and the broods developed and emerged by August 28, a period of 53 days. Thus it appears (1) that the first generation begins with eggs deposited probably in the latter partof June; (2) that the majority of the broods develop and emerge by the first part of September (a period of about 60 days), but that some may continue to develop and emerge until in October; and (3) that possibly some pupx and young and matured adults may hibernate along with the larve. Thus it may require 300 to 390 days or more for the complete development and emergence of some individuals of the first generation. SECOND GENERATION. Eggs deposited by adults of what appears to have been the first generation were found August 26 and as late as September 13. It will therefore be seen that there is a partial overlapping of the periods of the two generations. Larve were found as early as September 4, and on October 10, when the last observation was made, some larve were apparently full grown. No pupe or adults of this generation were found up to the time of the writer’s last observations—on October 10, 1905. Mr. Burke found adults, but probably of the first generation, excavating galleries and depositing eggs as late as October 26,1904. Thus it appears that the second generation, beginning with the first eggs deposited by adults of the first generation, passes the winter in the larval stage and develops and emerges by the middle of the following June to the first part of July. It therefore occupies a period of about 315 to 330 days, includ- ing about 60 days of activity in the fall, 165 days of hibernation, and 90 to 105 days of activity in the spring and earlv snmmer THE WESTERN PINE-DESTROYING BARKBEETLE. 25 It is probable that at higher elevations and farther north the majority of the broods would not develop in much less than a year’s time and that at more south- ern and warmer localities in the Pacific Coast region there would be two complete generations and possibly a partial third. HABITS. When first transformed, in May and June, the young bee- tles have very soft, delicate tis- sues. They therefore remain in their pupa cases until their bodies are fully hardened or chitinized. When nearly ready to emerge, the adults bore their way almost to the surface of the bark (fig. 12, a), but pause before emerging, appearing to rest in the burrows they have just made. They do not, how- ever, hollow out the space im- mediately adjoining the pupa case, as is the habit of another species of this genus. When quite ready to emerge, the bee- tles continue their burrows out through the remaining portion of the bark. The individuals of a brood do not appear to emerge simultaneously, but they come forth at irregular in- tervals until all are out, leaving the bark thickly punctured with small, round, clean-cut’ holes, as shown in figure 12. After leaving the tree or trees in which they went through f A eae eee? their fade eho the bee- we NOU NAL ae ee tles fly away to find trees in F.g. 11.—The western pine-destroying barkbeetle which to deposit eggs. They (Dendroctonus brevicomis): Pitch tubes on bark of may select trees close at hand = ‘®* (On8insl) or may fly quite a long distance before making aselection. They will also enter the living bark of recently felled trees. Large numbers of SSS = ss — 26 SOME INSECTS INJURIOUS TO FORESTS. the beetles usually settle upon a few trees close together and crawl about upon the bark from near the base to about two-thirds of the distance to the tree’s top, seeking suitable places for entrance. Crev- ices in the bark are favorite places with them for this purpose. The female appears to bore the entrance hole in the bark, and may or may not be closely followed by her mate. In some cases where gal- leries had just been started, females were found alone, that is, one female to a single gallery. In others, the female was followed by the male. As the first incision is made into the living inner bark, the tree begins exuding pitch to cover the wound made by the intruding beetle. This pitch or resin collects at the mouth of the entrance hole in the form usually known as a pitch tube (figs. 11 and 12, c). Where the attacking force of beetles is small, the efforts of the tree to heal these wounds not infrequent- ly succeed, the flow of pitch being so great as to overcome and suffocate the beetles. In such cases the dead beetles may be found in the pitch masses after the tree has re- covered. Where.the attack- ing force is large, however, the flow of pitch does not se- riously hinder the beetles. After completing the egg lay- ing, the parent adults remain for some time in the galleries and excavate irregular Fic. 12.—The western-pine-destroying barkbeetle (Den- branching burrows toward citset bata: mee eae sa eeemmice_ the end farthest from the en- (Original.) trance, where they remain until they die. After successfully effecting their entrance into the bark, th> females excavate, through the inner layer of bark, winding, irregular galleries, which run into and cross each other many times (fig. 8). The eggs are laid at the sides of the gallery, each in a little niche hollowed out to receive it and packed in with the borings made in excavating the gallery. Almost immediately after hatching the larva begins feeding upon the cambium surrounding the niche in which it hatched. For a few days it remains in the cambium, then bores out toward the outer bark. As it progresses, it is at the same time growing, and this growth is indicated by its constantly widening mine or burrow, which THE WESTERN PINE-DESTROYING BARKBEETLE. 27 is made larger to accommodate the size of the body. Having reached the outer bark, it hollows out an oval space or pupa case, in which to go through its transformations. NATURAL ENEMIES. INSECTS. Larve of the predaceous beetles of the genus Clerus, which are known to prey upon Dendroctonus larve, were quite common in and under the bark of the infested trees, and they doubtless help to some extent in keeping down the numbers of the barkbeetles. BIRDS. Birds contribute their part also in destroying larve and pupe. The work of woodpeckers was found upon most of the trees which had been killed by D. brevicomis, and these birds had evidently destroyed a large percentage ot the insects in some of the trees. METHODS OF COMBATING THE INSECT. FIRST RECOMMENDATIONS. The following information and recommendations relating to this insect and methods of preventing losses from its ravages were conveyed by Doctor Hopkins to Mr. E. M. Hoover, of Boise, Idaho, manager of the Payette Lumber and Manufacturing Company, in a letter dated January 23, 1906, and afterwards published, with Mr. Hoover’s reply, in a local newspaper. Our special field agent, Mr. J. L. Webb, has submitted his report on forest insect investi- gations in the vicinity of Centerville and Smiths Ferry, Idaho, during the past summer, and it will interest you no doubt to know that the insect which is primarily to blame for the death of pine trees was located and thoroughly studied by him. He found that the broods of the destructive species pass the winter in the grub state in the bark of trees which died during the late summer and fall and that they do not transform to the v:inged form and emerge until after the 1st of May. Therefore the method of combating the pest is simply to cut the infested trees any time between the Ist of October and the 1st of May and to remove the bark from the main trunk and burn it. It is necessary to burn the bark in order to kill the broods of this insect, because they occupy the intermediate portion between the inner surface and the outer scale portion; hence the drying of the removed bark will not kill them as it would if they occupied the inner moist portion. The infested trees can be located (1) by the yellowish and light reddish brown color of the foliage; (2) by cutting into the bark as high up on the trunk as a man can reach with an ax to determine whether the middle portion of the bark is infested with the smal! white grubs, which are about three-sixteenths of an inch long. If these are found, it will be conclusive evidence that the tree has been killed by the beetle and is infested with its broods. It must be remembered that there are hundreds of other kinds of insects which occupy the inner por- tion of the bark and wood of such trees, but none of the smaller ones pass the winter in the outer bark. * * * Perhaps the most important thing for you to do asa preliminary to any definite action you may take in the matter is to have a number of intelligent cruisers make a survey of your holdings for the purpose of locating the principal sections in which trees have died during the 28 SOME INSECTS INJURIOUS TO FORESTS. past summer and the location of the larger clumps and patches of infested trees within such sections; then, if the locations of the infested areas and clumps are indicated on a map, it will aid materially in planning effectual operations. If you could conduct your logging opera- tions in these sections and utilize the infested trees the desired results would be accomplished without much expense. It is not necessary that all scattering infested trees should be felled and barked, but it is of the greatest importance that all of the larger clumps and patches within the worst infested areas should be thus treated within the period mentioned. If this can not be done this year, the work of locating infested areas should be conducted next sum- mer (1906), in order that the more im portant sections may receive attention next fall and winter. We shall hold ourselves in readiness to give you further information and suggestions on subjects which may not be clear to you, and whenever there is doubt about the insect or its work specimens should be sent to us for authentic identification. In response to this letter, Mr. Hoover wrote: We are most gratified with the information given us and feel that it will be of much value to us in our woods operations. “* * * : The ferreting out of the insect pest and advising a way to combat it is a work of great value to the country and of especial interest to all persons interested in forests, and we wish to add our word of appreciation of the service of your Bureau. Your letter is clear and explicit, and we will be glad to take advantage of your suggestions in our logging operations and have conveyed the information to other lumber companies operating in this vicinity. Doctor Hopkins has, since then, prepared the following additional recommendations and summary: TRAP TREES. With our present knowledge of the life history of the western pine- destroyer and its habits of attacking girdled and felled trees, it is evi- dent that trap trees* may prove effective in keeping the insect under control, especially in localities where only a few trees are being killed each year or after a large number of the infested trees have been felled and barked in a badly infested locality. The time to girdle and fell trees to catch the first generations would be about the middle of June, the bark to be removed and burned in about 20 to 25 days, or before the broods emerge. Girdled or dead- ened trees are prepared by the ‘‘girdle to heartwood” method—that is, cutting through the sapwood all around the trunk 3 or 4 feet above the base or as high above the base as convenient to chop; for this pur- pose large, inferior trees should be selected. Felled trees should be lodged or allowed to fall on logs, rocks, etc., so that the prostrate trunks will be as far as possible from the ground. Trees prepared in this manner will usually be attacked by swarms of the beetles, which will excavate galleries in the bark and deposit their eggs. After the eggs have hatched and the larve are about full grown, the removal and burning of the bark will effectually destroy the broods and thus contribute greatly to reducing the numbers of the beetles— @ Living trees girdled or felled at the proper time to attract the Avine heetles to them and away from healthy trees. THE WESTERN PINE-DESTROYING BARKBEETLE. 29 which must occur in large numbers before they can attack and kill a tree. Some of the living trees in the immediate neighborhood of the trap trees may be attacked by beetles attracted to the vicinity by the felled or girdled trees. These should be felled and treated the same as trap trees. If the conditions appear to warrant it, additional trees should be girdled or felled about the first part of August to catch the second brood. These may be barked, to kill the broods, any time between the first part of October and the first part of the following May. SUMMARY. HABITS AND LIFE HISTORY. The western pine-destroying barkbeetle usually attacks and kills the best examples of western yellow pine and sugar pine. If neglected and under certain conditions favorable to the species, it is capable of devastating the pine forests over large areas. The broods of the beetle pass the winter in the outer bark of trees killed by it the previous summer. The adults of the overwintering broods emerge and fly in May, June, and July, the beginning and ending of the period varying with the seasons, latitude, and altitude. The first eggs from the first generation are deposited in June or July, and in some of the warm localities possibly as early as the middle of May. In localities intermediate between the colder and warmer regions the majority of the adults of the first generation evidently develop and emerge in August, but some individuals may remain in the trees until June of the next year. The first eggs of the second generation are evidently deposited in August and September, depending on locality, and it would appear that in intermediate localities all of the broods of this generation pass the winter (hibernate) in the larval stage in the outer bark. In the warmer localities some of them may develop and emerge in the fall, while in the colder localities there may be but one generation. The first evidence of attack on living trees is the presence of pitch tubes (figs. 11 and 12, c) on the bark or of reddish borings lodged in the crevices and around the base of the tree. During the fall, winter, and following spring, after a successful attack, the infested trees will be indicated by the fading yellowish and reddish leaves. The work of the insect will be indicated by the winding galleries through the inner bark (fig. 8). Trees from which the broods have emerged will be indicated by large numbers of small holes through the outer bark (fig. 12). REMEDIES. The principal areas of infestation and the principal patches of infested trees should be located in September and October. 30 SOME INSECTS INJURIOUS TO FORESTS. Beginning with the first part of October, the infested trees should be felled and the bark removed from the main trunk and burned, these operations to be completed. by the first part of the following May. If all of the trees within a given area can not be thus felled and treated, the work should be concentrated on the larger clumps and patches of infested trees. The cost per tree for cutting, barking, and burning the bark will range from about 30 cents to $1, depending on locality and accessi- bility. Summer cutting, except in regular logging operations, is undesir- able, since the cutting of a few trees in the midst of a large forest may attract the insects from a long distance, and thus result in extensive depredations in bodies of timber which it is most desirable to protect. TRAP TREES. In sections where it is known that the beetle is killing some of the ‘timber, trap trees should be provided in June and August. Ordi- narily, 4 or 5 inferior living trees within each section, on which there is evidence.of the work of the beetle, should suffice. Trap trees should not be prepared unless it is reasonably certain that the bark will be removed and burned before the broods of the beetles develop and emerge, otherwise such trees may contribute to the destruction of a larger amount of timber. STORM-FELLED OR LIGHTNING-STRUCK TREES. Storm-felled and lightning-struck trees are a menace to a healthy forest within the distribution of this insect, since they serve as breed- ing places and centers of infestation. Therefore, whenever practi- cable, such trees should be watched, and if found infested with broods of this beetle, they should be treated as recommended for infested and trap trees. PUBLICATIONS RELATING TO THE WESTERN PINE-DESTROYING BARKBEETLE. 1876. LeConte, J. L.—The Rhynchophora of America North of Mexico. Proc. Am. Philos. Soc., Vol. XV, Dec., p. 386. Species described. 1890. Dietz, W. G.—Notes on the species of Dendroctonus of Boreal America. Trans. Am. Ent. Soc., Vol. XVII, p. 32. Revision notes. 1899. Hopkins, A. D.—Preliminary Report on the Insect Enemies of Forests in the North- west. Bul. No. 21,n. s., Div. Ent., U.S. Dept. Agric., pp. 13-15. First notes on habits. ee 1904. Hopkins, A. D.—Catalogue of Exhibits of Insect Enemies of Forests and Forest a Products at the Louisiana Purchase Exposition, St. Louis, Mo., 1904. Bul. No. 48, Div. Ent., U.S. Dept. Agric., p. 18. Character of work described. . 1905. Currie, R. P.—Catalogue of the Exhibit of Economic Entomology at the Lewis and Clark Centennial Exposition, Portland, Oregon, 1905. Bul. No. 53, Bur. Ent., U.S. Dept. Agric., pp. 74 et seq. Reprinted fram Bn. 48. CIRCULAR NO. 61. United States Department of Agriculture, BUREAU OF ENTOMOLOGY, L. O. HOWARD, Entomologist. BLACK CHECK IN WESTERN HEMLOCK. By H. E. Burke, Special Field Agent. ECONOMIC IMPORTANCE. Black check is the lumberman’s name for a common defect, consist- ing of a dark brown or blackish resinous scar, in the wood of the western hemlock. foliacee, diervilla, honeysuckle; Urticacee, elm; Leguminose@, pea, locust ; MWagnoliacee, magnolia; Vitacez, woodbine. During the past season the caterpillars have been especially destructive to sugar maples. Nextto the maples they seemed to prefer basswood and elm, butin some localities were especially ‘destructive to poplar and oak. At Little Falls, N. Y., the writer observed them feeding upon ironwood (Oséryia), family Cupulifere, making a food-plant additional to the above list. DESCRIPTIONS AND LIFE-HISTORY. The egg.—The eggs are laid close together forming bands which encircle the twigs. These bands or masses are abruptly cut off on the edges and in this the egg-masses of this species differ from those of the apple-tree tent-caterpillar which are more distinctly oval in outline. The frothy covering also differs in color being a dull gray instead of brown. As referred to on a subsequent page there is a noticeable variation in their size this year. Plate II, fig. 1, is from a photograph of two egg- masses which differ greatly in size. The upper one has the more typical shape. The eggs are placed on end side by side with somewhat more regularity than those of the apple-tree tent-caterpillar. According to Riley * the female while depositing her eggs ‘‘ stations herself, for this purpose, ina transverse position across the twig.”’ The egg-laying habits of three females kept by the writer in the labora- tory were carefully noted. The actions of these females indicate that there may be exceptions to the habits observed by Dr. Riley; for none of them placed themselves in a transverse position across the twig, but stood lengthwise of it or nearly so, and moved sidewise while depositing the eggs. When one row was finished the next was immediately commenced. The eggs were placed very close together. With each egg an abundance of frothy 3 Amer. Ent. and Bot., 2: 261. 4t glue was discharged, completely covering it and hardening almost immediately. The females died within a few hours aftercomplet- ing oviposition. When first laid the eggs are nearly “eiuiita but soon became a dull gray. They measure on the average 1.2 mm. in length and -75 mm. in diameter at the upper end, tapering slightly to the lowerend. They are squarely cut off at the upperend but rounded at the lower. The upper end is also distinctly margined with white, the central area being darker and somewhat depressed. At first this depression is very slight but gradually more pronounced as the embryo caterpillar becomes fully formed. Small size of the egg-masses this year.—The egg-masses are said to contain from 300 to 400 eggs. Riley states “ that he found the number in five masses ranging from 380-416. Compared with these figures the egg masses this year are very small as indicated by the examination of a large number taken in the vicinity of Geneva and from various sections of the State. They average only half this size, containing, as a rule, but about 200 eggs. Many were much smaller than this. As each female moth probably deposits all of her eggs im one mass this indicates an unusual falling off in the number of eggs deposited. Time of egg laying and period of incubation.—In the latitude of New York the eggs are laid during the last week in June and first week in July. The young caterpillars are fully developed within the eggs before the summer is over, but do not escape until the following spring. On August 29,an examination of eggs showed fully developed caterpillars. Unlike the apple-tree tent-caterpillars which were found bent backward in the eggs examined, all of the caterpillars in about 100 eggs opened by the writer were bent forward nearly double so that the head and posterior part of the body came nearly together. The larva or caterpillar.—The earliest caterpillars probably appear with the first warm days of spring. This season they were found about Geneva during the last week in March, The period of hatching, however, extends over a month or more, as young caterpillars that had not yet passed their first molt were ™ Amer. Ent. a: d Bot., 2: 261. 42 found at Geneva as late as May 26, and colonies of newly hatched caterpillars were found at various times between, while by May 22 large numbers ot caterpillars had reached nearly full size. Growth.—Undet normal conditions the caterpillars are full- grown within about six weeks, but in case they hatch before the leaf buds of their food plants have burst, their development is retarded by lack of food. Coldor inclement weather soon after the young caterpillars have hatched also delays their growth. Dr. Riley’ states that the newly hatched caterpillars are able to fast fully three weeks and ‘‘to withstand any amount of inclement weather.’’ Feeding habits.—During the first three or four weeks the cater- pillars are gregarious, but as they approach full size,and especially after the last molt they scatter about the tree. During the earlier stages only a portion of the leaf is consumed, but later nearly the entire leaf may be devoured. Weed states” that ‘‘ the caterpillars commonly eat through the leaf in such a way that the outer end drops to the ground,’’ thus causing the insect to be relatively more destructive than if devouring the entire leaf. They feed chiefly during the night, and to a limited extent during the cool of the day. While not feeding they were oftef seen last season resting in small groups upon the leaves, as shown in Plate II, fig. 2, which is from a snap-shot taken on a very warm day: at 11:15 A.M. The natureof the injury to the leaves is also shown in this picture. Silk spinning habit.—From the first the young caterpillars spin a thread of silk wherever they go, but seldom if ever makea true nest. Sometimes a few leaves that the caterpillars have passed over will become covered with silk and attached to adjoin- ing leaves, thus giving the whole the appearance of a rude nest ortent. If disturbed the young caterpillars will drop quickly to the ground. In the bulletin just referred to Dr. Weed reports an observation by Mr. W. F. Fiske to the effect that the young caterpillars when suddenly disturbed while feeding will drop to the ground without attaching a thread. This is also true of the older caterpillars. When congregated upon a twig the young caterpillars are more apt to attach a thread which, Amer, Ent. and Bot., 2: 262. ON. H. Agr. Exp. Sta. Bull 64, pp. 83-84. 43 however, is quite likely to be broken before the ground is reached, This habit of dropping to the ground when disturbed, as they undoubtedly often are by birds or by the branches swaying in the wind, probably, as Weed has stated, accounts in part, at least, for the large numbers of caterpillars that are seen crawling up the trunks of infested trees. Observations upon caterpillars in con- finement showed that much less silk is spun after the last molt while crawling about than during the earlier stages. Sharing a nest with the apple-tree tent-caterpillar.—What is probably a very unusual occurrence is shown at Plate III, fig. 1. This nest was made by a colony of apple-tree tent-caterpillars. It will be observed that most of the caterpillars in sight are not the rightful owners of the nest, but are forest tent-caterpillars. The two species can be easily distinguished as the apple-tree tent- caterpillars have a conspicuous white line extending the whole length of the back, while the forest tent-caterpillars have the line replaced by arow of white spots. This nest was on an apple tree near the Station grounds. At the time this picture was taken, about 10:30 A. M., the caterpillars had collected on the sunny side of thenest. There were none on the opposite side. The writer watched this nest for several days and it was observed that the ‘‘guests’’ went out regularly with the other species to feed and returned with them. Upon no occasion, however, were the forest tent-caterpillars seen to enter the nest. Upon the fourth day the nest was cut open and although it was well filled with apple-tree tent-caterpillars none of the forest tent-cater- pillars could be found. A few days after these observations were made Mr. G. G. Atwood reported finding a similar case in an apple orchard a few miles distant. Although it is not uncom- mon to find two or three stray forest tent-caterpillars upon one of the nests of their near relatives, such cases as the above appear to be quite unusual. Congregating habit.—A very noticeable habit is that of con- gregating in large numbers on the trunks and branches of the infested trees. There appear to be two principal occasions for this, first, when resting during the heat of the day and, second, when about to molt. As an indication of the former, the writer has observed the caterpillars disperse toward evening after having 44 remained together during the greater part of the day. When about to. molt their usual places for congregating are upon the branches and trunks of the infested trees. The young caterpil- lars are more often found upon the former and those that are near- ing full growth upon the latter or on the large limbs of the larger trees. Plates IV is from a photograph of a group of caterpillars, most of which were not more than half grown, upon a limb of a young basswood tree. This photograph was taken at 11:30 A.M. In the sections of the State where the caterpillars were very abundant they were frequently found together, when preparing to molt, in such large numbers as to completely cover one side of the trunk of a full-grown sugar maple tree to the distance of three or four feet. Plate V is from a photograph taken at 3:15 P.M., of a comparatively small group of caterpillars about two-thirds grown upon a small plum tree in an orchard near Geneva. Restlessness of the full-grown caterpillars.—After the last molt the caterpillars become very restless, wandering up and down the trunks, along fences, etc., until finally the cocoons are spun. It has been observed that they feed but. little-during this period. This was also indicated by the colonies kept in our breeding cages. After the last molt they ate but very little, wandering about for three or four days and finally spinning their cocoons in all parts of the cages. Number of molts and descriptions,—The number of molts is usually four. A fifth molt occurs soon after the cocoon is spun. The molting periods, with the exception of the first, which was not observed, of a large number of caterpillars confined in breed- ing cages last spring were as follows: ‘The first molt was about May 8, the second May.16, the third May 31. About ten days later part of them molted a fourth time and within three days spun their cocoons. A small proportion of those that molted but three times spun cocoons. The remainder died. This lack of normal development was probably due to insufficient food as’ they were accidentally deprived of fresh food for nearly two days between the third and fourth molts. The periods of molting and the markings were observed and recorded by C. V. Riley”. in 1870. The following descriptions do not differ essentially from those "Amer, Ent, and Bot., 2e 262. 45 given by him. The caterpillars just after leaving the eggs measure on the average 2mm.in length. They are dull black in color with long grayish-white hairs arising from numerous minute tubercles. In a few days there is a slight change in color. The middle of the body becomes lighter, taking on a brownish tinge, while the extremities remain darker. The tubercles also become more distinct and a dark interrupted line conspicuous along each side. These markings become more prominent as the time for the first molt approaches. : The first molt.— The first molt occurs from ten days to three weeks after the caterpillars emerge from the eggs, the varia- tion in time probably depending upon the abundance of the food supply. Immediately after the first molt they measure about one-half inchin length. There are two pale yellowish sub-dorsal lines bordering the dark lines above referred to. ‘These lines become more conspicuous as the time for the second molt approaches ; the dorsal spots are also indistinctly seen. The second molt.—This molt occurs from a week to ten days after the first, when the length is about three-fourths of an inch. A row of eleven cream-white somewhat diamond-shaped or club- shaped spots extends the full length of the back. Also as Dr. Riley states in the reference above given: ‘‘The upper pale line becomes yellow, the lower one white, and the space between them bluish.’’ The third molt.—The third molt occurs about a week to ten days after the second. ‘The caterpillars measure about one inch in length. There is little change in the markings except that they become more distinct. The fourth molt,—Between the third and fourth molts is the most rapid-growing period of the larval life. After the fourth molt they measure from one and one-half to two inches in length. Last spring caterpillars that measured two inches were quite com- mon and a few were found that measured two inches and a quarter, The following technical description is by Dr. Asa Fitch.” ‘The caterpillar, after it has forsaken its nest and is wandering about is an inch and a half long and 0.20 thick. It is cylindrical and of a pale blue Fitch. Fifth Report on the Insects of New York, p. 821. 46 color, tinged low down on each side with greenish-gray, and is everywhere sprinkled over with black points and dots, Along its back is a row of ten or eleven oval or diamond-shaped white spots which are similarly sprinkled with black points and dots, and are placed one on the fore part of each seg- ment. Behind each of these spots is a much smaller white spot, occupying the middle of each segment. The intervening space is black, which color also forms a border surrounding each of these spots, and on each side is an elevated black dot from which arise usually four long black hairs. The hind part of each segment is occupied by three crinkled and more or less interrupted pale orange-yellow lines, which are edged with black. Andon each side is a contintious and somewhat broader stripe of the same yellow color, similarly edged on each of its sides with black. Lower down on each side is a paler-yellow or cream-colored stripe, the edges of which are more jagged and irregular than those of the one above it, and this stripe also is bordered with black broadly and unevenly on its upper side and very nar- rowly on its lower side. The back is clothed with numerous fine fox-colored hairs, and low down on each side are numerous coarser whitish ones. On the under side is a large, oval, black spot on each segment except the ante- rior ones. The legs and pro-legs are black and clothed with short whitish hairs. The head is of a dark bluish color flecked with numerous black dots and clothed with short blackish and fox-colored hairs. The second segment or neck is edged anteriorly with cream white, which color is more broad upon the sides. The third and fourth segments have each a large black spot on each side. The instant it is immersed in spirits the blue color of cater- pillar vanishes and becomes black. By referring to Plate III, fig. 2, the difference in the dorsal markings of the two common species of tent-caterpillars will be plainly seen. The caterpillar on the left is an apple-tree tent- caterpillar, the other two are forest tent-caterpillars, the one on the right being a lateral view. All are nearly full-grown and are natural size. The cocoon.—The cocoons are made of coarse white silk which soon becomes discolored by the weather. In size and shape they closely resemble those of the apple-tree tent-caterpillar described on pages 286-287 of Bulletin 152 of this Station, but are some- what more loosely woven and have less of the yellowish powder. In the vicinity of Geneva the spinning of the cocoons began last season about the last week in May and continued until the middle of July. Although it has been considered one of the characteristics of this species to utilize a leaf in making the cocoon there were many exceptions last season, for they were found in great numbers upon 47 the fences, out-buildings. and even upon the ground, where no leaves were to be had to aid in their construction. This may have been in part due to a scarcity of foliage in the woodlands where the trees had been entirely stripped. In sections where the caterpillars were less common, most of the cocoons were formed in the leaves, the leaf or leaves being brought around the cocoon as shown at Plate II, fig. 3. This picture shows a cocoon partly enclosed by two elm leaves held in place by the numerous threads of silk attached tothem. Some of the forest tent-caterpillars kept in the breeding cages showed a tendency to forsake this habit ; for out of about 150 over half spun their cocoons upon the sides of the cages,the remainder utilizing the leaves that were there in abund- ance. Most of these caterpillars spun their cocoons during the night, but a few kept in a darkened room began during the latter part of the afternoon. These were observed to require between five and six hours to complete the work. After completing the cocoon the imprisoned caterpillar molts once and then passes to the pupa stage. The pupa.—Both male and female pupe are reddish-brown in color. The former measures about five-eighths of an inch in length and the latter three-fourths. Moths: time of appearance ; habits.—Last spring in the vicinity of Geneva the moths were occasionally seen by June 20. A large number of cocoons gathered from various parts of the State where the caterpillars were very abundant furnish interest- ing data as to the length of time during which the moths are issuing, the percentage of males and females and the percentage parasitized. As will be observed the moths issued from these cocoons from June 26 to July8. The data in the following table was obtained from 2,500 of the cocoons.” 19 Cocoons to the number of 3757 were sent in from various sections of the state. Nearly 1,000 of them had hatched before being gathered leavin g about 2700 unhatched. For most of these cocoons the writer is indebted to Mr. A. R. Eastman, Waterville, N.Y., Mr. D. H. Burrell, Jr., Little Falls, N. Y., Mr. J. B. Tuckerman, Cassville, N. Y., and Mr. J. M. Budlong, West Schuyler, N. Y. 48 EMERGENCE OF MOTHS FROM CocooNs OF FOREST TENT-CATERPILLAR. Date. Males, Females. JME 26 ieee see seserensstns quiians 3 14 BE ADDS suse cutee aese sBSh nace a caven Io Io C0) 328 aus date AR Io 2 O99. eines ss's eaesars 42 Il OS 80 seaiee ads pares saps 31 5 July “Lesrcecsgese ens 73 67 G8 AR ahd pce thane meets 342 284 BE) CIA isan Sud 2S ycetu eset 75 84 OG AE a ahetiern anh Gadudeduiniaeud ! 132 132 OE) OG: spams nctib at eeactaacats 64 98 OO Be san nanan aesuedetianie 12 25 794 672 Total males and females...... Liisa OWengis Sarees Hates 1,466 Number of cocoons parasitized. ........... 00. cee e eee 312 Number cocoons unhatched.............. 0. ccc cece 722 These figures show that a little over 4o per ct. of the 2,500 cocoons failed to produce moths. Also that less than 47 per ct. of those that hatched were females and that the greatest number of moths escaped during the first five daysof July. A little over 12% per ct. were parasitized and more than 28 per ct. produced neither moths nor parasites. The moths are active, restless insects. They fly only at dusk and during the night. The females are ready to lay eggs soon after leaving the cocoons, but probably live but a short time after the eggs have been deposited. Some female moths kept in the breeding cages laid theireggs within two days after escaping from the cocoon and died before the end of the third day. Descriptions.—In general the moths resemble those of the apple-tree tent-caterpillar except that the oblique lines across the fore-wings are dark instead of light in color. ‘The general color of typical specimens is buff with a brownishtinge. An exami- nation of a large number of moths showed a wide variation from this even in the individuals that do not approach the varieties, referred to on a subsequent page. Both wings and body are sub- ject to decided shadings of either a yellow or brownish cast. A male moth of average size spreads about one inch, but in the 49 moths reared last spring a few were found that spread but 74 inch and a few that spread 134 inches. There is less variation in the markings of the females but an equal or greater variation in size. A female of average size was found to spread 134 inches, the smallest 114 inches and the largest 134 inches. The two upper rows of moths on Plate VI show the variation in size. The upper row are males and the second row females. The following detailed descriptions of the male and female moths are by Dr. Asa Fitch.” ‘‘The male moth usually measures 1.20 inches across its spread wings. Its thorax is densely coated with soft hairs of a nankin-yellow color. Its abdomen is covered with shorter hairs which are light umber or cinnamon brown on the back and tip and paler or nankin-yellow on the sides, The antenne are gray freckled with brown scales and their branches are very dark brown. The face is brown with tips of the feelers pale gray. The fore-wings are gray, varied more or less with nankin yellow, and they are divided into three nearly equal portions by two straight dark brown lines which cross them obliquely, parallel with each other and with the hind mar- gin. * * * * The fringe is of the same dark brown:color with the oblique lines, with two whitish alternations towards its outer end. But some times it is of the same color with the wings, and edged along its tip wih whitish. The hind wings are of a uniform pale umber or cinnamon brown, sometimes broadly grayish on the outer margin and across their middle a faint darker brown band isusually perceptible, its edges on each side indefinite. The fringe is of the same color with the wings or slightly darker and is tipped with whitish. The under side is paler umber brown, the hind wings often gray, and both pairs are often crossed by a narrow dark brown band which, on the hind wings, are curved outside the middle. All back of this band,on both wings,is often paler aud more so near the band.”’ ‘«The female is 1.75 inches wide andin addition to the shortness of the branches of her antenne, differs from the male in her fore-wings, which are proportionally narrower and longer, with their hind margin cut off more obliquely, and slightly wavy along its edge. Hence, also the dark brown lines cross the wings more obliquely, the hind one in particular forming a much more acute angle with the outer margin. And all the wing back of this line is sometimes paler or ofa brownish, ashy color. And the fringe of these wings has not the two whitish alternations which are often so con- spicuous in the male. The head and fore part of the thorax is cinnamon brown. The abdomen is black; clothed with brown hairs, though very thinly so on the anterior part of each segment, where these lines are inter- mingled with silvery gray scales.’ _ » Fitch, Asa. Fifth Report, p. 822. 5° Varieties. —Two varieties of this species have been described. Numerous specimens of both were reared from the cocoons above referred to. They are as follows: Variety sylvatica Harr. has the space between the lines filled in forming a broad brown band across each anterior wing. Plate VI, third row; the two on the left are males and the third a female. Variety thoracicoides Neumoegen and Dyar, has the bands wanting or very obscure. Plate VI, fourth row ; all males. Among the specimens reared in the laboratory there was an interesting series showing a gradual gradation from the light typical form with the two well marked bands, to the variety sylvatica having the space between filled in with brown forming the broad bands as above described. Plate VI, fifth row. SUMMARY OF LIFE-HISTORY. In the latitude of New York State the eggs are usually laid during the last week of June and until about the second week of July. They are placed in bands extending around the twig and are covered with a shining frothy glue. The caterpillars are fully formed in the eggs before the summer is over, but do not escape until early the following spring. ‘They feed upon the foliage of a large variety of trees and shrubs. They spin a thread of silk wherever they go, but do not build nests. When not feeding or when about to molt they gather often in large numbers upon the limbs or trunks of the infested trees. Pupation takes place during the latter part of May orearly in June, the cocoons being placed either upon the leaves or in almost any locality near the ground. The moths appear during the latter part of June and early July. The eggs are at once laid. Thereis but one annual brood. NATURAL CHECKS. The same natural agencies mentioned in Bulletin 1 52, page 289, as operating against the apple-tree tent-caterpillar probably have an equal influence upon this species. In addition to unfavorable climatic conditions, birds, insects and diseases have a marked 51 effect upon this species. According to Kirkland™ the common garden toad also feeds upon the caterpillars. Birds.—A careful study of the birds in the sections of the State which were infested with the caterpillars last spring would undoubtedly have reyealed many species not recorded here feed- ing upon this insect in its various stages. Reports from careful observers together with limited observations by the writer indicate that the following birds feed upon this insect in some of its stages: The black-capped chickadee feeds upon the eggs proba- bly chiefly during the winter when other animal food is not abundant. The writer has taken the eggs from the stomachs of chickadees shot during the winter in localities where the cater- pillars were not especially abundant. The yellow-billed cuckoo, Baltimore oriole, American red start, cat bird and robin feed upon the caterpillars. In addition Weed” reporting the observations of Miss Soule records chipping sparrows, red and white-eyed vireos, cedar bird, and nut-hatches feeding upon the caterpillars; chicka- dees upon the cocoons; and robins, chipping sparrows, yellow birds and English sparrows feeding upon the moths. Undoubt- edly many more of our smaller birds feed upon the young cater- pillars. , Predaceous insects —The predaceous insect enemies herein recorded may be divided into two groups: The coleopterous (beetles) and the hemipterous (bugs). The caterpillars fall an easy prey to these enemies when crawling about upon or near the ground. The following are included in the first group: Calosoma scrutator Fab., and Calosoma calidum Fab., two of our largest species of predaceous ground-beetles, which have frequently been observed attacking caterpillars of various species. Dr. C. V. Riley? and Mr. Wm. Saunders™ were probably the first to record them feeding upon the caterpillars of this species. According to Felt Burgess states that Calosoma wilcoxt LeC. fed readily in confinement upon the caterpillars. Included in the "Mass. (Hatch) Agr. Exp. Sta. Bul. 46, pp. 22 and 25. =Bull. 64 N. H. Agr. Exp. Sta. pp. 91-92. 2Amer. Ent. and Bot., 2: 265. Insects Injurious to Fruits, p. 57. Bull. N. Y, State Museum, No. 23, p. 196. 52 second group are the two predaceous bugs, Podisus placidus Uhler and Podisus seriventris Ubler, which Kirkland” has recorded feed- ing upon the caterpillars. Saunders records” a species of 7vom- bidium feeding upon the eggs. Parasitic insects:—The parasitic insect enemies may also be divided into two groups: The dipterous parasites and the hymenop- terous parasites. Of the former group Coquillett*® records the following as parasites of the caterpillars; Euphoracera claripennis Macgq., bred by C. H. Fernald, Amherst, Mass., Frontinia frenchit Will., previously recorded by Harvey” and Zachina mella Walk. also previously recorded by Harvey. During the past season the writer has also bred the last named species together with Calliphora erythrocephala Meigen, which Coquillett states is evidently a scavenger. Both species were kindly identified by Mr. D. W. Coquillett. The second group, the hymenopterous parasites, are probably more effectual in keeping the forest tent-caterpillar and other insects in check, because they are usually much more abundant. The following species have been recorded as preying upon the caterpillars. Limneria fugitiva Say recorded” by Riley,and Pimpla pedalis Cres., by Wm. Saunders.* From the 2,500 cocoons kept by the writer in the laboratory 287 individuals of the species Pimpla conquisitor were reared, of which 218 were females, leaving 69 males ; Pimpla pedalis, two females and one male; Theronia fulvescens, one male. The following species kindly identified by Mr. Wm. H. Ashmead, assistant curator of the U. S. National Museum, were also reared from these cocoons: Diglochis (Phromalus) omnivorous Walk. ; Miotiopis clisiocampe Ashm. As shown on page 48 but 312 or only about 12% per ct. of the 2,500 cocoons were parasitized. Disease.—A disease, evidently bacterial, attacked many of the caterpillars last season materially reducing their numbers. This °° Mass. (Hatch) Agr. Exp. Sta. Bull. 46, p. 25. 7Ann. Rept. Ent. Soc. Ont. 1878, p. 28-30. *Bull. No.7, U.S. Dep. Agr. Div. Ent. Tech Series, pp. 11, 16, 21, 24. 79=Psyche, May 1801, p. 85. x°Insect Life, 8: 157. 3"Insects Injurious to Fruits, p. 57. 53 appears to be the same disease that attacks the apple-tree tent- caterpillar mentioned in Bulletin 152, page 291. COMBATING THE INSECT. Owing principally to the fact that the caterpillars attack a large variety of trees, this subject is a somewhat complicated one. In badly infested localities, however, it has three distinct phases. First, combating the insect in the forest ; second, combating the insect when attacking shade trees ; and third, combating the insect in the orchard. We will discuss the subject under each of the three heads reversing the order given above. Combating the insect in the orchard ; destroying the eggs.—After the leaves have dropped the egg masses are somewhat con- spicuous. When pruning the trees they should be carefully looked for and destroyed. Ifthe orchard has been badly infested it will pay to make a special search for them. Destroying the caterpillars.—Many methods have been sug- gested for destroying the caterpillars but there are three especially feasible ones, which, if carefully carried out, will usually prove effectual. First, spraying with an arsenical compound.—Any good arsenical will answer the purpose if applied before the caterpillars are half-grown. Some of the principal arsenical insecticides are Paris green, green arsenite and arsenite of lime. For a discussion of green arsenite and arsenite of lime see Bulletins 143 and 152 of this Station. A third arsenical, arsenate of lead, has been found by the Gypsy Moth Commission cf Massachusetts to be especially effectual against the gypsy moth and to be almost harmless to foliage. The formula is as follows: 11 ounces acetate of lead, 4 ounces arsenate of soda, 150 gallons of water. The directions for making arsenate of lead as given by Professor C. H. Fernald® are as follows: ‘‘ Arsenate of lead is easily prepared by putting 11 ounces acetate of lead in 4 quarts of water, in a wooden (not metal) pail, and 4 ounces of arsenate of soda (50 per ct.) in 2 quarts of water in another wooden pail, and when entirely dissolved mixing them in a hogshead containing 150 gallons of water, when a chemical Ann. Rpt. Mass. Bd. Agr. 1897. 54 reaction will take place forming arsenate of lead in a fine white powder in suspension in the water. If cold water be used in the wooden pails, the solution of the acetate of lead will require a little time, but, however, if the water be hot, it will dissolve very quickly. It is customary to add from 2 to 4 quarts of glucose to the above amount of water. If it is desired to use larger proportions of the arsenate of lead, it is only necessary to use more acetate of lead and arsenate of soda, but a/ways in the proportions given above.’’ To ensure success in spraying two points should be kept in mind, namely, promptness and thoroughness. The poison will be much more effective if applied before the cater- pillars are one-fourth grown and of but little avail if the appli- cation is delayed until after they are half grown. Second, destroying the caterpillars when they have assembled upon the trunks or large branches.—This may be donein any convenient way. A very easy way is to crush them with an old broom which, to insure the death of all the caterpillars it touches, has been dipped in kerosene oil. The kerosene oil is fatal to them, and if preferred may be sprayed directly upon them. Third, jarring and banding.—Jarring is seldom practical except with small trees. The tree should be given a few quick, sharp raps with a padded mallet. The caterpillars will drop at once and may be collected and destroyed in curculio carts or upon sheets spread upon the ground. Banding is for the purpose of preventing those caterpillars that have been jarred off by the wind, or by birds, or have left the tree during the restless period just previous to pupating from again ascending the trunk; also to protect the trees from invading caterpillars, especially when the orchard is situated near infested shade or forest trees. The bands may be made of cotton wool in which the caterpillars will become entangled, or better by some sticky substance such as tar mixed with two parts of raw oil, or with raupenleim. Either of these substances should be smeared upon bands of paper at least a foot wide which can be tied around the trunks of the trees. By using the paper there is no danger of injury to the bark. Sticky fly paper is sometimes successfully used in the same way. The caterpillars will be caught upon these bands and soon die. Where the caterpillars are very 55 abundant so many will be caught upon the bands that other caterpillars can crawl safely over them. In such an event new bands will have to be supplied or the originals made wider. Of these sticky substances, raupenleim is one of the best. It can be obtained of William Meuzel & Co., 64 Broad St., New York, and the Bowker Fertilizer Co., Boston. It should never be applied directly to the bark. Collecting the cocoons.—Many of the cocoons are spun in places where they can be easily reached. In collecting and destroying them many useful parasites would be destroyed but in case of a serious outbreak the thorough collecting of the cocoons would accomplish more immediate good than the parasites. It would, however, be but little trouble to place the cocoons under a coarse netting and leave them until the parasites had escaped. The netting should be too fine to allow the moths to pass but coarse enough to allow the parasites to escape. Capturing the moths.—As previously stated the moths fly at dusk or later. They are attracted by a bright light, and may be captured by placing a lighted lantern over a tub of water, over which enough kerosene oil has been poured to make a thin film. The moths flying about the light will fall into the water. While this method may be of some value it is doubtful if many female moths will fly to the light before having deposited their eggs, after which of course, it makes no difference whether they are attracted to the light or not. Combating the insect when attacking shade trees.—All of the methods just described can be used to check the insect when attacking small shade trees. For large trees banding is of much value. In some of the villages in which the caterpillars were abundant last spring, they were dislodged from the large trees by streams of hydrant water and prevented from going back up the trunks by the sticky bands. For spraying the large trees special apparatus is required. Steam power isusually used. A suitable outfit can be purchased for from about $200 up. The increase of shade tree insect pests and diseases make it almost necessary for a village to own a spraying apparatus to ensure the preservation of its shade trees. A method of combating the insects which has been tried with 56 success is to encourage the school children to collect the egg masses by paying them a reasonable price per hundred. This may be done by the private individual or by the village or city authorities. In either case the expense would be trifling in com- parison with the good accomplished. Combating the insect when attacking forest trees.—When the caterpillars occur in such great numbers over such wide areas of woodland as they did last spring it is difficult to devise a method of destroying the caterpillars that would be practical for individual farmers to undertake. Banding the trees will be of much value. Also with comparatively little work many of the caterpillars which have assembled on the trunks can be destroyed. What- ever is done a united effort will be necessary to give the best results. BIBLIOGRAPHICAL LIST. 1797, ABBOTT and SMITH, Lepidopterous Insects of Georgia, p. 117. Colored figure of caterpillar. (G. xeustria.) 1822.? HUEBNER, Jacozp. Verzeichniss bekannter Schmetterlinge, p. 122. Original description. 1841. HARRIS, T. W. Ins. Inj. to Veg. tsted., p. 271. Brief reference. 1844. HAarRRIs, T. W. New England Farmer, 5: 412. Refers to the forest tent-caterpillar as ‘‘ a new depredator of the orchard.” 1852. Harris, T. W. Treatise on Insects (2nd ed.), pp. 291-2. Brief descriptions of larva and adults: life-history (C. sylvatica). 1854. EMMONS. Nat. Hist. N. Y.,5%240. Brief reference. (G. neustria.) 1856. FircH, AsA. Insects of New York. 2d Report, pp. 198-199. [N. VY. State Agr. Soc, Trans. 1855-1856, p. 430.] Brief reference, 1859. Fircu, Asa. Noxious and other Insectsof New York. Fifth Report p. 820. Brief account of life-history; detailed descriptions of full- grown caterpillar and male and female moths. 1862, Harris, T. W. Ins. Inj. to Veg. Flint’s ed., p. 375. Brief refer- ence, Morris Synop N. Am. Lep. p., 236. 1864. JaHzGAR. Life N. Am. Ins., p., 173. 1866. BRACKETT, G.E. Maine Farmer, July 12. Notes on C. disstria, 1867. WALSH, B.D. Practical Entomologist, 2; 72. Mentioned. 112-113. Brief account of life-history, 121. Mentioned. (C. sylvatica ) FERRIS, PETER. Ibid. 112-113. Brief account of outbreak in West- ern New York, 1869, WaALsHandRILEY. American Entomologist, 1: 208. Brief account of life-history, 210, Mentioned. 227. Ravages in Missouri. (C. sylva- tica.) \ 57 Harris, T. W. Entomological correspondence, p. 292. Briefrefer- ence. 1870. Moopy, H.L. Canadian Entomologist, 2: 176-177. Tenacity of life in larva. (C. sylvatica.) RILEY, C. V. Insects of Missouri, Second Report, pp. 7 and 37. Briefly mentioned. Am. Ent. and Bot., 2: 245. Mentions ravages in Arkansas. 261-266. General account. (C. sylvatica.) 1871, RILEY, C. V. Ins. of Mo. Third Report, pp. 121-29. Life-history, description, natural enemies and remedies, egg masses 380 to 416 eggs. BETHUNE, C. J.S. Rept. Fruit Growers Ass’n. Ont. Life-history and injuries. (C. disstria.) LeBaron, Wm. Prairie Farmer, 5:42. _Ravages and methods of combating. (C. sylvatica.) 1872, Rinky,C. V. Ins. Mo, Fourth Report, p. 41. Limmneria fugitiva Say parasitizing. (C. sylvatica.) ‘SAUNDERS, W. Can. Ent., 4: 134. Unusually scarce during the past season. 5:4. Life-history, methods of combating. (C. sylvatica.) BELL, J.T. Can. Ent., 4: 199. Unusual abundance, injury to oak trees. (C. sylvatica.) Diumock, G. New Eng. Homestead, June 29. Brief discussion. (C. disstria.) 1874. BEssEY, C.E. Iowa State Agr. Soc. Report, 1873-4. Brief mention. (C. sylvatica.) Lyman, H. H. Can. Ent., 6: 158. Unusual abundance. (C.sy/vatica.) Woop, J. G. Insects abroad, p. 680. 1875. SAUNDERS, W. Ann. Rept. Ent. Soc. Ont., 30-31. Brief descrip- tions. Serious injury to orchard and forest trees in Western Ontario a few years previous ; natural enemies. (C. sylvatica.) 1876. FERNALD, C. H. Agriculture of Maine,1875-6, pp.1g-21, [Third Ann. Rept. Maine State Pom. Soc. pp. 1g-21]. Observations upon life-history. Serious ravages in Maine during past two years, also in 1863 near Mon- mouth and 1867 near Belfast. (C. sylvatica.) 1877. SAUNDERS, W. Can. Ent., 5: 158-159. Abundance; habits and food plants (C. sylvatica), Tuomas, Cyrus. Ins. Ill. Sixth Report, p. 89. Caterpillars destroyed by Calosoma scrutator (C. sylvatica). Gorr, B. Ann. Rept. Ent. Soc. Ont , 1877, p. 41. Brief reference of injury to apple orchards in the vicinity of infested forests. KRIDELBAUGH, S. H. Iowa State Hort. Soc. Rept., 1876-1877, p. 329, mention. (C. sylvatica). 1878. RILEy, C. V. Ins. Mo. Eighth Rept., p. 23. Ravages in the south ; stopping trains. (C. sylvatica. ) SAUNDERS, W. Can. Ent-, Feb. Observations upon the eggs, larvze mature within eggs early in the fall, cari destructive to the eggs. Ibid 5: Habits and injuries of C. sylvatica. Am. Rept. Ent. Soc. Ont. 4. Brief mention. 28-30. Abundance in Western Ont. Life-history, 58 descriptions of all stages, natural enemies with special reference to a species of Zrombidium attacking the eggs. PERKINS, G.H. Fifth Ann. Rept. Vt. Bd. Agr., pp. 257-59. Brief descriptions, life history, remedies. FRENCH, G.H. Ins. Ills. Seventh Rept., p.198. Brief mention. (C. sylvatica). WILLIAMS, JOSEPH. Ann. Rept. Ent. Soc. Ont. 1878, p. 41. Mentions Calosoma scrutator as an enemy of the caterpillars. (C. sylvatica). 1879. SAUNDERS, W. Ann. Rept. Ent. Soc. Ont., 1879, 7-8. Brief refer- erence tofungus disease attacking caterpillars. Ibid,p.22. Brief refer- ence. ; Hay, P. R. Wis. State Hort. Soc. Trans. 1879, pp. 276-78. Brief account. (C. sylvatica.) CuTtinc, H. N.H. Bd. Agr., p. 20. Brief reference. 1880. SAUNDERS,W. Ann. Rept. Ent. Soc. Ont. 1880, p.9. Brief reference. Notes marked decrease in numbers of the caterpillars. (Same Can. Ent. 12.) FRENCH. Sixth Rept. Ills. Norm. Univ., p. 44. Brief reference. 1881. MARTEN, JOHN. Ins. of Ill,, Tenth Rept. pp. 123-4. Briefreference. (C. sylvatica. ) STRETCH, R.H. Popilis 1:68-69. Synonymic notes. 1883. RiLEy,C.V. U.S. Ent. Com. Third Rept., pp. 89, 101. Brief refer- ence. Mistaken for army worm. (C. sylvatica). SAUNDERS, W. Insects Injurious to Fruits, pp. 52-57. Descriptions, life-history and remedies. (C. sylvatica.) CiayvpoLz, HE. W. Can. Ent. 15: 38. Mentioned. [Ent. Soc. Ont. Rept. 1883-84, p. 34. Same.] CaSKE, MATTHEW. Inj. Ins. of the Orchard and Vineyard, pp. 85- 86. Brief account. (C. sylvatica.) 1884. Forsxs,S.A. Ins. of Ill. Thirteenth Rept., p.10, Ravagesin southern Ill. (C, sylvatica.) 1835. FLETCHER, JAMES. Ann. Rept. Central Exp. Farm Can., p. 48. Mentioned. Dimmock, A.K. Psyche, 4:275. Feeding on birch. (C. sylvatica.) 1885. LINTNER, J. A. Third Report, pp. 91-93. Account of injury to apple trees. New England Homestead, 6: 229. Descriptions, habits and remedies. (C. sylvatica.) Forbes, S. A. Bull. Ill. State. Lab. Nat. Hist. ‘Studies on the Contagious Diseases of Insects.’”’ An epidemic of Aluscardine in C. sylvatica (disstria), Ibid.Ins. of Ill. Seventeenth Rept. p.13. Men- tioned. 1887. FLETCHER, JAMES. Ann. Rept. Central Exp. Farm., Can., 1887, Pp. 24-25. Brief general account. P.29. Briefreference. (C.disstria.) 1888, LINTNER,J.A. Fourth Rept., p.178. Brief reference to Dr. Forbes’ experiment with J/uscardine. 59 RILEy, C.V. Ann. Rept. N.J. State Bd. Agr., pp. 498-499. Brief ref- erence, (C. sylvatica.) McMILLAN, Conway. Neb. Agr. Exp. Sta. Bull. 2. Life-history, food plants, natural enemies and remedies. (C. sylvatica). HaRVEY, F.L. Ann. Rept. Maine Agr. Exp. Sta., pp. 128-130. Life- history, descriptions of all stages and remedies. BETHUNE, C. J.S. Ann. Rept. Ent. Soc. Ont., p. 73. Brief reference, remedies. (C. sylvatica, ) 1889. RILEY and Howarp. Insect Life, 5: 58-59. Brief reference to abundance in Maine, where train was reported stopped by the cater- pillars. FLETCHER, JAMES, Can. Ent., 21: 75-76. Brief reference. EDWARD, HENRY. Bull. U. S. Nat. Musuem, No. 35, p. 78. Biblio- graphy. 1890. BRUNER, LAWRENCE. Neb. Agr. Exp. Sta. Bul. 14, pp. 33-38. Life- history, descriptions, food plants, natural enemies and remedies. (C. sylvatica.) PacKARD, A.S. Fifth Report U. S. Ent, Com., pp. 117-118. Life- history, technical descriptions of allstages (C. sylvatica.) LINTNER, J. A. Sixth Report, p. 106. Brief reference to recent out- break in Washington County, N. Y. Especially destructive to sugar maples. (C. sylvatica.) CAULFIELD, F. B. Ann. Rept. Ent. Soc. Ont., p. 64. On Ash. (C. sylvatica.) Harcirr, C. W. Insect Life, 3: 8. Mention. (C. sylvatica.) SmirsH, J. B. Cat. Ins. of N. J., p. 304. Listed. Harvey, F.L. Ann. Rept. Me. Agr. Sta., pp. 105-140. 1891. RILEY and Howarp. Insect Life, 5: pp. 477-8. Caterpillars stopped train in South Carolina. Food plants, Ibid, 3: 157. Parasitized by Limneria fugitiva Say. MourtTFELDT, M. E. U.S. Dep. Agr. Div. Ent. Bul. pp. 26, 40-41. Reports outbreak in vicinity of Minneapolis in 1891. (C. dzssiria.) FERNALD, C. H. Hatch. Agr. Exp. Sta. Bul. 12, pp. 24-26. Brief descriptions of all stages; life history, remedies. TowNSEND, C.H.T. Psyche, 6: 83-85. Parasites. (C. sylvatica.) Dvyar, H. G. Psyche, 6: 29. Listed. Harvey, F. L. Psyche, May ’g91, p. 85. Records Euphoracera claripennis, Macq. and Frontinia frenchii Will, parasitizing forest tent-caterpillar. : 1892. Perkins,G. H. Fifth Ann. Report Vt. Agr. Exp. Sta., pp. 144-59. Kirsy, W. F. Synonymic Cat. of Lepidoptera Heteroptera I. 840. Synonymy. Dvar, H.G. Psyche, 6: 326 and 364. Mentioned. 1893. LINTNER,J.A. Trans. Albany Institute, Aug. 1893, p. 227. Brief reference. SMITH, J. B. Trans. Am. Ent. Soc., 1893, pp. 20 and 36. 60 1894. Dvyar, H.G. Journal N. Y. Ent. Soc., 2: 154. Synonymy. BRUNER, LAWRENCE. Ann. Rept. Neb. State Hort. Soc. 1894, p. 156. Listed. 1895. Comstock, J. H. & A.B. Manual for the Study of Insects, p. 362. ' Brief reference. Dvar, H.G. Psyche,7: 189. Range. 1897. KIRKLAND, A. H. Mass. (Hatch) Agr. Exp. Sta. Bul. 46, pp. 22 and 25. Eaten by garden toad, Mass. State Bd Agr. Rept. on Gypsy Moth, Appendix, p. 56. Podisus placidus attacking the caterpillars. Burcgss, A. F. Mass. State Bd. Agr. Report on Gypsy Moth, Jan. 1897. Appendix, p. 68. Mentioned. CoguiLLetr, D. W. U.S. Dept. Agr. Div. Ent. Tech. Series Bul. 7. pp. 11, 16, 21, 24. Dipterous parasite. Comstock J, H. Insect Life,172. Mentioned. 1898. KIRKLAND, A. H. Mass. State Bd. Agr. Report on Gypsy Moth, Jan. ’98. Appendix pp. 118 and 131. Podisus placidus and Podisus serriventris preying on the caterpillars. Burcess, A. F. Ibid, pp. 107 and 108. Calosoma scrutator and Calo- soma wilcoxt preying upon the caterpillars. FLETCHER, JAMES. Ottawa Naturalist, April ’98, pp. 12-13. Ravages along Ottawa River. FELT, E. P. Fourteenth Report of the State Entomologist, 191-201. ‘Extent of ravages, descriptions, natural enemies and remedies. Country Gentleman, 63 : 450, 551, 567 and 690. Ravages in New York State. 1899. WEED, H. E. N. H. Coll. Agr. Exp. Sta. Bul. 64, pp. 77-98. Extended account inclnding life-history, food-plants, natural enemies and remedies. SLINGERLAND, M. V. Cornell Univ. Exp. Sta. Bul. 170, pp. 559-564. Account of life-history and remedies. Rural New Yorker, 68:74. Brief reference, 449. Brief reference, 624. Brief reference. SLINGERLAND, M V.(?) Rural New Yorker, 68: 463. Review of Bulletin 170, Cornell Univ. Agr. Exp. Sta. Munson, W.M. Rural New Yorker, 58:421. Recommends lead and sulphur equal parts, put on paper and tied around trunks to prevent caterpillars ascending. Hfmphrey ye Z Yr 7 PLATE I, PLATE II. PLATE III. PLATE IV. PLATE V. DESCRIPTION OF PLATES. Ptate I—Areaover which the caterpillars were most destructive in Nex York State during 1899. Flate II.—r. Egg masses, natural size. 2. Caterpillars at rest .. during the heat of the day. 3. Cocoon between two elm leaves, natural size. (Original.) Plate I1I.—1. Nest of apple-tree tent-caterpillars containing both Species, 2. Showing principal difference in markings between the two species. The one on the left ts the apple-tree tent-caterpillar, all about two-thirds grown. Natural size. (Original.) Plate [V.— Young caterpillars congregated upon a small basswood branch. (Original.) Plate V.—Caterpillars congregated upon trunk of plum tree pre- paring for last molt. (Original.) Plate Vl.—First two rows, male and female moths of Clisio- campa disstria Aubn, showing markings and variation in size. Third row, C. disstria var. sylvatica Harr, the two on the left are males and the third a female. Fourth row, C. disstria var. thoraci- coides, Meumoegen and Dyar,; allmales. Fifth row shows grada- tion from light form with tuo narrow dark lines across each fore wing to dark form with dark band across the wings; all males. All natural size. (Original.) Bulletin 170. May, 1899. Cornell University Agricultural Experiment Station, ITHACA, N. Y. ENTOMOLOGICAL DIVISION. w@ EMERGENCY REPORT ON TENT CATERPILLARS. By M. V. SLINGERLAND. PUBLISHED BY THE UNIVERSITY, ITHACA, N. Y. 1899. ORGANIZATION. BOARD OF CONTROL: THE TRUSTEES OF THE UNIVERSITY THE AGRICULTURAL COLLEGE AND STATION COUNCIL. JACOB GOULD SCHURMAN, President of the Waiveraiiye THOMAS F. CRANE, Acting President. FRANKLIN C. CORNELL, Trustee of the University. ISAAC P. ROBERTS, Director of the College and Experiment Station. EMMONS L. WILLIAMS, Treasurer of the University. LIBERTY H. BAILEY, Professor of Horticulture. JOHN H. COMSTOCK, Professor of Entomology. STATION AND UNIVERSITY EXTENSION STAFF. . P. ROBERTS, Agriculture. as CALDWELL, Chemistry. AMES LAW, Veterinary Science. . iH. COMSTOCK, Entomology. . H. BAILEY, Horticulture. . H. WING, Dairy Husbandry. EO. F. ATKINSON, Botany. . V. SUINGERLAND, Entomology. . W. CAVANAUGH, Chemistry. . A. CLINTON, Agriculture. 4 AG MURRILL, Botany. Ww. SPENCER, Extension Work. . L. STONE, Sugar Beet Investigation ISS M. F. ROGERS, Nature-Study. . L. KNISELY, Chemistry. : C. E. HUNN, Horticulture. G. W. TAILBY, Foreman of the Farm. A. R. WARD, Dairy Bacteriology. L. ANDERSON, Dairy Husbandry. emo SoOr €rox Peo OFFICERS OF THE STATION I. P. ROBERTS, Director. E. L. WILLIAMS, Treasurer. EDWARD A. BUTLER, Clerk. Office of Director, Room 20, Morrill Hall. The regular bulletins of the Station are sent free to all who request them. CoRNELL UNIVERSITY, ITHACA, May 22, 1899. HONORABLE COMMISSIONER OF AGRICULTURE, ALBANY. Str: Responding to your request of the 15th inst., for sug- gestions as to the controlling of the forest caterpillar, which has appeared in such numbers in Scoharie and Otsego Counties, 1 herewith submit a bulletin of advice by Professor Slingerland. Professor Bailey has already sent Mr. H. P. Gould, our expert in spraying, into the affected districts. It is now too late, how- ever, to avert the calamity of this year, but it is hoped that the people may be awakened for action during the coming winter and next spring. This emergency bulletin is submitted to be issued under Chapter 430 of the Laws of 1899. I. P. ROBERTS, Director. TENT CATERPILLARS. Commissioner of Agriculture Wieting, reports ina recent letter to Director Roberts that many orchards, in the eastern part of the State are overrun with forest tent caterpillars. The writer is also receiving daily from village authorities in eastern New York, appeals for aid in destroying the ‘vast hordes of the hairy caterpillars of the same insect which are defoliating thousands of beautiful shade trees, especially maples, in many village streets. A trip to Oneonta convinced us that an alarming state of affairs exists wherever this insect occurs in such almost incredible numbers as we saw on many of Oneonta’s fine maple shade trees. Thousands of the shade trees in many New York villages are doomed unless prompt measures are taken to destroy the cater- pillars, or ‘‘ maple worms,’’ as many call them. We began mak- ing observations upon this insect last year, when it stripped the leaves from many maple sugar groves in our State, and we have been watching it this spring, when it seems to be more numerous and destructive all through the state than in many years. Our studies are not yet completed, but there is such a general ‘call for information regarding the insect that this preliminary report, or emergency bulletin, has been hastily prepared to meet the demand. We expect to publish a full account of the forest and the apple tent caterpillars, and will also discuss canker- worms in the near future. ” THE APPLE-TREE TENT CATERPILLAR. Many are familiar with the common apple tent caterpillar (shown in figure ror), its work, and especially its large silken tent which a colony of the caterpillars spin and use as a nest or home. These tent caterpillar nests have been altogether too conspicuous objects in the nearby landscape in most parts of our state during the past twoyears. It is the work of only a few moments to wipe out with a rag, or burn out one of these tents with its writhing mass of worms. The sooner this operation is ‘performed after the nest is begun, the easier and more effectual will it be. Wild cherry trees along roadsides should be destroyed, for they are a favorite breeding-place for the apple tent caterpillars, fall web worms, and other injurious insects. 558 BULLETIN 170. Our orchardists should learn to familarize themselves with the egg-masses of the apple tent caterpillar, for one of the easiest and most effectual methods of controlling the pest is to collect and burn these egg-masses at any time between August and the following April; the egg- mass is very similar to, but a little larger than that of the forest tent caterpillar shown at ¢in figure t1o2. Pay the boys and girls a few cents for each score or hundred of the egg-masses they collect; you will be doubly repaid when spring opens by a decided scarcity of caterpillar nests to wipe or burn out. Those who spray their orchards thor- oughly with Bordeaux mix- ture, to which Paris green or some similar poison has been added at the rate of one pound to 150 gallons of the Bordeaux, report little trouble in controlling apple tent caterpillars by this method alone. Caterpillar nests are usually a scarce article in orchards which have had three thorough applications of the above spray. The first applica- to1.—A trio of Apple Tent Caterpillars, tion should be made just natural size, . before the blossoming per- iod, when thecaterpillarsare very smalland require but little poison to kill them ; the second spraying should follow as soon as the blossoms have fallen,anda third application is usually necessary and advisable about a week or ten days after the second. Unless canker-worms occur in extraordinary numbers in an orchard, Tent CATERPILLARS. 559 not many of them will live through the three applications above specified, if they are thoroughly made, and the same statements will apply to the forest tent caterpillars. Tur LIrE-STORY OF THE TENT CATERPILLARS. In order to combat an insect pest the most effectively, one should know its life-story. This story of the lives of the apple and forest tent caterpillars may be briefly told by the aid of the pictures in figure 102. These two tent caterpillars are dis- tinct kinds of insects but are very nearly related to each other and each has practically the same general life-history, differing only in some details of habits. The story of the Apple-tree Tent Caterpillar (Clisiocampa americana) has been interestingly told in the Teacher’s Leaflet No. 5, which anyone can get free by apply- ing to the Bureau of Nature- Study, Collegeof Agriculture, Ithaca, N. Y. At the date of writing (last week in May), the forest tent caterpillars (Ciiszocampa dis- stria) are nearly full grown ; the picture at c in figure 102 was recently taken from life, 102.—The Life-story of the Forest Tent Cater- pillar. m,male moth ; f, female ; p, pupa ; In about two weeks, or early @, ege-ring recently laid; g, hatched egg- : 5 ring ; ¢, caterpillar. Moths and caterpillars in June, the caterpillars will are natural size, andeggs and pupa are e slightly enlarged. be seen wandering about seek- ing a suitable place to undergo their wonderful transfor- mations. They may select a leaf on or under the tree on which they fed, as did the one shown in the frontispiece, or some angle in your house or rail-fence may afford a more suitable place. Here the caterpillar will begin to spin about itself a white é 560 BULLETIN 170. shroud orcocoon, composed of silken threads, in which are mixed the hairs from its own body and the whole is given a powdery appearance by the caterpillar ejecting a liquid which becomes a yellowish powder upon drying. A cocoon is shown in figure 103. Within this cocoon the caterpillar soon chaages to the curious brown object—a pupa—shown at pin figure 102. In about ten days or two weeks after the cocoon is spun, or during the latter part of June, there emerges from it the adult insect—a buff- brown colored moth marked with a slightly darker band across each front wing; m and/ in figure 102 represent the male and female moth respectively. The moths fly mostly at night and are often attracted to lights. Soon after emerging, the female moths deposit their eggs in masses of about two hundred each around the smaller twigs, as shown ate in figure 102. The eggs are covered with a varnish- like substance ; at g in figure 102 is shown an old, hatched egg- mass with the varnish-like coating worn off. The eggs thus _ deposited early in July will remain unhatched until the following April. Thus there is but one brood of the caterpillars in a year. A very important difference in habit between the forest and the apple tent caterpillar should here be emphasized. Itisthis: A colony or family of forest tent caterpillars hatching from thesame egg-cluster, like their near relatives, work and live together during most of their life but they never make any tent or nest. ‘The only approach to a web made by the forest tent caterpillars is athin carpet spun on the bark or sometimes over several terminal leaves on which the whole family 103.—Cocoon spun by a Forest usually rest in a cluster (as shown aoe Se oie "a maple in figure 104) during the day or when they are shedding their skins. TENT CATERPILLARS. 561 METHODS OF COMBATING THE ForEsSt TENT CATERPILLAR. Fortunately both the apple and the forest tent caterpillars are preyed upon by many enemies, including insects, spiders, toads and birds. Where the forest tent caterpillars confine their work to their native haunts—the forest trees—we must depend largely upon these natural enemies to hold the insect in check. That these enemies are capable of doing this is evidenced by the fact that this insect usually appears in alarming numbers only at long intervals and its outbreaks usually last only a few years, as their enemies soon reduce their numbers to the normal. We visited several maple ‘‘sugar bushes ’’ last year where the caterpillars had just finished stripping the foliage from all the trees, and we never saw so many parasitic foes; the little Ichneumons and Tachina flies were surprisingly numerous and busy getting in their deadly work on the caterpillars. Most owners of ‘‘ sugar bushes ’’ will have to depend on these little friends to check the depredations of the forest tent caterpillars, because it would usually be too expensive a job for an individual owner to under- take to combat the pest in hissugar grove. We hopeand believe that the enemies of the caterpillars can be depended upon to get the upper hand and control the pest in the forests and sugar groves of New York in a year or two. Where the forest tent caterpillars are present in alarming numbers in fruit or shade trees, however, the case is very different, and man should take prompt measures to check their ravages. In orchards the methods of gathering the egg-clusters and spraying with Bordeaux and Paris green, discussed on a pre- vious page, will usually control the forest tent caterpillars. The presence of these caterpillars is not so readily discovered because they erect no tent or ‘‘signboard’’ in the tree as does the apple tent caterpillar. The two kinds of caterpillars often occur in the same tree. The control of the forest tent caterpillar on village shade trees is a special problem, but not a difficult one, we believe. Enlist the aid of the school teachers, and the school children will soon become an invaluable army to help in protecting the trees. Let a few public spirited citizens or the village Board offer a prize to 562 BULLETIN 170. those pupils who collect over a certain number, say 1,000 or 10,000 of the unhatched egg-clusters at any time between August ist and April 1st of the following year; or pay the children a certain sum, a few cents for every hundred unhatched egg- clusters collected. All egg-clusters collected should be burned. The rivalry between the children will soon spread to rivalries between schools and the result will be that the number of the caterpillars will be reduced to the minimum by a single season’s crusade of the children ; and what may be of more value still is the fact that the teachers, children, and many citizens will get lots of fun out of the warfare and all cannot help but learn a very instructive lesson in Mother Nature’s ways. The above suggestion is not a theory, for just such a crusade has been successfully carried out even in so large a city as Rochester, N. Y. We believe there is no cheaper, and more instructive method of controlling these forest tent caterpillars in village shade trees. Begin the warfare in August or September, 1899, or better, after the leaves have fallen so that the eggs can be more easily seen on the twigs, and keep it up until the last egg-cluster is burned before April 1st, 1900. Let the beautiful and valuable shade trees begin the new century free from the devastating caterpillars. Shade trees can be, and have been, sprayed with a poisonous mixture and these forest tent caterpillars killed thereby. But the spraying must be done early in the spring after the little caterpillars hatch, when the first leaves are unfolding ; and to spray large shade trees requires very expensive ($250.00 at least) apparatus, and experienced men to operate it. It is the nastiest kind of work, and the chemicals would be quite an item. Hence it is doubtful if spraying could be successfully employed to con- trol these caterpillars in many villages. When the caterpillars get half or two-thirds grown as they are now (last week in May) they are so large that it would be a very expensive matter to feed them enough Paris green to kill them. We believe it would be cheaper, easier and more effectual, to either enlist the children, or to carry on a vigorous warfare against the nearly full grown caterpillars during the latter part of May and the first week or two in June along the following lines : Tent CATERPILLARS. 563 Colonies of the caterpillars can be seen at almost any time of day clustered together on the bark of the trunk or large branches of the infested trees. Such a cluster of caterpillars is shown in figure 104. The apple tent caterpillar may usually be found in its nest during the day, but its forest relative makes no such retreat or home. Where these clusters of caterpillars occur in reach on the trunks of the trees it is an easy matter to sweep them off and crush them. It is also an easy matter to dislodge the clusters occurring high up in the tree on the branches. One has simply to climb the tree with a padded mal- let and suddenly jar (shaking will not do) the branches on which the caterpillars are clustered, when nearly every caterpillar will drop to the ground as if shot, some spinn- ing down by a silken thread, which, how- ever, they seem to be unable to ascend as a canker-worm does. One should not be sat- isfied with jarring the caterpillars onto the ground, but a sheet or canvass should have been previously spread beneath the tree, and someone employed to at once sweep the caterpillars into some 104.—A family of Forest Tent Caterpillars rest- receptacle where they 7g during the day on the bark, about one third natural size. can be burned or otherwise destroyed. ‘Two men could thus remove and destroy nearly all the forest tent caterpillars on a large shade tree in a few minutes, and thus stop the breeding of the insect for the next 564 BULLETIN 170. season. This jarring method is also applicable to orchards, and is in fact the only practicable method to reach the caterpillars after they are half or two-thirds grown, or after May 2oth in most localities in our state. The method can be practiced by individual owners of fruit or shade trees, but where village shade trees are infested, we would recommend that the village authorities hire two or more men, equip them with padded mallets, brooms, and sheets, and have them make a busi- ness of examining every shade tree and killing the caterpillars, All of the shade trees in a village could be thus gone over ina few days and millions of the caterpillars destroyed before they can transform. A second scrutiny of the trees by the same gang of mena few. days later would doubtless pay. One hundred dollars expended in this way, zow, by a village, to combat these caterpillars would not be felt by the individual tax-payers, and would doubtless result in saving the lives of shade trees worth ten times this amount. It would not be advisable to trust to individual property owners to jar their trees, for many would not do it, and thus would breed a crop of the caterpillars for their neighbors the next season. Cotton batting, coal tar, or similar bands put on trees to pre- vent the caterpillars from crawling up, will avail but little in reducing their numbers, for only those which fall from the trees or happen to wander from the defoliated trees will thus be kept from going up. : These hordes of tent caterpillars which are now ravaging shade and fruit trees in our state can be readily controlled if prompt and intelligent action be taken. M. V. SLINGERLAND. BY CLARENCE M. WEED The caterpillars lay their eggs on the branches of apple trees, and being hatched by the warmth of the spring, they form clusters, and inclose themselves in a web, whence they issue forth in quest of food, and destroy the leaves of this and other trees.—Jeremy Belknap, His- tory of New Hampshire, 1792. NEW HAMPSHIRE COLLEGE - AGRICULTURAL EXPERIMENT STATION DURHAM Bulletin 38 August, 1896 These pernicious pests spread in every direction from the trees of the careless and the indolent to those of their more careful and industrious neighbors, whose labors are thereby greatly increased, and have to be followed up year after year without any prospect of permanent relief—T. W. Harris, 1841. A WILD CHERRY TREE IN “THE LeaFy MonrTH OF JUNE” There is certainly no justice or reason for permitting a few or many men ina community to shield and shelter insects that will soon swarm over the grounds of neighbors, but as nothing less than the severe lash of the law will reach the stolidly indifferent in such matters, we are forced to submit and fight these enemies as they invade our gardens and orchards.—ANDREW S, FULLER, 1893. THE TENT CATERPILLAR BY CLARENCE M. WEED MONG the many insect pests of the Granite State none is more in evidence during spring and early summer than the Tent Caterpillar,* which for more than a century has ravaged the orchards of New England. In 1790 Samuel Dean wrote from Portland, Mass.: ‘' The principal inconvenience the farmer meets with from caterpillars is the damage they do to his orchard. A hairy kind of caterpillars build their nests on apple trees in May, and are gone entirely in June. But they feed so industriously on the leaves as to destroy a great part of them if they be not timely prevented. As they are far less mischievous than the canker-worm, so they are more easily subdued.’ F Fifty years later Dr. T. W. Harris, of Cambridge, Mass., wrote of ‘* the caterpillars that swarm in the unpruned nurser- ies and neglected orchards of the slovenly and improvident husbandman, and hang their many coated webs upon the wild cherry trees that are suffered to spring up unchecked by the wayside, and encroach upon the borders of pastures and fields.” During recent years these insects have also been very abun- dant, and have often defoliated orchards, either alone or with the assistance of the canker worm. Apparently, many people do not realize the seriousness of *Clisiocampa americana. + New England Farmer or Georgical Dictionary, 1790, p. 41. 48 THE TENT CATERPILLAR the injury when a fruit tree is stripped of its leaves. In its effort to repair the damage the tree will put out new foliage, thereby using up the stored materials that otherwise would be utilized for growth or fruit. Even in case no blossoms appear the season the damage is done, so that no loss of fruit that year may be felt, the effects will be evident in next year’s crop. The preservation of the leaves in wholeness and health is necessary to the preservation of the tree ina profitable condition; the orchardist cannot afford to have the leaves removed or injured. Fic. 3.—Apple Leaves eaten by Tent Caterpillars (Original) The injury done by the tent caterpillar is at once distinguished from that of the canker worm by the fact that the former eats the body of the leaf, veins and all, leaving only the midrib or larger veins (Fig. 3), while the canker worm feeds upon the surface of the leaf, leaving the brown network of veins. A severe attack of the tent caterpillar renders the tree almost as bare in June as it is in mid-winter—a condition shown in the illustration on the second page of this bulletin—while a similar attack by the canker worm gives the tree a brown appearance, somewhat as if it had been scorched by fire. THE HISTORY OF A CATERPILLAR’S LIFE EW insects pass so long a portion of the year within the eggs as do the Tent Cat- erpillars. In July the eggs are laid in masses of 200 or more in a cylindrical cluster upon the twigs of apple and wild cherry. After they are deposited the parent moth covers them with a viscid liquid, which dries into a sort of varnish that completely coats them, as represented in Fig. 4. The insect remains in this egg state from July until the following spring, when the little caterpillars emerge from the eggs and begin feeding upon the ten- der foliage of the buds about them. Ina few days they begin to make a silken tent, utilizing generally, for this purpose, a fork of the branch. As time goes on the nest is enlarged. The caterpillars retire to the Fie. 4 Egg Mass tent at night, and during cold and wet (Original) weather, and when not feeding. They have regular times for their meals, leav- ing and returning to the nest in processions. They become full grown in about six weeks, being extremely voracious dur- ing the latter part of their development. They are then nearly two inches long, with a hairy body, ornamented with a dis- tinct white stripe along the middle of the back, on each side of which are numerous short, yellow, longitudinal lines, rather irregularly arranged. The sides are partially covered with paler lines, spotted and streaked with blue, while the lower surface of the body is black. The full-grown caterpillar is represented in Fig. 5. When the caterpillars become full grown most of them leave the tree where they have developed, and craw! about in search of shelter. Early in June thousands of these caterpillars may be seen rapidly crawling along the ground, especially by the 50 THE TENT CATERPILLAR ANN At Fig. 5.—Tent Caterpillar (After Riley) roadside. When they find a satisfactory situation, beneath a board, in the cracks ofa fence, or between pieces of rough bark, they spin an oval, silken cocoon (Fig. 6), yellow when completed, within which they change. to the quiet pupa or chrysalis state. Fic. 6.—Cocoon of Tent Caterpillar (Original) THE TENT CATERPILLAR 51 Two or three weeks later another change takes place, and from each cocoon there comes forth a reddish-brown moth (Fig. 7). The male moths are considerably smaller than the = females. These moths are nocturnal, flying only at night, and are to be found throughout the greater part of July. The females deposit the eggs upon the twigs of trees and soon die. As already stated, these eggs remain unhatched until the following spring. Fic. 7.—Female Moth (After Riley) THE EXTENDING RANGE OF FOOD PLANTS The ordinary food-plants of the tent caterpillar are the apple and the various kinds of wild cherry. The moths apparently choose these in preference to all other trees for the reception of the egg-masses. But during the outbreaks of the insect in New England the last few years, as in fact in previous outbreaks in other regions, many of the caterpillars have been forced by hunger to attack the foliage of other trees and shrubs. In many localities the leaves of the apple and cherry trees upon which the insects fed when first hatched, have been wholly devoured before the caterpillars were half grown. Of course this must be the result when more egg-masses are laid upon a tree or shrub than can be matured upon its leaves. Thus threatened by star- vation the caterpillars have been forced to leave their nests, descend to the ground, and crawl about in search of food. Many of them ascend the nearest trees and shrubs, and nibble at their leaves. If these: leaves are. not too distasteful the caterpillars are likely to remain and complete their growth upon the new food-plant thus found. If the insects are unable to live upon the leaves they are likely again to crawl away in quest of some- thing better. Doubtless thousands of them perish outright in this search for food, while myriads of others prematurely change to pupe, and either die before maturing into moths, or develop into feeble adults. But it is very probable that many of these caterpillars which are able to complete their larval growth upon new food plants 52 THE TENT CATERPILLAR will survive all vicissitudes and mature into moths that appar- ently are likely to deposit eggs upon the variety of tree that has furnished them food. In this way the insect will be likely soon greatly to extend the limits of its food-supply, and become much more difficult to subdue than it now is. The case is sug- gestive of the famous Gypsy Moth, that has lately been causing such alarm in Massachusetts. The unusual noxiousness of this Fic. 8.—Oak Tree partially defoliated by Tent Caterpillars (Original) pest arises from the ability of the caterpillars to feed upon leaves of all sorts—hard wood trees, evergreens, shrubs, and herbaceous plants. Therein lies its menace; and if the tent caterpillar is permitted to continue establishing itself upon new food plants, our descendants may have a somewhat similar pest to contend with. ‘ FOOD PLANTS 53 That this is not an imaginary danger can be seen from Fig. 8, and from other photographs which we took but have not reproduced in this bulletin, showing the work of the tent cater- pillar upon trees and shrubs not on its usual bill of fare. And the most suggestive fact in connection with these changes of food is to be found in the great dis- similarity of the other food plants. The apple and cherry belong to the great rose family of plants ; botanically speaking they are related to each other as well as to the rose, the peach, the pear, the plum, the mountain ash, and others. It is well known that insects have family preferences in the matter 4 of food; that if a given 4 insect feeds upon a given Fic. 9—Diseased Tent Caterpillars (Original) plant we need not be sur- prised to find it also upon another plant closely related, belong- ing to the same family. In view of this we should expect the tent caterpillar when it was forced to increase its range of food to attack the peach, culti- vated cherry, rose, and other plants of this family. This has been done, and each of these is now on the tent caterpillar’s food list, but we have also found it feeding freely and appar- ently thriving upon such widely separated plants—so far as botanical kinship is concerned—as the oaks (Fig. 8), the hicko- ries, the birches, (see photograph on title page,) the barberry, and the willows and poplars. I found a large tent even upon the low evergreen known as the juniper, but the caterpillars from it evidently fed upon a neighboring barberry. DISEASES AND OTHER NATURAL ENEMIES During the latter part of the caterpillar season one can frequently find dead and dying caterpillars upon the outside of the tent, stretched at full length. Some of these will be simply sluggish, others evidently nearly dead, others dead and ruptur- ing at a touch, letting escape the liquid decomposed body con- tents. Some will be hanging by one end of the body to the tent or twig, as shown in Fig. 9. These caterpillars appear to be affected by one of the bacterial diseases that are known to develop in many insect larva when they become very abun- dant. The army worm and common cabbage worm are fre- quently destroyed in great numbers by such diseases. While there appeared to be more of these diseased larve this year than last in southern New,Hampshire, the disease was not suffi- ciently destructive to give great hope for the immediate sup- pression of the outbreak. The fact of each colony being somewhat isolated from others will tend to prevent the germs from affecting all the caterpillars of a region. After the tent caterpillars are half grown there may be found in many of the nests small dead specimens with the body swol- len and the skin dry and hard. (Fig. 10). If these are placed in bottles by themselves, a fortnight or so later small four-winged flies will emerge from them. Fic. 1o—Parasitized Cater. These are parasitic ichneumon flies. piles -qoaginal) They have developed from eggs placed in the young caterpillars by ,similar parent flies. The eggs hatched into grubs or larve that developed on the inside of the caterpillars, killing them and absorbing all the bodies except the skin. Within the latter the larve pupated, to emerge later as flies. We reared many of these parasites, which were kindly determined by Mr. L. O. Howard as Pimpla inguisitor. Comparatively few birds feed upon hairy larve like the tent caterpillar, but some, like the cuckoos and blue jays, devour them eagerly. The European cuckoo is said to regurgitate the mass of hairy skins swallowed with the caterpillars, and prob- ably our species have the same habit. Many observers have noticed that both the Black-billed and the Yellow-billed Cuckoos NATURAL ENEMIES 55 feed upon the tent caterpillars. For example, Mr. C. E. Bailey states :* ‘* On May 104 Black-billed Cuckoo came into a tree near me at 3 Pp. M., and sat there until 4:40 Pp. m., then he went straight to a tent caterpillar’s nest. He looked it over fora short time, and then commenced eating the caterpillars. He picked twenty-seven caterpillars out of the nest before he stopped. The bird ate them all and did not drop one.” Mr. E. H. Forbush gives* the following list of birds found Fic. 11.—Yellow-billed Cuckoo (After Brehm) feeding on tent caterpillars in a Massachusetts orchard in 1895 : Crow, Chickadee, Baltimore Oriole, Red-eyed Vireo, Yellow- billed Cuckoo, Black-billed Cuckoo, Chipping Sparrow, Yel- low Warbler. Other birds have also occasionally been reported to feed upon these pests, but birds do not do so much toward their destruction as they do toward the destruction of the can- ker-worm, the latter being a much more edible insect. My observations upon the natural checks upon the tent cater- * Mass. Crop Report, July, 1895, p. 29 56 THE TENT CATERPILLAR pillar lead me to believe that it is not good policy to depend upon them for subduing the pests. It will.be much better for the intelligent people of each community to attempt to arouse public opinion so that each man will destroy the caterpillars upon his own premises and along the adjoining roadsides. METHODS OF DESTROYING TENT CATERPIL- LARS The tent caterpillar is open to attack in a variety of ways, and should by no means be allowed to injure orchards and dis- figure the roadsides as it has been doing recently. Beginning with the eggs the principal remedial measures may be summa- rized as follows: 1. Destroying the Eggs.—During winter and early spring the egg masses may readily be seen upon the smaller branches, and are easily removed and burned. In this work boys may be employed to advantage ; their sharp eyes and nimble limbs are likely to accomplish as much as their elders. A few winters since a society in a Massachusetts town offered prizes to the youngsters of the community for the collection of the tent caterpillar egg-masses, and thousands were thus destroyed. The same result may to a large extent be accomplished by cut- ting off and burning the thickets of wild cherry that line the roadsides, and stand in clusters in pastures and fields. This should be done after the eggs are laid, and before they are hatched—any time between September 1st and April 1st would do. Ifina given community the eggs on these wild cherries were thus destroyed the next season’s crop of worms would be greatly lessened, and attention could be concentrated on the tents in theorchards. Sucha burning of the wild cherry would also destroy millions of spores of black knot—the fungous dis- ease that is always threatening cultivated plums and cherries because of its almost universal presence on the wild cherries. The pest-breeding, neglected apple trees bearing natural fruit, so often seen along the roadside, should also be converted into firewood, and the branches burned during fall or winter. 2. Killing the Young Caterpillars.—When the caterpillars are young and the nests are small, it is easy to destroy the REMEDIAL MEASURES 57 colony by swabbing it out of the crotch with a mass of rags, a gloved hand, a forked stick, a scrubbing brush, or almost any- thing that can be used to crush the tiny worms huddled beneath the tent. Ofcourse this destruction should take place when the caterpillars are at home rather than when they are abroad on the branches feeding. In rainy weather one can generally find them in the tent almost any time, while in fair weather - they may be attacked either early or late in the day. The colony can also be removed by taking hold of the outside of the tent with the hand and lifting it with the worms inside: then drop it to the ground and step on it. When the tent is on a small branch the latter may be cut off and then burned or crushed. ‘+A slender pole long enough to reach the highest nest in the tree,” writes Mr. A. S. Fuller, ‘* with two or three shingle nails driven through the end, leaving the heads sticking out a half inch, makes a very handy and efficient implement for dislodging the nest and caterpillars. By thrusting the end into the tent and then twisting it around two or three times the tent will be rolled about the end and can be drawn forth with contents,” and destroyed. There appears to be a considerable variation in the time of hatching of the different egg-masses, so that it is often necessary to go over the trees more than once to get all the nests. As a rule one should not be satisfied with a single attack upon the pests, but should renew the battle if necessary. 3. Burning with Torches.—A rather common method of -destroy- ing tent caterpillars is to burn them out by means of some substance sat- urated with kerosene. An asbestos torch advertised by the seedsmen and implement dealers for this purpose is represented in Fig. 12. The asbes- tos is saturated with kerosene, light- ed and held under the tents for the cremation of the caterpillars. Rags tied to the end of a pole and satu- Fic. 12.—Asbestos Torch 58 THE TENT CATERPILLAR rated with kerosene are also used, as well as various other devices. But burning is a remedy which is likely to cause more harm than good. It may not injure the tree much, but-one is always tempted to use it on the larger branches where the bark is very likely to be seriously damaged. I have seen a fine young apple tree killed by the use of a torch on its tent caterpillars, and have known many larger trees to be seriously injured in the same way. 4. Spraying with the Arsenites.—On many accounts there is no more satisfactory method of subduing the tent caterpillar in the orchard than by spraying with Paris green or London purple mixed with water. Not only is this pretty certain to kill off all the young caterpillars on the trees, but it also destroys canker worms and also other leaf- eating caterpillars as well as the larvz of the Codling Moth or Apple Worm, discussed in Bulletin 35 of this Station. Fortunately spraying has been adopted by a great many commercial fruit-growers as an essential part of the season’s opera- tions, and the practice is growing in favor yearly. Four or five ounces of Paris green, with a pint or two of fresh lime water, are added to a bar- rel holding forty or fifty gallons of water, thoroughly mixed and sprayed upon the trees soon after the worms hatch, by means of a force pump and spray nozzle. A simple and effective spray- ing outfit; which has been used to good advantage in the experiments at this Sta- tion, is represented in Fig. Fig. 13 REMEDIAL MEASURES 59 -13. It consists of a kerosene barrel holding fifty gallons, a force pump having a double discharge, with a short line of hose running into the barrel to keep the liquid stirred, and a long line of hose fitted at the end to a slender brass rod tipped with a spray nozzle. This outfit can be obtained through any hardware dealer, or direct from any of the nu- merous manufacturers of spraying machinery. Fic. 14.—Tent Caterpillar on Oak (Original) The Forest Tent Caterpillar SECOND REPORT BY CLARENCE M. WEED NEW HAMPSHIRE COLLEGE AGRICULTURAL EXPERIMENT STATION . DURHAM Bulletin 75 May, 1900 Fic. 37 —Distribution of Forest Tent Caterpillar in New Hampshire, 1899. Circles, caterpillars present; circles with dot, rather destructive; circles with cross, very destructive. THE FOREST TENT CATERPILLAR BY CLARENCE M. WEED ce 4 The outbreak of the Forest Tent : Caterpillar in New Hampshire in 1899 was more widespread and seri- ous than during any previous year of which we have record. A very great amount of damage was done to maple sugar orchards, shade trees, and apple orchards, as well as to the general forest growth; and eggs were laid for a 1900 brood of worms, which, in many localities, at least, threatens to be equally destructive. The present bulletin is issued to furnish the people of the state with the latest available infor- mation regarding the pest, both as to its habits and life his- tory, and as to the means of combating it. In the bulletin I have embodied the results of the observations made last sea- son by myself and my assistant, Mr. W. F.. Fiske, as well as several valuable observations kindly communicated to me by Miss Caroline G. Soule, who studied the insect at Brandon, Vermont, and the notes of more than one hundred correspond- ents who kindly replied to a circular letter I sent out. A few of the paragraphs are reprinted without important change from Bulletin 64, issued a year ago. F1c.38.-Cocoon in Barberry Leaves. DISTRIBUTION IN 1899 The localities in which these caterpillars were destructive last season are indicated in the map.on the inside front cover of this bulletin. The circles with a cross inside indicate places. TIO THE FOREST TENT CATERPILLAR of very serious damage; those with a dot inside, less serious damage, and the simple circles, places where the insects were numerous enough to be noticed by our correspondents, but were not very destructive. It is likely that many of these latter places will have the insects in greater numbers this season. An interesting fact brought out by the preparation of this map is that the insects seem to follow rivers closely in their spread from one locality to another. The injury has been most severe along the Connecticut river, where the insects first appeared in destructive numbers about four years ago. THE LIFE HISTORY OF THE INSECT These Forest Tent Caterpillars pass the winter within the eggshell, the eggs being attached to the twigs in cylindrical rings, more or less covered with a grayish varnish. In spring, when the leaves of the trees begin to unfold, the young cater- pillars gnaw through the eggshells and come forth. They are then tiny creatures, scarcely one tenth of an inch long, show- ing under a lens that the blackish body is thickly covered with rather long brown- ish, or grayish, hairs. The tiny caterpillars feed upon the ten- der leaves of the ‘twig near where the egg-mass was placed. In‘ about two weeks each increases in size to such extent that the skin in which it came from the egg is too small Fic. 39.—Cast skins of Forest Tent Caterpillars. for it. This skin } 1 - ‘ . Fic. 40.—A mass of Caterpillars on the trunk of a crab-apple tree. (Photographed by Dr. F W. Russell.) 112 THE FOREST TENT CATERPILLAR then splits open along the back, and the caterpillar crawls out, clad in a new skin that had gradually been forming beneath the old one. This skin-shedding process is called moulting: it is the general way in which insects provide for increase in size. Some of the cast skins are shown in Fig. 39. Wherever they go, these little larve spin a silken thread which marks their pathway, although the thread is so slender that a single one is generally to be seen only through a lens, but in places where the larvae congregate to rest when not feed- ing, a habit that they have, it becomes quite noticeable. It is especially so after moulting, for then one can often find on the end of a forked twig such a miniature tent as is represented in the picture on the title page of this bulletin, the cast skins being intermingled with the silken threads. Soon after the first moult the caterpillars begin feeding again, eating, of course, more and more of the foli- age as they become larger. A week or so later they again moult, a process which is repeated twice, thereaf- ter, at similar intervals. At. the time of the later moults, the caterpillars are in the habit of congregating upon the trunks or larger limbs of the tree, often not far from the ground. Beneath the mass of larve there is an inconspicuous web, in which the feet are more or less entangled. The ap- pearance of the caterpillars at such times is well shown Fic. 41.—Cocoons in Apple Leaves. in the photograph repro- duced in Fig. 4o. At the end of about five weeks from the time of hatching from the egg, the Forest Tent Caterpillars become full grown in this, THE LIFE HISTORY OF THE INSECT 113 their larval state.. They are now ready to enter upon the next stage of their exist- ence, that of the pupa, or chrysalis. This is a quiet stage, in which the insect takes no food, and is unable to move about, and it needs to protect itself from its various enemies. Conse- quently, each cater- pillar spins from cer- tain silk glands in the mouth a shroud of silken threads, sur- Fic. 42.—Cocoon in Currant Leaves. rounding itself by an oval cocoon composed of several layers of silk, the outer ones much looser than the inner, with Fic, 43.—Cocoon on Fringe-tree. the hairs of the caterpillar inter- mingled with the silk on the inside layers. When this co- coon is first spun it is white, but the caterpil- lar soon colors it yellow with an excretion from the body. The caterpillars generally prefer some sort of frame-work to build their co- I1t4 THE FOREST TENT CATERPILLAR coons upon.. They commonly choose the leaves of trees for this purpose. Sometimes a single large leaf will be used, its edges being folded over, as in the case of the cocoons in apple and currant leaves, shown in Figs. 41, 42 and 48, while, at others, several smaller leaves may be deftly drawn together, as in the barberry leaf cocoon shown in Fig. 38. Ifthe insect happens to. be in a pine tree it will utilize the pine needles for this purpose, and even such delicate structures as the panicles of the smoke bush or fringe tree may serve the purpose. (Fig. 43.) Where the caterpillars are numerous, the foliage of the trees is almost wholly webbed up when the cocoons are made, giving the trees a strange, bunchy appearance. Many of the caterpillars, however, leave the trees, and seek shelter in other situations, such as crevices in the rough bark, beneath boards .or stones upon the ground, in the crannies of a fence, along the clapboards or beneath the gables of buildings. Wherever the cocoon is spun the caterpillar inside of it soon changes'to a pupa or chrysalis—an oval brown object without Fic. 44.—Moths of Forest Tent Caterpillar; «, male; 4, female, Natural size. legs or wings, able to move only by a feeble wriggle of its body. In this condition it takes no food, but its tissues undergo such remarkable changes that about ten or twelve days after the cocoon is made, a buff-brown moth emerges from the chrysalis and makes its way through one end of the cocoon. This is the adult form of the Forest Tent Caterpillar. The male moths are slightly smaller than the females, as may be seen from Figs. 44a and 4, the first of which represents the male and the second the female, both natural size. The moths generally make their appearance the latter part 4 THE LIFE HISTORY OF THE INSECT 115 of June. Soon afterwards the females deposit their eggs in masses of about two hundred, each upon the twigs. The moths, having completed the cycle of life, die soon after the eggs are laid. The eggs thus deposited early in July are to remain un- hatched until the following spring. The actual formation of the tiny caterpillars from the contents of the egg takes: place, however, within a few weeks after they are laid. The minute but fully-formed caterpillars may be found within the egg shells, by a careful examination, any time between September and the following April. The caterpillars remain during this long period quietly confined within their narrow houses, but when the warmth of the spring sunshine penetrates ‘their abodes, they eat off the tops of the egg shells, and come out ready to break their long fast upon the tender foliage of the opening buds. As aresult of much patient. watching, Mr. Fiske was fortu- nate enough to observe one of the moths depositing her eggs. He has recorded his observations in his notes as follows: On the afternoon of June 27, three pairs of freshly-emerged Clisiocampa disstria moths were found in the breeding cages mating, and two of them placed, without separating, under a bell jar with some green twigs of apple. At8 p. m. one pair had separated, and the female was very active, buzzing around the interior of the bell jar. Fifteen minutes later she had taken notice of the apple twigs, and was more slowly crawling over them. By g o’clock she had selected a site for an egg ring, and had just begun its deposition. About a dozen eggs were laid at this time, in the form of a right triangle, one side forming what was to be one edge of the future egg ring. On what would correspond to the hypothenuse of this triangle she was now busy depositing more eggs, making each row longer and increas- ing consequently the width of the future band, still keeping the general form of the egg mass the same. The placing of the first egg in each row is accomplished with some difficulty, and is also a matter of some delicacy, for if it is not placed correctly, the whole band may suffer; but after this is done, the remainder are easily fixed in their proper positions, the abdomen, which is stretched nearly to its limit, so moving that each egg slips into the space between the end egg on the row under construction, and the corre- sponding egg in the row just completed. The eggs are laid at intervals of about half a minute, and after each is deposited there is a second’s pause, followed by a little pile of bubbles of creamy whiteness, which rise around it and help to form the tough, protecting winter coat. It is very difficult to get a good view of the operation at close hand, on account of 116 THE FOREST TENT CATERPILLAR the position in which the wings of the moth are held, drooping and well covering the abdomen, and it cannot be stated with certainty whether the egg itself is deposited just before or just after the extrusion of the froth. The width of the band being decided upon, the rows are made of uniform length thereafter and the girdle begins to take form. In the case under observation, as the moth was undersized the band was a narrow one, and the number of eggs in each row was about seven. When the band was nearly completed, after about an hour’s work, the moth was disturbed, and for the remaining distance the rows were anything but regular. Whether as a result of this break or otherwise, there were a lot of eggs left over after the ends of the band were united, and these were deposited slowly and irregularly, with much preliminary feeling about on the lower edge of the band. This part of the operation required above an hour, or as long for the placing of a few dozen eggs as it did for the construction of the girdle proper. The whole time, from the first observation until the egg mass was finally left, was about two and a half hours. The moth did not long survive the completion of the ring, but within a few hours, before it had been a whole day in its perfected form, it died. A condition that has been repeatedly noticed during the last three years seems to indicate that in general the instinct of the moth teaches it to deposit eggs only on trees bearing leaves at the time the eggs are laid. When a maple orchard is defoliated one year, it is likely. to escape the next year, unless it is invaded by caterpillars hatched on the surrounding trees. The moths that develop on such a lot of defoliated trees apparently fly to the surrounding trees that still bear leaves before depositing their eggs. Of course this habit is of advantage to the insect, for the chances of a sufficient food supply for. the caterpillars are greatly increased by it. In some cases, however, the explanation is that the caterpillars completed the defoliation of the trees before they were full grown, and then migrated to new feeding grounds. THE POPULAR NAME OF THE INSECT There has been considerable discussion of late among ento- mologists as to the best popular name for this insect. As was said in my former bulletin, “its common name, Forest Tent Caterpillar, is not very satisfactory, because, first, the insects are as likely to be found in apple orchards as in forésts; and, second, they do not make tents in the complete sense that the THE POPULAR NAME OF THE INSECT 117 Fic. 45.—Caterpillars feeding upon Elm Leaves. nearly-related American Tent Caterpillar does.” Various sub- stitutes for this name have been recently proposed, none of which, however, seem to me sufficiently satisfactory to warrant achange. Mr. ™M. V. Slingerland of New York has proposed that the insect be called the Forest Tentless Caterpillar, but the objections to this are, first, that it is not absolutely a tent- less caterpillar, many of the caterpillars making in early life miniature tents, like the one shown on the title page of this bulletin; and, second, as Dr. L. O. Howard has pointed out, there are a great many other tentless caterpillars that’ feed upon forest trees. . 118 THE FOREST TENT CATERPILLAR DESCRIPTION OF THE LIFE STAGES Egg.—tThe egg mass of this Forest Caterpillar is in the form of a belt encircling the smaller twigs of the various food-plants. Its general shape is represented in Fig. 46, the length of the belt varying from one fourth to one half of an inch; the diame- ter is usually one fourth of’an inch.. The belt terminates abruptly at each end, although it is not as a rule squared off. The outside of the belt consists of a glistening, varnish-like, brownish or lead-gray material, which covers the eggs. When the eggs are first laid, and for some months after- ward, this covering remains entire, but as the winter passes it becomes more and more broken, so that by spring it generally has a rather rag- ged appearance. By removing the covering the eggs will be found be- neath, resting side by side at right angles to the supporting twig. Each egg is a trifle longer than wide, and is covered with a reticulated network of the same varnish-like material that conceals the mass as a whole; this network serves to attach the eggs to the twig and to each other. The eggs are of a dull gray color, showing white in some places. When the caterpillars hatch they gnaw off a circular cap on the upper end of the egg, and come out through the hole thus made. Each egg is about one twentieth of an inch long. The number of eggs in one belt varies from less than 150 to more than 225, the average being nearly 200. When the in- sects are so abundant that there is a partial exhaustion of the food supply of the caterpillars, the: normal number of eggs are not laid, the egg rings being much smaller than usual. Larva.—The full-grown Forest Caterpillar is about two inches long and about one fourth of an ‘inch thick. In shape it is cylindrical, with six jointed legs arranged in pairs directly back of the head, eight thick prolegs along the middle, and Fic. 46.—Egg Masses. DESCRIPTION OF THE LIFE STAGES TIg two prolegs at the head end of the body. The head is dark bluish, and the body in general has a bluish appearance, more or less modified by the longitudinal series of marks and stripes. Along the middle of the back there is a series of whitish or cream-colored marks of the shape shown in Fig. 47 a. Along Fic. 47.—Forest Tent Caterpillar ; 2, markings on one ring of the back; 4, markings on one ring of the side. the upper part of each side there is a broad blue stripe, bordered above and below by a narrow, irregular, yellowish-white line. On the lower surface the color is bluish black. The whole body is sparsely clothed with rather short hairs. Cocoon.—When the cocoon is not made within a leaf. the loose outer silk varies greatly in the area occupied. An average size would be about one and three-fourths inch long by one inch wide. The inner firmer part of the cocoon is generally a little less than one and one-fourth inch long by one-half inch wide. The inner cocoon is. colored yellow by the material voided by the caterpillars just before pupation, but the outer fluffy silk is generally white, because it is not reached by the yellow liquid. As already stated in a previous paragraph, when the cocoon is made within a leaf its outer appearance varies greatly, according to the material employed. Pupa.—The pupa is the dull brown, mummy-like object to be found within the cocoon. It has neither legs nor wings, and is unable to move otherwise than by a wriggling motion of its body. The pupa that is to develop into a female moth 120 THE FOREST TENT CATERPILLAR is larger than that of the male. The sizes are approximately as follows: Male, length three-fourth inch, width five-sixteenth inch; female, length nine-tenth inch, width three-eighth inch. The. pupa is commonly more or less covered with the light yellow powder which gives the cocoon its yellow color. * Moth.—The male moth (Fig. 44 2) is considerably smaller than the female (Fig. 444). The former has a wing expanse of one and one-fourth inches, while the latter expands one and one- half inches. Both are light buff-brown, the color of the male being considerably deeper than that of the female. Along the middle of the front wings there is an oblique darker band, as shown in the figures. ‘he feelers or antennz of both sexes are feathery, but those of the male’. are much broader as well as somewhat longer. BIRD ENEMIES OF THE CATERPILLARS In Bulletin 64 mention was made of many sorts of birds that feed upon these insects. During last season these feath- ered allies continued their good work. Under date of June 26, Miss Soule wrote from Brandon, Vt.: ‘‘I am almost sure that the caterpillar has drawn the birds here, for in four summers I have never seen nearly so many as this year, though I have been observing birds for years. Too much cannot be said for the birds. The orioles and the redwinged blackbirds especially are stripping the trees of pupe. Yesterday I saw orioles at work on a beech and an oak that had been badly eaten at the top, and I pulled down some of the branches and examined each of the many cocoons. Every one had the neat slit these birds make, and every pupa was gone. The baby orioles all learn to do this as soon as they can fly from one twig to another.” A little later cedar birds were seen flocking to the trees, opening cocoons and devouring the pupa. On July 8, Miss Soule wrote: “The number of birds is really amazing, and the thorough work they do is delightful.” Re- garding the birds that eat the moths, the same keen observer, in an admirable article in the Springteld Republican, said: “Many cocoons gave the moths in July, and these little brown moths could be seen in great numbers flying about the maple, “ BIRD ENEMIES OF THE CATERPILLARS 121 elm, apple, pear, ash, and other trees, laying their eggs near the tips of the twigs,—flying by daylight. Then the birds had another feast. Vireos of four kinds, fly-catchers of three kinds, both cuckoos, robins, rose-breasted grosbeaks, tanagers, cedar- birds, cat-birds, orioles, redwinged blackbirds, martins, and sparrows fed on the moths as they had done on the pupae and larve. Chipping sparrows became expert ‘lofty tumblers’ in x - | | | | | | Fic. 48.—Apple Leaves, partially eaten ; one showing cocoon. their zigzag pursuit of the flying moths, and even the English sparrows had a brief season of usefulness, for they really ate some of these moths, though they would not touch either pupz or larvae.” : The Baltimore orioles were among the most efficient ene- mies of the caterpillars, destroying them in great numbers for their own food as well as to feed their young. These orioles are exceedingly useful birds, as they generally feed freely upon 122 THE FOREST TENT CATERPILLAR Fic. 49.—Baltimore Oriole attacking nest of American ‘lent Caterpillar. hairy caterpillars, being among the most destructive enemies of the common American Tent Caterpillar. (Fig. 49.) They should be encouraged to nest and remain about the farm and garden. INSECT PARASITES The most numerous parasites of these caterpillars were the small two-winged flies called Tachina flies. At least three species * of these friendly insects were destroying the hosts of caterpillars. One of these flies is represented somewhat mag- 1 The three species were kindly determined by the Entomological Division of the U.S. Department. of Agricultureas Tuchina mella Walk., Exorista futilis O. S., Frontina frenchii Will, INSECT PARASITES 123 nified in Fig. 50@. It looks much like a common house-fly, and is of about the same size. This fly deposits a whitish egg upon the skin of the caterpillar, generally after it is more*than half-grown. The egg soon develops into a tiny grub that bur- rows through the egg-shell and the skin of the cater- pillar into the inside of the body. There it remains, absorbing the tissues of its host, and gradually increas- ing insize. In due time it Fic. 50.—Tachinid Parasite of Forest Tent heaciwes fully developed _ Caterpillar: «, fly; 4, puparium. this grub state, and breaks through the skin of the caterpillar. It is then a good-sized, white, oval, footless grub. The cater- pillar has generally spun its cocoon before the parasite comes from its body, so that the parasite finds itself inside the cocoon when it gets outside the caterpillar. The grubs of two species of these Tachinid parasites work their way through the cocoon and drop to the ground, while the other seems to remain in the cocoon. The parasitic larve have now to enter upon the quiet pupa stage. For this purpose the outer skin turns brown, and becomes hard, forming a protective covering for the insect inside. This is called the puparium (Fig. 50 4). Within this covering the insect changes to a pupa, to change again about two weeks later into an adult fly. These parasites were very abundant last season, and are, doubtless, one of the most efficient checks upon the caterpil- lars. In some localities they seem to have nearly brought the outbreak to an end, and it is probable that they will do still more good this year. A correspondent at Campton, N. H., writes that in June great numbers of strange flies were seen in the woods and pastures. They were probably these tachinids. The Ichneumon flies of the genus Pimpla‘also did good ser- vice in destroying the caterpillars. The adult is a four-winged fly that deposits eggs in the caterpillars or newly-formed chrysa- \Pimpla conguisitor was the most abundant species; a few P. fedalis were also reared. 124 THE FOREST TENT CATERPILLAR lis after the cocoons are spun. The method of egg-laying is shown in Fig. 51. The eggs hatch into minute grubs that develop at.the expense of the chyrsalis, finally eating up near- ly all their substance. About two weeks from the time the eggs are laid the parasitic lar- ve change to pup, and very soon afterwards again change to adults. Two other small parasites of the Chalcid family were also reared, although they were not at all abundant. One of these was the species called by entomologists Diglochia omnivorus, while the other has not been determined. We have also reared one species of parasite from the eggs of the Forest Tent Caterpillars. Fic. 51.—Ichneumon fly depositing an egg within cocoon. (Slightly magnified.) BACTERIAL DISEASES * Itisa well-known fact that seasons of dry weather are favora- ble to the development of insects injurious to plant life. This is especially true of caterpillars, and so the extraordinary dry- ness of the spring and summer of 1899 was very favorable to the increase of the Forest Tent Caterpillars. Their various bird and insect enemies did good service in destroying them, but the bacterial diseases that are likely to affect such insects during wet seasons did them little harm. The recent outbreak of the common American Tent Caterpillar was brought to an -end two years ago chiefly through the agency of such a dis- ease, the wet weather being favorable to it. These bacterial.and fungus diseases have been present, to a limited extent, among these caterpillars, both last year and the year before. Should next June be a very wet month, these diseases would probably do much to check the outbreak. SUCCESSFUL REMEDIAL MEASURES 125 USELESS REMEDIAL MEASURES As is always the case when a little-known insect becomes destructively abundant, a great many useless remedies for these caterpillars have been proposed. One of the most fool- ish of these is the insertion of sulphur in the trees in holes bored by an auger—a time honored fake that has, at various times, been proposed for all the ills that trees are heir to. Kerosene has also been applied to bands around the trees, greatly to the injury of the latter, as the kerosene soaks into the sapwood and kills the tree. The authorities of one Ver- mont town ‘“‘sprayed many trees with a mixture of kerosene, Paris green, and soapsuds, which burned the leaves very. badly and seemed to injure the trees.” Such measures are usually the result of ignorance. SUCCESSFUL REMEDIAL MEASURES In Bulletin 64 I printed a summary of the remedial meas- ures, which, after a careful study of the insect, seemed likely to be useful. As I then wrote, the practical value of most of these measures depends largely upon the conditions under which they are to be applied. A suggestion that is easily applicable to a few. small trees in an apple orchard may be wholly inapplicable to the larger trees in a woodland. The abundance of the caterpillars, the nature and number of the trees infested, the season of the year, and the means at hand are all to be taken into consideration. In the paragraphs below I have revised these directions by incorporating the knowledge which the past season’s experi- ence with the pest has given, from our own observations as well as from those of the various correspondents who replied to the circulars sent out. Egg destruction—There seems to me no reason for modify- ing the statements made under this heading in Bulletin 64, except to emphasize the fact that this method is not at all practical in cases of serious infestation. On a bright day, when the trees are bare of leaves, egg-masses may be easily seen, The cutting off and burning of these masses is often 126 THE FOREST TENT CATERPILLAR practicable in a young apple-orchard, although it is generally considered impracticable in orchards of large trees. It gener- ally would be out of the question in woodlands, of course, although in case of a few ornamental maples or other trees on the home grounds such egg-collecting might well be worth while. The gathering may be done by sending a sharp-eyed boy into the trees to cut or rub off the glistening masses, or by means of a pruning hook ora pair of long-handled pruning shears. The belts of eggs should be burned after they are gathered. When the insects are abundant these egg masses are so thick that to cut them off one must cut off nearly all the twigs—a ruinous proceeding. In such cases it is better to spray with arsenate of lead. Killing the young caterpillars——On small trees, where the caterpillars are easily reached, something may be accomplished by swabbing the colonies of young larve when at rest by means of a bunch of cotton waste, old rags, or something simi- lar. In rainy weather one is more likely to find the larve massed together during the day than in bright weather. Use of water.—One of the easiest ways of knogking the caterpillars off the trees is by the use of a forcible stream of water from a hydrant or good force pump. In Hanover the town authorities used streams from the hydrants with an eleven- sixteenth-inch nozzle from the fire service to good effect in - clearing the caterpillars from the magnificent elms of that beautiful village, and the same method has been successfully used in various other places. Of course the caterpillars that fall to the ground are to be destroyed, or at least prevented from again ascending the trees. The Hanover authorities washed the trees from two to four times. The trees were banded, so that those caterpillars which were not crushed on the ground immediately after falling were prevented from ascending the trees, and destroyed when they congregated on the bark below the bands. It would be well worth while to try this washing method in early spring, just after the cater- pillars hatch and before the leaves expand. _ Spraying with poisons.— The season’s experience has shown that spraying with arsenical poisons is a practical and SUCCESSFUL REMEDIAL MEASURES 127 effective remedy against these caterpillars, especially in apple orchards and on comparatively small shade trees. On larger trees itis simply a question of reaching the foliage with the spray. ‘The chief drawback in the use of Paris green—the commonest of these insecticides—is the danger of scorching the foliage. In'this respect the arsenate of lead is much safer, as it does not injure the foliage at all. When Bulletin 64 was published this substance was not upon the market, and conse- quently had to be prepared by the user. It is now obtainable, however, from Wm. H. Swift & Co., 75 Broad street, Boston, Mass., who manufacture it in quantity, and offer it for sale in wooden packages at from fifteen to eighteen cents per pound. It is also for sale by the Bowker Chemical Com- pany, 43 Chatham St., Boston, Mass. This is cheaper than Paris green at the prices the latter has recently sold for. The arsenate of lead is said to remain on the tree longer than Paris green. It is a white powder and a deadly poison, so that great care should be taken not to leave it around where it might be mistaken for something else, or where it might be reached by children or stock. Spraying with arsenical mix- tures is most effective when it is done before the caterpillars are one-fourth grown. It should certainly be done before they are half grown. Later than this it is comparatively ineffec- tive. Banding to prevent invasion—In case of an uninfested apple orchard in the vicinity of an infested woodland, it will be advisable to band the apple trees with cotton or raupenleim before the caterpillars are half grown, to prevent invasion from them. The same advice would hold in the case of other uninfested trees in the vicinity of those infested. Banding the tree-trunks—The remedial measure that has been most generally employed is that of banding the trees with some substance to prevent the ascent of the caterpillars. It has already been pointed out that a large proportion of the caterpillars drop off the trees from one cause or another, and have in consequence to ascend the same or neighboring trees in order to reach the leaves. The placing of some substance around the trunk to prevent the upward progress of the insects 128 THE FOREST TENT CATERPILLAR causes them to congregate below the band, where they are easily reached and destroyed. The commonest material em-. ployed for this purpose seems to have been ordinary cotton batting, tied around the trunk of the tree. This is cheap, and answers the purpose very well. Various mechanical barriers have also been employed with more or less success, such as bands of hemp, tin, and tarred paper. In some cases corre- spondents reported that tar or kerosene was poured upon the cotton. The use of kerosene in this way is not to be com- mended, because of the danger that it may kill young and thin-barked trees by being absorbed through the outer bark to the sapwood beneath. Another sort of these barriers is found in the various viscid: substances with which the trees have been banded. These prevent the progress of the caterpillars either by killing them through contact as they attempt to cross, or by smearing their legs in such a way that they turn around as.soon as they come upon it. The materials of this sort that have been used most are lard, cottolene, sticky fly-paper, printers’ ink, tar, and ‘“rau- penleim,” or caterpillar lime. In many places rancid lard or cottolene was used in considerable quantities, being smeared around the trunk of the tree in a band about six to ten inches. wide. While this substance does not penetrate through the outer bark of large elm trees, it should be understood that there is danger in its use upon young, smooth-barked trees, on account of the probability that the oil will penetrate to the sapwood. Printers’ ink seems to answer very well, as does the sticky fly-paper until it is injured by rains. The raupen- leim, or German caterpillar lime, recommended in my first bulletin on this insect, has been tried in several localities, and has. given very satisfactory results. A material similar to- raupenleim is now offered by the Bowker Chemical Company, Boston, Mass., under the name “Bodlime.” It should be re- moved from the tree after danger from insects is past. On the whole, cotton seems to be the most advisable material to use for banding the trees. It is not expensive ; every one can get it; it can be applied to all sorts. and sizes of trees with little trouble, and with no danger to the tree. In case the: SUCCESSFUL REMEDIAL MEASURES 129 caterpillars are very abundant, two bands might be used, one ‘a foot or two above the other. It is simply to be tied around the trunk of the tree with a stout string. If frequent rains render the outside compact and useless, it can easily be taken off and reversed, or a little new cotton added to it. Killing the caterpillars.—Of course the caterpillars that con- gregate below the bands are to be destroyed. The simplest way to do this is by the use of a stiff broom. This or some similar method is also to be used whenever the caterpillars ‘appear upon the tree trunk in sufficient numbers. After the caterpillars are half grown, they commonly come down to the lower branches or the trunk to undergo the moulting process. To this end they gather in great masses ‘on the bark, where they may be destroyed as suggested, or by collecting the caterpillars in pails containing a little kerosene and water. Vast numbers of the caterpillars have been de- stroyed in these ways in New Hampshire during the last two years. . Yarring and banding.—It has already been stated that these caterpillars drop downward when disturbed, breaking the fall by means of a thread spun from the mouth; although when young and suddenly jarred apparently the thread may not be used. This habit leads to the suggestion that by a combina- tion of jarring and banding much injury may be prevented, at least in the apple orchard and on the home grounds, and especially on small trees. After the trees infested have been banded, a boy with a padded mallet may be sent into them with instructions to jar the limbs on which the caterpillars are working, beginning at the top. This should be done when the caterpillars are feeding upon the leaves, as they are then much more easily disturbed than when they are at rest. Of course it is not to be expected that going over once will wholly vid the tree, but by two or three repetitions of the jarring most of the caterpillars should be removed. A sheet of cloth may be spread beneath the tree to catch the caterpillars as they fall, or a light roller might be run over the ground to crush them. Those which escape destruction will congregate in masses upon the trunk, below the bands, where they may be 130 THE FOREST TENT CATERPILLAR destroyed by use of a stiff broom or by various other methods. The earlier this is done after the larve are all hatched the less will be the injury to the foliage. The masses of caterpillars below the bands are sometimes killed by pouring on kerosene. If this method is employed, great care should be taken not to add enough to saturate the bark. Many trees have been killed by carelessness in such use of kerosene. Collecting cocoons.—A large proportion of the cocoons are commonly spun where they can be reached. The destruction of these will lessen the number of moths that lay eggs for the next season’s brood of caterpillars, although it will also lead to the destruction of large numbers of parasites. This. collecting of the cocoons has been done extensively in ~ certain towns. In Hanover and Claremont the selectmen offered a reward of five cents per hundred cocoons, and in the former town 80,000 cocoons were collected and destroyed. The poster gotten out by the Claremont authorities is repro- duced on the opposite page. The chief objection to this method is that it leads to the destruction of large numbers of parasites. The proportion of parasites to moths is likely to vary considerably in different localities. Our observations indicate that at Claremont, last season (1899), about 30. per cent. of the pupa were para-— sitized, while at Brandon, Vt., more: than 40 per cent. were parasitized. Now these parasites are Nature’s means of checking the outbreaks of this Forest Caterpillar, and it seems unfortunate that in destroying our foes we should also destroy our friends. It must be borne in mind, however, that any parasite found in these cocoons will not take effect upon next year’s brood of caterpillars until they have completed their growth and done the damage, so that as regards the next sea- son alone it is better to destroy the pupz, even if some of the parasites are destroyed at the same time. A simple method, however, may be adopted by which the moths may be destroyed and most of the parasites saved to continue their good work. It was first suggested to me by Mr. Fiske. Select a piece of shaded grassland, which is not BOUNTY CATERPILLARS ! IY ui Lat a rT The Selectmen of Claremont will pay Five Cents a Quart for this year’s -Co- coons of the Forest Tent Caterpillar, gathered in Claremont, during the next ten days. Coceons must be delivered at the Selectmen’s Room, Town Hall, between the hours of 5 and 6 in the afternoon of any week day during said time MALL LL aL aL ae TTT TEETER eTETOET TOTP. There is the utmost need that the public should awake to the danger that threatens the trees from this pest. The destruction of woodland and of shade trees seems imminent unless some way of killing the caterpillars is devised.. At the present time this year’s caterpillars are beginning to go into cocoons. They remain in this state about ten days. when a moth is hatched from the cocoon. This moth lays from 200 to 300 eggs. each of which becomes a caterpillar to ravage the trees next summer. Let all good citizens understand that each cocoon is a source of very great injury: and that every cocoon destroyed will aid in the preservation of trees which cannot’be spared. Let young and old join in the work of gathering co- coons. It is for the direct benefit of the town that this should be done. A. C. STONE, Selectmen C. A. FISHER, of W. T. FREEMAN, } Claremont. Claremont, N.H., June 20, 1899. Facsimile of hand-bill offering bounty for cocoons. 132 THE OREST TENT CATERPILLAR much tramped upon by ,people or animals, scatter over this. the cocoons as they are collected, not making the layer more than an inch deep; leave the cocoons in this position until the moths begin to emerge; then rake the cocoons up and. burn them. During the week or ten days that the cocoons. remain here most of the parasites will have left them and found shelter in the turf, where they will complete their devel-. opment. By keeping two or three hundred cocoons in a box. under observation, the time when the first moths come out can. be readily determined. i ‘ CiRcULAR No. 8, SECOND SERIES. United States Department of Agriculture. DIVISION OF ENTOMOLOGY. THE IMPORTED ELM LEAF-BEETLE. Galerucella luteola Mull, (Galeruct xanthomelena Schrank.) Ta. 1.—Galerucella luteola: a, eggs; b, larve; ¢c, adult. e, eggs (enlarged); J, sculpture of egg; g, larva (enlarged); h, side view of greatly enlarged segment of larva; t, dorsal view of same; j, pupa (enlarged); k, adult (enlarged); J, portion of elytron of beetle (greatly enlarged). From Riley, in Ann. Rept. Dept. Agr. for 1883. GENERAL APPEARANCE AND METHOD OF WORK. The chief insect enemy of the elm is the imported elm leaf-beetle, the larve and adults of which frequently so disfigure the trees as to make them useless for shade and hideous rather than ornamental. The beetle—a small, yellowish-brown insect— appears first and fills the leaves with small irregular holes, while the following 1 2 broods of slug-like yellow and black larvw® skeletonize the leaves in irregular spots between the veins, working on both surfaces, but chiefly on the lower side, causing the leaves to assume a dry brown appearance, to curl, and ultimately to fall. The second crop of leaves sent out by the trees in the southern range of the insect meets a like fate. DISTRIBUTION. The elm leaf-beetle is a well-known depredator in the Old World, particularly in south Germany, Austria, and France. It was imported into this country, on the authority of Glover, in 1837, and its earliest attacks were particularly severe about Baltimore and in New Jersey. Its spread in this country has been comparatively slow, and, while wherever it has appeared it has established itself very firmly and now frequently occurs in enormous numbers, it is limited in its range, so far as the records go, to the middle Atlantic seaboard, including the District of Columbia, Maryland from Washington eastward, Virginia in the immediate vicinity of Wash- ton, Delaware, southeastern Pennsylvania, New Jersey, Long Island, the Hudson River valley, and southern Connecticut. On the authority of Prof. C. H. Fernald itis not known to occur in Massachusetts, and Prof. Gerald McCarthy reports the same for North Carolina. This range, as pointed out by Mr. Howard, practically conforms to the northern limit of the upper austral life zone, outside of which the insect has not established itself as yet, so far as can be learned. NATURAL HISTORY AND HABITS. Characteristics of Different Stages.—The insect occurs on the trees in three different stages, and the fourth stage is passed on or under the surface of the ground at the base of the tree; i. e., the egg, larva, and beetle on the tree, the pupa in the ground. The beetle is a little over a quarter of an inch long, of a general yellowish or yel- lowish-brown color, with three somewhat indistinct brownish-black stripes on the wings. It is shown natural size at c, and enlarged at i, in the figure, The eggs are placed on the lower sides of the leaves in vertical clusters of from 5 to 20 or more eggs, closely arranged in two or three irregular rows. They are oblong-oval in shape, tapering to a rather obtuse point, orange yellow in color, and the exterior surface is covered with beautiful hexagonal reticulations. They are shown natural size on the leaf at a, aud enlarged at e, with the reticulated surface still more enlarged at f. The larva is elongate, reaching a length of about half an inch, and when newly- hatched is nearly black. As it increases in size it becomes, with each shedding of the skin. more distinctly marked with yellow, and when mature the yellow pre- dominates, occurring as a broad dorsal stripe, and two lateral stripes. The larva is represented natural size on the leaves, and somewhat enlarged at g, with portions still more enlarged at h and i in the figure. The pupa is uniformly light orange yellow, oval in shape, strongly convex dor- sally, and a little over a quarter of an inch in length. It is shown in the illustra- tion at j, enlarged. The egg state lasts about a week, and the larva normally fifteen to twenty days, and the pupa six to ten days. Number of Broods and Dates of Appearance.—In the more southern range of this insect, including Maryland, Virginia, Delaware, and most of New J ersey, there are two annual broods, with an occasional small third generation, Further north, including northern New Jersey, Long Island, New York State, and Connecticut, there is iu general but one well marked brood, with sometimes a supplemental or partial second brood. Throughout the double-brooded area the beetles make their appearance in spring about the middle of April, beginning to come out before the elms have put out their leaves and continuing on the trees through Mav. nerishing soon after eoo-laving is 3 finished. The eggs of the first brood are deposited during May and into June, the larve of this brood occurring from early in May throughout June. Pupation takes place during June and July, and beetles of the second or summér brood emerge during July and into August. The eggs for the second brood of lurve are deposited by these beetles from the middle of July through August,and the larve of the second brood skeletonize the second growth of elm leaves during the latter part of July and August, the later specimens occurring up to October. Pupation occurs chiefly during August and September, the beetles appearing from the last of August through September, and entering winter quarters during September and October. In the one-brooded regions the beetles do not appear in spring until the last of May, and in general the periods are fully a month later for the different stages than for the southern districts, the beetles of the summer brood transforming most abun- dantly about the firstof August. After feeding on the leaves a little while, and doing very inconsiderable damage, they go into winter quarters during August and Sep- tember, remaining dormant eight or nine months. Habits of Larve and Hibernation of Adults——The larve from each batch of eggs feed together somewhat gregariously for a time, but ordinarily become separated and scattered later, especially with a scantiness of food. When full grown they normally crawl down the branches to the trunk and then to the ground, puapating almost immediately on or very near the surface of the soil just about the base of the tree. They are apt to seek partial protection about grass bunches, but fre- quently accumalate in masses, exposed on the surface 1n such a manner as to make a striking yellow carpet about the tree from a few inches to a foot or more wide. With very large elms, however, many of the larve are shaken off by winds or fall directly to the ground, sometimes fairly covering the surface over a diameter equal to the limb-expanse of the tree. Hibernation is in the adult state both where there is but one brood and where there aretwo. For this purpose the beetles frequently enter houses and barns or outbuildings, sometimes assembling in such numbers that it is possible to collect them by the quart. They also enter cracks in posts, telegraph poles, fences, etc., or wherever they can secure partial protection from winter storms. Susceptibility of Different Elms.—European elms seem to be especial favorites witb this msect, and this would naturally be expected from its European origin. Its preference for the European elms is especially noticeable where these are grown in conjunction with American elms, the former being frequently entirely denuded, while the latter remain practically uninjured. In general the coarser-leaved sorts of elms are distasteful to the beetles, and the smooth, thin-leaved varieties are especially subject to attack. The American species, CImus americana, is notably exempt, and this, together with the general immunity of other American species, is a strong argument in favor of restricting planting to our native sorts. All species of elms, however, are attacked more or less, and in the absence of sufficient foliage of the favorite varieties, the injury to less palatable sorts becomes almost equally marked. REMEDIES. In nearly every stage of the life-history of this insect it is easily subject to treat- ment. The best means against the adults and larve consist in the use of arsenical Poisons in the form of sprays on the foliage. The adults, for a week or two after emerging, feed on the newly-expanded foliage, and a spraying with Paris green or other arsenical will destroy the great majority of them. Especial pains should be taken to accomplish the destruction of the insect in this stage, in order to prevent the partial disfigurement which will result if the matter be delayed until the larve begin to appear. “If rains interfere with spraying for the adults, or if 1t be neglected, the trees should be sprayed with arsenicals promptly on the first appearance of the lurve, and the application perhaps renewed a week or ten days later, especially if Tains have intervened. 4 Paris green is the best arsenical, and may be safely used on elms at the rate of one pound to 100 to 150 gallons of water. If London purple be used, an amount of lime equal to the poison in weight should be added to combine with any free arsenic and prevent scalding of foliage. The liquid should be applied with a strong force pump with a long hose and a nozzle, such as the Vermorel or Nixon, which will make a fine mist-like spray. In spraying for the larve it is very essential to thoroughly wet the lower side of the leaves, on which they principally feed. In the case of the adults, this is not so necessary, because they eat the entire substance of the leaf, and will get the poison from either side. On elms fifteen or twenty feet in height, the treatment can be made from the ground or from a wagon. For larger elms, it will be necessary to climb up into the tree, using a hose 50 to 100 feet long, and directing the spray by this means into the upper branches. By removing the spray tip from a large size Nixon nozzle, 80 as to get a direct discharge, the upper branches of comparatively tall trees may be reached and sprayed in a more or less satisfactory manner. In the case of very large elms in city parks or streets, the use of stronger apparatus may be advisable, such as a fire engine or steam pump and a larger nozzle, such as a graduating spray tip, capable of throwing either a direct stream or a spray. During spraying the poison should be constantly stirred to prevent it from settling to the bottom of the tank. The first effort should be to destroy the beetles and larve at their earliest appear- ance, to save the trees for the current year. Sometimes, however, larva in the tops of tall trees will escape, and, whenever from inefficient spraying or neglect they are allowed to reach maturity, a strong effort should be made to destroy the insect when it reaches the ground to transform, and thus limit or prevent damage from the second brood or on the following year. The collection of the larva for pupa- tion, frequently in enormous numbers immediately about the base of the tree, makes it comparatively easy to destroy them in this situation. This may be accom- plished eithér by wetting them with boiling water or with kerosene emulsion, diluted about four times. Frequently they may be collected by hand or shoveled up, and burned or otherwise destroyed. Remedial treatment is much simpler in the northern areas of the range of this insect, where it is single-brooded, and becomes more difficult in the southern dis- tricts, where the number of broods is doubled, and the appearance of the insect becomes somewhat irregular, continuing practically throughout the summer. C. L. Maruatt, First Assistant Ent logist. ie creet, ntomologis Cuas. W. DaBney, Jr., Assistant Secretary. WasHINGTON, D.C., May 28, 1896. AGRICULTURAL EXPERIMENT STATION THE UNIVERSITY OF NEVADA BULLETIN No. 65—FEBRUARY, 1908 The European Elm Scale (Gossyparia spuria, Aodeer) BY SAMUEL B. DOTEN, B. S. ENTOMOLOGIST PUBLISHED BY THE UNIVERSITY OF NEVADA RENO, NEVADA THE BOARD OF CONTROL Tur REGENTS OF THE UNIVERSITY OF NEVADA Hon. Oscar J. Smiru, Chairman............202.-----esseeeeeeeeceeeeeee Reno Hon. CHartes B. HENDERSON..........-.2-2-::0c--ceccec cc ceeeeee cece te eeeseeeeeteeees Elko HON. JOHN SUNDERLAND. ...02222222-::c21cccceececccececccececececeeeteeeeeeeneeteeeneees Reno HON: J: EL, SGUGHERBA Uiecccycocees pesuecseds aecsees Gaver hay iaeettnee ees Verdi Fon. CHARLES R. LEWERG.._.00222.22--2---2-c2ccceccec cece eceeseeecesteeteetoeeeneeseeees Reno Hon. Gro. H. Tayuor, Secretary.............-------eeeceeeeeeeeeeeeeeee reece Reno STATION STAFF Jos. Epwarp Stupss, LL. D., Director...............222.............- Publications NATHANIEL E. WILSON, M. 8.*...0000.0020000000--- Chemistry and Dairying P. Breveripocge Krnnepy, Ph. D......Botany, Horticulture and Forestry PrErer FRANDSEN, A. M............ Consulting in Bacteriology and Zoology Gorpon H. Trus, B. 8.........-....-. Agriculture and Animal Husbandry SAMUEL B. DOTEN, By ALwo....oecccecee cece cece cece cee eee eeeeeeteeeseeeees Entomoligy Sanrorp C. Dinsmore, B. S........000202--200---- Chemistry and Dairying J. BE. Cauron, Ph. Dw Pircscat tose MaE Ea asada Shy dade Peete ooces Co-operative Observer in Climatology and Meteorology Winrrep B. Mack, D. V. M........Bacteriology and Veterinary Science THEODORE W. CLARK. .02......2--2-ececccecceeeeeeeeeteeeeeeees Superintendent of Farm Mrs. T. W. Cowan, Me Aone cecceeececesceseseseeeeeesess Librarian CaROLYN M. BreOK WITH ooo... ecccececceecec ce eeteeeeeeeee eens Stenographer *Absent on leave. TABLE OF CONTENTS PAGE NOTES ON THE LIFE-CYCLE... .2.0.2...0cc0cescccc ec ceceeeeeecceeecececeeeeeteeeee 5-15 The Diaryae: in Wanter: ee. ee ste es es ee 7 Phe Males Insect.ix ces cect es tae eee 7-10 eb lies Bena le Lm OC te sea a teu LG lg es 10-12 b= ame ae EE ee a 11 Newly-Hatehed: Wiarvae) sxc ccccccececsescceccetsececcscuveccecscceceecesvseessveseneds 13 Raté- Of WiGreas@ ccc ee le el es nee 13 Mears of (Spread s.5 2 Gl ee 14 Wrees, Witested cixcicciccssteteeee Gute eae A ee 15-16 REMEDIAL MEASURES: Spraying— , With Lime-Sulp hur... cece eee ecee cece cece ececeteeeee reese 16-25 With Kerosene Emulsion. ............0......2.2:2-:100eee 26-29 With. Scalecide: .¢4.40)-0.5 een Se 29-31 Washing the Elms With the Garden Hose...............-.------------- 31-34 fr LIST OF ILLUSTRATIONS Teton Fite SSCA Ty RAT cae ce shensse scanenon se easarclanees Plate I 1. Dead Females in Winter on Cork Elm, Natural Size. 2. Living Females in Summer. (X. 4). FHIBERNATING LARVAB...........c0.22 00 ccesececcesee ec ceeecsneeescecececeeccecenecceeesees Plate IT 1. On Elm Bud. (X. 16). 2. Surrounding Dead Females. (X. 8). 3. In Crack of Elm Bark. (xX. 8). 4. About Base of Twig. (X. 8). LARVAE IN EARLY SPRING. ...0....0....ccecccceeececeececceeceeceeeeeeecseeeeneeees Plate III 1. Crack in Elm Bark Full of Hibernating Larvae. (X. 4). 2. Larvae and Male Cocoon. (X. 16). FIIBERNATING LARVAB...W..0......22---ecceecceeececeeecccceeeeeeeeceeceeeceeeeceecoeees Plate IV 1 and 2. Larvae Hibernating Beneath Dead Females. (X. 16). COCOONS OF THE MAULB..000. 2... eect cce ieceeceeeeeece eee ceeeeeeeereeceesnecsneeeenees Plate V 1. Larvae Excreting Cocoon. (X. 16). 2. Cocoon Finished, Anal Filaments of Male Protruding. (X. 16). 3. Cocoons. (X. 4). Gossyparia spuria, MALE. (CX. 16) oe ee eeeeceeeeeeeeeeeeeeeteeteeeeteces Plate VI 1. Cocoon With Protruding Wings and Anal Filaments. 2 and 3. Wingless Males. 4. Male. 5. Cocoon. PupPAk OF MALE. Drawing... 2... ceeeeeceee cee cece cee eeteeecececeneeeeeeeee Plate VIL 1. First Pupa. 2. Second Pupa at an Early Stage of Development. DETAILS OF MALE. Drawings ..............cecceeceeeeceeeeee cee eeeeeeeeeeee Plate VIIT Gossyparia spuria, FEMALE. (X. 16) oo... eeccecceceeeeeeeeeeeeee Plate IX 1. Just Before Impregnation. 2. Excreting Semi-Cocoon. 3. Fully Mature, Engorged With Eggs. DETAILS OF FEMALE. Drawings... cece cee cceeeseeeeeeeeeeeeeeees Plate X EGGS ANp ARVARY oe a eeeecee See eee, Plate XI land 2. Egg-Shells and Struggling Larvae Beneath Female. (X. 16). 3. Eggs and Hatching Larvae. (X. 40). 4. Larvae. (X. 16). Newzy-Hatcuep Larvan. Drawings...........0ceeceeeecceeeeeseeees Plate XIT THE LARVAE IN SUMMER..........20..2200.20cc2200s2ceseceeesseeteceecceeseceeeceee Plate XIII 1. (X.8) and 3. (X.16). Along Mid-Rib on Under Surface of Leaf. 2. (X. 16). Recently Hatched Larvae on the Upper Surface of Leaf. INUCKERS: Mo Angad. cient ieee eel eet elle Plate XIV A Thicket of Sprouts Surrounding an English Elm. PLATE I—European Etim Scate, FEMALE (From Photographs by the Author) 1. Dead Females in Winter on Cork Elm. Natural Size. 2. Living Females in Summer. (X 4) THE EUROPEAN ELM SCALE (Gossyparia spuria, Modeer) By Samurt B. Doren In the study of many insect problems there are three related sides of the matter to be taken into consideration; the nature of the pest, the nature of the infested plant, and human nature, which third fac- tor is the most difficult of the three. When the San Jose Scale first appeared in western Nevada, apple trees were much used in the principal towns as shade-trees in door- yards; they were hardy and ornamental trees and in favorable years were profitable as well. With the advent of the Pernicious Scale they became diseased and unsightly, many were ruined, while others only slightly infested were cut down because it had become necessary to have them sprayed every year or two. Now the reason for this whole- sale destruction of apple trees lay not so much in the nature of the pest or the nature of the tree as in human nature. Before the Pernic- ious Scale was introduced, the apple tree within the city limits was looked upon as an ornamental tree which often proved a source of no small profit; after the Scale became established, these trees became much less ornamental, less profitable, and a source of yearly annoyance and expense during the spraying season. The Horticultural Law in Ne- vada makes spraying compulsory, the labor supply was short and its price high; spraying was expensive and none too efficient. The situation was such that many householders came to regard their apple trees as sources of more annoyance than profit and so had them cut down. At the present time the European Elm Seale presents a somewhat similar problem. For several years it has been injuriously abundant in the neighborhood of Carson City, in more recent years it has ap- peared in Reno where most of the residence streets are lined with young elms. Some of these have been killed outright, while hundreds of others have been greatly injured. Up to the present time the elms have been our most highly-valued shade trees, in this new country they are of necessity still young and very susceptible to the attacks of the PY 6 Turn EvRoPEAN E_mM SCALE Elm Scale which threatens their serious injury. This is an insect problem which demands a prompt and practical solution. The purpose of the present bulletin is to state this problem fully and to suggest means for its solution. We have chosen pictures as the readiest means of stating the nature of the pest and its relation to the tree in a way which the average man can understand. We chose spraying with lime-sulphur in the winter as the most promising means of destroying the half-grown insects; a careful study of the problem has nearly convinced the writer that better results can be attained by far simpler means in this vicinity. It is even likely that if it should prove necessary to spray the elms every year or two with lime-sulphur in order to keep the Scale under control, human nature will play the same part that it did in the destruction of apple trees which had be- come a source of more annoyance than profit. THE NATURE OF THE PEST As the common name indicates, the European Elm Scale is an insect introduced into this country from Europe. It was first observed in America at Rye, New York, in the year 1884. It is or has been seriously abundant in Vermont, Connecticut, Massachusetts, Ohio, and the State of Washington.* For fifteen years it has been present, in Nevada, where it has proven destructive to our most valuable shade trees, the Cork Elm, Ulmus campestris and the American Elm, Ulmus Americana. It is still abundant in this vicinity and is spreading rap- idly. It belongs to the order Hemiptera, family Coccidae, and is known to entomologists as Gossyparia spuria, Modeer. In its earlier stages it is a minute, six-legged insect which can crawl actively over the bark . . . and leaves, but which spends most of its time in one spot on bark or leaf with its slender beak inserted in the tissues of the plant on whose sap it feeds. In summer the surest sign of the presence of this insect is a pre- mature yellowing of the leaves on the lower branches of infested trees. Late in the summer, seriously infested branches turn prematurely yellow or brown to such an extent that one can pick out at a glance the elms on which the'scale insects are present in large numbers. Other branches still more seriously infested, die in mid-simmer. The wilted leaves on such branches bleach to a dull grey-green or dull brown wholly unlike the normal clear brown of elm leaves in the *“Since its advent in Spokane it has multiplied so rapidly as now to be a serious menace to the propagation of shade trees in that City.’’—Melander, Washington Experiment Station. Bulletin 74. “8B oX) AIM Ju osu nedy p (SX) Mave, WG Jo Youryg uT “g (8 X) ‘BeewMey Pea Suypunoting '3 Cl NX) “pNe wisT uO ‘T (1oyjny 94} Aq SYdBIFOIOY. Wot) AVAUVY] ONILVNUAAI[T[—]] WLW Id “(ST XX) ‘uood0D B1VW pues avsrwy 3 (h X) ‘“OVAIVTT Suryeuseqiy jo [Ng yaw wg UL yovrp T (loyjny ey} Aq sydersojoyd wos) DNINdG ATIVG NI AVAYVY]—TIT ALVI1d PLATE IV—HIBERNATING Larvar (From Photographs by the Author) 1 and 2, Larvae in Winter; Around and In, and Beneath the Semi-Cocoons of Dead Females. (X 16). THe European Etm Scare 7 autumn. Scattered twigs, dead and dry in midsummer and covered with wilted leaves, autumn colors on the lower limbs long in advance of the proper time; these are the surest signs of Gossyparia spuria in destructive numbers. Often, even in midwinter, one can pick out the infested elms ata glance, for the wilted leaves on branches which died in midsummer do not fall, but hang on the twigs until the following March. THE LARVAE IN WINTER As this Bulletin aims primarily to detail methods of destroying the winter stages of this insect, we will begin with an illustrated ac- count of its appearance during the winter months. In midwinter it is an easy matter to find on an infested tree great numbers of such in- sects as those shown on Plate I, closely adhering to the bark of the lower limbs, especially on the underside. At this season these insects are all dead and dry; they are the female scales of the previous summer. Their progeny, the hibernating larvae, are not so easily seen, owing to their small size and to their grey color which is much like that of the bark on which they rest; still without seeing them one may dem- onstrate their presence by running the thumb along the bark and crushing them, leaving the bark and thumb stained as with tiny streaks of blood. The accompanying photographs are magnified illustrations of the hibernating larvae. Plates II and III. A few larvae hibernate within the semi-cocoons of the dead females or in rings around them, Plate IV; some are scattered over the twigs on buds and leaf-scars, Plate II; many occur in rings about the bases of small twigs, Plate II; others occur in large patches on the under- side of limbs whose bark is smooth and green, Plate III; very many are to be found in long rows between the projecting ridges of cork on the younger branches of infested cork elms. Cracks in the rough bark of the larger and lower branches of both the cork elm and the American elm are often crammed full of hibernating larvae, Plates II and III. THE MALE INSECT The winter larvae remain fixed in one position until spring, when they begin to complete their growth and become sexually mature. In 1907 the first signs of maturity were observed early in March, when eighteen more or less complete cocoons were found. The male cocoon is oblong, about one-sixteenth of an inch long by half as wide. At the anal end there is a horizontal slit through which the cast skins 8 Tur European Exum SCALE of larvae and pupae are ejected and through which the mature insect escapes. Newly excreted male cocoons are pure white in color and re- semble tiny grains of rice. When clustered about the bases of small twigs or when occurring in patches on smooth bark or in long rows between the projecting ridges of cork on cork elms, they are decidedly conspicuous; on badly infested trees, patches on the bark. of some limbs are fairly white with them, Plate V. FIRST PUPA Length, 1.11 mm. to 1.38 mm. Breadth, .54 mm. to .63 mm. Out- line ovate, narrower toward head. Thoracic region narrower than the abdominal, whose lateral margins curve bluntly to an obtuse three- lobed apex with lobes of about the same shape, the central one broad- est. Division into head, thorax, and abdomen obscure. The wing- pads are fleshy sacs of about equal length and breadth, turned under obliquely on the ventral surface. The legs and antennae are short, elongate sacs without distinet segmentation. Plate VII. SECOND PUPA Length, 1.11 mm. to 1.38 mm. Breadth of abdomen, .48 mm. to .60 mm. Breadth of thorax, .45 mm. to .51 mm. Outline elliptical. Thoracic region slightly narrower than the abdominal, which tapers Reno, Nevada, March 11, 1907. *Among three thousand larvae, eighteen had excreted more or less complete cocoons; eleven of which contained living larvae almost com- pletely denuded of their usual dorsal covering of waxen bristles. Six cocoons were incomplete, the larvae within them were distended and dark, the seg- ments showing distinctly. The cocoon consists of filaments of wax which are excreted in abundance from both the dorsal and ventral surfaces. On the bark there were several larvae whose backs were covered with curving filaments of wax, the beginnings of cocoons, Plate V. April 9th, 1907. Male cocoons are now abundant. Some occur in cracks in the bark; others are concealed in and around the semi-cocoons of dead females. Clusters may be seen here and there on the bark; in one instance I counted one hundred on less than one square inch of space. In fifty cocoons from various situations on the bark, there were no mature males and none of the cocoons were empty. Pupae are not numerous as yet; about one in each dozen cocoons. April 15, 1907. On cocoons kept in the laboratory for a few days, cast larval and pupal skins are found adhering loosely to the posterior end out of which they were ejected by insect. These cast skins are yellowish or cream colored; the larval skin is easily distinguished from the pupal integuments by its long proboscis. Male cocoons formed in the laboratory are pure white, those excreted out of doors soon become dirty-grey from accumulated dust. PLATE V—Cocoons or THE MALE (From Photographs by the Author) 1, Larva Excreting Cocoon. (X 16). 2. Cocoon Finished. Anal Filaments of Male Protrud- ing. (X 16). 3. Cocoons. (X 4). PLATE VI—Gossyparia spuria, Male. (X 16) (From Photographs by the Author) 1. Cocoon With Protruding Wings and Anal Filaments. 2-3. Wingless Males. 5. Cocoon, Cast Skins of Larva and Pupae - PLATE VII—Pwtpae or MALE (From Drawings by the Author) 1. First Pupa. 2. Second Pupa at an Early Stage of Development PLATE VIII—Detais or MALE (From Drawings by the Author) i a i i a ee Mall, ee Tur European Ewtm ScALe 9 to an acutely-pointed, three-lobed apex, whose central lobe is long and pointed and far broader than the two small, rounded, lateral lobes. Division into head, thorax, and abdomen fairly distinct. Wing-sacs longer than broad, nearly lateral in position. Legs and antennae longer than in the first pupa; their segmentation distinct. Through the integument the structure of legs and antennae may be seen dis- tinctly in advanced specimens. THE WINGLESS MALE Length of head and body, 1.20 to 132 mm. Breadth of thorax, .42 to .45 mm. Breadth of abdomen, .44 to .51 mm. Lateral margins of abdomen full and curved, rounding posteriorly to a three-lobed apex, whose pointed central lobe bears the generative organs. The two rounded lateral lobes bear several short hairs as in the winged male, but lack the long, white terminal filaments. Wing pads about twice as long as broad, their length being usually less than the width of the thorax. Surface of pad wrinkled and folded in a most complex manner. Halteres fleshy, often irregularly constricted in the central portion, the terminal hook short, stout, only partially developed. Antennae as in the winged male, but more compact. Legs as in the winged male, but somewhat fuller in outline. Plate VI. None of the above characters are at all constant. The wings are often long enough to cover half of the abdomen, which is occasionally slender and elongate as in the winged male. Anal filaments frequently partly developed, but crooked and slender. The wingless male is sexually mature, mating with the newly-moulted females, (1908). WINGED MALE Length of head and body, from 1.32 mm. to 1.56 mm. Body of slender form, broadest at the thorax. The abdomen tapers back in lines nearly straight from its point of union with the thorax; in fully matured specimens the outline of the abdomen is trapezoidal, while in specimens removed from their cocoons after full development of the wings and anal filaments, the abdomen is broader, with rounded lat- eral margins as in the pupae. The posterior extremity of the abdomen is three-lobed; the pointed central lobe bears the generative organs; the rounded lateral lobes give rise to two long white, waxen bristles whose length is to that of the head and body as 17 is to 14. Wings white-hyaline, iridescent in sunlight, about twice as long as broad. Halteres with fleshy lobe tapering bluntly at the distal end to a slender rod with hooked extremity, which engages the rim of a purse-like cavity in the posterior margin of the wing. Antennae long, 10 Tue EuRoPprFAN ELM SCALE slender, moniliform, ‘hairy. Second joint with distal end rounded and club-like, about twice as broad as any other segment. The tenth segment is the shortest, the seventh and eighth are of about equal length. The third is longest, comparing with the tenth as 5 is to 9. The lengths of femur, tibia, and tarsus are as 20, 26 and 9. Plate VIII. After moulting three times within its cocoon and pushing out the. cast skins through the slit in the anal end, the male emerges. Within its cocoon the male larva has undergone three changes in form, pass- ing through two pupal stages and finally emerging either as an active, wingless male or in the fully-mature winged form. Plate VI. THE FEMALE INSECT On April 15th, 1907, the first wingless males were observed, and on the same date many newly-moulted female larvae. Such females are brown or olive-brown in color, broader and more flattened than the hibernating larvae. The division into segments shows more distinctly, and in many instances the dorsal surface slopes toward each lateral margin from a faint longitudinal ridge. Under the magnifier the newly moulted females appear slightly pubescent and covered with short, stout bristles, Plate IX. Honey dew was first observed on the infested elms on May Ist, when ants and flies were attracted to it in large numbers. On May 17th, 1907, a few females now nearly mature were begin- ning their semi-cocoons. These consist of tough envelopes of felted waxen fibers excreted from the lateral portion of both the dorsal and ventral surfaces. The completed semi-cocoon adheres closely to the bark and curls over the dorsal surface of the insect far enough to give it support in its usual inverted position on the underside of the branch. Within this supporting semi-cocoon, the eggs are laid and the young are born. The mature females gather together in great numbers on the under- sides of the lower branches where the bark of an infested tree is often covered with them; they are easily seen from the ground, even at a considerable height; for the oval ring of white wax surrounding the lustrous, deep-brown insect is a conspicuous object. On fairly smooth bark they gather in clustered hundreds; but onthe rough bark of the smaller cork-elms they occur in irregular clusters and rows between the projecting wings of cork. Not all of them, by any means, are found on the larger and lower limbs; many are to be found on the sides of vertical branches, clusters occur on the lower side of small horizontal limbs, many are scattered throughout the tree in the axils of buds and tiny twigs. In the main, however, and as a general and ‘S330 UM pesiosuq ‘aInyeW ATINY “g ‘uooo0D-1WIag Supeioxg “Z ‘wolyeuseidwy elojog ysne ‘T (goyjny ey} Aq sydvasojoyq wo1q) (91 X) ‘eyemeg ‘nunds viundhissop—xXI ALY Id PLATE X—DETAILs OF FEMALE (From Drawings by the Author) a.b. Leg and Foot. c. Antenna. d.-e. Ventral and Dorsal Views of Anal Extremity Tue HuROoPEAN Etm SCALE 11 limited statement, it is fair to say that by far the greatest number of females in the egg-laying season are to be found on the bark of the larger and lower limbs on the underside. On June 19th, 1907, practically all the females had completed their semi-cocoons and were engorged with eggs; at this stage they resemble tiny sacks of tough, leathery material filled with hundreds of eggs and the usual red-brown body fluids. No larvae, however, were to be found on leaves or bark up to June 19th.* BEFORE IMPREGNATION Length from 1.23 mm. to 1.47 mm.; average 135 mm. Breadth from .63 mm. to .78 mm.; average .695 mm. Outline ovate, twice as long as broad; tapering to the two-lobed posterior extremity each lobe of which bears four stout, blunt, dorsal spines and a terminal filament whose length is about equal to one-fifth that of the body. Dorsal surface olive green to dark brown. Entire dorsum and the lateral margins thickly set with stout, blunt spines. The antennae are rather short and stout; their length is to that of the body as one is to six. The segments of the antennae are not so deeply incised as in the male; but the segmentation is distinct. The third segment is the longest; fifth and sixth are shorter than the terminal seventh, which bears a number of short hairs and two longer ones, whose length is to that of the segment as 58 is to 41. Of the leg-segments the femur is longest ; the tibia. is shortest. The lengths of femur, tibia and tarsus are to each other as 13, 11, and 12. The genito-anal ring is surrounded by eight slender, flagelliform hairs not extending to the ends of the anal lobes. After impregnation the female becomes distended with eggs; so engorged, in fact, as to resemble a tiny, leathern sack, roughly glob- ular or ovoid, pointed posteriorly, flattened dorsally ; the back smooth and shining, of a deep mahogany-brown color, distinctly segmented. The power of locomotion is lost; but the female is held in place on the bark by a semi-cocoon of wax while the eggs are laid. Plate X. THE EGG On June 26th, 1907, larvae were appearing so rapidly that within each semi-cocoon there was a struggling mass of them entangled with Reno, June 18th, 1907. *Females full of eggs are now abundant on infested elms. Male cocoons are empty. Branches of elms are smeared with honey-dew. Upon dorsal pressure from u dissecting needle, the females extrude two white anal organs between which a clear fluid is ejected, sometimes pubbling out in tiny drops, sometimes in a jet with force enough to throw drops far from the body. No larvae as yet observed on leaves or branches. 12 Tur European Eum SCALE the exceedingly delicate egg-shells, and among them a few eggs. The egg is oblong in outline, pale yellow in color, about one-eightieth of an inch long and half as wide. Upon the drying of the shell or membrane in which it is enclosed the larva within bursts its covering and emerges head first, leaving within the semi-cocoon of the female the delicate egg-shell. As the oviduct opens on the ventral surface of the body near the anal extremity, the newly-hatched larvae find themselves within the semi-cocoon, protected by it and the body of the female. One such egg-laying female, when attached to a glass slip by means of a tiny drop of Canada balsam, expelled four eggs in about twelve minutes; all of them hatched within half an hour. THE NEWLY-HATCHED LARVAE These are so minute that they would be invisible in bright sunlight if it were not for their bright yellow color. In sunlight they appear as tiny, lemon-yellow specks crawling slowly about on the bark. On June 24th, 1907, many of them had already occupied positions on the leaves. Some were in the groove of the mid-rib on the upper surface. More were to be found, however, on the underside of the leaf along the mid-rib in the axils of branching veins. They were partially con- cealed by the pubescence of the leaf, Plate XIII. On June 26th, the larvae were appearing far more rapidly than they could escape from the semi-cocoon, Plates XI, and XII. On July 2d, 1907, newly- hatched larvae were very abundant. They were still abundant in the semi-cocoons of the females and along the mid-ribs of the leaves on August 9th. Some larvae just out of the egg were photographed on September 16th, 1907. Most of the larvae pass the summer on the leaves, largely on the under surface, some settle permanently in the axils of the leaves or upon the buds; many remain upon the leaves until they fall in the autumn. ‘THE EGG, PLATE xI Length, approximately .82 mm. Breadth, .16 mm. Outline an ellipse whose length is to its breadth as two is to one. Color, bright lemon-yellow. Surface smooth and glistening as though viscous at first; becoming wrinkled as it dries and finally bursting a few minutes after it is deposited. Through the superficial integument the eyes of the larva within are distinctly seen as two black specks. Reno, Aug. 12th, 1907. I observed some females laying eggs today. I have seen nothing so far to indicate that the young of this species are born ovovivipacously. The egg is expelled from the female, and upon contact with the air, bursts and the larva emerges. PLATE XI—Egaes anp Larvae (From Photographs by the Author) 1-2. Egg-Shells and Struggling Larvae Beneath Female. (X 16). 8. Eggs and Hatching Larvae. (X 40). 4. Larvae. (X 16). s rigeeige DT AMINGY WTTF .,T...... Tue European Eum Scape 13 NEWLY-HATCHED LARVAE Total length of body approximately .41 mm. Breadth, .21 mm. Outline oval, twice as long as broad, tapering posteriorly to two fleshy lobes each of which bears three stout dorsal spines and a long terminal filament whose length equals half that of the body. Color, lemon- yellow. Entire lateral margin of dorsum fringed with stout, thick spines. Of these each abdominal segment bears two. Along the tho- racic and interior margins the bases of the lateral spines are set higher up on the dorsum. Between the antennae the row is made double by the addition of four spines whose bases are marginal in position. There are two such spines on the ventral surface between the bases of the antennae, curved a little and directed forward. The dorsum bears a double central row of paired spines of the same shape and gen- eral character as the lateral ones. Of these dorsal spines, pairs seven to ten inclusive and often pair eleven also are reduced to rudiments. The antennae are stout and fleshy, the division into segments not strongly marked. Their length is to that of the body as 11 is to 19. They are six-jointed, the sixth segment is longest. Its length is to that of the third segment as 27 is to 22. It bears a number of short hairs and two longer ones whose length is to that of the segment as 61 to 27. Of the leg-segments the femur is the longest, the tibia shortest. The lengths of femur, tibia and tarsus are to each other as 65, 37 and 54. The anal ring is surrounded by six hairs. Plate NIT. RATE OF INCREASE Toward the end of the season a little mass of delicate egg-shells has accumulated in the waxen cradle of the female; and it would seem as though one might form a good idea of the number of eggs laid by one female simply by counting the shells. I reached in this way no satisfactory result, however, partly because of the difficulty of sepa- rating and counting things so small and fragile and partly because of the fact that some of the shells are lost when the body of the female shrinks toward the end of the laying season. Then, too, larvae which have become entangled with the shells drag some of them out when they make their escape. In another way we may reach an unsatisfactory idea of the number of eggs laid by a single female. In some instances the vitality of the larvae is so low that they cannot escape from the semi-cocoon and die there shortly after birth. In such instances from sixty to nearly three hundred larvae have been counted beneath a single female. 14 Tue EuropEAN ELM SCALE DEATH RATE IN 1907 While Gossyparia spuria was abundant and highly injurious in the summer of 1907, it seems likely that the conditions governing their increase were on the whole not so favorable as in the previous summer. We have spoken of the large numbers of larvae which died within the cocoon of the female and of the high percentage of dead larvae found on some of the leaves (382 in 1000). There were other things which indicated a considerable mortality among these insect pests. Very many males in the spring failed to complete their transforma- tions and died within their cocoons. The elms, on the whole, appeared not quite so seriously infested in this vicinity in 1907 as in 1906 and but few were killed outright, though many were rendered unsightly by dead branches and dull foliage. People living in the vicinity of Carson City stated that their elms had been healthier than usual this summer, but that the elm is always a rather sickly tree in that vicinity owing to the constant presence of the European Elm Scale. ONE WAY IN WHICH THE ELM SCALE SPREADS FROM TREE TO TREE Late in the summer leaves on infested branches turn prematurely yellow and fall to the ground, carrying down with them no small number of larvae. On September 5th, 1907, it was an easy matter to tell which trees were infested; for on such trees the foliage of the lower limbs was yellow or reddish brown, thin, and falling. Groups of yellow leaves in the midst of foliage otherwise dark green and Dec. 14th, 1907. *Under all the dead females which I examined today, there were dense masses of larvae which had died shortly after hatching. In many instances hundreds of them were massed together with the egg-shells. In one such mass I counted 191 dead larvae, in another, there were 280. To a degree this may serve as an indication of the large number of larvae to which one female gives birth. Many, however, may have escaped. Sept. 5th, 1907 The color of Gossyparia spuria on infested leaves ranges from lemon- yellow to orange and chocolate brown. Newly hatched and newly moulted larvae are yellow, those more fully grown and not recently moulted are darker. Sept 9th, 1907. Twenty-six per cent of the females examined today were still soft and apparently alive. Under the fresher females a few newly hatched larvae could be found occasionally, some few were present here and there on the bark. On the whole the egg-laying season is nearly at an end as the fresh- est females to be found contain very few eggs. PLATE XIII—Tue Larvakz In SUMMER (From Photographs by the Author) 1. (X 8) and 3. (X 16). Along Mid-Rib on Under Surface of Leaf. 2. (X 16). Recently Hatched Larvae on the Upper Surface of Leaf. THr EuRoPEAN EwLm SCALE 15 glossy often betray the presence of the European Elm Scale. On the date mentioned I took from a tree which seemed only slightly infested ten leaves on which there were just one thousand larvae, 618 of which were living. Both dead and living were of all sizes, from those just hatched to some as large as the winter larvae. On October 18th, 1906, larvae were still abundant on leaves recently fallen from infested branches, especially along the mid-rib on the underside. A few were discovered in slight recesses along the mid-rib on the upper surface. Leaves which had fallen some days previously and which had since been lying on the lawn bore very few larvae. On October 24th, 1906, larvae were still numerous on leaves which had fallen before the frost. On November Ist, after a heavy frost, one or two could still be found occasionally on fallen leaves, very few on the leaves which remained on the tree. On the trunk of an American elm near at hand I found large numbers of larvae clinging to the trunk within one foot of the ground. They were present in a similar position on the trunk of an English elm growing near at hand. The unusual position of these clustered larvae leads me to infer that they had fallen to the lawn on the falling leaves, had abandoned them, and taken up positions on the trunks of the adjacent elms. THE NATURE OF THE INFESTED TREES The Cork Elm, (English Elm, Ulmus campestris, Smith). This is the favorite shade tree in western Nevada and we have used the name by which it is commonly known in this region, although many of these elms are almost wholly devoid of cork, while on others all of the smaller limbs are shaggy with it in thin longitudinal plates which radiate from the axis of the branch in all directions. The habit of growth is broader and more spreading than that of the American elm. The trunk is comparatively short and stocky, it divides into from three to ten large branches which in turn divide repeatedly and bear a dense mass of deep green foliage which lasts from May until November, giving a most welcome shade in this climate of dry summer heat and intense sunlight. In moist soil the English elm has the bad habit of sending up little thickets of sprouts and suckers about the roots. Thousands of these elms have been planted along the residence streets and in parks in Reno and Carson City; they are not so common as yet in the country districts. In western Nevada they are young trees of necessity, few of which are over forty feet in height, and though vigorous and hardy they are very susceptible to the attacks of the European Elm Seale. Plate XIV. 16 THE EuRopeaAN ELM SCALE The American Elm, (White Elm, Ulmus Americana, Linnaeus). Of a taller, more slender, and more graceful habit of growth than the English Elm. The bark is of a lighter grey color and is devoid of cork. Some specimens branch almost as diffusely as the English Elm, although the general habit of growth is never so stocky and the indi- vidual branches are lighter and more slender. Many of these Amer- ican elms are already tall and elegant trees, fifty feet in height, with long, sweeping branches.. They are apt, however, to be somewhat mis- shapen and unsymmetrical because of their greater height and conse- quent exposure to the full sweep of the wind. In this region the American Elm is apt to be more seriously injured by the European Elm Seale than is the English Elm. While the bark is smoother it is apt to be full of ckacks and crevices, which offer much protection to the hibernating larvae. On the whole, it is a much less sturdy and hardy tree than the English Elm and is much more subject to insect attacks. LIME-SULPHUR AS A REMEDY FOR THE EUROPEAN ELM SCALE As the preparation and use of this insecticide is understood by nurserymen and others who do commercial spraying in this vicinity, and as it is the recognized standard remedy for the San Jose Scale, I sprayed a number of elms with it in February, 1907, to see whether it would also check Gossyparia spuria. FORMULA PUTS (2th A Pa Sea TN tet st ea 20 Ibs Sulphur 0.0. SEERA cater 15 Ibs. WWE CTS ea pe ats has PL ee ht ho es, 50 gals. The lime-sulphur mixture was boiled with steam from a traction engine for two hours or more in about thirty gallons of water, twenty gallons more were then added and the mixture used while still warm. The trees were sprayed with the greatest care; we aimed to wet every inch of bark on the tree from the smallest twigs down to the ground. At first we did not succeed in this entirely; for it is far more difficult to spray a cork elm than an apple tree of the same size. If any large portion of the hibernating larvae are to be reached, the bark between the projecting ridges of cork must be soaking wet with the spraying mixture. In this we failed at first. A careful inspection of the sprayed trees showed many spots that had not been covered at all. All such spots were sprayed a second time, and several of the trees were thor- J pa hed PLATE XIV—SucKers (From Photograph by the Author) A Thicket of Sprouts Surrounding an English Elm Tue European Etm Scate 17 oughly sprayed twice or even three times. Even at that, some of the hibernating larvae hidden between the plates of cork escaped the spray entirely. As the trees varied in size and in degree of infestation, they were divided into lots; and as the results varied somewhat, the different lots will be discussed separately. LOT I Fifty-eight young cork elms in the park opposite the Court-house, Reno, Nevada. Trees twenty to twenty-five feet in height; a few of the higher branches were trimmed in order that the whole tree might be covered with the spray. The trees were sprayed, inspected and re- touched to cover spots missed in the first application. They were not badly infested on the whole; six showed evidence of serious injury in September, 1906. Many were only slightly infested; others appa- rently not at all. In the spring following the spraying, leaves appeared on these trees one week later than on surrounding unsprayed elms of the same age. In June on some of the sprayed trees there were no small rumber of mature females on the underside of some of the branches. On one such tree which could scarcely have escaped a thorough spray- ing in February, there were a great many females present on the lower limbs late in the following June. These were all washed away with a strong stream of water from a garden hose; and the gardener was instructed to follow the same plan with the remaining trees. A close examination of the bark on September 16th, showed that few female insects had escaped. On the leaves there were a few larvae. On December 13th, after the leaves had all fallen, a most careful examina- tion of those trees which had been most seriously infested in 1906 dis- closed a few winter larvae in the axils of buds and leaf scars, or clus- tered about the few remaining dead female scales. The total result of the treatment given the trees in Lot I was very good. Throughout the summer their appearance gave no evidence that the Elm Scale was present ; the foliage was dark green and glossy in late summer in strong contrast to the prematurely yellow leaves of the unsprayed trees. LOT If Ten trees at the corner of State and Center Streets, Reno, Nevada. Cork elms, very rough and shaggy with cork, about twenty-five feet in height. Slightly infested, with the exception of one, which showed signs of serious injury in the late summer of 1906. Early in the sum- mer of 1907, Mr. Westerfield found some female scales on the under- 18 Tue EurRopeaAN ELM SCALE side of the lower branches and immediately washed them all off with the garden hose; throughout the summer he followed the same_ plan, washing the bark of all accessible limbs and the undersides of the leaves occasionally with the strong stream from the garden hose. The result of this treatment was so good that the trees appeared entirely healthy and made a vigorous growth throughout the summer. Unsprayed trees across the street were badly infested and turned pre- maturely yellow. An examination in the winter following disclosed a few hidden dead female scales. A few scattered larvae were to be found about the buds and leaf scars. On a few branches hiber- nating larvae were found in considerable numbers along the bases of projecting ridges of cork. In this instance the escape of the few female insects and the consequent number of hibernating larvae were due in large part to the extreme roughness of the bark. LOT III Two American elms and fourteen young cork elms all recently planted. They range in height from four to sixteen feet. Winter larvae were exceedingly numerous, trees completely infested. Well sprayed once late in the afternoon of Feburuary 11th, 1907. The lime-sulphur used had been well-cooked with steam; it was, however, the remainder of a barrel left after spraying a number of other trees and was rather thick with sediment. The trees were examined about three weeks after spraying, on March 6th, 1907. The material chosen for this examination consisted of twigs about one-quarter inch in diameter, thoroughly sound and green, taken from different parts of several trees. These twigs had all been well coated with the lime-sulphur; the wintering larvae between the projecting ridges of cork were all still more or less encrusted with it. A count of one thousand hibernating larvae showed that 330 were dead and 670 were living. Dried and shrunken larvae were counted as dead. Those plump, of normal color, and full of the usual clear-brown body fluids were considered alive; most of them gave further evidence of life by moving legs or antennae. Many of them with backs totally encrusted with lime-sulphur moved legs and antennae when lifted from the bark on the point of a needle. On May Ist, 1907, these trees were well covered with living Gossy- paria, hibernating larvae, newly moulted females, and male cocoons. Ants and flies were attracted in large numbers by the exereted honey dew. The two trees worst infested were young American elms about sixteen feet in height. The undersides of many of the branches were literally crowded with different stages of the insect in question. These Tre European Exim Scate 19 two elms were well washed down with a strong stream from the gar- den hose, the nozzle of which had one small circular outlet and threw a strong, round stream. Every bit of bark was washed; from twig to trunk and down to the ground. The trees were vigorous and young, just coming into leaf; the washing was done at noon of May Ist, 1907. Both trees made an excellent appearance through the following summer, in strong contrast to other trees not so treated. On December 27th, 1907, a searching examination of one of these trees showed that it was almost wholly free from winter larvae. The bark looked unus- ually healthy and clean, and though it presented many long and deep crevices such as form the usual hiding places of the larvae, almost none at all were to be found. A few dead females in the forks of some small twigs showed that they had escaped both the lime-sulphur and the stream from the garden hose. There is no reason for spraying or washing this tree in 1908. LOT IV Four cork elms twenty-five or thirty years old and about forty feet in height; in August, 1906, these trees were so badly infested that the limbs were nearly all dead and had been deserted by the insects, which drop to the ground upon the death of a limb in the summer time. These trees were headed back to the trunk in the autumn leav- ing nothing but the stubs of the limbs with a few living twigs. On February 12th, 1907, they were sprayed until all the bark was wet and dripping with lime-sulphur. In the course of the following sum- mer they were well washed at intervals by the gardener employed about the grounds who kept the bark and the undersides of the leaves clean by means of a strong stream of water from the garden hose. The result of trimming, spraying and washing these elms was good. They put out a vigorous growth of leafy twigs and looked healthy and vigorous through the summer, promising an entire recovery from the effects of the Elm Seale. Trees in an adjoining yard which were sim- ilarly infested and which were trimmed in the same way, but which were not sprayed, made a stunted and sickly growth. LOT V Six young cork elms about twenty-five feet in height, Mill Street, Reno, Nevada. Bark rough with projecting plates and ridges of cork, trees planted too close together, branches interlocking, making thor- ough spraying difficult. In October, 1906, they showed marked evi- dence of injury, for many of the smaller branches were dead or dying and the leaves of infested branches had turned yellow. A thorough application of lime-sulphur was made on February 12th, 1907; eight 20 Tue EvuRopeaAN Etm Scape or ten gallons were sprayed on each tree, and the appearance of the bark after spraying showed that apparently the whole tree in each in- stance had been well covered. Counts of one thousand dead and living scales were made on March Tth, 1907, giving the following results: Dead, 286; living, 714. The insects counted were all on smooth twigs which were green and in good condition. Some were smooth, others rough with projecting plates of cork. Some of the insects counted were clustered about the bases of twigs or in the axils of buds; others were ranged along the bases of the projecting ridges of cork. More were counted in the latter situation, for they are far more numerous there than upon the buds or the leaf scars. At the time when the count was made these twigs were still grey with the lime-sulphur and appeared to have been well and thor- oughly sprayed. Female scales were present in considerable numbers on the under- sides of the lower branches all through the summer following the spraying. They were not washed away by the gardener, and received no treatment of any kind after the first spraying with lime-sulphur. Until late in autumn these trees made a vigorous growth and showed no signs of injury due to the scale. The leaves remained dark green and glossy until late in October. On September 16th, 1907, they were handsome and thrifty young trees. An examination of these trees December 13th, 1907, showed many winter larvae on leaf scars, in the axils of buds, grouped in irregular rings about the bases of small twigs, or partly concealed in and around the semi-cocoons of the dead females or within and around rifts and crevices in the bark. Dead females were fairly abundant on the un- dersides of the lower limbs. These six trees had been well-sprayed February 12th, 1907, with lime-sulphur. They had not been washed later in the season with the garden hose. Winter larvae, abandoned male cocoons, and dead females were abundant enough in the winter following to justify the statement that these trees in the winter follow- ing the spraying with lime-sulphur were still moderately infested with the Elm Seale. They would be benefitted by another spraying. LOT VI Two American elms of unknown age. Height 40 feet, girth 3 feet, 6 inches. Badly injured in the summer of 1906, when many of the lower branches were in a dying condition and the leaves were prema- turely yellow in the lower portion of the tree. In February, 1907, hibernating larvae were present in great abundance. Sprayed Feb- ruary 12th, 1907. Count of living and dead larvae made March 7th, 1907. Living scales in one thousand then numbered 667; of dead ones THe HKuropeaN Etm ScALe 21 there were 333. Small branches and twigs, green and sound, but of low vitality were chosen for the count. The bark was smooth, with little or no cork present; it was coated, even incrusted with lime-sul- phur. Scales counted as living were plump, ful! of normal body fluids, and of the usual color. Those shrunken and discolored or dried were counted as dead. Owing to the height of these elms the tops were reached with difficulty, if at all. They were not washed down later in the summer with the garden hose. They stood the summer of 1907 well and seemed the better for the application, but did not make so good a growth nor so prompt a recov- ery from the injuries of the preceding year as the other elms which had been both sprayed and washed. An American Elm of about the same height and age, growing in the same row was not sprayed, but was used as a check tree. It was rather more seriously infested than the others and died late in the following summer. Counts of three thousand dead. and living scales from the check tree made at the same time as the counts from the sprayed trees showed that on it about ten per cent of the scales were dead. A Brief Summary and Some Inferences (LIME-SULPHUR ) It is not generally profitable to draw general conclusions from the results of a single experiment or from the experiments of a single sea- son; still from the results of the experiments detailed in the foregoing pages it seems safe to infer: 1. That in every instance many of the hibernating larvae escaped destruction by the lime-sulphur; some because they were not suffic- iently affected by it, others because they were concealed in the semi- cocoons of the female insects or protected by projecting ridges of cork, or hidden in deep crevices in the bark. 2. Before spraying with lime-sulphur it would be well to wash away. from the bark all visible clusters of dead females in order to destroy the winter larvae concealed within and around them. 3. After spraying in the winter with lime-sulphur, the trees should be washed down with a stiff stream of water under high pres- sure late in May or early in June to destroy the living female insects which escaped the action of the insecticide. Some Questions and a Bit of Discussion In the last few pages I have given a brief account of the methods used in the vicinity of Reno, Nevada, in 1907 to check the European Elm Scale. Those who realize that even within a limited area the com- 22 Tre EuroPpEAN ELM SCALE plete extermination of any scale insect is something not to be hoped for will agree that on the whole these methods were thoroughly suc- cessful; for every elm treated made a vigorous growth all through the following summer and showed no further signs of injury due to the insects; while elms on the same street which had not been treated were still badly infested, sickly and unsightly. Out of all the treated elms very few were sufficiently infested with winter larvae in the winter following to require further treatment. The few which did re- quire further treatment at that time were those which were sprayed with lime-sulphur in February, 1907, but which were not washed down with the garden hose early in the summer following. In 1907 spraying alone proved highly beneficial to the elms in Lots V and VI. Spraying followed by washing proved much more bene- ficial to those in Lots I, II, IIJ and IV. Thus, in general, the result of the methods employed was good; still, a closer examination of the details give rise to many questions. We naturally ask: (1). How does the lime-sulphur cause the death of those larvae which it kills? (2). Why is its action so slow and how long is it active? (3). How is the lime-sulphur affected by rain and snow after it is applied to the tree and how does this affect its power as an insecti- cide? In answer to these questions we will say that the lime-sulphur is a very complex combination of sulphur salts of calcium when applied to the tree, that after its application in contact with air and moisture it undergoes a long, slow process of chemical change lasting for weeks, perhaps for months, during which time it is injurious to some forms of insect life in ways not yet fully understood. The efficiency of the wash is reduced by rains following soon after its application to the tree. For a further discussion of the chemical nature of the lime- sulphur wash and the changes which take place after its application, see Bulletin No. 101, Bureau of Chemistry, U. 8S. Department of Agri- culture, Haywood. These considerations lead to a final series of questions which are of the utmost significance: (1). The good result attained in 1907 was due to two things, spraying and washing. Which was the more effective? (2). Which would have killed more if the elms had been washed first with the hard stream of water and then sprayed? (3). What is the use of spraying the elms at all? Why not let them go until spring and then simply trim them and wash down the scale from the bark ? Tur European Exum ScaLe 23 (4). It took the labor of three men to make the lime-sulphur and to apply it, one at the boiling vat, one on the pump handle, and one at the nozzle. Three men sprayed the elms once; and later, one man washed off the female scales which escaped the three. If one man had washed the trees three or four times, would that have cost more? Would it have been as effective? (5). Why not trim the elms in the winter, wash them with the hard stream once in the spring just before the leaves appear, and finally wash down at the end of May all the females which escape the earlier treatment, omitting altogether the use of lime-sulphur or any other insecticide? I can only answer, ‘‘It all depends upon the man behind the nozzle.’? In all the experiments under discussion the Entomologist was the man behind the nozzle. He had climbed the trees. He knew just where the hibernating larvae lay hidden. He was not paying for lime, or sulphur or for labor. He was perfectly willing to work his spraying gang through a whole forenoon to spray four small trees. It cost him nothing except when the doctor dressed his lime-sulphur burns. The atmospheric conditions following these experiments are given in the following tables: 24 Tur European Exim Scare TABLE I STATION, RENO, NEVADA; MONTH, FEBRUARY, 1907 TEMPERATURE __ | Precipi- i (Degrees Fahrenheit) (inches Character of Max. | Min. | Mean urns day dredths 1 56 | 43 50 | O.| Cloudy 2 57 45 51 | 0] Partly Cloudy 3 56 | 46 | 51 0 Cloudy 4 58 47 52 0 Partly Cloudy 5 60 42 51 | 0O- Partly Cloudy 6 59 33 46 0 Clear 7 63 30 46 0 Clear 8 59 30 44 0 Partly Cloudy _9 58 30 44 0 Partly Cloudy 10 69 36 | 52 | 0 Clear 11 65 29 47 0 Clear 12 | 64 | 29 46 0 Partly Cloudy 13 61 34 48 0 Partly Cloudy 14 | 64 | #31 48 0 Clear _15 | 61 31 46 0 Clear 16 55 35 45 Te Cloudy 17_|_51_|_ 39 45 0 Cloudy 18 59 31 45 0 Clear 19 60 | 28 | 44 | _ O- Partly Cloudy 20 61 34 48 0 Cloudy _2i 48 40 44 | 013 Cloudy 22 51 39 45 0 Cloudy 23_|_ 57 | 29 43 0 Clear 24 57 29 43 0 Partly Cloudy 25 | 46 | 33 40 0 Clear 26 39 28 34 T Cloudy _ a7 48 20 34 0 Clear 28 58 26 40 0 Partly Cloudy * Trace Tue Evropean Etm Scare TABLE II STATION, RENO, NEVADA; MONTH, MARCH, 1907 TEMPERATURE. __| Precipi- (Degrees Farenheit) tation Date (inches Character of Max. | Min. | Mean ry day dredths) 1 | _ 46 33 40 aT Cloudy 2 51 30 40 ms Cloudy 3 52 27 40 | 0.08 Cloudy 4 43 31 37 | 0.36 Cloudy 5 51 36 44 | 0 21 Cloudy 6 49 30 40 | 001 Partly Cloudy 7 | 4 31 40 | 003 | Partly Cloudy 8 50 | 26 38 | 0 Partly Cloudy 9 49 29 39 | 0 20 Cloudy _10_ | 40 28 34 | 0 31 Partly Cloudy _11_} 40 24 | 32 | 0 20 Partly Cloudy 12 36 19 28. | eT Partly Cloudy 13 41 13 27 0 Clear 14 51 18 34 0 Clear 15 51 27 39 0 Partly Cloudy 16 46 35 40 | 0.11 Cloudy 17 57 44 50 | 0.33 Cloudy 1g | 48 | 42 | 45 | 066 Cloudy 19 59 38 48 | 0 20 Partly Cloudy 20 52 33 42 | 002 Clear 21 46 32 39 0 Partly Cloudy 22 43 30 | 36 0 Clear 23 39 30 34 | 1 25 Cloudy 24 40 27 34 |.0 18 Cloudy 25 39 17 28 0 Partly Cloudy 26 40 17 28 0 Clear 27 40 15 28 0 Clear 28 47 24 36 0 Clear 29 59 | 29 30_| 0 Clear 30 66 29 48 | -0 Clear 31 65 36_! 50 0 Cloudy *Trace 26 Tue European Exim SCALE OTHER INSECTICIDES KEROSENE EMULSION FormuLs—One bar, one-half pound, Commercial Soap Company’s Pale Savon, a common yellow washing soap, cut in thin slices and dis- solved in two quarts of boiling water. One gallon Warden & Oxnard’s Elaine Oil, Kerosene of good grade, poured into the boiling soap solution after its removal from the fire, the whole mixed and emulsified by pumping through the force pump for ten minutes or until no free oil separates on standing. The emulsion made after the above formula seemed perfect, it mixed readily with water in all proportions without the separation of any free oil. Repuctions—(a). Three parts of the original emulsion with sev- enteen parts of water. 10 per cent Kerosene. (b). Three parts of the original emulsion with thirteen parts of water. 12 1-2 per cent Kerosene. (c). Three parts of the original emulsion with nine parts of water. 16 2-3 per cent Kerosene. SPRAYING EXPERIMENTS January 31st, 1908, Reno, Nevada. LOT I (With Atomizer in Laboratory) Mater1st—Hibernating larvae in cracks on the smooth bark of a small branch of American Elm. The limb was dead, but the larvae appeared normal in every way. The cracks were all moderately filled with larvae and were of about the same depth and general character throughout the limb. In some, larvae were numerous enough to be- come crowded. Very few dead females or their semi-cocoons were present. APPLICATION—Kerosene emulsion of different strengths applied as a fine mist by means of an atomizer. The cracks in every instance were filled to overflowing with the solution, which dripped from the bark and stood in the cracks like milk. The branch was in its normal position with the larvae on the underside. The application repre- sented a thorough spraying in every instance. ConpiTIons—Room temperature, 60 degrees. Temperature of solu- tion, 100 degrees. After spraying the branch was kept indoors in a warm room for nearly a week in order that the larvae which had been killed by the emulsion might dry rapidly and so be ready for counting Tue Evropran Eun Scape 27 somewhat promptly. As a result, a few of the more active larvae had begun to wander about on the table over which the branch was sus- pended and a few undoubtedly escaped. This would render the per- centage of deaths due to spraying a little too high, probably a trifling error in this instance. The contrast between the temperature of the solution and that of the room was a matter of no importance in the present instance, as the emulsion was atomized by a current of air. Tests by the thermometer with a room temperature of sixty degrees and a solution temperature of one hundred showed that when the bulb of the thermometer is sprayed with the atomizer under the conditions named the mercury does not rise more than a degree or two. This is not true with the large spray pump, however, for when water whose temperature stood at 130 degrees was sprayed on the bulb in a room whose temperature was 50 degrees the mercury rose to 80. The mechanism of the spray pump is entirely different from that of the atomizer ; for in the former a column of air is not used to atomize the solution, but the fine spray is formed by discharging the water under high pressure with a rotary motion from a small aperature. RESULTS, KEROSENE EMULSION, LOT I Test ror Deatu—Material examined in the laboratory at a room temperature of 80 degrees, under the dissecting microscope, by the strong diffused daylight of a north window. Scales of the normal, clear purple-brown color, not shrunken, with body fluids not thickened, were counted as living if they moved legs or antennae when inverted hy the point of a dissecting needle. Those shrunken, blackened and oily or deep purple in color, motionless, were counted as dead. With the 16 2-3 per cent emulsion the test for death was easily applied. With the weaker emulsions it was applied with increasing difficulty, as many of the living were more or less shrunken and discolored and their motion was exceedingly sluggish in many instances. It would seem to me that better results would have been reached if the exami- nation had been conducted at an interval of three weeks instead of a single week. The conditions of the test, however, made this impos- sible. There is a strong probability that some of those counted as liv- ing would have been ranked among the dead at a later date. As very few of the larvae were in any case thoroughly dry, I assume that very few were dead at the time of spraying. Counts oF DEAD anp Livinc—Note. Many of the ‘‘living’’ were motionless until stimulated by the near approach of a hot needle. Mixture 16 2-3 per cent Kerosene. Counted 200; dead, 157; living, 43; per cent dead, 78.5; per cent living, 21.5. 28 Tur EvropEAN ELM Scale Mixture 12 1-2 per cent Kerosene. Counted 200; dead, 101; living, 99; per cent dead, 50.5; per cent living, 49.5. Mixture 10 per cent Kerosene. Counted 250; dead, 116; living, 134; per cent dead, 46.4; per cent living, 53.6. . KEROSENE EMULSION, LOT II (With Atomizer in the Open Air) Reno, January 30th, 1908. Materiat—Hibernating larvae more or less concealed in cracks in the bark of limbs of American Elm. The limbs chosen were of various sizes, but an effort was made to secure material for each test which would be of about the same character. The limbs were so sep- arated from each other as to prevent the mixture used in one test from falling on the limb to be used in another. In general the mate- rial represented fairly the usual position of the hibernating larvae. As the trees were badly infested, most of the trees contained great numbers of larvae. Conpirions—A clear, sunny afternoon with a brisk wind from the west. The applications were made between 1:30 and 3:00 P. M., when the thermometer stood at about forty degrees. APPLICATION—Each sample was blown on the bark in a .fine spray with an atomizer of a usual pattern. In each instance it soon wet the bark so thoroughly that every sprayed crack was full of the solution, which filled the cracks and stood on the bark in drops like milk. A strong effort was made to have the work with the atomizer represent a thorough job of spraying, in which the bark should be wet to a dripping condition. With the earlier and weaker samples, evap- oration was so rapid that the emulsion soon dried on the bark leaving no trace of its use except a clean and somewhat oily appearance of the bark. The cracks chosen were all on the underside of the limb. They were filled as full of the emulsion as they would hold. Sprayed January 30th; examined March 3d, 1908. Test ror DratH—As the weather since the spraying was warm and dry the larvae had ample time to dry and shrink after their death and before examination. This made the test for death an easy one to apply. Those larvae which were shrunken and blackened and motionless were counted as dead; the remainder as living. Each larva was inverted with the point of a dissecting needle and the ven- tral surface examined in a strong light. The room temperature stood at 65 degrees during the examination and the motion on the part of Tus EuROPEAN Etm SCALE 29 the living larvae was usually prompt; in some instances, however, ’ motion was stimulated by the near approach of a hot dissecting needle. Sources oF Error—The larvae were no longer wholly dormant; for many of the males had begun their cocoons. Before beginning their cocoons the males often wander about on the limb and settle in new situations. I do not think that in the present instance this habit had progressed far enough to cause any important error. A second source of error lies in the fact that some of the dead larvae may have become detached from the branch by wind or rain and so lost to the count. The crowded condition of the dead larvae in the cracks, to- gether with their protected situation on the underside of the limb makes this source of error seem unimportant. REsutr or Count—Mixture 16 2-3 per cent Kerosene. Counted 1109; dead, 912; living, 197; per cent dead, 82.2; per cent living, 17.7. Mixture 12 1-2 per cent Kerosene. Counted 723; dead, 350; living, 373; per cent dead, 48.4; per cent living, 51.6. SCALECIDE This is an insecticide which in appearance and action closely resembles the Kerosene Emulsion. Its base, however, is a heavier oil than kerosene, and it seems far more effective as an insecticide. The Sealecide used was part of a ten-gallon sample sent out for trial by the manufacturers. As it had been standing for some time, the sample in the original can was first stirred thoroughly with a stick, the can itself was then rocked back and forth violently for several minutes in order that the small amount, about one pint, which was drawn off, might fairly represent the contents of the can. The small sample was then mixed with water in the proportions indicated in the accounts of the experiments which follow. The tree chosen for the experiments represented natural conditions of temperature and the other climatic factors; for it stands in the open air in the midst of the infested dis- trict on Mill Street, Reno, Nevada. In each of the following atomizer experiments the larvae were first examined with a magnifier to see that their appearance was wholly normal, and in every instance the bark was examined to ascertain whether or not it was sound. Much care was exercised to prevent the possibility of the spray used in one test touching the bark which had already been sprayed or which was to be sprayed in another test. These atomizer experiments should give a good idea of the efficiency of the sample of Scalecide used, under the conditions named. 30 Tur EuROPEAN Em SCALE SPRAYING EXPERIMENTS, SCALECIDE (With Atomizer in the Open Air) 10 Per Cent Solution. One Part Scalecide With Nine Parts of Water. Mareriat—(1). Colonies of hibernating larvae surrounded dead females on a green and healthy quarter-inch twig. (2). Scattered clusters of hibernating larvae on a healthy limb well up in a tree. Some of these larvae are partially concealed in cracks, others fully exposed to the action of the insecticide. (3). Three irregular rows of hibernating larvae apparently in a healthy condition in cracks in the bark of a badly infested American Elm, the bark surrounding the larvae is partly dead. Conpirions—A clear and sunny afternoon, 2 P. M. Tempera- ture, 42 degrees. APPLICATION—The insecticide was applied with an atomizer of a usual pattern, whose misty spray wet the bark until the solution stood in the cracks and ran along the bark in drops like milk. RESULTS Trust For DeatH—The same tests were applied as in the experi- ments with kerosene emulsion. Resutts or Counts—Of 1283 larvae examined, only four were living, giving a percentage of efficiency of 99.7 per cent. This should be total, for the four living ones were sluggish and discolored and would in all probability have died soon. . Sealecide, 1 in 15. One Part Sealecide With Fourteen Parts of Water. Material, conditions, application and tests for death were of the same character as with the 1 in 10 solution. ResuLTs—Out of 1359 larvae counted, 145 were living, giving evi- dence of life by moving legs or antennae when the test for death was applied. Most of them remained under observation for several min- utes. In some instances the motion was very slight and the larvae appeared to be in a dying condition. To the naked eye they seemed to be of wholly normal appearance, though perhaps a little shrunken. The count probably errs by stating too small a proportion of dead; for there is much to indicate that some few at least were washed away by rains after the branch was sprayed. On the whole the larvae were in such situations on the bark that they were fairly exposed to the spray. Many of those which escaped were concealed in the deeper crevices. The percentage of efficiency with the one in fifteen solution was nearly ninety per cent. : Scalecide is manufactured by the B. G. Pratt Co., No, 11 Broadway, New York. Tus Europran Exum Scape 31 With weaker solutions the percentage of efficiency fell rapidly. A Sealecide solution of one in twenty gave an efficiency of 67 per cent under similar conditions to those detailed above for the stronger mix- tures. A solution of one part in thirty gave only 34 per cent. Scalecide and Kerosene Emulsion.. A Summary and Some Inferences The atomizer experiments which I have detailed above were not ex- tensive in character nor continued over any long period of time; but they were thorough, and may well serve to indicate the relative effic- iency of the two insecticides. I am confident that in order to penetrate the white flocculent wax beneath the hibernating larvae, to penetrate the deeper crevices in which they are hidden, or even to penetrate the masses of semi-cocoons which shield so many of the hibernating larvae one must use kerosene emulsion which is at least one-sixth pure kero- sene; one-fifth would be better. I cannot recommend the use of such strong kerosene emulsions even on dormant elms. It seems to me that if such strong emulsions were used for a series of years a serious in- jury to the elms could not fail to follow. Much weaker solutions of Scalecide proved far more efficient and it is likely that this insecticide can be used at a strength as low as 1 in 15 with thoroughly good results if the application wets the hiber- nating larvae completely. With this, as with the lime-sulphur, it does not pay to economize material, as the main cost of spraying is in the labor, and a poor job is worse than none, for it fails of effect and gives the materia] and methods used a bad name. THE GARDEN HOSE AND THE ELM SCALE In this connection I would gladly make three points so clear that there can be no possibility of a mistake concerning them. The first is this: The stream must have force. A gentle sprink- ling probably simply refreshes the female scale insect and improves her appetite. I have spoken of it as a hard stream, a stiff stream, a strong stream, a powerful stream. I do not say that the insects are to be simply wet, or given a chill, or even drowned out; but that they must be hit hard and knocked out. My second point is this: The washing must be done thoroughly. Most of the mature females are, indeed, to be found on the underside of the lower branches; yet there are others and many of them scattered over the entire tree, in the axils of tiny twigs, on the under sides of small horizontal branches high in the tree, and in cracks in the rough bark of vertical limbs. In April wash every limb from twig to trunk, then wash the trunk. Do it again in the beginning of June. My third point is this: The washing must be done at the right 32 Tue European Exim SCALE time. In December, 1907, I examined two young elms which were literally covered with hibernating larvae. Dead females were com- paratively scarce. The owner of the elms said that it was useless to wash the trees, that in the summer he had washed away the female scales and, ‘‘Now, just look at them!’’ I asked, ‘‘When did you wash them?’’? He replied, ‘‘In July or August, I have forgotten which.’’ He had washed away the almost empty females when the young were nearly all out on the leaves. Had he used the strong stream twice on those elms, once in April, just before the leaves began to show, once in June before the young scale insects appeared, his trees would have been comparatively clean in the following winter; and this at no expense, for he had enough hose to.reach the elms from all sides and a nozzle which threw a powerful jet twenty feet in the air. There is but one generation of Gossyparia spuria each year. If all the females could be destroyed at the beginning of the season there would be no generation. In every stage of its growth Gossyparia spuria can be washed from the bark readily with a strong jet of water. I have searched the winter larvae out of cracks and crevices with the strong stream ten feet from the nozzle. I have knocked females and their semi-cocoons out from between plates of cork on elm branches leaving no trace of insect or semi-cocoon. I have stood on the ground and washed away winter larvae from branches twenty feet above. In this work the following apparatus is very useful: One hundred feet of three-quarter inch garden hose with tight connections at all joints, six feet of half-inch galvanized pipe with pipe-to-hose connec- tions at both ends to one of which is attached a nozzle which throws a hard, strong jet of water. For the lower branches the hard stream may spread a little. For higher branches a long tapering nozzle whose single, round opening throws a powerful, round jet is very suit- able. THE AXE, THE GRUBBING HOE, THE PRUNING SAW AND THE GARDEN HOSE These are the tools which we expect to use in our future experi- ments in controlling the European Elm Seale. We do not expect to use the axe as thoroughly as we would like. No finer program for future Arbor Days in this vicinity could be chosen than the cutting down of half the elms and other trees: along our streets for the sake of the other half. Along State and Mill Streets in Reno, half the elms should be sacrificed immediately. Some people seem to think that the elm is a hedge plant instead of a tree. Often Tue KuROoPEAN ELM SCALE 33 from five to seven elms are choking the life out of one another in front of a single 50-foot lot. Two good elms are twice as good as four poor ones. Twenty-five feet in every direction is too little for a broad and spreading tree like the cork elm. Two trees in front of one 50- foot lot would not be very crowded at first. We should not think of planting more. The use of the grubbing hoe is a pleasant form of light exercise in the spring time. It should be indulged in freely wherever the cork elms have sent up thickets of young growth from the roots; for these unsightly thickets of young elms are nurseries for the scale. See Plate XIV. With the pruning saw the elms should be trimmed into an open and spreading form of branching. Cuts should be made at the very base of the limb which is cut leaving no stub whatever. The mutilated stump of what was once a limb is unsightly, injurious to the tree, and suggestive of ignorant and slovenly trimming. It is bad practice to cut off the end of a branch; for on the remaining end a perfect broom of twigs soon forms, making spraying and washing doubly difficult. In Reno the elms are planted so close together that, deprived by one another of their necessary air and sunlight, they shoot up in spindling forms which in the course of time attract the attention of even the owners, who instead of cutting down half or two-thirds of their crowded trees, try to trim them all into shape by cutting off the ends of the branches. This is simply ruinous to the appearance of the elm and to its normal and healthy growth. The cork elm espec- ially is a broad and spreading tree by its inherited habit of growth. As a general principle of tree culture it is safe to say that an orna- mental tree fails of its purposes unless it is given so much room that it can spread out in all directions into its own characteristic shape. It is going to be no easy matter to care for the elms which line our resi- dence streets if the European Elm Scale and other insects continue to spread. It is a very hard matter to spray a shaggy cork elm thor- oughly even under the best of circumstances, but where they are crowded together with interlocking branches as they are about the Capito! Building at Carson City or along many of the residence streets in Reno, it is simply impossible to do any effective spraying. HUMAN NATURE AGAIN Now in all probabilty the plain, homely methods of destroying Gossyparia spuria which are here suggested will fail to appeal to some people. The garden hose may appear too simple a remedy to be effec- tive. The dark brown color of the lime-sulphur and its sulphurous 34 Tur EuRoPpEAN ELM SCALE smell suggest something mysterious, half-diabolical, ‘‘scientific.’’ Then, too, there is something still attractively novel and up-to-date about the appearance of a spray pump, especially when operated by a gasoline engine. There was once an old woman whose family was very large and whose cares were correspondingly many. A neighbor asked her, ‘*How is it, Mrs. Murphy, that you ever succeeded in raising so large a family?’’ Mrs. Murphy answered, ‘‘Sure, when they reach a cer- tain age I just give ’em to God and let ’em go!’’ We seem to follow much the same plan with our elm trees. Human disease is often due to the fact that unwise ways of living have supplied the conditions under which disease flourishes. How natu- ral it is then to go to a doctor and demand some mysterious ‘‘cure’’ rather than change our rooted habits and ways of living. With our elms it is much the same. Gossyparia spuria flourishes on crowded and neglected elms. We supply ideal conditions for its growth and spread. Let us first change those conditions with axe, pruning saw and grubbing hoe; then fight the battle out with the garden hose, using the spray pump as a last resort. AN IMPORTANT ELM INSECT. NEVADA STATE UNIVERSITY. Agricultural Experiment Station. BOUaDETinNW WoO. esa, Reno, Nevapa, NovEMBER, 1895. Agricultural Experiment Station BOARD OF CONTROL. Tue REGENTS OF THE UNIVERSITY. STATION COUNCIL. PRESIDENT JOSEPH EDWARD STUBBS, R. H. McDoweE Lt, B. S.........-..- Agriculture and Horticulture F. H. HItuMAN, M. S....... eee eee es Botany and Entomology N. E. WILSON, M.S... eee cece eee eee Chemistry and Dairying W. MGN. Minter, M. Diese sees cere see tise eee dees Bacteriology STATION STAFF. PRESIDENT J. E. STUBBS... 2.0. eee cece cece eee eee eens Director PROFESSOR R. H. McDoOWELL......... Agriculture and Horticulture ProFEsSOR F. H. HILLMAN..........+0545 Botany and Entomology PROFESSOR N. E. WILSON... 66. eee cece cnet eee eee eee Chemistry Proressor W. MCN. MILLER............ sryigcenavenuaheats Bacteriology R. As LOUNSBURY 3 a453ue eked GS aa se wegie Foreman of Farm Address all communications to THE DIRECTOR, AGRICULTURAL EXPERIMENT STATION. Reno, Washoe County, Nevada. AN IMPORTANT ELM INSECT, F. H. Hittman, M. S. The present brief bulletin is issued as a preliminary report upon an injurious insect new to Nevada, whose depredations are sufficiently serious to demand early attention in at least a single locality. Our present knowledge of the insect in relation to its history in Nevada, will admit only of an account of its single known attack within the State, together with a brief statement of the insect's history in this country, its nature and more important life-habits, and the result of ‘preliminary experiments leading towards its control or eradication. It is hoped that the investigations of another year will better prepare us for the presentation of reliable information relative to remedies; also further facts regarding the extent of the attack of the pest in Nevada. Of the few trees thus far used tor shade and ornament in Western Nevada each has some insect enemy, with the possible exceptions for our region at the present time of the maples and box-elder. The majority of these insects, however, have appeared in sufficiently small numbers to escape popular notice, and so, continue to-appear from year to year unmolested and generally unknown. The most popular of our ornamantal trees, the elms, represented by two species, principally the white elm (U/mus Americana) and the cork elm (U/mus racemosa), have shared, with others, this immunity from destructive insects, until now these trees are threatened by a most destructive insect of comparatively recent introduction to this country. \ This insect has made its appearance at Carson City upon the elms in the State Capitol grounds and on the streets in the immediate vicinity. So far as is known, this is the only locality within the State in which this insect has made its appearance. Early in October of the present year the writer's attention was called to the presence of the insect upon the elms about the Capitol by Mr. C. ’ a ae A. LaGrave, State Comptroller. Specimens of infested bark were sent to the writer for examination. From these the insect was at once identified as Gossyparia u/mi Geoffroy, an insect little known in this country, but well known in Europe, where it is a serious enemy of the elms in France. ; The following information regarding the history of this insect in this country is taken from the government publication, ‘‘ Insect Life,’’ (Vol. II, p. 34). The first locality in the United States from which it was recognized was Westchester Co., N. Y., in 1884, where it was found on nursery stock in great numbers. _n 1887 it was found on the slip- pery elm at Cambridge, Mass. It had been observed in New York City the previous year. In 1888 it was found on elms on the grounds of the Department of Agriculture at Washington, and soon after on trees in the streets of the same city. Up to this time the insect remained unidentified in the American entomological collections, but in 1889 more complete material was received by the Division of Ento- mology of the Department of Agriculture, from which the insect was determined to be identical with the elm pest of Europe, (Gossyparia zulm2) Geoffroy. So far as is known, the insect confines its attacks in this country to the elms, but presents some variability in its preferences for the various species of elms in different localities. In Europe, however, it has been found on the alder, from which fact the synonym Gossyparia alni Modier has arisen, the specific name a/zz being derived trom Adnws, the name of the genus of plants to which the alder belongs. According to the reports of the observers at the above-mentioned localities, the insect attacks the American elms more vigorously than the introduced European species, and thus it is added to the already long list of immigrant animals and plants that have found in this country conditions more congenial than those of their foreign home. THE ATTACK AT CARSON CITY. On October rgth the writer visited Carson City for the purpose of investigating the attack of the insect at that place. The first tree examined was a white elm, twenty or twenty-five feet high, standing beside the walk on the north of the Capitol, midway between the build- ing and street. Last year this tree was observed to be dying, which fact was even more evident at the time of the present examination, when only the uppermost branches were leaf-bearing. With the aid of a painter’s ladder a careful examination of -the attack of the insect was made, Standing on the ground, one could plainly see the characteristic rows and blotches of old insects, which nearly covered the under side -5-— of the lower branches. These were the dead bodies and empty wax cups of insects of the two or three preceding years. No living young ‘were found here, although male cocoons were abundant. These remains were to be counted by the thousands and the cracked and displaced bark was sufficient evidence of the cause of the death of the branches. As the examination proceeded upward, the same condition was exhib- ited by the higher branches. The number of insects seemingly increased towards the middle of the tree, where living young were seen in countless numbers. Nearer tze top of the tree the insects seemed to be but a year old. Here the male cocoons were much fewer than on the intermediate and lower branches. The uppermost leaf-bearing branches showed comparatively few insects which were confined to the bases, the upper parts being free from insects and apparently in a healthy condition, In all cases the old insects were confined to the under side of the more horizontal branches and seemingly to the shaded sides of those more nearly vertical. Very few old remains were found on the trunk, and these only in the deeper recesses of the bark. An‘examination of other trees on the grounds showed them to be very generally affected, though few so badly as the first tree examined. The smooth-bark trees exhibited the greater number of insects. This is probably due to the protection afforded the cork elm by the plates of cork which cover a large part of the living bark on the branches and twigs of this elm. One young tree, twelve feet or more high, standing beside the east walk, showed a scattering few mature females, which were noticed only on careful examination, but thousands of young were found clusteredin various protecting cracks and depressions in the bark. This tree had evidently been attacked for the first time the present year, and, although the mature insects were comparatively few, yet they were able to thoroughly stock the tree. As the bark at this time was very thin and tender, a large proportion of the young insects would be likely to survive and produce a host of matured insects the coming year. . A tree in the street, two blocks from the Capitol, was badly intested. The insects all appeared comparatively young, however, and the tree was in full leaf. Many young lice were found on the under surface of the leaves, especially at the axils of the veins. Presumably, these were stragglers which would not return to the branches for hibernation. As was expected, no other kinds of trees were found affected, although maples and box-elders stand among the elms in different yarts of the grounds. APPEARANCE OF THE INSECT DESCRIBED. One is most apt to first notice the presence ot this insect by seeing =—o= great numbers of elliptical or circular whitish rings surrounding a darker center clustered along the under side of the lower limbs and Fic. 1—G@ossyparia ulmi— Section of branch showing the usual appearance of the insects; a, females over a crack in the bark. (Two small groups are seen in the upper part of the figure.) e. a cluster of small cocoons. (Another cluster is at the left of the figure ) branches. If the bark is cracked, rows of the insects will be found to cover the cracks and so be arranged longitudinally to the branch. These light margined objects are the bodies of old female lice and may Le of one, two or three years’ standing. A closer examination will re- veal the fact that many of the central darker parts, which are the bodies proper of the lice, are absent, these having fallen away with age The white marginal ring surrounding the body of the insect, consists of a somewhat fir brous, waxy material, secreted by the develop- ing insect It becomes firmly attached to the bark and curled inward, arching over the back of the insect, where its edge is somewhat fringed. The body becomes with age dark brown, smooth, convex longitudinally, the seg- mentation usually remaining distinct. The preceding description applies to the female only. The male insect assumes a very different form. As the males do not take food, they may be found at any point on the bark, usually, however, in more or less protecting spots. On nearing maturity, the males secrete a minute pocket-like case, or cocoon, within which they cast their larval skin, and acquire a single pair of wings. They then emerge from the the cocoon, and mating with the fe- males, disappear. The empty cocoons remain attached to the bark. They occur singly, but usually in clusters, each a minute white object less than a twelfth of an inchlong. Where the plates of cork are numerous on the branches of the cork elm, the female lice ‘become fixed to the narrow strips of living bark between the plates of cork, while the male cocoons may be found in the narrow crevices in the cork. The young lice, as they appear at this season, can be seen with the unaided eye only on close examination. Under a strong lens, a cluster of them presents a dull grayish appearance. Fic. 2—Gossyparia ulmi— Section of branch of cork elm, showing female insects between the plates of.cork. Male cocoons are often ‘ound in the smaller crevices of the corky plates ) Individually they are somewhat oval in shape, and are covered with minute whitish spines. -7I- Most of them are quiet in their place of hibernation, but on being dis- turbed many will leave their positions, moving sluggishly. RELATIONSHIP AND LIFE HISTORY. This insect belongs to the family of insects Coceid@, which is repre- sented by many very injurious insects. Fic... 3—Gossyparia ulmi— Female insects greatly en- larged. - he upper two show the dark bodies proper; the lower is the cup-like waxy secretion, the body of the insect away Young lice are shown clustered about the mother insects.) havin ig fallen: The various scale insects, some of which are particularly injurious to the citrus fruits of California; also the mealy bugs, one of which is common in conservatories, and an- other most destructive to the orange in Florida, are closely allied to this elm insect. Thus, on investigation, it is found that the near relatives of the insect in question are notorious for their injurious habits, a fact which should give us some assurance that our enemy of the elm is worthy of earnest consideration. Owing to the short period during which this insect has been under observation, an account of its life-history in Nevada cannot be given at the present time. In lieu of this a brief state- ment of its principal habits, as recorded by observers in the East, is pre- sented. ; The young lice are born in late June and early July. .They soon mi- grate to the leaves, where they remain until August, when they return to the twigs and branches, probably for hibernation in protecting crev- ices. On thereturn of warm weather in Spring, they again become active and the males form their cocoons. Early. in May the males emerge from their cocoons, when mating occurs, after which they dis- appear. The females now become permanently fixed to the bark, and the life cycle is closed upon the birth of young in June and July. REMEDIES. The destruction of this insect should not be attended with the diffi- culty that has characterized efforts in this direction against the San Jose and other scale insects. The latter are protected bya roof-like scale which protects the tender parts of ‘the body and enables the insects to very effectually resist the remedies ordinarily employed. In the case of the elm insect, the body remains exposed and thus is more likely to yield to the action of corrosive washes. RESULTS IN THE LABORATORY. Freshly cut infested branches were treated in the laboratory with kerosene emulsion, whale-oil soap and the fumes of hydro-cyanic acid ’ SD Ries gas. As might be expected, the latter remedy proved fatal to the insects. Nota living one could be jound after the treatment. which was continued but a few moments. The results from kerosene emulsion and whale oil soap were very similar, with those from kerosene emulsion possibly the more favorable. From sixty per cent. to eighty per cent. of the lice were estimated as killed by these washes with one application. The branches treated bore many cracks and protecting scales of bark, and the lice surviving the treatment seemed in all cases to be those that -had shared the pro- tection of these places in the-bark. SUMMARY. 1 . The smooth-bark elms seem to be more subject to serious attack than the cork bark elms, owing to the protection afforded the latter by the plates of cork on the branches. 2. The possible present confinement of the disease to the vicinity of Carson City warrants active and thorough measures to eradicate the pest and prevent its spread to other parts of the State 3. The danger of getting young nursery stock at Carson City is evident. 4. Judging from the history of the insect in America, it is not likely to attack trees other than the elm. 5. Kerosene emulsion and whale-oil soap seem to be effectual reme- dies when the insects]are reached by them. Spraying will probably have to be done at different periods and may be found to be most effectual when the insects are most active. 6. The fumes of hydro-cyanic acid gas effectually destroy the lice, but the use of the remedy necessitates the employment of a tent to cover the tree and confine the gas sufficiently long to kill the insects. 7. A careful study of the insect’s habits, extending through an entire year at least, will be necessary to determine the most vulnerable period in the insect’s life-history. November 12, 1895. OCTOBER, 1905. BULLETIN 233 CORNELL UNIVERSITY AGRICULTURAL EXPERIMENT STATION OF THE COLLEGE OF AGRICULTURE Department of Entomology TWO NEW SHADE-TREE PESTS: SAWFLY LEAF-MINERS ON EUROPEAN ELMS AND ALDER By M. V. SLINGERLAND ITHACA, N. Y. PUBLISHED BY THE UNIVERSITY. ORGANIZATION Or THE CORNELL UNIVERSITY AGRICULTURAL EXPERIMENT STATION, BOARD OF CONTROL THE TRUSTEES OF THE UNIVERSITY. THE AGRICULTURAL COLLEGE AND STATION COUNCIL JACOB GOULD SCHURMAN, President of the University. FRANKLIN C. CORNELL, Trustee of the University. LIBERTY H. BAILEY, Director of the Agricultural College and Experiment Station. EMMONS L. WILLIAMS, Treasurer of the University. JOHN H. COMSTOCK, Professor of Entomology. THOMAS F. HUNT, Professor of Agronomy. EXPERIMENTING STAFF LIBERTY H. BAILEY, Director. JOHN HENRY COMSTOCK, Entomology. HENRY H. WING, Animal Husbandry. GEORGE F. ATKINSON, Botany. JOHN CRAIG, Horticulture. THOMAS F. HUNT, Agronomy. RAYMOND A. PEARSON, Dairy Industry. MARK V. SLINGERLAND, Entomology. GEORGE W. CAVANAUGH, Chemistry. JOHN L. STONE, Agronomy. JAMES E. RICE, Poultry Husbandry. JOHN W. GILMORE, Agronomy. HERBERT H. WHETZEL, Plant Pathology. SAMUEL FRASER, Agronomy. JAMES A. BIZZELL, Chemistry. ELMER O. FIPPIN, Soil Investigation. CHARLES E. HUNN, Horticulture. Office of the Director, 17 Morrill Hall, The regular bulletins of the Station are sent free to persons residing in New York State who request them. I. A EUROPEAN ELM SAWFLY LEAF-MINER Kaltiosysphinga ulm Sundeval The American elm often develops into the most beautiful, majestic and graceful of shade-trees. It usually suffers less from insect foes than most other shade-trees. The English and Scotch elms and their varie- ties also have been largely planted for shade-trees in many parts of this country, and for a long time they were equally as free from insect depredations as the American elms. In com- paratively recent years, however, several of the insect enemies of the European elms in their native home have become established in America. The European elm leaf-beetle (Galerucella luteola) has been ravaging elms, mostly the Euro- pean species, for nearly 70 years, and is doubtless now the most serious elm pest in New York and neighboring States (Fig. 22). Since 1884, European elms in widely scattered localities in the United States, and especially in New York, have suffered from the European elm bark-scale (Gossyparia ulmt). In 1896, my attention was called to little case-bearing caterpillars (shown in Fig. 23) working on European elms in Brooklyn Parks. The insectis apparently another importation, the Euro- pean elm case-bearer (Coleophora limosipennecla), and it is spreading and increasing its injuries. I must now add to this list another serious insect enemy which has followed the European elms to America. This new elm pest is a near relative of the worey Fic. 22.—L£im leaf-beetle larva at work. Natural size. 50 BULLETIN 233. alder sawfly also discussed in this bulletin. It ‘‘ blisters ’’ and kilis the leaves and thus far works almost entirely on English elms (U/mus campestris), and Scotch elms (C/mus scabra or montana), including the ‘‘ Camperdown ”’ variety. Historical.—Apparently the first and only record of this new elm pest in America is the following brief note by Dr. Felt in 1898 (Bull. 17, U. S. Div. of Ent., p.c1; 14th Rept. of State Ent., 237): ‘‘ An elm leaf-miner. This insect has been unusually destructive in Albany and Troy the present season. For the past three years the Camperdown elms in Washington Park, Albany, have suffered rather severely from this species. The present season Fic. 23.—A European elm case-bearer at work on an elm-leaf from Brooklyn Parks. Natural size. the miner not only seriously injured the Camperdown elms but extended its ravages to the English, Scotch and American species. From half to two- thirds of the leaves on certain English elms in Troy were nearly destroyed by this insect, and many others presented a sorry appearance on account of the numerous mines.”’ In July, 1899, I received from New Brighton, N. Y., ‘‘ blistered ’’ leaves from a Camperdown elm, which had been nearly defoliated. Only the dried remains of a few larvae remained in the ‘' blisters ’’ and it was not until 1901 that I got living specimens of the depredator. It was then found that a group of Scotch elms on the Cornell University campus had been seriously infested for several years by a similar insect. The adult insect was not found and attempts to breed it in 1903 failed, and it was not until May 27th, 1904, that I first saw the adult insect which was then present on the elm leaves in large numbers, The pest is evidently the common elm sawfly leaf-miner of Europe, Two New SHavE-TREE Pests. 51 Kaliosysphinga ulmi Sundeval.* I have found the insect working on the European elms scattered through the city of Ithaca, and it is apparently on the increase. It doubtless occurs in most localities in New York, and perhaps, in other States, where European elms are planted. The insect must have been in this country at least ten or fifteen years. In England and Scotland, this elm pest is common but apparently rarely does noticeable injury. It is also widely distributed through Sweden, Germany, France and Russia. The insect.—The adult insect (Fig. 27) is a small, shining-black sawfly measuring about three millimeters in length, with its wings projecting beyond the body a little. The wings expand to about eight millimeters across. The antennee and femora are black and the remainder of the legs are light brown with a blackish tinge. The wings are considerably clearer than those of the alder sawfly (Figs.27 and 28). The saw-like ovipositor of the female is shown in Fig. 27.f The eggs are stuck into the elm leaves (Fig. 25), and the tiny whitish larvae which hatch therefrom begin life at once as miners, finally con- suming practically all of the interior tissues of the leaf over an area about half an inch in diameter. Full-grown larve measure about seven millimeters in length, and several are shown in Fig. 24. I found no striking characters for distinguishing them from their near relatives working in alder leaves.{ The full-grown larvee eat through the epidermal floor or roof of their mines and drop to the ground where, about an inch below the surface, they make small, thin, elongate, cylindrical, brown, papery cocoons in which they transform early in May, through tender, whitish pups into the black adults or sawflies. Food-plants.—In Europe this insect is recorded as feeding on English * This species was described in 1847 by Sundeval(Forhandl. red de Skand. Naturforsk. Christiania, p. 240, 241). For other European references see Dalla Torre’s Catalogus Hymenopterorum, Vol. 1, p. 158, and Cameron’s Mon. British Phyt. Hym., Vol. 1, p. 295. This species is easily separated from the others in the same genus by the position of the radial cross-vein as given in Konow’s Table on p. 59, and which can be readily seen by comparing the wing venation in Figs. 3 and 8. t It is an interesting fact that every specimen of over 125 of the sawflies collected one day on elm leaves at Ithaca, N. Y. were females. Further collections gave similar results; I have seen no males during two seasons’ observations. Cameron says the males are ‘‘similar, but with thicker and longer antennz, the joints from the fourth being percepti- bly thicker than the basal ones.’’ Brischke says (Beob. Arten der Blatt und Holzwespen, 1883, p. 261, as ztermedia) in his brief account that he knew only the females. ¢ The very young larve are said (Healy in The Entomologist, for 1896, p. 298) to have a large dark spot on the venter of the first thoracic segment, with two small brown dots on each side and a small black dot on the venter of the remaining body segments except the Jast. But at the first moult these decorative markings are all thrown off. The full-grown larva is distinctly segmented and of a whitish color with the green food particles giving it a greenish tinge. The much flattened head is light brown with mandibles darker. The six true legs are slightly brownish and are little used, the larve moving about in their mines with a wriggling motion of the whole body. Rudimentary pro-legs are present on segments 5 to 12. 52 BULLETIN 233. and Scotch elms. In this country, Dr. Felt reports it on these trees and on American elms also. On the Cornell campus there is a case where American and Scotch elms grow so near that their branches often mingle, and although the sawflies are often seen on the leaves of both trees, yet not a leaf on the native trees are ‘‘blistered ’’ by the insect while the foreign trees are badly infested. In this locality the American elm seems to be almost entirely exempt from the pest. The Camperdown variety of Scotch elms is often infested. Work and destructiveness of the insect.—Its work is quite conspicuous, as is shown in Fig. 26. Twenty or more of the larve often mine in a single elm leaf, and their mines soon coalesce forming a large ‘‘ blister ’’ often involv-° ing the whole leaf. Many mines just begun are shown in the leat in lower left-hand comer of Fig. 26, and larvee can be seen at work in larger mines in the leaf in the right-hand corner of this figure. Oftentimes a mine begun near the midrib of the leaf is confined to the area between two large veins until it gets nearer the outer edge where it extends under the smaller veins or into neighboring mines. The whole interior of the leaf is eaten, leaving only the outer epidermis which soon turns brown. The ‘‘ blisters ’’ are nearly as conspicuous from the lower as from the upper side of the leaf. The mines of its near relative in alder (Fig. 29), scarcely show from the underside of the leaf, possibly because the alder leaf seems thicker than the elm. In July, after the larve leave the ‘‘ blisters’? on the elm leaves, the mined areas bleach out to a dirty whitish color, shrivel and curl. The picture of an infested branch in Fig. 26 was taken at this stage. Unless the leaves are wholly mined out, most of them remain on the tree a considerable time longer, the mines often becoming holes. Infested trees present the worst appearance about July rst, or soon after the larve disappear. As many of the leaves drop off, as the new growth comes on, and as no other broods of the insect appear, the infested trees begin to recover by the end of July, and by September rst., trees which were badly infested in July often show but little signs of the insect’s work to the casual observer. I have seen small trees almost defoliated, and thus stunted and rendered unsightly by this sawfly miner, and from one-half to two-thirds of the leaves on several large trees on the Cornell Campus have been badly infested for several years. These large trees present a very ragged and unsightly appear- ance about July rst, but in two months have nearly recovered their beauty. The insect is thus capable of defoliating and checking the growth of young trees, and of rendering large trees unsightly for a time in midsummer. Its life history and habits.—In 1869, Healy recorded (The Entomolo- gist, Vol. IV, p. 297) many interesting details of the life of this sawfly, and the European literature contains but few additional notes. After July 15th, I have not found the insect on the trees again until the next May. In July the larvze which mined the leaves go into the ground beneath the trees for a short distance, an inch or less. There they make small, thin, Two New SHave-TREE PEsts. 53 brown, elongate, papery cocoons in which they remain as larve for nearly ten months, or until late in April. About May rst, they transform through tender pale-yellowish pupz, apparently in about a week, into the black adults or sawflies which begin to emerge about the middle of May. Many had emerged by May roth, in 1905. ; On May 27th, 1904, I found hundreds of the flies on the elm leaves. About 1:30 P. M. only few of the flies were seen, but at 3:00 p.m. when it was more sunny, they were very numerous. The flies are almost invariably on the upper surfaces of the leaves and are so ‘‘ tame ’’ that one can often pick Re as a a as Fic. 24.—Larve of elm sawfly leaf-miner, much Fic. 25.— Three eggs of elm sawfly enlarged. This figure also serves for the alder leaf-miner stuck in veaf. Much sawfly larve as the two species are much alike in enlarged. this stage. them up with the fingers and easily collect them in cyanide bottles. None have been seen mating and I have found no males. When disturbed, they fly but a short distance, so that the insect spreads slowly. The round, thin-shelled, milky-whitish eggs about .3mm. in diameter are stuck into the leaves, often near the midrib, through slits cut with the female’s saw-like ovipositor (Fig. 27). The location of the eggs is more readily deter- mined from the under side of the leaf where pimple-like elevations of the epidermis appear in two or three days over the eggs, as shown in Fig. 25. But the eggs are stuck into the leaves from the upper side, as I observed repeatedly, the ovipositor evidently reaching nearly to the lower epidermis, It requires from forty to sixty seconds to lay an egg. ‘The eggs hatch in about a week. Many larvee had begun their mines by May 18th in1g05. Ihave found forty- Fic. 27.—Zhe European elm sawfly. The saw-like ovipositor projects from the abdomen of the lower sawfly, The flies are shown much enlarged, as they measure only 3 millimeters in length. Fic. 28.— The European alder sawfly and its eggs stuck in leaf (above), both much enlarged; the fly measures only 3 millimeters in length. Fic. 26.— Work of the European elm sawfly leaf-miner. The branch was taken Srom a badly infested tree in mid-summer after the miners had left ; it well illustrates the destructive work of the insect (about half natural size). The leaf many mines just begun in it, and the leaf in the opposite corner shows nearly full-grown larve at slightly reduced.) in lower left hand corner shows work in their mines (bath leaves 56 BULLETIN 233. three unhatched eggs and at least twenty-five mines just begun in a single large elm leaf (Fig. 26).* I have not found any characters which will readily separate the nearly-grown larva of this elm sawfly from those of the alder saw- fly discussed on page 61. : On May 27th, 1904, I found on the Scotch elms on the Cornell Campus many of the sawflies, many recently laid eggs and many larval mines just begun in the leaves. By June rst, some of the larvae were nearly grown and on July 4th, practically all had left the leaves, no stage of the insect being found on the trees. The larvae (Fig. 24) apparently live as miners in the leaves for about, three weeks when they moult for the last time, bite through the roof or floor of their home and drop to the ground. Burrowing in an inch or less, they soon make the thin, brown, papery cocoon in which they remain in hiber- nation as larve for about ten months, or until the next May. There is thus but one brood of this elm sawfly in a year, its destructive period being the month of June, but many of the ‘‘blistered’’ and unsightly leaves remain on the trees as mementoes of its work until autumn.f Itis a fortunate provision of Nature that there is but a single brood of this pest in a season, otherwise it would certainly defoliate badly infested elm trees, which now have a chance to largely recuperate and regain their beauty before autumn. The single-brooded habit of this elm sawfly is in striking contrast to the three * The following interesting details of the larval stagesare quoted from Healy’s account (The Entomologist, IV, 298). ‘* The larva has a white body, and is in possession of 22 legs, the first six of which are annulated with dark brown; the claws are also dark brown ; the head is tinged with pale brown of a darker tone at the sides, mouth reddish brown, eye- spots brown, and its dorsal vessel is dull green; the under side of the second segment has a dark, oblong-shaped plate down its centre, and on either side of this there are two brownish dots; on running our eyes down the remaining segments we observe that, excepting the anal segment, all are furnished with a small black-colored dot; the fifth segment has no organs of progression. At the first moult the decorative markings of the larva are all thrown off, and if at that time we closely inspect the under surface of the body we perceive a slight remnant or pigmentary deposit on the segments situated as the exact spots where the black ventral dots were located previous to the moult; these dusky marks, however, soon fade away, and leave the segments entirely spotless ; the head and eyes slowly resume their original color, and the six thoraic legs regain their annulations; When full-fed it ceases to feed, and lies in its mine in a state of repose, and throws off its skin for the last time; by and by a faint yellowish tinge spreads itself over the body of the larva. At the appointed time the larva liberates itself from its mine by biting a hole init. At the last moult the brown-colored bands on its six anterior organs of locomotion are thrown off entirely. Escaping from its mined abode, the little creature drops to the ground, and now, every time it is touched, it instantly partially curls its body up, remaining in that position only for a moment or two.”’ + Healy states (The Entomologist, IV, 298) that in England there is only one brood dur- ing the season, and that by the end of June they are all under ground. Cameron states, however, that he has captured the flies in August in England (Mon. British Phpt. Hym. 1, p- 296), and intimates that there is probably an autumnal as well as a spring brood, but Cameron’s experience must be very exceptional. Two New SHADE-TREE PESTS. 57 or more broods of its very near relative, the alder sawfly miner, discussed on page 58, which continues to work in the alder leaves from May until October. Remedial suggestions.—The suggestions given on page 62 for con- troling the closely allied alder sawfly will also apply to this elm sawfly miner. Last autumn a treatment that doubtless materially reduced the numbers of these sawflies was unwittingly applied to some of the worst infested elm trees on the Cornell Campus. In grading, several inches of new soil was spread over the ground beneath the infested trees. Apparently many of the little sawflies failed to emerge through this layer of soil in the spring. As practically all of the sawflies transform within an inch of the surface immediately beneath the infested trees, it would be practicable in some cases to apply a layer of soil several inches thick under the trees in autumn and remove it about June 1st, or after the time for emergence of the sawflies. Whenever practicable, how- | ever, [ would advise the removal or spading under and packing down of the sod from beneath the trees as described on page 62, for I think this method is more effectual. Last spring other peculiar conditions occurred in the clump of badly infested European elms on the University Campus. It was the fruiting season for several of the trees and they bloomed and fruited profusely. This process delayed the appearance of the [leaves until after most of the sawflies had emerged and laid their eggs, which they were thus forced to do in the leaves of the few non-fruiting trees. Had many of the worst infested branches on the larger trees and the smaller crowded and stunted trees been removed early in June, and their hordes of sawfly larvee left to dry up and die in the leaves, the infestation could have been still further checked, but it was delayed and finally neverdone. Whenever practicable and advisable, this pruning of infested branches early in June should be done, as it will materially aid in controlling the pest. As a result of the earth-mulch or earth-smothering treatment and the delay in appearance of the foliage due to the fruiting of several of the trees, the infestation in 1905 was concentrated on fewer trees and was not so severe as during the previous year. Il. A EUROPEAN ALDER SAWFLY LEAF-MINER Kaliosysphinga dohrnii Tischbein The European alder (Anus glutinosa) and its cut-leaved varieties are often planted as ornamental trees in America where they have become naturalized in some localities. In Europe the leaves of this alder are preyed upon by several insects, and at least one of these enemies has been injuring these trees in America for several years. In June, 1891, a nurseryman at Newark, N. Y. sent me several leaves of European alder with large brown patches or ‘‘ blisters ’’ on the upper side, as shown in Fig. 29. I soon found that a large tree on the Cornell University Fic. 29.— Work of the European alder sawfly leaf-miner. Several larve lived in the brown blisters or mines. Nearly natural size. Campus, and one tree of the cut-leaved variety near the Campus also bore ‘many of these ‘‘blistered’’ leaves. There were several small larvee living in each large ‘‘ blister ’’ which they had caused by mining in the leaf just under the upper epidermis. The half dozen European alders planted on the Campus in later years were soon infested by the insects, and during the past season many of the leaves on these trees were so badly ‘‘ blistered ’’ that the ground beneath was strewn with the brown, dead leaves, and the trees presented a very ragged appearance from July till autumn. Thus the insect is capable of seriously injuring these desirable ornamental trees. A study of the life and habits of this alder pest was begun in 1891, but was interrupted for several years, and finally completed during the past year. The insect.—Within the brown mines or ‘‘blisters’’ on the leaves may be found in summer from one to a dozen or more slender, whitish larve or ' Two New SHave-TrEE PEsTs, 59 e ‘‘worms”’ (Fig. 24.), varying from 2 to 7 or 8 millimeters in length. When full grown, these larvee leave their mines and drop to the ground. An inch or less below the surface of the soil they make a small, thin, brown, papery cocoon to which particles of soil adhere. In this cocoon the insect trans- forms through a tender, white pupa into the small, black four-winged sawfly shown much enlarged in Fig. 28. In this adult form the insect’s body and head are shining black, and measure about 3 millimeters in length ; when the wings are folded they extend about a millimeter beyond the tip of the abdomen. When expanded, the front wings measure about 8 millimeters across. The antennae and femora are black and the tibiae and tarsi are light brownish with blackish tinge, especially on the hind legs. The wings are quite dusky, con- siderably more so than those of the elm species herein described. These two species are easily distinguished by the position of the radial cross-vein (com- pare Figs. 27 and 28) as indicated in the table* for separating the species of this genus of sawflies. The females are provided with a saw-like ovipositor, as shown in Fig. 3, with which their eggs are laid in the leaves. * The following table for separating the species of the genus Kaliosysphinga is given by Konow, the European expert in this group of insects (Wien. Ent. Zeitung, Vol. V, p. 269, 1886): A. The radial cross-vein meets the second cubital cell just before the second cubital cross-vein —1. ulmi Sundeval (= intermedia Thoms). AA. The radial cross-vein lies behind the second cubital cross-vein. B. Third antennal joint twice as long as the fourth which is distinctly shorter and thinner than the second —2. pumila Klg. BB. Third antennal joint only about a half longer than the fourth. C. Fourth antennal joint scarcely longer and a little thinner than the second, the third a good half longer than the fourth; wings clear —3. dohkrnii Tischb. CC. Fourth antennal joint plainly longer and thicker than the second, the third scarcely a half longer than the fourth; wings very dark —4. melanopoda Cam. (= nigricans Thoms). In a foot-note Konow says: ‘‘ Dokrnii is very nearly related to melanopoda and only by a close observation"of the characters given can it be separated; moreover, it is always somewhat smaller, hardly 3 mm. long while me/axopfoda is somewhat longer." But in his description of me/anopoda and in his table for separating it from its allies (Mon. of British Phyt. Hym., Vol. 1, p. 292, 1882) Cameron states that the third anten- nal joint is ‘‘more than double the length of the fourth ” which would put it in B instead of BB in Konow’s table. Cameron mentions dohrni only in a foot-note (1. c. p. 291) say- ing that the description of it so far as it goes, agrees with either pumila or melanopoda. The sawflies I bred on European alder in 1891 were determined by Konow (in 1896) as Kaliosysphinga dohrnii Tischbein (Stettin. Ent. Zeit., V1l., 1846, p. 80). What is pro- bably the same insect has been recorded several times in American literature under the names melanopoda Cameron (Can. Ent. XXIII, p. 252) and varipes St. Fargeau (Can. Ent., XXV, 59 and 247; Fletcher’s Rept. for 1892, p. 147). According to Dalla Torre’s Catalogue (1894) pp. 122 and 287, Lepeletier (Count of St. Fargeau) described two sawflies as varifes, now placed in the genera Amphytus and Priophorus. One of these is considered a variety of Z. #5za/is and the other an aberration of P. sadz7. As neither of these species work on alder, it is at least very doubtful if Harrington was correct in designating the species injuring alder in Canada as Fenusa varipes St. Fargeau (me/anopoda Cameron). 60 BULLETIN 23 3. Historical Notes.—This insect was first described in Germany in 1846, but it is apparently not a pest and has attracted very little attention in Europe.* Just when this sawfly miner was introduced into America is not known; butit was doubtless at least twenty years ago. For I found it in injurious numbers at Newark and Ithaca in New York in 1891, and the same year, Dr. James Fletcher, the Canadian entomologist, reported a serious outbreak of what was probably the same insect, which ‘‘for three years had entirely spoilt the appearance of the European alders upon the grounds of the Experimental Farm at Ottawa’ (Can. Ent., XXIII, 252). The insect was also reported as working on native alders in a swamp néar this Experimental Farm in 1893 (Can. Ent., XXV, 59, by Harrington); and the same year an American alder, Alnus rugosa (serrulata), at Woods’ Hall, Mass., suffered seriously from this this pest (Can. Ent., Sry 247 by Dyar). I have found no other references to such an alder enemy in American literature. If it is the same species, which is quite probable, that has beer working on both European and native alders in such widely separated localities from Massachusetts through New York into Canada for ten years or more, doubtless it is now widely distributed over this country. In Europe it is recorded as working on Alnus g/utinosa and zzcana ; the former species in its many varieties is now widely planted in America, and incana ‘is the common native alder along our northern streams. ‘Its work.—The work of this alder sawfly is conspicuous and easily recog- nized. It is well shown in Fig. 29. Small brown spots first appear on the upper sides of the leaves where a single larva has begun its mine. As the larvee feed and grow, the brown ‘‘ blisters ’’ increasé in size and often several of them join and form one large ‘blister’? which may involve nearly the whole leaf and contain 15 or 20 larve. The mines are just beneath the upper surface of the leaf which is thick enough so that the work of the insect scarcely shows on the undersides of the leaves. Throughout the season, the infestation begins on the newest or youngest leaves. Badly infested or ‘* blistered ’’ leaves die and drop off, thus spoiling the ornamental effect of the trees, and checking their growth. The life-history and habits of the insect.—As late as October a few of the larvae were making their characteristic mines and brown “‘ blisters ’’ on the leaves of the trees on the Cornell Campus. The winter is passed as larvae tucked away in their little, brown, elliptical, papery cocoons mostly about half an inch below the surface of the soil beneath the infested trees. In May these hibernated larve transform, in about a week, through tender, pale yellowish pupz with brownish-black eyes into the shining black adult insects or sawflies. The adults usually begin to emerge by May rsth, and begin laying eggs at once. On June 8th in 1904, I found many of them busy laying eggs in the * Apparently the only account in Europe of its life and habits is a paragraph by Brischke in 1883. (Beobach. Arten der Blattund Holzwespen, 2nd Abth., 261 as Fenusa pumila) in which the life and habits in late summer are briefly described. Two New SuHape-TreeE Pzsts. 61 younger leaves, and a few larvee had already nearly completed their mines. I have never seen the flies mating, and have found no males. Thus the insect seems to breed parthenogenetically. A small, thrifty tree which was putting out much new growth in 1904, was severely attacked in June while older trees nearby suffered but little, until about a month later. The egg is about .3 mm. in diameter, round, thin-shelled and of a deli- cate milky-white appearance. The female sawfly saws a slit in the leaf from the upper surface and tucks her egg in just under the upper epidermis of the leaf. Most of the eggs are laid in the central portion of the younger leaves between the larger veins. It requires about a minute to lay an egg. Over the egg the surface of the leaf is slightly elevated and: turns yellowish, thus enabling one to easily locate the egg (Fig. 28); this is more distinctly seen from the upper surface of the leaf.. Evidently the eggs hatch in a few days and the little larvae begin their life'as miners. The greenish-white, slightly flattened, distinctly segmented larvae with light brownish heads and short apparently useless legs are shown much enlarged in Fig. 24. The duration of the larval period I have not determined, but it is probably about three weeks.* -One larva mines over an elongate area, about the size of.a one cent coin, which is often bounded by two large veins for some distance before it merges into a neighbor’s mine (Fig. 29), Frequently the rusty brown ‘‘ blisters ’’ or mines of ten to twenty larve coalesce and involve nearly the whole leaf, which soon dies. The excrement and cast skins of the larva are left within the mines. When full grown the larvae burst through the upper epidermis of the leaf or the roof of their home, and fall to the grdund into which they work themselves for a short distance, usually about half an inch, sometimes an inch, and there make their thin, brown papery cocoons. In summer they scon transform in these cocoons, probably in a week or two, into the black sawflies. Eggs are soon laid and another brood of larve begin their destructive work of ‘‘ blistering ’’ the leaves. I have not been able to determine definitely the number of broods of this sawfly which develop during the growing season, as the broods overlap, but there are at least two or three broods, perhaps more. Beginning in May, their work continues throughout the summer until October in this latitude. After about June rst, 1 have found the insect in all stages on or under the infested trees almost any day until September. This is in * Dyar has described in detail six larval stages (Can. Ent., XXV, 247). In the fifth or last feeding stage, the larva is translucent whitish with a greenish tinge from the food, and it measures 6 to 7mm. The head is much flattened and of a light brown color with the mandibles and ocelli darker. The true legs, the ventral surface of the first thoraic seg- ment, small spots on the venter of the other thoraic segments, and the cervical shield are brownish. The abdominal legs are rudimentary and present on joints 5 to 12. No tuber- cles or setz are distinguishable. I have found no striking differences between these larva and those of the European elm sawfly leaf-miner, Kaliosysphinga dohrnit, therefore Fig. 6 may represent both species, 62 BULLETIN 233. striking contrast to the well defined, one-brooded life of its near relative, the elm sawfly, herein discussed. The insect hibernates as a larva in the soil near the surface in its brown, papery cocoon, the transformation to the pupa occurring in May. Thirty-one cocoons were found in an area of only four square inches under a small tree last May. Remedial suggestions.—During the past season I have tested a simple, practicable, and effective method for controlling this insect. Finding that it hibernates within an inch from the surface of the soil, I buried several cocoons at depths of 2, 4 and 6 inches. But very few of the flies emerged from any of the buried cocoons. A thin layer of the sod beneath the infested trees was at once removed and should have been carried away promptly, but it was delayed until many of the fliesemerged. Thus the infestation was not checked so completely as it should have been, but the trees are not nearly so badly injured this year as in 1904. By promptly removing about one or two inches of the sod or soil from beneath trees infested by the insect about May rst, and carrying it to a con- siderable distance or burying it, this insect can be easily and effectively con- trolled. By thus preventing the emergence of the spring brood of sawflies, the development of succeeding broods is stopped. In many cases, it would doubtless be practicable to simply spade under the sod to a depth of six oreight inches, and pack it down.hard. Care should be taken to remove the sod over an area extending a foot or two beyond the circle bounding the points to which the longest limbs reach. Thorough and prompt burying of the cocoons u this manner about May rst, will control this sawfly miner and preserve the beauty of this desirable European tree. CONNECTICUT AGRICULTURAL EXPERIMENT STATION NEW HAVEN, CONN. BULLETIN 155, MAY, 1907. ENTOMOLOGICAL SERIES, No. 14. The Elm Leaf Beetle Thevelm leaf beetle: .o.ccsceans oe sewaeaaieewreeceseaseaeewe cay ee $3 3 History and distribution in America....... 00... .ceece eee eens 3 Iuife history amd! habitsicociesitie css cacsccngadciaid e udenadie aiesedcarei@uree Sous 5 PQOSOPAP tL OU h5 6:6 aseissscausetinstaav sy iuschubuexes suchanentmiatin Adal byaadndecanenelaee wager 7. Effect upon the trees .......... 0.0 c cece cece eee eeee Iatosesr babepere a5 8 OGG Plants: — cave ,dcgjcesvava weiwitvinss ana arave cava civ atihinwn aides glove nvaleghe ange yeeeee © & Number of generations: « .sesciie cs ve scena se heesad bese gansmnieeens 9 Natural enemiesi: se:ustcnes oases cece augatrnn sane se xanerdeny os 9 Reniedies «vs5¢scux weieeeed 1352 cease RAE ESE ENE RETR BeOS 10 Spraying with poison wisvscisvderaivaencee vaceeetecinene 10 Destroying the pupae........ 6... eee eee 12 ‘Destroying the adult beetles.............. 00. c cece eee ees 12 Outfit for spraying elm trees ........... 00. c cece ccc nee ene 12 SuMiM ary wadage naa cauieawrnnitig Awadaimma ments } a negeusaauaiye 4 13 The Bulletins of this Station are mailed free to citizens of Con- necticut who apply for them, and to others as far as the editions permit. CONNECTICUT AGRICULTURAL EXPERIMENT STATION. OFFICHRS AND STAFF. BOARD OF CONTROL. His Excellency, Rottin S. Wooprurr, Ex officio, President. Pror. H. W. Conn ............224- eer Middletown. Pror. W. H. Brewer, Secretary ......--...0ee eee New Haven. Bi Wer GOBUEN Sli koraci hace vans Saibedscete Ve eGasheagens Meriden. CHARrES: Mic JARVIS) cies 288 «dacnawle aides aac ea vin Berlin. EDWIN HOYT. vosscencecs Soon ee atta deed eee New Canaan. Jo A WEBB: cleo icenaachs dicia dts wre bien 4 SRN Bak ee Hamden. E. H. Jenxins, Director and Treasurer .......... New Haven. STATION STAFF. Chemists. Analytical Laboratory. Joun P. Street, M.Sc., Chemist in charge. E. Monroe Batrey, M.S. E. J. SHaney, Pu.B. Kate G. Barzer, Pu.D., Microscopist. Laboratory for the Study of Proteids. T. B. Osporng, Pu.D., Chemist in Charge. C. A. Brautiecut, Pxu.B. Botanist. G. P. Cuinton, S.D. Entomologist. W. E. Britron, Pu.D. Assistant in Entomology. B. H. Watpen, B.Acr. Forester. Austin F. Hawes, M.F. Agronomist. Epwarp M. East, M.S. Stenographers and Clerks. Miss V. E. Cote. Miss L. M. Brauttecurt. Miss E. B. Wuitrtesey. In charge of Buildings and Grounds. WILLIAM VEITCH. Laboratory Helper. Huco Lance. Sampling Agent. V. L. Cuurcuint, New Haven. The Elm Leaf Beetle. BY W. E. BRITTON, State Entomologist. . Twelve years ago an account of this insect was published by this Station in Bulletin No. 121, which has for some time been out of print. Since then only a few scattered notes have appeared in the bulletins and reports. The object of the pres- ent paper is to place in the hands of the people of Connecticut a fairly complete and comprehensive account of the elm leaf beetle with up-to-date remedies and methods of treatment. There is a constant demand for such information from public school teachers, members of village improvement societies, and men employed in the street and park departments of our cities and towns, as well as from private individuals who desire to give the best care to trees on their home grounds. HISTORY AND DISTRIBUTION IN AMERICA. The elm leaf beetle was introduced into this country probably more than seventy years ago. In its native country, Europe. where it had long been known, it had from time to time caused serious injury in Italy, Austria, and the southern portions of France and Germany. In Northern Europe the insect occurs sparingly, but can hardly be called a pest. Harris states* that the elm leaf beetle attacked and seriously injured the elm trees of Baltimore, Md. in 1838 and 1839. The beetle seemed to spread chiefly northward, though slowly, until Southern New England was reached in the early nineties, and much damage done. In the coast towns of Connecticut many fine old elms, including some historic trees, were killed by its depredations. *Insects Injurious to Vegetation, page 124. 4 CONNECTICUT EXPERIMENT STATION BULLETIN 155- Stamford, Norwalk, Bridgeport, Stratford, Milford and New Haven especially lost many noble trees. Later the inland cities were invaded, and the elm trees ravaged. In New Haven the pest was perhaps at its worst in 1895 and 1896. In 1896 many of the trees on the older streets about the center of the city were sprayed with poison by the street department. The following season the pest was less serious, and continued to subside until 1901, when it was again comparatively destructive. From Fic. 1—Elm leaves showing larvae and the damage which they do by feeding on the under surface, natural size. 1902 it diminished in abundance until 1906, when considerable damage was done to the trees. So far as is known the distribution of this insect in America is confined chiefly to the lower altitudes of Southern New Eng- land and the Alleghanian region. From Charlotte, N. G,, its southern limit, the elm leaf beetle now extends as far north as North Conway, New Hampshire. Up to this time, however, the beetle has done no particular damage in New Hampshire. Regions generally infested include the whole of Massachusetts, THE ELM LEAF BEETLE. 5 Rhode Island, Connecticut, southeastern New York, New Jersey, eastern Pennsylvania, Delaware, Maryland and a por- tion of Kentucky, though isolated outbreaks have occurred in western New York, Pennsylvania, West Virginia, Ohio and North Carolina. It is of course found in Virginia, Vermont, New Hampshire, and probably in Maine. Kentucky, therefore, contains the western limit of the distribution of this insect, though we may expect that soon adjoining states may become infested. The insect exhibits a marked tendency to spread farther along river valleys than over mountains, and is dis- tinctly a pest of city and village trees rather than of trees in the open fields and roadsides of the country. . Fic. 2—Cluster of eggs, greatly enlarged. LIFE HISTORY AND HABITS. The overwintering beetles come out of their winter quarters during the warm days of early spring, mate, and as soon as the leaves unfold they begin to eat small round or oval-shaped holes through them. Many leaves are thus riddled as though shot had been sent through them, and appear like the illustra- tion on the front page of this bulletin. During the latter part of May and early in June the females deposit small clusters of yellow eggs on the under sides of the leaves. The period of ovipositing extends over about four weeks, and each female may lay five or six hundred eggs. In 6 CONNECTICUT EXPERIMENT STATION BULLETIN I55. about a week the eggs hatch and the young larvae or grubs feed upon the under surface of the leaves, eating off the green tissue between the veins and leaving the veins and the upper epidermis, as is shown in Fig. 1. In about three weeks the larvae or grubs are fully grown, and crawl down the trunks of the trees or drop from the ends of the branches to the ground and transform to the naked pupa stage. The great proportion of the pupae are found close around the base of the tree or lodged in the crevices of the rough bark of the trunk and larger branches. Except for being Fic. 3.—Larvae and pupae, twice natural size. in crevices, they are unprotected. The writer has seen trees in New Haven where it would be possible to gather several quarts of these pupae at the base of a.single tree. The pupa stage lasts about ten days, then the adult beetles appear, and lay eggs for the second generation, which. seldom does much harm in Connecticut. Those emerging late prob- ably do not lay eggs for a second brood, but may be seen crawl- ing and flying about for a time, feeding more or less, but early going into winter quarters, usually in church belfries, attics of houses, barns, sheds or other out-buildings. They also pass the winter in cracks of fences, telephone poles, or under the edges of the loose bark of the trees. In some of the cities worst infested the adults sometimes gather in church bel- fries in such numbers that they can be swept up by the half THE ELM LEAF BEETLE. 7 bushel. The.elm leaf beetle often occurs with the two-spotted lady beetle in dwellings, simply because they both seek the same kind of a place for hibernation. Correspondents frequently send both species to the writer and desire to know if they are not in some way responsible for the injuries to their carpets. There is, of course, no relationship or similarity in food habits of the three species. The lady beetle is predatory, and in the larval stage destroys numbers of plant lice, and therefore should never be destroyed. The elm leaf beetles should, of course, be killed wherever they are found. DESCRIPTION. The eggs are bright yellow in color, bottle-shaped, and resemble the eggs of the Colorado potato beetle, but are smaller. They are fastened vertically to the under side of the leaf in clusters of from five to twenty-five arranged in two or three irregular rows. When first hatched, the larva is dark or nearly black, covered with tubercles bearing black hairs. As the larva increases in size it molts several times and on becoming full-grown is about one-half inch long, dull yellow in color, with a pair of longi- tudinal black stripes along the back. Head, legs, lateral tuber- cles and two rows of small tubercles between the dorsal stripes are black. The tubercles also bear black hairs. The pupa is about one-fourth inch in length and bright orange yellow in color, with black hairs or spines. It is not enclosed in an earthen shell to protect it, but is found at the base of the tree perfectly naked and wholly unprotected. The adult beetle is light yel- low in color when it first emerges, but soon takes on a duller hue, and finally becomes a dull olive green. An indis- tinct black stripe extends from the base to the extremity of Fic. 4.—Adult beetles, twice each wing cover just inside of natural size. the margin. Small black spots or markings on the pronotum of the thorax vary greatly in size and shape. Legs and antennae are yellow. 8 CONNECTICUT EXPERIMENT STATION BULLETIN 155. EFFECT UPON THE TREES. It has previously been mentioned that the adult beetles do more or less feeding, always eating holes entirely through the leaves, as is shown on cover of this bulletin. This of course injures the tree, but is much less serious than the damage caused by the larvae, which eat away the under surface of the leaves. The larvae are always more abundant than the adult beetles, and are more voracious in their feeding habits. The worst infested trees usually drop their leaves in Connecticut about the middle of July. If this happens, and is followed by a rainy season, new leaves will be put out, but in a season ofa protracted drought the trees may fail to put forth new leaves. In either case the tree is undoubtedly weakened, and often seri- ously so. Sometimes the second crop of leaves is devoured by the second generation of beetles, but in Connecticut the white fungus mentioned in another part of this bulletin is apt to serve as an important check to the beetle in a wet season. Two complete defoliations, one succeeding the other, usually kill a tree. Usually, however, the defoliation is not quite complete, and the trees continue to exist in a greatly weakened and devitalized condition. In the cities and larger towns, on account of further injuries* by horses, by leaky gas pipes in the ground, and pave- ments which cut off the supply of moisture, many trees have died. In 1901 the writer was called to Norwich, where nearly every elm had died for a distance of about one and one-half miles on a prominent residential street. These trees had been weakened by the constant attacks of the beetle year after year, and a leaky gas main finally destroyed what little vitality remained. Most of the maple trees along the street ‘survived. In many cases young or newly planted trees seem to be especially subject to attack, and therefore should receive extra attention. FOOD PLANTS. Elms constitute the only food plants known for this insect, and the European species suffer more than the American ones. The English elm (Ulmus campestris) and its weeping variety *For a discussion of these injuries the reader should consult Bulletin 131 of this Station. : THE ELM LEAF BEETLE. 9 known as the Camperdown elm are favorites of the beetle. The writer has seen these trees entirely defoliated in New Haven when the common white, or American elms, were uninjured. The American elm is, however, the next choice, followed by the Scotch elm (U. montana), and though no variety is wholly exempt from attack, the winged elm (U. alata), the slippery elm (U. fulva), the cork elm (U. suberosa) and the rock elm (U. racemosa) are much less frequently attacked. NUMBER OF GENERATIONS. According to Burgess,* “in New Jersey, Professor J. B. Smith has recorded only a single brood and sometimes a partial second brood, while in the latitude of Washington, D. C., according to the observations of Messrs. Riley, Howard and Marlatt, of the Division of Entomology, two annual broods and sometimes a partial third brood have been found.” Dr. E. P. Felt, ‘State entomologist, of Albany, N. Y., findst two well marked broods and a partial third brood at Albany and Troy, N. Y. i The writer has not followed out this matter carefully in Connecticut, but all stages are found on the trees during the first half of September, so presumably there are at least two broods, but the egg-laying period of the adults is so prolonged that the lines of demarcation are nearly obliterated. In Con- necticut the leaves of the trees severely attacked by the first brood generally turn brown and drop about the middle of July, when the larvae are descending the trees to pupate. NATURAL ENEMIES. One of the most important natural enemies of the elm leaf beetle in Connecticut is a fungus known to botanists as Sporo- trichum globuliferum Speg. (S. entomophilum Peck), which attacks the pupae and adults in late summer, especially in a moist season. In 1902 this fungus was prevalent, and the fol- lowing season the elm leaf beetle did little damage to the trees. In 1906 the beetles were abundant, but as the month of July was * Bulletin No. 4, page 17, Ohio Dept. of Agriculture, Div. of Nursery and Orchard Inspection. 1905. + Bulletin No. 57, N. Y. State Museum, p. 14, 1902. ~ 10 CONNECTICUT EXPERIMENT STATION BULLETIN 155. wet, the fungus developed and killed a great many beetles. Beetles attacked by this fungus are covered with white mold, as shown in Fig. 5. Predatory bugs of at least three species of the genus Podisus feed upon the larvae and pupae, and Riley* records three species of beetles that also devour full-grown larvae and pupae. The praying mantis (Stagmomantis carolina Linn.) is also an enemy of the elm leaf beetle in the southern portion of its range. , Fic. 5.—Pupae and adults killed by fungus. Healthy specimens at the left, natural size. REMEDIES. Spraying with poison. Covering the foliage with some arsenical poison is the only sure means of preventing injury to the trees, and for this purpose arsenate of lead is unquestionably the most satisfactory of these poisons. It remains better in suspension and adheres to the foliage longer than Paris green or London purple, and is less liable to injure it. As there are now several brands of good arsenate of lead on the market, it * Div. of Entomology, U. S: Dept. of Agriculture, Bulletins No. 6, p. Io and No. Io, p. 13. THE ELM LEAF BEETLE. Il will no longer pay to make it up each time from lead acetate and arsenate of soda. The arsenate of lead made by the Merri- mac Chemical Co., Boston, Mass.; Schoonmaker & Son, Cedar Hill-on-Hudson, N. Y., and the Bowker Insecticide Co., Boston, Mass., (Disparene) have all been used in our tests and have given satisfaction. Arsenate of lead should be used in the following proportions :— Arsenate of lead ................. 3-5 lbs. Formul re ee Wx sues o oe ER eee eed ee 50 gals. There are two methods of spraying elms: (1) To spray as soon as the leaves unfold, the treatment being aimed especially at the parent beetles, and to forestall all injury. As growth takes place, new leaves are constantly appearing, and these will not carry poison unless the application is from time to time repeated. This should be done often enough to ‘keep the foliage well coated with poison until July ist, when growth usually ceases, and both sides of the leaves should be coated. (2) The other method is to spray the under sides of the leaves very thoroughly about June Ist, or soon after the eggs begin to hatch. This treatment is aimed at the larvae, and sometimes a single spraying is sufficient, as the poison will remain throughout the season. By it the great bulk of damage will be prevented, but the leaves will show the small holes made by the parent beetles before the poison was applied. If arsenate of lead cannot be procured and it seems desirable to use other poisons, Paris green can be substituted. This should be used at the following rate: ea Greehivenaceusncss hose g aed t lb. Formula { Fresh lime.............. 0000000 3 lbs. Water en vex -qe sr ohiaa ys cede dale 50 gals Paris green is quicker in its action upon the insects than arsenate of lead, but will not remain as long upon the trees. Unless the lime is added, there is danger of “burning” the leaves. Lime is not needed with arsenate of lead. The cost of spraying elm trees will vary from ten cents each in case of small trees to five dollars or more for the largest trees, according to the price of labor and the efficiency of the outfit. 12 CONNECTICUT EXPERIMENT STATION BULLETIN 155. Destroying the pupae. If the trees have not been protected by spraying, and have been attacked and injured by a horde of beetles and their larvae, it is always advisable to destroy the insects in the pupa stage at the base of the trees, in order to reduce the crop for next year as much as possible. These can often be swept up in large quantites; they can be killed by sprinkling them with hot water; but best of all is to spray the ground not only close to the tree but as far away as the branches reach, and also spray the bark of the trunk and large branches, with kerosene emulsion or some other contact insecticide. The pupae are easy to kill, but as they remain in the pupa stage only about ten days, it is essential that this work be done at the right time, and it is only when we observe that most of the larvae descending the trunk have transformed to bright yellow pupae that we can know when is the proper time to act. : Destroying the adult beetles. The beetles should of course be destroyed in attics, belfries and other places where they hibernate. This can best be done by sweeping them up before they become very active in spring and dropping them into the fire, hot water or kerosene to kill them. OUTFIT FOR SPRAYING ELM TREES. The barrel hand-power pump can be used for spraying small trees or for a limited number of large trees, but if one expects to make a business of spraying street trees, it will pay to pro- cure a power sprayer; this may be a steam or gasoline engine with pump, or what is perhaps better, the “Niagara Gas Sprayer,” which utilizes cylinders of carbonic acid gas to furnish pressure, thus doing away with a pump. Each large village and city should have at least one power sprayer that can be put to immediate use for spraying street or park trees. Strong one-half inch hose should be provided in long lines of from fifty to two hundred feet, and from four to six of these can be attached to each power sprayer. Even a larger number might be attached, but while in operation some workmen would be in the way of others, so that nothing would be gained. Mr. H. L. Frost of Boston, who is in the spraying business, informed the writer that four lines of hose is about the most economical number for each outfit. Each hose is furnished with an extension rod with closing valve at the lower end THE ELM LEAF BEETLE. 13 and a cluster of nozzles at the upper end. These rods should be of different lengths, from four to twelve or fourteen feet for the different kinds of work. Any of the standard nozzles such as “Vermorel,”’ “Mistry,” or “Spraymotor”’ will be found satisfactory, and if several are used together in a cluster one is able to cover more leaf surface in a given time. For getting about in tall trees it will be necessary for the men to be provided with climbing irons and extension ladders. SUMMARY. The elm leaf beetle was introduced into this country from Europe about seventy years ago, and caused serious injury to trees at Baltimore, Md., in 1838 and 1839. From this point it spread slowly, chiefly to the northward, reaching Connecticut in the early nineties, and injuring and killing many fine old trees in the coast towns. Later, inland towns were attacked, and the trees ravaged. The insect is now found from Charlotte, N. C., as far north as North Conway, N. H., and as far west as central Kentucky, but has not proven destructive to elm trees north of Massachusetts. It is preéminently a pest of shade trees in cities and towns, and seldom injures trees in the open fields. _Since 1896 the attacks have diminished, but the pest was again serious in 1906. The winter is passed by the adult beetles in attics, belfries and cracks in fences, and they come forth in April, and later feed and lay their yellow eggs upon the unfolding leaves. Beetles eat holes through the leaves, eggs hatch in a week, and the larvae eat off the green tissue from the under surface, caus- ing the leaves to turn brown and fall about the middle of July, at which time the larvae are about full grown. Then they descend to the base of the tree and transform to naked pupae; ten days later the adult beetles emerge and lay eggs for the second brood or go early into winter quarters. Two complete defoliations in succession will kill a tree. How to Fight the Elm Leaf Beetle. (1) Search all attics, church belfries and cupolas for the dormant beetles in winter and early spring. Sweep them up and burn them. 14 CONNECTICUT EXPERIMENT STATION BULLETIN 155. (2) Spray the leaves with poison as soon as they have opened, if their shot-hole appearance shows that the beetles are there in abundance, and the under sides of the leaves should be coated about June 1st to destroy the larvae or grubs. (3) When, later in the season, the yellow pupae appear on the trunks of trees and the ground beneath, kill them with a spray of kerosene emulsion or by sweeping them up and burn- ing or soaking with kerosene. The first and third measures should be taken by each house- holder, church or social organization, at individual expense. The spraying, which is difficult and expensive if the trees are large, can only be done by concerted action of the town or borough authorities. For extensive spraying work power sprayers are desirable, but small elms or a few large trees can be treated successfully by means of a hand pump of barrel size. The “Niagara gas sprayer” in operation is shown in Fig. 6. ” - . O.— Niagara y x tr ew E i f gas sprayer y TSe a 10n for I90 Fic. 6 and outfit f or spra ‘ é t fi ing street trees, (After Ss t mith, Report N : y xpt Sta’ HATCH EXPERIMENT STATION ——OF THE—— MASSACHUSETTS AGRICULTURAL COLLEGE. BULLETIN NO. 76. THE IMPORTED FLM LEAF-BEETLE. JULY, 1901. . AMHERST, MASS. : PRESS OF CARPENTER & MOREHOUSE, 1901. HATCH EXPERIMENT STATION Massachusetts Agricultural College, AMHERST, MASS. STATION STAFF: Henry H. Goopse1yi, LL. D., Witu1aM P. Broogs, Pu. D., Grorce E. Stones, Pa. D., ‘CHartus A. GOESSMANN, Pu. D., LL. D., Joszera B. Linpsey, Pu. D., Caries H. FERNALD, PH. D., SAMUEL T. MaYNakRD, B. Sc., J. E. OsTRANDER, C. E., Henry T. FERNALD, Pu. D., Henry M. THomson, B. Sc., RatpH E. Smits, B. Sc., Henri D. Hasxrys, B. Sc., SAMUEL W. WILEY, B. Sc., JaMgES E. HaLwican, B. Sc., EpwarRp B. HoLuanp, M. Sc., Puitie H. Smira, B. Sc., Jamus W. Kewxoaa, B. Sc., Grorce A. Drew, B. Sc., Ratpeu I. Smita, B. Sc., CHarRLEs L. Ricr, Director. Agriculturist. Botanist. Chemist (Fertilizers). Chemist (Foods and Feeding). Entomologist. Horticulturist. Meteorologist. Associate Entomologist. Assistant Agriculturist. Assistant Botanist. Assistant Chemist (Fertilizers). Assistant Chemist (Fertilizers). Assistant Chemist (Fertilizers). First Chemist(Foods and Feeding). Ass’t Chemist(Foods and Feeding). Ass’t Chemist (Foods and Feeding). Assistant Horticulturist. Assistant Horticulturist. Observer. The co-operation and assistance of farmers, fruit-growers, horti- culturists, and all interested, directly or indirectly, in agriculture, are earnestly requested. The Bulletins will be sent free to all news- papers in the State and to such individuals interested in farming as may request the same. General bulletins, fertilizer analyses, analy- ses of feed-stuffs, and annual reports are published. Kindly indi- cate in application which of these are desired. Communications may be addressed to the Hatcn Experiment Station, Amherst, Mass. DIVISION OF ENTOMOLOGY. H. T. FERNALD. THE IMPORTED ELM LEAF-BEETLE. Galerucella luteola Mull. During the present summer much injury to the elms in this State has been caused by the Imported Elm Leaf-Beetle, and as it is to these trees that Massachusetts owes much of its beauty, many inquiries have been received as to the life history of this insect and the treatment necessary for its control. 5 HISTORY. This insect is a native of Southern Europe though sometimes found as far north as England and Sweden. It appears to have reached this country at Baltimore, about 1835, since which time it has slowly spread in all directions, though checked in its westward progress by the Appalachian ranges. It probably reached south- western Massachusetts in 1892 or 1893 as it was found in Amherst in 1895. Since then it has gradually spread until it has become abundant over the entire State. LIFE HISTORY. The elm leaf-beetle passes the winter as the adult beetle (Fig 1, cand #), hiding wherever it can find protection. House attics, unused chimneys, church towers, barns and other places easy of access appear in this locality to be preferred to cracks in fences, crevices in the bark of trees, etc., for the purpose. In the spring the beetles leave their hiding places about the time the leaf buds open, and after mating, feed upon the tender leaves, making irregular holes. When the leaves become full grown egg laying begins, each female depositing from 400 to 600 eggs. These 4 are yellow and are placed on the lower side of the leaves, usually in about two irregular rows close together, and from five to twenty-six in number. After depositing a cluster the adult beetle feeds for a longer or shorter time before again depositing, and in this way the period of egg laying is not only extended over a considerable time, but the injury caused by the beetle feeding is correspondingly increased. The eggs (Fig. 1, a and ¢) are oval in form, attached by one end, and somewhat pointed at the tip. They hatch in less than a week after they are laid, and as egg laying continues for quite a period, eggs and young more than half grown, may often be found on the same tree. ; The young larvae or grubs (Fig. 1, J, ,) feed on the under sur- faces of the leaves leaving the upper surfaces and veins entire, thus skeletonizing the leaf. They complete their growth in from fifteen to twenty days at which time they are about a third of an inch in length, with a black head and a yellowish body with a black stripe extending on each side of the middle line of the body, from the head to the posterior end where the stripes unite. The larvae now stop feeding and crawl down the trunk until some crevice is found in which the next stage may be passed, or continue to the ground at the foot of the tree. In some cases they drop from the limbs instead of passing down the trunk. As soon as a satisfactory spot has been found, the grub changes to a pupa (Fig. 1, 7) and in this condition remains quiet for a week or ten days, after which the adult beetle escapes from the pupa, to lay eggs for a second brood, the history of which is the same as that of the first brood, just described, except that the adults of the second brood hide during the winter and lay their eggs the following spring. During the present year egg clusters were abundant by the fifteenth of June and most of the grubs had completed their feeding and had begun to crawl down the tree by the twelfth of July, though two weeks later a few belated individuals were still making their way downward, while beetles to lay eggs for the second brood were begin- ning to appear, coming from the grubs which were first to pupate. The adult beetle (Fig. 1, 4) is rather more than a quarter of an inch long, greenish or sometimes reddish yellow in color, with two black eyes and a black spot between them, on the head, three black 5 spots on the thorax, and a broad blackish stripe along the back on each side. Between these stripes the yellow ground color is divided by a very narrow black line which runs along the middle of the back where the wing covers meet. At the front end of the two strips of yellow on the back is a black spot. Altogether the beetle somewhat resembles a large Striped Cucumber Beetle. FIG. I.—-THE ELM LEAF-BEETLE: a, eggs; 4, larvae; c, adult; e, eggs; g, larva; 7, pupa; 4, beetle; a, band ¢, natural size; ¢, g,7 and &, much enlarged.—From U. S. Department of Agricultuie. FOOD PLANTS. The food of the elm leaf-beetle seems to be limited to the elm though it has been known to deposit its eggs on one or two other plants, perhaps under exceptional conditions. Among the elms the English elm Udmus campestris and its variety the Camperdown elm are most preferred, though after the pest has become established the American elm. U/mus americana is also attacked. TREATMENT. Where this insect is abundant, treatment for it is necessary if the elms are to be preserved. Generally speaking, a tree will suffer defoliation once or even twice without being killed, but if defoliated three times in succession serious injury at least, if not death, must be the result. Spraying is undoubtedly the best way to check the attacks of the elm leaf-beetle, and the cost is much less than might be supposed. The spraying should be done first when the leaves are partly grown in spring, as at this time the beetles which have wintered over feed on the leaves for some time before laying their eggs as well as during the intervals between the deposition of the different clusters. This treatment will destroy many, at least, of the beetles, which would otherwise produce young to do damage later in the season. A second spraying will often be necessary however, soon after the eggs hatch, and as the young grubs feed on the under side of the leaves, not eating the upper surface, the aim should be to spray so that the poison may reach the under surface of the leaves as far as possible. If these treatments have been neglected, or for any reason have proved inefficient, the insects may be attacked while on the trunk and ground where they are more accessible than when scattered over the tree. At this time however, the damage has already been done and by destroying the insects at this time only the size of the following brood will be reduced. Still, this is well worth doing with a view to protecting the trees from another attack while still in a weakened condition. For the same reason the destruction of all the beetles found in hiding during the winter, is extremely desirable. In spraying the trees Paris green or arsenate of lead may be used, the latter being preferable as it does not burn the leaves at any strength when properly prepared. For destroying the insects on the trunk and ground boiling water is excellent, but as it is often impos- sible to get it to the trees sufficiently hot, kerosene emulsion or the mechanical mixture of kerosene and water may be found more con- venient for use. SPRAYING MIXTURES FOR THE ELM LEAF-BEETLE, ARSENATE OF LEAD. Arsenate of Soda, 4 OZ. Acetate of Lead, - I1 02. Water, - - 100 gallons. Mix together and it is ready for use. PARIS GREEN. Paris green, - 1 |b. Quick lime, 2 Ibs. Water, - too gallons. Slack the lime in part of the water and gradually add the Paris green: then add the rest of the water. KEROSENE EMULSION. Hard soap shaved fine, 1-2 lb. Water (soft), 1 gallon. Kerosene, fe 2 gallons. Dissolve the soap in the water, boiling ; remove from the fire, pour in the kerosene and churh with the spray pump till it becomes, first creamy, then soft and butter like. One part of this mixed with five parts of soft water should be sufficiently strong to accomplish the desired purpose. During the present summer a soap powder known as Laundry Chips has been used in Amherst with good success, prepared as follows : “Laundry Chips,” 2 Ibs. Kerosene, - 8 gallons. Water, “ee 35 gallons. This was prepared with hot water and churned upon adding the kerosene as in the directions above. KEROSENE AND WATER MIXTURE, This mixture is made entirely by the pump which consists of two tanks so connected that the operator may fix at will the proportion of the fluids to each other. For the elm leaf-beetle the proportion should be 1 of kerosene to 3 of water. SUMMARY. Spray the tree with Arsenate of lead or Paris green when the leaves are about half grown in spring. Repeat this treatment soon after the eggs hatch—usually about the first week in June but varying with the season and locality. Remove all loose bark on the trunk and main limbs of the tree, that the grubs may find no place to pupate in, and so go to the base of the tree. Destroy the grubs and pupz at the base of the tree with boiling water, kerosene emulsion or the kerosene and water mixture, and repeat after five days if necessary. E Destroy all beetles found in hiding during’ the winter. THE SPINY ELM CATERPILLAR Larva Bulletin 67 BY October, 1899 Clarence M. Weed 4 Chrysalis NEW HAMPSHIRE COLLEGE AGRICULTURAL EXPERIMENT STATION Butterfly DURHAM Fig. 40. Spiny Elm Caterpillars at work. THE SPINY ELM CATERPILLAR BY CLARENCE M. WEED In New Hampshire during the last three years there have been frequent complaints of injury to the foliage of elm trees by a black, spiny caterpillar. The extent of the injury ap- pears to have been increasing from year to year until, in 1899, it attracted very general attention. In some localities the damage done was compared to that done by the hosts of the Forest Tent Caterpillar or Maple Worm. The correspond- ence of this station, as well as trips in the field, has shown the desirability of a full statement of the life history of the insect, and of the remedial measures to be taken against. it. Fig. 41. Mourning Cloak or Antiopa Butterfly. This bulletin, therefore, is issued: it embodies a statement of the results of the studies of the insect carried on at this sta- tion by the entomologist and his assistant, Mr. W. F. Fiske, as well as a summary of the previous knowledge of the species. It aims, in short, to place before the people of the state a brief account of all that is known of the pest in so far as it may be of practical value. 126 THE SPINY ELM CATERPILLAR THE LIFE HISTORY OF THE CATERPILLAR During sunny days in spring one may often see a beautiful purple-black butterfly, having a cream-colored border along the outer margin of its wings, flying leisurely about. This butterfly is called the Mourning Cloak or Antiopa Butterfly; it is represented nearly natural size in Fig. 41. It has passed the winter in this adult condition, having found shelter in some retreat where it was not directly a to the storm and stress of the weather. Fig. 42. Butterfly just after depositing eggs (a). When the leaves of elm, willow, and poplar trees are nearly expanded these butterflies deposit their eggs upon the twigs. These eggs are laid in clusters encircling the twig, there being twenty or more in each cluster; their general appearance is shown in Fig. 42. In the act of oviposition the butterfly keeps her wings spread out, moving the body and abdomen about as the placing of the eggs necessitates. About two weeks after the clusters of eggs are thus laid upon the twigs of the food- plant they hatch into small blackish, caterpillars, each emerg- ing from the egg-shell through a small hole that it eats out of the upper surface. They thus enter upon the second stage of "LIFE HISTORY OF THE CATERPILLAR 127 their life-history—the larva or caterpillar stage. As soon as hatched they crawl to the nearest leaf, upon which they range themselves side by side, with their heads toward the margin of the leaf. They feed in this position, nibbling at the green surface of the leaf-blade, and leaving the network of veins untouched.. ' Pa 5 Fig. 483. Denuded twigs showing cast skins of the caterpillars. These caterpillars continue to feed in this manner for about a week, remaining side by side when feeding, and marching in processions from one leaf to another, as the food supply is exhausted. Wherever they go each spins a silken thread on the surface traversed, so that the combination of all the threads makes a sort of carpet that serves as a foothold for 128 THE SPINY ELM CATERPILLAR ° the caterpillars. At the end of the week they moult or cast their skins, a process in which the skin of each insect splits open along the back, and the caterpillar crawls out of it, being covered with\a new skin that had been formed beneath the old one. This new skin stretches somewhat after the caterpillar emerges, so that the insect is able to increase con- Fig. 44. Colony of Caterpillars feeding upon willow. siderably in size. At the period of moulting the caterpillars remain quiet for a short time, but they soon become active again and begin feeding with increased voracity. During the next three weeks this moulting process is re- peated three times, the caterpillars becoming larger each time, and leaving their cast skins upon the denuded twigs, as shown in Fig. 43. They soon scatter more or less over neighboring LIFE HISTORY OF THE CATERPILLAR 129 leaves, but remain in closely associated colonies, as repre- sented in Fig. 44. As they increase in size they dat more and more of the leaf substance; when half grown they devour all but the midrib and the side veins, but when they get larger only the midribs arc left, as may be seen in Fig. 43. Fig. 45. Denuded Elm twig showing carpet web. The carpet-web that they form becomes more conspicuous as the caterpillars develop, and often binds the ends of neigh- boring twigs together, especially in those places to which the caterpillars retire for rest after feeding. Examples of such webbing of the denuded surface are shown in Figs. 45 and 50. - 130 THE SPINY ELM CATERPILLAR About four weeks from the time of hatching these Spiny Elm Caterpillars become full grown. They then leave the tree or shrub on which they have been feeding and scatter ‘ about, seeking some sheltered situation. Having found this,—perhaps beneath a stump or along the underside of a fence,—-each caterpillar spins a web of silk along the surface. It then entangles the hooked claws of its hind legs in this silken web and lets its body hang vertically with the head end curved upward. It ‘remains in this position’ for some hours before the skin along the back just behind the head splits apart and is gradually wriggled upward until it is finally all removed, and there hangs in place of the caterpillar a peculiar object having no definite form. But it rapidly as- sumes a definite form— that of the chrysalis Fig. 46. Four views of the chrysalis. which is represented in See a Fig. 46. These pictures will show sufficiently the shape and size of the chrysalis, which is of a grayish brown color, different specimens varying, some- what in shade. In this quiet chrysalis the insect is apparently almost as inert as a mummy. If you touch it, it will wriggle a little but otherwise it hangs there mute and helpless. On the inside, however, the tissues are being made over in ‘such a wonderful way that in about two weeks, from the mummy- case into which the caterpillar entered, there comes: a beauti- ful butterfly. When it first breaks the mummy-shell its wings FOOD-PLANTS OF THE CATERPILLARS 181 are very small, although its body, “feelers,” and legs are well developed. By means of the latter it clings to the empty chrysalis while its wings expand. A butterfly in this posi- tion with its wings nearly expanded, is shown in Fig. 47, which - like all but one of the photographs of the insects illustrated in this bulletin was taken from the living specimen. In the course of half an hour the wings become fully developed, and the butterfly is likely to crawl to some firmer support where it will rest an hour or so before venturing upon its first flight. FOOD-PLANTS OF THE CA'TERPILLARS The caterpillars of the Mourning Cloak Butterfly are re- stricted to comparatively few food-plants. In regions where they are not especially abundant they are likely to be found upon willow, pop- lar, or elm. In general our observations indicate that they are as likely to be found 4 ‘on any one of these food- plants as upon either of the other two; but in certain localities where they become especially abundant it seems that they are more likely to occur upon the elm. There is considerable evidence to show that they prefer the American elm to other spe- Fig. 47. Butterfly hanging to empty cies of the genus, although chrysalis as its wings expand. . e in the case of willow and poplar there seems to be little if any preference as to spe- cies. Miss C. G. Soule has seen the butterflies depositing their eggs upon the white and canoe birch, and in Labrador , and Europe it has been recorded as feeding upon a species of birch. There is one record of the caterpillars having been found feeding upon the hackberry (Celtis occidentalis), and 182 THE SPINY ELM CATERPILLAR also one of their having fed greedily upon the leaves of rose, and another of their having almost defoliated a pear tree. Linden and nettle are also included in the European lists of the food-plants of this species. It is evident, however, that all of these except the three first named—willow, poplar, and elm—are to be regarded as exceptional cases, and that the normal food of the species is the foliage of.a plant belonging to one of these three genera. BROODS AND HIBERNATION It has generally been supposed that this species is double- brooded in central and southern New England, the butterflies of the first brood appearing early in July. These are said to ~ deposit eggs which hatch into caterpillars that mature into butterflies early in September. These butterflies live through the winter, laying eggs the following spring. Unless the summer of 1899 was exceptional, however, this idea of the yearly history of the species will have to be modi- fied, for during this season, in New Hampshire and Vermont at least, there was practically but one brood. Continual observations by Miss Caroline G. Soule at Brandon, Vt., and by Mr. Fiske and myself in this state show that there was scarcely a trace of a second brood of caterpillars, for with allt our searching in July and August we found but a single col- ony of larve. These were discovered on a willow at Durham August 3. During the period when the second brood of cat- erpillars are supposed to be at work, I traveled by carriage and on foot over hundreds of miles of roadway in southern New Hampshire and southern Maine, and though there was every- where evidence of the presence of the first brood, none of the second were seen. During the same period Miss Soule was. watching in the region of Brandon, Vt., and Mr. Fiske took an extended trip through central New Hampshire. But save for the single colony mentioned, all our looking did not reveal a trace of the second brood. Nor was there a single com- plaint from correspondents of injury at the supposed time of the second brood, although many accounts of the depreda- tions of the first brood were received. BROODS AND HIBERNATION 133 In view of all this evidence it seems safe to conclude that in the region under consideration a single brood is the rule rather than the exception. This involves the conclusion that the butterflies seen upon the wing early in autumn are the same ones that developed in July, and that these same but- terflies remain alive through the winter and until, in thé following May, they lay their eggs. Thus there is a period of ten months of existence in the butterfly state, an extraordi- nary length of. time for a butterfly to live. To a large extent the butterflies disappear in August, and the question arises as to what becomes of them. Our observa- tions lead to the conclusion that they go into summer quar- ters similar to those which they seek out for winter shelter. Appar- | ently they fly about for a few days after coming from the chrysalis and _ 4 then retire to cool woods, where under the side of a log or beneath the loose bark of a dead tree they settle down and to all ap- pearances go to sleep. The instinct to remain : quiet is very strong in “~ Fig. 48. Butterfly ‘‘playing possum”. these butterflies. In mak- ing the photographs that illustrate this bulletin I found that even shortly after coming from the chrysalis the butterflies when disturbed would fold their wings with the antenne be- tween them, and drawing the legs against the body, would lie quietly on their sides for a long time; the position thus assumed by the living butterfly is shown in Fig. 48. These same butterflies would also’ hang downward from a limb by the hour in the hibernating position as shown in Fig. 49. In the cooler weather of early autumn the butterflies come from their summer retreats and fly about in the sunshine. 134 | THE SPINY ELM CATERPILLAR They are especially likely to be seen along the borders of woods or in open glades. At this time they love the sun- shine, and will settle in a sunny place to bask in it. On a spring-like day early in November (the eighth) I came across one of these butterflies basking in the sunshine upon the ties of a railway track. It rested with its wings wide open. On being disturbed it would fly a short distance and then alight, and I was interested to notice that after alighting it would always turn about until the hind end of its \ Fig. 49. Butterfly hanging from branch in hibernating position. body pointed in the direction of the sun, so that the sun’s rays struck its wings and body nearly at right angles. I repeatedly observed this habit of getting into the position in which the most benefit from the sunshine was received, and it is of interest as showing the extreme delicacy of perception toward the warmth of sunshine which these creatures possess. During the colder part of the year in bright weather when these butterflies are most often abroad, they commonly hold their wings open when they alight, but during the warmer: summer days they are more likely to rest with the wings closed. FEEDING HABITS OF THE BUTTERFLY 185 When the warm days no longer tempt them abroad the Mourning Cloak Butterflies seek shelter in many sorts of situations,—under loose bark, in hollow trees, under culverts and bridges, in woodpiles, in crevices of rocks, alongside logs lying on the ground. In such retreats they remain until the sunshine of spring again calls them forth. . FEEDING HABITS OF THE BUTTERFLY The Mourning Cloak Butterflies subsist upon a consider- able variety of liquid food which they suck through their long tongues. In spring, when they first come’ from. their’ winter quarters, they visit the stumps of recently cut trees: and suck the exuding sap, a habit which they continue when- ever opportunity offers. Mr. Fiske has noticed that they :com- monly sip the sap of maple twigs where the squirrels have ° gnawed the bark. A little later they visit the: willow catkins to suck the nectar secreted by :these blossoms, and.still later they hover about the delicate blossoms of the mayflower or trailing arbutus for a similar purpose. Probably.- mahy other flowers are thus rifled of their sweets, although. this butterfly seems to be a less regular visitor -to:flowers than are: many of its allies. A little later, when the .aphides or plant- lice have become sufficiently abundant so that the so-called “honey-dew” is to be found upon. the infested shrubs,. these Mourning Cloaks sometimes sip the liquid sweet from the surface of the leaves. In April and May they occasionally: visit the flowers of moosewood, .and later in the season: have been observed upon the blossoms’ of the common milkweed.. ° From the time the early apples ripen these butterflies..may often be seen beneath the orchard trees sipping the » Nai of the fallen and decaying fruit. - POPULAR NAMES OF THE BUTTERFLY In Germany this butterfly is called Trauermantel, from the translation of which is derived the common American. name, Mourning Cloak. Its other common name with us, Antiopa Butterfly, is derived from its Latin name,—Vanessa antiopa. 186 THE SPINY ELM CATERPILLAR In England it is called the Camberwell Beauty, from its hav- ing been found at an early date at or near Camberwell. A still earlier title adopted for it in England was “The Grand Surprise,’ given by butterfly collectors because at the begin- ning of the century after a long absence it appeared in con- siderable numbers. In most books upon insects the technical name of this but- terfly is given as Vanessa antiopa. In his recent writings Mr. §. H. Scudder has called it Huvanessa antiopa, although in one of his earlier books he called it Papilio antiopa. Questions of nomenclature, however, need no consideration in this connection, and I mention these names-only for the guidance of any readér that may wish to study what has been printed about the species. THE CATERPILLARS NOT POISONOUS During the earlier years of our country’s history many peo- ple regarded these caterpillars as “venomous and capable of inflicting dangerous wounds.” Dr. T. W. Harris states that he had known people to cut down poplar trees around dwell- ings to prevent the presence of such dangerous caterpillars. But these insects are not poisonous, and may be handled with little fear of injury, although the sharp spines might perhaps penetrate the delicate skin of a child’s hand. GEOGRAPHICAL DISTRIBUTION The Mourning Cloak Butterfly is one of the most widely distributed insects in existence. Not only is it found in North America as far south as Bermuda; Florida, and Mexico, but it is also found throughout northern Europe, and in Asia and Japan. Consequently, as Mr. Scudder has said, it appears to be distributed “over the entire breadth of the northern hemisphere, below the Arctic circle as far south as the thirtieth parallel of latitude.” This is an extraordinary distribution for an-insect, and shows a remarkable power of adaptation to the varying surroundings in which the species occurs. In the northern United States this is one of the commonest and most familiar butterflies. ABUNDANCE AND INJURIES 1387 ABUNDANCE AND INJURIES As a rule thej caterpillars of the Mourning Cloak Butter- flies are to be. found only in occasional colonies, so that the damage they do attracts little if any attention. But some- times the weather or other conditions are so favorable to their Fig. 50. Poplar twig denuded by caterpillars, showing carpet web. development that they multiply beyond this normal limit and are to be found in great numbers. At such times serious damage is often done. In this country such local outbreaks of the species have frequently occurred, generally, however, over very limited areas. So far as I can learn the insect has 138 THE SPINY ELM CATERPILLAR never caused such widespread destruction as the Forest Tent Caterpillar has recently caused in New England. In the tree plantations of the prairie regions of the West, these cater- pillars are, according to Prof. Otto Lugger, “very injurious and sometimes denude whole rows of willows and poplars.” The same observer adds: “They are still more fond of the leaves of elms, and I have seen them so numerous upon those trees in Michigan that branches were broken by their weight.” In other regions of the West similar records have been made. NATURAL ENEMIES Like most other insects the Mourning Cloak Butterflies have many natural enemies to contend against. From the moment the egg is laid until the ey dies it is in constant danger. Some of the eggs never hatch ‘ait geese ‘because a tiny fly, scarcely one twentieth of an inch in length, finds the egg mass, and deposits in each egg another egg,—the latter being microscopic in size. This tiny egg soon hatches into a maggot almost equally tiny, and the maggot grows by absorb- ing the contents of the butterfly egg. In due time it changes to a minute pupa, later to change to a minute fly like the one that laid the microscopic egg. This minute fly now gnaws a hole through the egg-shell of the butterfly and comes out into the world. The little creature that has thus developed at the expense of the egg of the butterfly is called an egg para- site. There are many species of these egg parasites and they attack the eggs of many kinds of insects. The particular spe- cies that develops in the eggs of the Mourning Cloak Butter- fly is called by scientists Telenomus grapte. After hatching from the egg the caterpillars are subject to the attacks of various parasites. One of these is quite:mi- nute,—not a great deal larger than the egg parasites. It is a tiny four-winged fly which deposits many eggs in a single caterpillar. The eggs hatch into tiny maggots that grow at the expense of the caterpillar, finally killing it and changing to four-winged flies again. As many as 145 of these para- NATURAL ENEMIES 139 sites have been known to emerge from a single dead cater- pillar. These little flies are called Chalcids by entomologists. There is still another group of four-winged flies, some of which attack the Antiopa Caterpillars. These are much larger than the Chalcid flies, and are called Ichneumon I Flies. In the case of these only: one or two parasites develop in each cater-~ pillar or chrysalis. In addition to these various four- winged flies there are cer- tain two-winged flies, called Tachinid Flies, that develop at the expense of the caterpillars. In New Hampshire, during recent years, these appear to have been the most abundant parasites of these insects. An egg is laid on the skin of the caterpillar by a two- -winged fly, similar in general appearance to Fig. 51. The contents of this. egg shortly develop into a tiny grub that burrows through the egg-shell and the skin of the caterpillar into the inside of the body. Here it remains absorbing the body substance of its host and gradually increasing in size. In a few weeks it becomes fully developed in this grub state. By this time the cater- pillar has become sluggish from the effects of the parasite. If the branch .Fig. 51. Tachinid fy. upon which it feeds is disturbed the (Redrawn from Scudder.) other caterpillars are likely to crawl away, but it remains in its place. The caterpillars illustrated onthe web in. Fig. 45 were parasited specimens that thus remained. after the.others had crawled ‘away. Shortly after -becoming full. grown the Tachinid grub breaks through the skin of the dying caterpillar and falling to the ground changes to a peculiar pupa; the outer skin of the grub turns brown and becomes hard, forming a protective covering for the body inside. A week or two later the insect undergoes another change and emerges as a two-winged Ta- chinid fly like the one that laid the egg some weeks before. Our observations indicate that during the last season a comparatively small proportion of the caterpillars were af- fected by parasites of any kind. 140 THE SPINY ELM CATERPILLAR PREDACEOUS, INSECTS Besides those insects which develop on the inside of the bodies of these caterpillars, called parasites, there are other insect enemies that attack them from the outside and devour them bodily. Such enemies are called predaceous insects. ‘The most notable of these, perhaps, is a large beetle called the caterpillar hunter; it is known to entomologists as Calo- soma scrutator. Some cases are on record in which this insect has been observed to destroy many of the Antiopa Caterpillars. In New Hampshire, however, this beetle is comparatively rare, and it can be relied upon for but little help. In the Southern states a large reddish wasp has been observed to attack. and destroy the Antiopa Caterpillars. There are probably also various other insect enemies at work, although definite observations upon them have not been re- corded. These Elm Caterpillars are such spiny creatures that com- paratively few birds attack them. They are devoured, how- ever, by the cuckoos, of which we have two species in New England,—the yellow-billed and the black-billed cuckoos. It is probable also that these insects are eaten by Baltimore orioles and various other birds. These caterpillars are also greedily devoured by toads, but of course as a rule they do not come within reach of these useful animals. REMEDIES In general the most satisfactory remedy for these caterpil- lars is to cut off while they are still young the branch on which they are feeding, andcrush or burn the insects. After they become larger they may be shaken off and crushed. Or the colonies may be brought down with a torch, care being taken to kill the caterpillars that fall to the ground, as prob- ably many of them will not be seriously injured by the flame. Jarring the limbs with a padded mallet will also be a useful way of bringing down those out of reach; or they may be brought down by use of a strong stream of water from a force pump or hydrant. BANDING THE TREES 141 These caterpillars are also open to destruction through spraying with arsenate of lead or other forms of arsenical poisons. , BANDING THE TREES IS USELESS FOR THESE CATERPILLARS In one city in this state where the Spiny Elm Caterpillars were rather abundant last season, many owners of shade trees applied bands of various sorts to the trunks of the trees to prevent the injury. Presumably this was done on the theory that as bands are successfully employed against canker worms, they are equally good against other caterpillars. In the case of canker worms, however, the female moth which lays the eggs is wingless, so that the bands prevent her from ascending the trees. But with the Spiny Elm Caterpillar the parent insect that lays the eggs is a butterfly which can easily fly to the tops of the tallest trees. The eggs are deposited on the twigs by these butterflies, and the caterpillars remain in the close neighborhood of the place where they hatch until they are full grown. Consequently, any banding of the tree is a waste of energy so far as this insect is concerned. [P Is } University of the State of New York New York State Museum Freperick J. H. Merrity Director Epuraim Porrer Feit State entomologist Bulletin 57. ENTOMOLOGY 15 ELM LEAF BEETLE IN NEW YORK STATE PREFACE This bulletin appeared in June 1898 and as the first edition is practically exhausted, a revision embodying the more essen- tial facts observed since then has been prepared in order to meet the demand for information concerning this deadly enemy of our elms, which is still extending its range in this state. This beetle has abundantly demonstrated its injurious powers in the vicinity of Albany, and in turn the feasibility of control- ling it at a very reasonable expense has been proved. The life history and habits of this beetle have been given somewhat in detail because unless they are thoroughly under- stood it is very easy to adopt means that are futile or only partially successful. In order to give the bulletin a more prac- tical value, short accounts have also been included of three other insects, which, working with the elm leaf beetle, have aided greatly in ruining many noble elms. In the portion devoted to remedies prominence has been given to the cost of spraying per tree, the proper apparatus and the time and manner of application. It is surprising to see what mistakes some make in dealing with insects and how methods of no value are clung to. To offset this tendency, two of the more common fallacies are mentioned and their futility shown. E. P. Feit ' Albany N.Y. January 1902 4 NEW YORK STATH MUSEUM \ ELM LEAF BEETLE IN NEW YORK STATE Galerucella luteola Miiller Ord. Coleoptera: Fam. Chrysomelidae This insect has committed such extensive injuries to elms in cities and villages along the Hudson that it may be regarded as the most important natural enemy of shade trees in this state. Its depredations in this section probably outrank those of all other natural agents combined. Residents of places where this pest has established itself have repeatedly observed the grubs working on their elms and in many instances have seen two, or even three, crops of leaves destroyed in a single season without taking steps for the protection of their trees. The causes for this condition of affairs are not hard to find, as the majority, if they notice the work of this pest at all, are inclined to trust in Providence and hope that its ravages will not be as severe the next season. Others see the grubs at work on the under side of the leaves or crawling about the tree but not being quite sure of the best method of controlling them, and as any method takes considerable labor, usually make no effort to subdue the pest. Bad reputation of its family. This beetle is a member of the large, leaf eating family of Chrysomelidae, which com- prises a number of our most injurious insects. It includes such well known pests as the asparagus beetle, Crioceris as- paragi Linn., the Colorado potato beetle, Doryphora 10- lineata Say, the 12 spotted Diabrotica, D.12punctata Oliv. and the striped cucumber beetle, Diabrotica vit- tata Fabr., all well known insects against which the farmer must wage a more or less perpetual warfare. Another member of this family, the cottonwood leaf beetle, Lina scripta Fabr., recently inflicted serious damage on the large basket industry in the willow growing districts about Syracuse, Roches- ter and other localities in that part of the state. Judging from the well known records of its allies, we may expect that the elm leaf beetle will continue to be very destructive. Recent injuries about Albany. The elm leaf beetle was recog- nized in Albany by the late Dr Lintner about 1892, having BLM LEAF BEETLE IN NEW YORK STATE 5 probably made its way here a year or two earlier. Its ravages became more and more serious from that time till 1897, when most of the European elms along our streets were completely defoliated in early summer. The second growth of foliage was seriously injured the same year and some trees had their third set of leaves attacked. It was estimated in 1898 that fully 1000 elms had been killed within the city limits by this perni- cious insect and many more would have suffered a similar fate, had it not been for the systematic spraying undertaken then and since continued. See pl. 3 and 4 for representations of the injury caused by this pest. The record of this insect in Troy has been even worse than in Albany. It probably made its way to that city about the same time that it came here, and up to 1898 practically no effort had been made to check its ravages. At that time probably 1500 elms had been killed within the corporate limits of Troy and since then many others have suffered a similar fate, though not so many have died the last few years on account of the large amount of spraying done in different parts of the city for pri- vate parties. Even now it is possible to go into sections of the city and see within two or three blocks 50 to 100 or more dead elms. These are not aged trees that would have died irrespec- tive of attack by insects, but are in most cases-trees which a few years ago were as thrifty and vigorous as anyone could desire. The story of the city of Watervliet has been virtually that of Troy except that less effort has been made to check the pest; also, as a large proportion of the elms in Watervliet were of the American or white variety on which the beetle does not thrive 80 readily, the destruction was not quite so rapid. It hardly seems possible, however, that fewer than 1500 magnificent trees have been killed or practically ruined by this insect in Water- vliet. A brief note published in December 1900 in one of the Albany papers is of value because it gives the testimony of one who probably had little idea of the true cause of the condition ‘complained of. Under Watervliet items was a short paragraph calling attention to the fact that numerous dead trees were a menace to the safety of pedestrians and stating that they were to be found on almost every block in the city. It might further 6 NEW YORK STATE MUSEUM have very truthfully added that this condition was almost en- tirely due to the destructive work of the elm leaf beetle. Practically the same story has been repeated here and there in small towns along the Hudson river valley where this pest has established itself in force; and, unless the insect is checked on its advent into a village, this is likely to be the record where- ever it makes its way. Inaction means death to the elm. The defoliation of a tree in midsummer is a serious injury since the leaves are breathing organs, and if this occurs for successive years even once a season, the early death of the elm may be expected; when it occurs two or even three times in a summer, it is very easy to see that the danger to the tree is increased manyfold. Such is the record of the elm leaf beetle in this section. The time to control this pest is not after it has become enormously abundant in a city or village and has seriously weakened or nearly destroyed the majority of the elms; the work should be begun at the outset and in the future the insect prevented from establishing itself in large numbers in any uninfested city or village in New York. Village improvement societies and public spirited individuals interested in the welfare of a community where this beetle occurs would do well to undertake at least an educational campaign against it. It is comparatively useless to hope that in the course of a few years the pest may not be so destructive. It shows a remark- able vigor and prolificacy in our climate. At Washington D. C. it has been known for a long series of years and is still very in- jurious. In New Jersey, New York city, New Haven Ct. and other localities it has been found necessary to spray the trees with a poisonous mixture in order to avert serious injury. Parasites, diseases of various kinds and predatory enemies seem to have little effect in reducing its numbers. Distribution. The insect, as stated by Dr Howard, is found over a large part of Europe, but it is abundant and destructive only in the southern portions of Germany and France and in Italy and Austria. The records of the earlier entomologists in- dicate that the beetle must have made its way to this country about 1834, because in 1838 it was reported as very injurious to elms in Baltimore Md. Its southernmost range has been given ELM LEAF BEETLE IN NEW YORK STATE 7 by Dr Howard as Charlotte N. ©., and Prof. Webster records having found it north of Salem Mass. It has made its way as far west as Keutucky, at least. Its progress up the Hudson is interesting to follow, indicating as it does, its distribution along the lines of travel. In 18791! it was abundant and destructive at Newburg, 12 vears later it was reported to this office from Poughkeepsie, in 1890 from Hudson, in 1891 from New Balti- more and in 1892 it had reached Albany and Troy. It was found at Mechanicville in 1896 by Dr Howard and that same year larvae in considerable numbers were discovered by the writer at Averill park in the town of Sandlake about 7 miles southeast of Troy, the beetles evidently having been transported thither by the numerous electric cars running to that place. The writer also located the. pest in 1900 at Hoosick Falls, Rens- selaer co. where it had inflicted considerable injury the preced- ing vear, and he found that it had established itself pretty gen- erally in the towns of Stillwater, Schuylerville, Salem and prob- ably Greenwich. Its presence at Salem and its being found at Saratoga in numbers in 1902 indicate a possibility of still farther progress north, though there were reasons for hoping that it would not be very injurious north of Mechanicville, except possibly in an unusual season. The occurrence of this insect at Oswego, Hastings and Rochester, brought to my notice through Dr Howard, is a much more serious matter. Prof. C.S. Sheldon of the Oswego normal school states that he has examples of it taken at Oswego in 1896, and Prof. M. H. Beckwith of Elmira reports that he has known it to occur for several years in considerable numbers in his locality. It is also extending its range through the Mohawk valley, having recently been found in considerable numbers at Schenectady. These last records are of very great importance since they show that the insect has already established itself in several widely separated localities in the western portion of the state and we have no good reason for thinking that it will not, in the course of a few years, be as injurious in that section as it has already proved in the Hudson valley. 1 Unfortunately most of these dates indicate only the time when the ravages of the insect were serious enough to attract the attention of someone, and so only approximately the year of its arrival. 8 NEW YORK STATE MUSEUM It has spread over a large proportion of Connecticut and into Rhode Island. It had.made its way up the Connecticut river valley to Springfield by 1891 and to Amherst by 1895. It has now attained a rather general distribution over the eastern por- tion of Massachusetts, having been recorded by Mr Kirkland from Worcester and towns in that vicinity, Ayer, Groton and places in the eastern and southeastern part of the state. It has also been found in a number of places in western Massa- chusetts. The above records indicate most clearly that this pest has not made its way to all portions of New York state where it may be expected to thrive. The climate of the upper austral life zone seems to agree with the insect, judging from its abundance and the number of broods in Albany and vicinity. The area within the state embraced by this zone is rather crudely repre- sented on pl. 2, which was first published in the 11th report on the injurious and other insects of the State of New York for the year 1895. Briefly, it embraces Long and Staten islands, the valley of the Hudson river north about to Saratoga and a large portion of the northwestern and central part of the state ad- jacent to Lake Ontario and including Oneida, Cayuga and Seneca lakes and neighboring bodies of water. This insect will probably make its way along the lines of travel to most of the cities and larger villages lying within the above limits. The fact of its having’ become established at localities not yet included within this zone indicates that it may have a somewhat wider range, though climatic conditions will probably prevent its becoming destructive outside this area. Description. The work of this pest is so striking as to excite the attention of even the most casual observer. The majority have little idea of the appearance of the insect in its various stages and but faint conception of its life history. In order to control it, it must be recognized and its nature understood to a certain extent. The parent insect may be recognized by aid of the colored figures (pl. 1, fig. 5, 6) though care should be taken not to con- found it with the striped cucumber beetle Diabrotica vit- tata Fabr., which it resembles in a general manner. The elm leaf beetle is about } inch long with the head, thorax and ELM LEAF BERTLE IN NEW YORK STATH 9 margin of the wing-covers a reddish yellow. The coal-black eyes and the median spot of the same color on the head are prominent. On the thorax there is a median black spot (not infrequently two triangular ones) of somewhat variable shape and size and a pair of lateral ovoid ones. The median black line of the wing-covers is separated from the broad lateral stripes of the same color by a variable greenish yellow. The elytra or wing-covers are minutely and irregularly punctured and bear a fine pubescence and at the base of each elytron there is an elongated black spot in the middle of the greenish yellow stripe. The markings are usually constant in the adult but the color is quite variable during life and changes more or less after death. Some beetles emerging from winter quarters have the con- spicuous greenish yellow stripes of the wing-covers nearly obscured by black. The antennae are a golden yellow with more or less brownish markings. The legs are yellowish with the tibiae and tarsi marked with brown. The under surface of the head and prothorax is yellowish, that of the metathorax and abdomen black. The orange yellow eggs are deposited in irregular rows side by side, forming clusters of from five to 26 or more on the under surface of the leaf. Several of these are shown natural size in fig. 7.. Each egg is somewhat fusiform, attached vertically by its larger end and with the free extremity tapering to a paler, rounded point (pl. 1, fig. 1, la). Under a powerful lens the fine reticulations of the eggshell are easily seen. The recently hatched larva (pl. 1, fig. 2) is about ,5 inch long, with the head, thoracic shield, numerous tubercles, hairs and legs jet black. The integument between the tubercles is a dark yellow. The tubercles are so large and the hairs so prominent that the prevailing color of the larva at this stage is black. As the larva increases in size and molts, the stiff black hairs become less conspicuous and the yellowish markings more prominent (pl. 1, fig. 8) till the last stage. A full grown larva is about 4 inch long, more flattened than in the earlier stages, with a broad yellowish stripe dorsally and a narrower stripe of the same color on each side, the yellow stripes being separated by broad dark bands thickly set with tubercles bearing short, dark colored hairs. The dorsal yellow stripe is broken on each side 10 NEW YORK STATHD MUSEUM by a subdorsal row of dark tubercles, which increase in size posteriorly. The lateral, yellow stripe includes a row of promi- nent tubercles with dark tips bearing short hairs of the same color. The predominating color of the ventral surface is yellow. The pupa (pl. 8 fig. 4) is bright orange yellow, about 4% inch long and with a very convex dorsal surface which bears trans- verse rows of stout, inconspicuous setae. Life history. In order to control this insect successfully it must be known and its habits understood. Trite though the preceding may appear we have observed men in several places spraying for this pest without accomplishing anything for the simple reason that they did not understand the fundamental principles of fighting insects. In one case the trunk of the tree was sprayed while the grubs were on the leaves; in another paris green and water was used when kerosene emulsion or whale oil soap solution should have been employed. The beetles pass the winter in attics, sheds, outhouses and various other sheltered places. With the advent of warm weather in the spring they emerge from their retreats and may be found on the walks during the sunny portion of the day or on the windows of houses, vainly trying to escape. Even as early as May 12, numbers of these beetles were to be seen in 1898 on the office windows of the fourth story of the capitol, showing to what a hight they will fly in seeking secure winter quarters. On the appearance of the leaves, the last of April or the early half of May in the latitude of Albany, they fly into the trees and eat irregular holes in the foliage (pl. 1, fig. 9). After feeding some time, and pairing, the orange yellow eggs are deposited on the under surface of the leaves in clusters of about five to 26. The period of oviposition of the overwintered beetles extends from the latter part of May throughout the greater part of June in the vicinity of Albany. The duration of the egg stage in July averages about five days; in cooler weather it may be longer. Feeding and oviposition continue for several weeks in the spring, probably four to six. During this time the beetles consume a large amount of foliage, which is evidently necessary for the development of the eggs, as clusters are laid every day or two till the full complement, which is in the neighborhood of from 481 to 623, is discharged. ELM LEAF BEETLE IN NEW YORK STATE 11 As there seems to have been no attempt, at least in this country, to determine the prolificacy of this insect, the following ‘may be of interest. May 31, 1898, two heavy gravid females ‘were isolated, provided with plenty of food, and the eggs removed and counted nearly every day. The results are tabu- lated below. Record of eggs deposited by two elm leaf beetles! FEMALE IN VIAL DATE CLUSTERS OF TOTAL ASUDE © i sce Sea des series Baa es (2) 29 Deccduibidstnaecenduncataiecaiaaann) Yee 36.65 Value of plants ge 9g ab Aber 107.43 Total cost for twelve acres a $156.98 Notice two things! A. Close planting yields timber free from knots. B. A carpet of dead needles densely covers the surface of the soil, thus quieting it. I like this plantation; but one fool, with one match, may destroy it in one hour. In 1899, the slopes now covered by the White Pine looked like the accompanying picture taken on this very spot. 4 THE BILTMORE FOREST FAIR . The plantation marked No. 2, on “Long Tip No. 2 Ridge,’ covers forty-five acres of steep slopes which were cleared some sixty years ago; abandoned for farming some thirty years ago; covered in 1895 with sedge grass, and cut by deeply eroded gullies on the side facing the East. In 1895, Mr. Vanderbilt desired the entire hill to be planted in hardwoods. It was my wish to show him (and to all Amer- ica) that forest planting could be done by a good forester (e. g. by myself) at an expense of $5.00 per acre. ~~" ~In the Winter of 1895 and 1896, six bushels of Chestnuts, two bushels of Shag Bark Hickory, and two bushels of Pig-nut Hick- ory were planted on the slope facing the East, between the creek and the road; the plantation, covering an area of 114 acres, was made at an expense of $10.36. THE BILTMORE FOREST FAIR 5 In the Spring of 1896 I had planted A. On the slope facing North 2,000 yearlings of Chestnut Oaks, 2,000 yearlings of Ailanthus, 5,000 two-year old Cherries, (Black), - 2,000 yearlings of Hickory. B. On the slope facing West (in a hollow where the sedge glass was particularly heavy) 4,825 four-year old Douglas Firs, (Glauca) 4,800 three-year old Sugar Maples, 1,600 three-year old White Walnuts, 1,400 three-year old Black Walnuts, 3,100 two-year old Black Cherries, 2,000 one-year old White Oaks. The Douglas Firs are illustrated by the picture following next; but you had better see them on the spot. The expense of these plantings was: For plants... ee wee we = $89.69 For work vn a) ee, “See cad Oe ee 151.37 Total ge eee ewe we = 241.06 6 THE BILTMORE FOREST FAIR This picture of the Douglas Fir is poor; the plantation is not much better; so far, it exists; it does not thrive. It may (I suppose it will) disappoint the pessimists in the future. The reward for hard work is more hard work. The Sugar Maples are bully. Look at the soil, and see it covered with a dense layer of humus! Look at the tops of the saplings, and see the height growth proportioned to the position of the individual stem in the bottom of the hollow here, and at the edge of the hollow yonder! The Black Cherries have done poorly; I have “doctored” them by Pitch Pines in the East, anno 1900; by White Pines in the West, anno 1908. In the Fall of 1897 I had planted: 48 Bushels of White Oak acorns, 34 Bushels of Chestnut Oak acorns, 8 Bushels of Walnut nuts, 1 Bushel of Hickory nuts. This part of the plantation covers an area of fourteen acres on the Eastern aspect of Long Ridge. The expense was: For seeds is we ww oe we oe «©66871.88 For plowing oh RE WS Gey eee 8.82 For planting... ww. 89.60 Totalexpense .. .. .. . « « $120.30 ‘I also had “fixed,” at that time, the erosion in the gullies. When you see these plantations you will be amazed; I am not going to tell you the reasons for your amazement, unless you come to see the plantation. There can be no denying of the fact that, even today, miracles do happen. If men should hold their peace, the trees would cry aloud: “Honor and thanks to you, George W. Vanderbilt!” THE BILTMORE FOREST FAIR 7 In the Spring of 1899, I tackled 1314 acres of steep land forming the Northwest aspect of the Long Ridge. The little plants were planted with cleft spades; the clefts were made onto reversed sods, where the turf of sedge grass was particularly dense. 6,000 specimens per acre were planted as follows: 21,500 One-year old White Oaks, 16,000 One-year old Chestnut Oaks, 25,000 One-year old Red Oaks, 9,500 One-year old White Ash, 500 One-year old Buckeye, 7,300 One and Two-year old Black Walnuts, 800 One and Two-year old Hickories, The entire expense was: For plants... ee ee = $68.77 For planting «ow 8 = (98,07 Totalexpense .. .. . « « « $156.84 In magnis et voluisse sat est. In the Fall of 1899, the success of the plantations of seeds and seedlings of hardwood on Long Ridge seemed doubtful; I got scared for my reputation; I then abandoned the idea of plant- ing “as cheaply as possible.” The result was an additional planting, in the Spring of 1900, all over the forty-five acres composing the Long Ridge as follows: 60,000 Two-year old White Pines, 2,000 Six-year old Soft Yellow Pines, 10,000 Four-year old “ponderosa” and “devaricata,” 3,600 Two- and Three-year old Picea pungens and Pi- nus cembra and devaricata; Abies concolor, bal- samea and nordmanniana; Larix leptolepis and sibirica, 3,000 Four-year old White Oaks. 8 THE BILTMORE FOREST FAIR The total expense was: For plants .. « + « « «© + $333.00 For planting .. «+ 4 © :134.10 Totalexpense . « « «+ «©—$467.10 The 3,000 White Oaks just mentioned were planted on five acres of land (on the West slope) only then abandoned by the farmer, in rows alternating with rows of White Pines. From 1900 on, the plantation did finely; the next picture shows a corner thereof; you should see all of it, William; and you should get the ole man’s explanations on the spot. THE BILTMORE FOREST FAIR 9 If you are interested in erosion, the best lesson near Long Ridge appears on the spot above the old “‘Cocke’’ house, near Compartment 95. It used to be a nasty spot, and a scar in the landscape. It is now a pine wood obtained, in the Spring of 1900, by the planting of 10,000 ball plants of six-year old Yellow Pines, at an expense of $89.00. My platform: ‘My fatherLAND!” . . . . Underscore the “LAND,” William! And its every square foot shall blossom. Amen! This history of “Long Ridge” is getting dull, it was also dull to me when it was a reproach to me . . . in days past, Suffice it to say that I had the plantations reinforced, in the Spring of 1901 with Locusts (stump plants) one year old, and with a few Yellow and White Pines, at an expense of $65.00; in the Spring of 1902 with 4,000 Yellow Poplars two years old; in the Spring of 1903 with ball plants of White and Yellow Pines . at an expense of $113.48. That is all! Nowadays it is a joy for me to crawl through this plantation! I feel like the Lord on the Seventh day of the creation when I am crawling. The man who looks for a reward does not deserve any. . Here, William, I shall show you a “thin- Tip No - 3 ning” in progress. It is made,—First for the benefit of the Pines, and Second for the benefit of our exchequer, the former profitting more than the latter. In the Summer of 1908, the insects have killed quite a bunch of the Pines. They have been removed—I mean the Pines. I could not catch the insects; I wished I could! The thinning yields some two cords of fuelwood to the acre. In this particular place close to town, a cord nets $1.20 above expenses. é eS 12 THE BILTMORE FOREST FAIR I tell you, William, what is so: “Money kept in timber is safer than money kept in the safe.” . . . . Stop the fire, William! . Now we traverse some irregular hardwoods where I have been acting as undertaker, “burying the dead,” or rather seeing to it that the “dead were cremated,’’—as firewood in Asheville. i. To the right, in 1895, there was a hopeless Tip No. 6 growth of brush; and I have shown it, ten years ago, to this and that visitor as an illustration of the effect of reckless cutting. A fire ran over this lot, in 1894. Today I have marked in it the best saplings by colored labels. There are. lots of them! This second growth obtained free of charge is as good as the best that I might plant. Leave nature alone,—or help nature! Give it increased chances! Do not hitch it up, using narrow-mindedness for the harness! William, I tell you! Skip the lectures on sylviculture and learn from nature! All men great and good, have changed their minds from time to time; Washington did when he ceased to drink the health of the King; Luther did when he mar- ried a run-a-way nun; and William J. Bryan, too, has changed his mind from time to time,—indeed, quite frequently. Now then: Why should not I have a metabolic conviction when so many better men were kaleido- scopic? William! You, too, will be a better man .. . when you change your mind. THE BILTMORE FOREST FAIR 13 ve We are now on the “Ridge road.” Tip No ‘ Where the sign No. 7 stands, I have made a “Borggreve” thinning in 1906, cutting 14 cords of “wolf trees” per acre. This lot looks somewhat dishevelled; it will look fine in 1915. s Here, anno 1895, the bark beetles had Tip No . § killed the Yellow Pines forming the main part of the stand. See how the hardwoods have taken advantage of the death of their former suppressors! Having a fine system of transportation, the value of trees killed by calamities can be saved by me. Forestry is paraphrased neither by the anastrophe: —Saw “Nothing”; and say “Wood !""— _nor by the proverb: Say “Nothing”; arid saw “Wood”. 14 THE BILTMORE FOREST FAIR This illustration shows the work of forest fires; a big Chest- nut is “split open” and “hollowed out.” The dead log, in front of the Chestnut, has added to the trouble by feeding the flames. A tape four foot long hangs in the blackened hole. The picture is taken in my “virgin forests;’ . . . only one tree in a hundred, in the Appalachians, has not suffered from fires. The debris on the ground is a curse to the trees of the moun- tains by feeding) fires; and a blessing to the waters of the moun- THE BILTMORE FOREST FAIR 15 tains by preventing erosion, by hording the moisture in wet weather, and by forcing the rain to enter into the subsoil. The trees whilst living are the greatest consumers of water on earth; the trees, when dead on the ground, are the greatest water preservers. Stop the fire, William! Tj N Notice, please, that the Pines prevail, gen- Ip 0. Gg . erally, on the. ridge which we _ traverse.. 0 The Oaks form, usually, an admixture _.merely to the Pines, keeping the Pines free from limbs and shading the soil, to mutual advantage. In this proximity, I have made, between the years 1895 and 1907, a number of improvement cuttiags, removing the fellows which were ‘“‘no good,” and giving the promising boys more air to breathe, more soil to suck, and more light to enjoy. The forest is a boarding house; whea some of the boarders are gone, those remaining obtain more food to eat. On the average acre along this road, I have removed four cords of wood in the course of twelve years. All of the trees removed were decayed, crooked, big-crowned, fire-scarred. Notice, please, that there is left a huge number of poor, ragged, measly, mis-shaped, dwarfy saplings. I have left them on purpose. These dwarfs are the servants of the healthy, promising poles; they prevent the moisture of the soil from evaporating; they furnish humus during their life as well as after their death. It does not pay to remove these dwarfs; it does pay to re- tain them. The future on this ridge belongs to the Pines,—not to the Oaks. Prior to 1895, this ridge was burned over continuously; after burning, it was used for the pasture of cattle. The good Pines were used for lumber; the best of the hardwoods for firewood. In days to come I shall treat this ridge as a “composite for- est,” with the Pines standing in the upper story and the hard- woods in the lower story. _ Later on I. shail fell you - -more “about ai at Pe a 16 THE BILTMORE FOREST FAIR By the way: All over the Estate the rule holds good that A. Stumps over six inches high are the stumps of fine trees removed prior to the establishment of the Estate; B. Stumps under six inches high are the indications of cuttings, under the regulations of forestry, since the establishment of the Estate. The man in overalls should Jord it over -all. Yours truly, GOMPERS. Under the conditions here and elsewhere prevailing it is necessary to individualize . . . . it est, wholesale methods of sylviculture won’t do. Therein lies one of the difficulties confronting the forester and forestry in America: In Germany, timber is high-priced, and homogenous woods prevail; they can be treated methodically after a general plan. In America, timber is low-priced, and heterogenous woods form the rule; and each separate bunch or group of trees re- quires a separate and distinctive treatment sylviculturally; which requirement cannot be fulfilled, by forestry as a business. Giving my directions quickly—which I do—and controlling the execution of my orders insufficiently—which I do—many a mistake is made by me or permitted by me. Do not blame me, William! That I prefer to do myself. The Biltmore Forest, in this proximity, yields an annual surplus revenue of 22 cents per acre. The taxes are 17 cents per acre, and must be deducted from the above “surplus.’”’ My own salary, also, is not covered by the above “surplus.” That is a poor showing,—unless the forest increases in value, per acre and year, latently. It does increase latently. 0 John D. R,, dear Jobn D. R.! : Come with a trust or two; and save the woods! THE BILTMORE FOREST FAIR 17 2 This plantation consists, practically, of Tip No . 10 White Pines only; they were planted, at the rate of 4,000 per acre, in the Spring of 1900, on a strip of fairly good farmland covering 22 acres. The White Pines were two years old and the Yellow Pines, as many as there are, were one year old. The seedlings were planted two and a half feet apart, in rows four and a half feet apart. The expense was: For plants... ww we © $832.00 For planting 2. we) 180.79 $512.79 In the planting expense are included two items spent (—that is my present opinion—) unnecessarily, to-wit: I have spent $51.16 putting a few handfuls of forest soil into each planting..hole;.. i I have spent’ $17:00 ‘putting: a stone | ‘over’ “each hole when the act! 6f planting was finished) 2 2.2 2d. poke se I shall give you the whys on the-spot. - . Right here,..we shall have a Mille ea yatill, in 30. years: or so; and we shall get rich quick, then. And the scene will look like this picture: eae 18 THE BILTMORE FOREST FAIR s The plantations of White Pine now tra- Tip No . 11 versed are twenty years old. Aesthetically, they are a success; I object to them com- mercially on the ground A. That the growing space of the individual specimen has been, and still is, too large; B. That early returns cannot be obtained by way of thin- nings. See, however, the fine layer of dead needles carpetting the soil! See the fine shoots made by the tops of the trees! The expense account of these plantations is unknown. They were made, under contract, in 1890 by a northern firm of nur- serymen. There are several hundred acres of this type of White Pine forests on the estate. A DECLARATION OF FAITH. I believe in the immortality of all that is good; and—thank God!— I believe in the mortality of all thatis bad. Amen. 7 Along the macadamized roads, the land- Tip No. 1 2 scape department of the Estate rules su- preme. Thus, for two miles of road, you may enjoy the landscapes, the sweeping views over the moun- tains, and you may take a nap, also, preparatory for a walk of one mile beginning at station No. 13. = Another White Pine plantation twenty Tip No. 13 years old, with a few Hemlocks, Douglas Firs (poor) and Black Cherries. The soil is covered with humus. If this plantation were denser I would like it better. By this time, you long to see some fine Chestnut trees, or Poplars, or White Oaks. THE BILTMORE FOREST FAIR ‘19 There are none left, near Biltmore; they were removed before you were born; I can show you the stumps on- ly of big trees along our route; and I show you, in this booklet, some trees standing in my for- ests some fifteen miles from here. We shall actually see them on Satur- day next; here is one of the finest; and a fine girl, standing at its base on-a log, holds her hat on a stick, so as to give you a chance to measure the size of the tree. - The illustration shows a_ typical scene in the woods. The tall tree is a “Yellow Poplar,” worth $120.00, when converted into lum- ber. I shall cut it and saw it up within less than five years. If you want it saved I shall save it upon receipt from you of $120. yp? “Special privileges to nobody Thus cried the mob. And there upon the truth, too, was forbidden to go naked. 20 THE BILTMORE FOREST FAIR 7 This grove is produced by nature alone, Tip No is 14 absolutely without help, on an abandoned field. It is Yellow Pine, some twenty-five to thirty-five years old. Within twenty years, we shall obtain, by way of thinning, as much money from it as we have paid for the land, originally. A slope of this character should not be cleared and used— as this one was—agriculturally. Look at these frightful gullies! Erosion was rank, in this lot, prior to the time at which the slope was left alone,—left unburned, unpastured, unused! We want conservatism, and we want conservation! Washington, November 26, 1908. Dear Conservation: Conservation, dear Conservation! How I would love to serve you! You are right, good, noble,—no- body denies it. But helas! Your service is perfect self restraint, — yea, it is, self denial! I am 60 sorry! Yours sisterly, AMERICAN LIBERTY. . We enter a plantation (Browntown plant- Tip No - 15 ation) which forms an everlasting monu- " ment for two good men; for Cyrus T. Rankin and for Ernest Allen who have worked with us, in rain and shine, for twelve long years. They are responsible for the success of the plantation at Browntown. ; The land in question, some sixty acres, is poor in the ex- treme; it was burned and pastured and cropped till the occupants had either to sell or to starve. They sold, of course. THE BILTMORE FOREST FAIR 21 The Browntown lands were planted in Spring 1905, at the following expense for work per acre (average): Lifting plants in nursery Hauling plants to plantation Healing in = Demarkation of rows Making holes and planting Total In order to stop erosion we have spent, altogether, $66.98 prior to planting. The entire area is subdivided into lots numbered A, B, C, etc., as shown in table on the page following. 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[POS SSae esses Tere | ae aaa See = O00-F q ysy ev ee 9 000‘ T - Jequinong || 000% T Array) |) 00'S z snqoijs ‘qd 4 alee = SRSSEASSs: oos TL jetdem wodeig || 000‘T T Ysy wose19 T a Soo 7} tT 77 YT oats T 90x} dyn |) 000°% z snqous‘d| 6" q ens 7p morerme> | 90% T aerL TNL || OOF'T z sngos‘d| 8" 3 000‘ T ArzeqQ || 000'9T | T | ede zedng |; 000‘8 3S snqoijs *q gg a aia - fo cmoremm--" |) Qgo'et | oF snqozjs ‘d || 000'0S | & ByeUIYyIE “ 8'0T Vv ‘ON | HOV aNIx ‘ON | a9V aNIXa ‘ON | aOV ania Sauov | LOT THE BILTMORE FOREST FAIR 23 Lot D was omitted. This plantation must be seen. It is excellent. The Ash was clipped back, after planting. The Oregonians have vanished. The Yellow Pines (trans- planted in my nurseries when one year old) were handicapped by a severe frost in September, 1906. The cost of the plants (to us) is: Echinata $1.00 per M (transplants) Strobus 1.50 per M (average) Hardwoods 40 per M (seedlings) In 1912, the Sugar Maples will look like the next illustration. I'll show them to you alive, in 1912! 26 THE BILTMORE FOREST FAIR - In compartment 40 and 42, there is the Tip No. 22 finest second growth of Yellow Pine, I have ever seen, produced free of charge, from self sown seed. I confess that I would prefer a better admix- ture of hardwoods to the pure stand of Pine.. The superstructure of older trees (Oaks, notably) was removed by me in the year 1897-8. The cut was 38.4 cords per acre. Cyrus T. Rankin did the work; and he did it finely! Believe it if you will: In 1880, these woodlands were so bare from undergrowth (being burned annually) “that a fellow could see his milk cow pasturing in the woods at a distance of half a mile.” The old Pines were cut and milled in or about the year 1885; they must have been cut in a seed year; and by good luck, and owing to a change of ownership, there has not been any fire since. A soft snap is hard to chew. s This field was used, agriculturally, up to Tip No. 23 the year 1894. In the Winter of the year 1895-1896, I had planted altogether in its Western section, at an expense of $43.34,— 4 bushels Red Oaks, 4 bushels White Oaks, 10 bushels Chestnut Oaks, 4 bushels Black Walnuts, 5 bushels White Walnuts, 8 bushels Chestnuts. In March, 1897, I had planted in the middle section, near the old cabin, in rows three feet apart 5.8 bushels Red Oak, 4.5 bushels White Oak. At that time, there was not a Pine visible in the sedge grass covering the field! How is this now? THE BILTMORE FOREST FAIR 27 Things sweet to taste prove in digestion sour. Ti N 2 We are traversing several compartments Ip 0 _ 4 lined along the Cherokee road. These compartments have furnished the follow- ing returns, by way of improvement cuttings: COMPARTMENT ACREAGE YIELD IN NO. IN ACRES CORDS 39 37 190 41 42 701 45 33 282 The present plan of action is: Hands off! In 1920, or thereabouts, we can begin to treat these com- partments methodically as “coppice under standards.” In the meanwhile, the fertility of the soil which was badly checked by fires in the past, will have had a chance to return. = Here you will be given a chance to plant, Tip No i 25 with your own aristocratic and bejewelled hands, a White Pine seedling! You will see the boys doing the stunt, too, at the rate of 1,200 plants per man and day. Learning from us how to plant, you can begin to teach others at home. We are planting White Pines, four seasons old, transplanted in Spring 1906. The stock is fine; the roots are many-fibrous; the buds are six to ten in a bunch. We are reforesting a field which nature is slow to reforest, for reasons to be explained on the spot. Since the taxes are 15 cents per acre, it is well worth while to raise something on this barren land which will, in time, defray the taxes. For every two acres reforested, we may increase the annual cut by one cord, without depleting the principal investment of wood. There is no truth but one: “There is none.” 28 THE BILTMORE FOREST FAIR . The slope to the right was poorly stocked, Tip No. 26 with hardwoods, in 1900. I had it “un- derplanted,”’ by Ulysses Reeves, with a few thousand White Pines, Mr. Reeves selecting the spots where there was the least superstructure overhead. In 1902, we found the White Pines suffering from shade; we made an improvement cutting, for the benefit of the White Pines, cutting heavily in the southern part of the lot, on the top of the spur. In 1906, I made a clean sweep of the “superstructure,” so as to save the White Pines, and so as to simultaneously encourage the natural regeneration of Yellow Poplar. The slope exhibits, today, a vigorous sprout growth of hard- woods acting asa ‘‘companion” for the White Pines and Poplars. Give me, O God, plenty of struggle, strife and strain; and Give me, O God, plenty of strength to withstandthem! . An abandoned field densely restocked, Tip No é 21 alone by nature, absolutely without human aid. The Pines are some twenty-eight years old, and the stand comprises some 6,000 specimens per acre. No forester can do better than nature does, when she is allowed to act at will. . A plantation (twelve acres) of Black Wal- Tip No. 28 nut obtained from nuts planted, in Fall 1897, into furrows ploughed 314 feet apart. The expense incurred was as follows: 62 bushels of Walnuts .. . .. .. $33.00 Ploughing furrows .. . . « « « 3.00 Planting nuts «ow 6 we we oe) «18.85 Total (ai we Gey Ga ae ae Gas eer SBDABS, The plantation has succeeded finely on the good soil, along the edge of the bottom, below the “Hillside road.” Above the road, the trees have suffered from the arenas of the sedge THE BILTMORE FOREST FAIR 29 grass; and have been frequently clipped by the fall frosts;—and many of them would not be visible to you today, were they not labelled by red labels. In order to help the Walnuts where the struggle was too hard for them, the plantation was “doctored” by me in the Spring of 1900, with one year old seedlings of Pinus rigida. The latter have developed wonderfully. I am confident that I can save the Walnuts by the Pines,—in time. The “doctor bill”? amounts to the following: 4,000 pine yearlings .. .. .. . « $4.00 Hauling and miscellaneous .. .. .. .. .30 Planting pines Ge Yes! we ia es 7.50 Total .. 0. oe ce te te we we we | 11.80 Particularly interesting is the absolute failure of this plan- tation beneath an old Walnut tree standing in its midst. Don’t dodge the issue! s The Pines at No. 29 have established them- Tip No is 29 selves, on an abandoned field, free of charge. Three species of Pines (Echinata, Rigida and Virginiana) have united their efforts to stop erosion. I draw your attention to the gullies in the hillside which have been quieted down by nature left alone. Obviously, the present stand of Pines is branchy; and it commands little, if any value. We can use it, however, for the end of securing a valuable new growth by successive cuttings, properly timed. At an American flag, the barkbeetles have killed a bunch of Pines in 1903. 7 An even aged stand of Oaks, Chestnuts Tip No - 30 and Hickories, some forty years old, from re ee which an improvement cutting has re- moved, in 1898, eight cords of wood per acre. ae Here, in or about 1918, a thinning will be made, yielding three cords of wood to the acre, approximately. The growth of 30 THE BILTMORE FOREST FAIR the hardwoods is slow, and logs ‘fit for lumber cannot be obtained, in this compartment, be- fore the end of the present century. The White Oak which I embrace is 350 years old. See? Tip No. 31 This proximity has been miscut, at the time of an improve-.. ment cutting of 12. cords per acre, the ranger in charge fail- ing to watch the con- tractor. Fine trees were removed, and poor trees were left. I have tried to make up for the failure by planting, on both sides of the road, in 1900, a few thousand seedlings of White Pine, one year old. These seedlings have been smothered by leaves falling on them, and by shade to an interesting degree. Here, the influence of light on the development of White pine seedlings is very marked. An improvement cutting for the bene- fit of White Pine as well as Yellow Pine might seem advisable— to others; not to me. Greater men than I have planned ahead and built ahead for centuries. Pardon me, William, when I have the cheek to meddle with the decades! THE BILTMORE FOREST FAIR 31 . Below the road at sign No. 32, western Tip No. 32 Douglas Fir (red labels) was planted in 1897, also Colorado Blue Spruce (blue labels), European Spruce (yellow labels), Silver Fir (white labels). Watch the superiority of the White Pine over the foreigners of the same age! Above the road, there is an extensive plantation of rather unusual development, made on a poor, stony, barren field aban- doned by the farmer when it was covered with sedge grass. “We planted as follows: A. In Fall 1896: 43 bushels White Oak acorns 10 bushels Chestnut Oak acorns 4 bushels Buckeye ¥% bushel Chestnuts 16 bushels Hickory nuts. The expense of this stunt was forseeds .. 0. 0. 0) ee ee ee ee «= 62.17 for ploughing . «6 0 oe oe «17.05 for planting 6 32.05 Total .. «ce ae Ge ae ae we oe SULLOT B. In Spring 1897: 22,500 Black Locusts, 1yearold, worth $36.00 3,500 Black Cherries, 2 “ “ e 6.00 2,000 Black Cherries, 3 “ “ nS 8.02 2,000 Basswood as fe 10.00 2,500 Sugar Maple 5“ " 9.25 2,000 Black Walnuts 2 “ “ fe 6.50 6,000 Hickory (ovata) 2 “ “ as 20.10 2,000 Hickory (alba) 2 “ “ a 2.20 1,000 White Pines’ 2 se o 35 1,000 Buckeye a ee 3.55 The expense of ploughing the furrows into which the seed- lings were placed was $30.90; the expense of planting the seed- lings $52.90; and the expense of hauling, etc., was $36.57. 32 THE BILTMORE FOREST FAIR The plantations under “A” were made in furrows alter- nating with those given under “B.” At the same time, 5,000 White Pines, all two years old, were planted on a sample plot in the midst of the plantation,—the first plantation of seedlings two years old on American soil—at a total expense of $30.75. In another sample plot (14 acre), there were planted 3,000 Locusts and Cherries,,1 and 2 years old, worth $6.22, and 2,500 White Pines, 2 years old, worth $15.00, at an outlay for work of $12.05. In another plot, two year old White Pines raised at Bilt- more were planted so as to alternate with four year old White Pines bought in Germany. The results have been strikingly interesting; success has been mixed with failure; you will see it on the spot. C. In Spring 1900: 24,000 White Pines 2 years old, worth $96.00 24,000 Rigida Pines1 year old, ‘“ 48.00 The cost of planting was (for work, etc.) $74.15. This reinforcement (under “C’’) was necessary, indeed! The hardwood plantations had suffered frightfully from ground mice; the rodents had mowed down, underground, one row after the other row of Hickories and of White Oaks, before and after sprouting. During the years following, the surviving Oaks had to suffer severely from the rabbits which, today indeed, do not allow the young Oaks to develop. The Locusts, also, did poorly . . . . excepting on good soil, e. g. on an old garden spot in the plantation. The Sugar Maple which, at one time, was badly attacked by fungus disease, kas done remarkably well; it kills the White Pine on the best soil, and it sutserves it on the poorest soil, keeping it free from limbs. On the whole, this plantation is wonderful, now! Yellow Peplar is seeding into it spontaneously. THE BILTMORE FOREST FAIR 33 To facilitate the identification of the hardwoods—which are not conspicuous in Winter—we have attached labels to them: White label means White Oak, Yellow label means Hickory, Red label means Cherry, Green label means Walnut, Blue label means Locust. The Oaks have done best at the edge of the plantation, ad- joining the high woodlands. Here, the sedge grass is kept in check; and the soil kept covered with leaves. After another 200 years the Oaks may be “snaked” out by six yoke of cattle,—after the fashion illustrated herewith: 36 THE BILTMORE FOREST FAIR . An abandoned field sparsely seeded by na- Tip No ‘ 35 ture in Pine. The present stand is worth- less; it will have value, in days to come, by reseeding the ground densely. Deny it if you can! The forests: managed by a trust (a good trust) would never be depleted; and there would be forestry. I trust in trusts; in good trusts; and mark my words: You shall share my creed, hereafter. . The form of forest which should prevail Tip No é 36 on the more sterile parts of the Biltmore Estate is that known as “coppice under standards.” The Yellow Pines have proven, in the primeval times of this locality, their fitness for the roll of “standards.” The average volume of timber per acre available on the Estate is in keeping with the form in question. The form yields fre- quent, early, regular returns,—hence my predilection for it, under many conditions. Please mark the following, William! A. We have cut in this lot, anno 1904-5, thirty cords of hardwood per acre at a net profit of $42.00 per acre. B. We shall do tetter anno 1934-5, cutting the hardwood every thirty years. C. The Pines, in the meantine, have a fine chance to rapidly grow in thickaess; and I shall prove to you on the spot that they are now growing at a high rate of interest. D. The soil is covered with debris, and seedlings of Pine are developing freely everywhere. E. We have four size classes of Yellow Pine, namely— Seedlings, Saplings, Poles, Trees (too few of the latter). THE BILTMORE FOREST FAIR 37 I am introducing this form of forest gradually on 5,000 acres (approximated) of Biltmore woodlands. Its first stage is illustrated herewith; the sprout growth has been coppiced; and the “standards” are left. Join the garde, Guillaume! La garde meurt; mais ne se rends pas. 38 THE BILTMORE FOREST FAIR . The woodlands in this proximity were par Tip No. 3] ticularly poor. The soil is dry; and it had suffered badly, particularly, from fires prior to 1888. After improvement cuttings in 1900, yielding 17 cords per acre, I have spent a few dozen dollars for reinforcing in Yellow Pine. i At the American Flag, a “fail place,” barren and bare in 1898, is now fully restored to productiveness by planting. Opposite this fail spot, to the right, there is a fine pole wood getting ready for a first “thinning.” = We drive over a plantation of White Pines Tip No. 38 (white labels) and Western Yellow Pines (red labels) (ponderosa), made on an aban- doned field in Spring 1806. Both Pines were two years old when planted, the Western Pine, at that time, three times as large as the White Pine. There is a sprinkling of “advance growth,” all over this field showing nature’s tendency to reconquer the old field. This advance growth, if left alone, develops as seen in TIP NO. 35. ‘ This small plantation (four acres) costs us for 5,200 White Pines, 2 years old ( ; 3,500 Ponderosa, 2“ “ j together .. $24.10 hauling and demarkation .. .. ww. 4. + 3.66 planting itself .. .. . .. woe ow) «611.65 weeding and hosing i in Sumner 1906 we we oe 8,08 $42.49 Why do you dream, O Thomas Alva, of a meang for the storage of solar energy? Your dream has been reality,—ever since the fourth day of creation. The trees in your yard swallow solar energy; digest solar energy; and they store it away for you; and your “storage battery” is battered to frazzles by your trees. THE BILTMORE FOREST FAIR 39 I hope my plantation will not meet the fate of the White Ash, shown herewith, —the fate of the majority of the trees in the Appalach- ians! The fires have bursted it, from root to crown; and it is as hollow as a gun. Tip No. 39 This lot has not been touched by my axe; so far it does not need any help; here and there, I might remove, by way of improvement cutting, a decrepit “torso-tree,” so as to convert it into money. Otherwise, I have to wait for the trees to develop. Their growth is slow; it aver- ages, for the diameter of the trees, one inch in ten years, approximately; and for the whole stand, seven cords per acre in ten years. Be good, William, and be patient. ; The forest, near No. 40, will be cleared Tip No. AQ away this coming Winter and will be con- verted into farmland. Mind you: For- estry is business; forest destruction is quite frequently the best business; and destructive forestry is quite frequently the best forestry. 40 THE BILTMORE FOREST FAIR . An abandoned field reforested by nature in Tip No és A Pinus virginiana! Do you see the signs of erosion? Can you distinguish the deep gullies now hiding beneath the Pines? The Pines average twenty- five years in age. It is wise to be good when you must; It is good to be good when you mustn’t, = Here, the Pines average ten years in age. Tip No. 4 The stage of the woods at No. 41 is fifteen years ahead of that at No. 42. All of this growth is spontaneous. a We pass at the edge of two plantations Tip No. 43 covering forty-one acres made in Spring 1907 (known as the “lone chimney plan- tation”) and in Spring 1806 (known as the “old school plan- tation’’). The soil, where we enter the plantations, is extremely sterile. Here we find alternating rows of Pinus echinata (yellow labels) planted with a dibble in Spring 1907 (as yearlings) and of White Pines (white labels) planted (as two year olds) with a spade. A layman would not be able to see my “plantation,’’—un- less I pushed his nose on the plants; five years from now it will be denser than the plantation at TIP NO. 32,—if St. Hubert keeps the fire out of the plantation. Nothing can hinder the growth of the trees,—except fire. There were planted, per acre. 2,000 Yellow Pines, one year old, worth .. $1.10 1,500 White Pines, two years old, worth .. 2.25 at an expense (for work) of $2.95 per acre. The plantation was particularly cheap, the loose soil being worked easily and the plants being small. Blessed are they which receive hard knocks! THE BILTMORE FOREST FAIR 41 s White Pine three years old and Sugar Maple Ip 0. three years old planted in Spring 1906, on good but steep soil. There are planted, per acre: 2,200 White Pines, worth .. .. .. .. $11.00 800 Sugar Maples, worth .. .. .. .. .80 at an expense for workof .. .. .. . 10.10 Total, peracre .. «. «4 oe © $21.90 Listen, John! This plantation is three times as expensive as the preceding one, for the reason that the plants used were three times as large in size when planted; and for other reasons to be explained on the spot. The Sugar Maples suffer from the rabbits until they are beyond the rabbits’ reach. This then is the stuff filling the “pots of oil” of widows and others; and the more you give away of it, the more do you retain of it: The stuff is love. And now we must quit; we have not seen more than the fiftieth part of the woods and of the plantations on the Home Estate. My lords and gentlemen: The barbecue is ready! At a meeting of the Sciences, “Forestry” was heard to say: “I have my fill of foresters; I need some Rockefellers, now.” Whereupon, there was a holobolloo . . - And “Economics” and “Politics,” with an oath or two, jumped to their feet; and the Lady of the Woods was laid low. And “Law” laughed. 44 THE BILTMORE FOREST FAIR I shall show you the records; and I shall show you the re- cords of other streams nearby, too; and I shall-contrast the dis- charge of streams draining Vanderbilt’s forests with the discharge of the others. The contrast is not so startling as you might assume. The fluctuations in the discharge of the Vanderbilt streams are less wild than those of the others. The extremes of discharge are further apart in the case of the others than in the case of the protected streams. ASSOCIATED PRESS NEWS: At a meeting of the Irish League, at Odd Fellows Hall, New York, the following resolution—(moved by Patrick O’Leary)—was passed unanimously: . . . “That William Waldorf Astor—the renegade—should be banished to Ireland, for his life time.” . Some few months ago, old Davidson River Tip No. 48 has tried to change its course. I have forced it,.I hope, by the measures taken at sign No. 48, to stick to the old course. , The bottomlands in this vicinity were cropped to death, prior to their acquisition by the Biltmore Estate. Used as pasture, a fair revenue is obtained from them. Reforestation, in this case, would be folly. Farm lots form an integral part of systematic forestry ;— just as wood lots form an integral part of systematic agriculture. a Mark the difference between the slopes to Tip No. 49 the right and.the slopes to the left of the river! On the slopes facing South, the Pines prevail. These Pines are worthless, so far. On the slopes facing North, the Oaks and Chestnuts pre- ponderate. The slopes were opened up by roads; the finest trees THE BILTMORE FOREST FAIR 46 were logged for export; the Chestnuts were cut into tannic acid wood; the Chestnutoaks were stripped of their bark. The scene illustrated herewith shows a Vandal engaged in Vandalism : Nevertheless, the stands continue to appear dease. Wherever we have cut, spontaneous regeneration of the woods begins immediately. The regeneration is best, usually, where the “destruction” was the. worst. The taxes on cutover woodlands are, in this valley, four cents per acre... 46 THE BILTMORE FOREST FAIR The citizens of the county do not realize—do not want to realize—that my work is meant for their benefit as well as for that of my employer. We have never found any encouragement whatsoever in our work on the side of the state, the county, or the town. We ar2 aliens; we do things out of the ordinary; that is cause enough for suspicion,—for antagonism and enmity. A yearning for love is a poor means to get it. We have never succeeded, so far, to stop trespass and fire in Pisgah Forest by the help of the usual “channels.” The natives cannot forget that these woods were theirs, for all. intents and purposes, prior to 1890; theirs for squatting and logging; theirs for pasture and chase and moonshine. Can we expect assistance from those who consider themselves dispos- sessed? Deeds are the megaphone for words, without the noise. . You will be amazed over the large number Tip No. hf) of decrepit fruit trees found on the farms lining the road. After squandering several hundred dollars in attempts at orcharding, I have abandoned the hope of drawing an adequate revenue from any investment in orchards. d ' Late frosts,—occurring as late as the end of May,—form the deterrent. : You have never been, I suppose, as near Tip No. 51 to the site of a moonshine plant as you are at Tip No. 51; Jim Perry used to tend the plant; and I used to tend Jim. Tempi passati! There used to be a time when the hugest species in the flora of the Carolinas was “Planta lunaris L;”? and the hugest thing in the fauna was “Tigris caecus L.,” the blind tiger. The moonshiners used to reside in the hovels lining our road. Imagine! THE BILTMORE FOREST FAIR 47 ee Strips of farms or pastures along the water- Tip No. 52 courses, and strips of pastures along the ; ridges are the cheapest and the most ef- fective “fire lanes” imaginable. I use artificial firelanes in rare cases only, e. g. in the jungle known as the “Pinkbed Valley.” The best means of protection lies in several hundred miles of roads and trails traversing the woods; in watchfulness during dry weather; in the availability at the logging camps of a loyal staff of fire fighters. The picture shows a trail maintained as a firelane, in the primevaljwoods. 48 THE BILTMORE FOREST FAIR “I,” said the sluggard, “‘would be willing to die for my country.”— “Indeed,” said the blackguard, “she will do better without you.’’— . We pass by the site of a sawmill operating Tip No. 53 in 1838. You will see at a glance that the operations were—or rather had got to be— very conservative at that time. The next illustration shows a pile of debris (slabs, edgings, sawdust, bark) left by the mill; and also the fine condition, today, of the woods surrounding thelold mill site. THE BILTMORE FOREST FAIR 49 The value of the trees, in 1898, was $2.50 per 1,000’ of lumber contained in them. Today, the values have trebled. In case of doubt, O Hercules at the crossroads,— Stick to the tall timber! . After leaving the carriages, we pass through Tip No. DA an old field, and by a roof without a cabin. This tract—some 80 acres—I bought at $2.50 per acre in 1901. The orchard is used for pasturage, at an annual rental of $10.00. It would be folly to reforest it. - This is a second growth, and also a third Tip No. a) growth, established on a slope from which the trees were cleared, in or about 1840, with a view to the use of the land for farming. The second growth consists of Chestnut, Locust, Poplar, Basswood and Ash. The third growth consists of Poplar and Ash. We are about to cut the second growth of Chestnut; and you see the piles of timber growing along the road traversed. There has been a fine mast of Chestnuts, this Fall; and the regeneration will be fine. . At this point, observe the entire absence TI p No 3 56 of any primeval timber. A fine stand of Yellow Poplar, forty years old, has sprung up spontaneously “after the war” at a time at which this site was abandoned by the squatter. I draw your attention, also, to the presence of Ash, Hickory, Locust, Walnut and Sassafras mingling with the Poplars. You may ask: ‘What, O Sire of the Woods, do you pro- pose to do in this locality?” 52 THE BILTMORE FOREST FAIR . A piece of primeval woods, badly burned! Tip No. 58 See how the fires have crept up on the three prongs of the big Chestnut herewith illustrated,—up to the hats and handkerchiefs! After the fires, THE BILTMORE FOREST FAIR 53 the silky timber beetles and the fungi have been at work con- tinuously; and the Chestnut is worth, today, three dollars; instead of being worth thirty dollars! . At this station, a squatter named Deaver Tip No. 59 had a potato patch and a cabin in 1850. After the Civil War, the patch grew up in Yellow Poplar. This is the finest stand of second growth on Vanderbilt’s domain; the trees are tall, straight and free from branches. There are 370 trees to the acre, 48 years old on an average. The trees are too small for logging; as pulpwood or as match stock, they have a value of 25 cents apiece, approximately. Do not call me a liar! Call me a poet when I indulge in fiction! 5 The “Ed Smith cutting’? was cleared of Tip No. 60 Chestnut (40 cords per acre) in 1901-1902; was logged for Poplar and Oak in 1898 and in 1906; and has seeded itself in Ash, Poplar, Hickory, Locust and Oak, spontaneously, ever siace. The bulk of the second growth consists of the sprouts of Chestnut and of Silverbell. I have labelled, for your benefit, the White Ash, by white labels; the Black Locust, by blue labels; the Yellow Poplar, by yellow labels; the Hickory, by red labels; the Oak, by green labels. Mind you, Johnny! Nowhere in Pisgah Forest have there been made any investments in sylviculture, the second growth is spontaneous altogether. We protect it from fires; that’s all. A few Poplars, Ashes and Locusts have been left as “‘stan- dards.” 54 THE BILTMORE FOREST FAIR My worst abuser lives with me: Hisname is Fear,—of Failure. - Here we cross and recross a log chute used Tip No. 61 by me in 1906 and in 1907 as a means of transportation. Watch the colored labels! They show the first stage in the development of a second growth. If the cut had been harder than it was along the chute, in the first growth, the regeneration would be better in the second stage of the game. . A cove logged in 1898 and 1906; cut for Tip No - 62 tanbark in 1906, and for tannic wood in 1908. Ernest Allen d did the work. You see the pile of _wood, ready f for ‘Feinoval, tod! tfyou? per Fi a: emi! ee ee a THE BILTMORE FOREST FAIR 55 . One of our saw mills! I love to hear its Tip No. 63 singing; here it is, pictorially: Ruf Galloway is the kand master who Leaps the saws in proper tune. Shake hands with Ruf; and fe2l as proud as if his grip were a president’s. The narrow gauge road supplying the mill with logs is just completed. Let’s run up on it! Do not talk to the conductor; the conductor isan ox. You will agree with me when you se2 him. Happiness sought without— leaves you without happiness; happiness sought within— leaves you within happiness. Tue INLAND PRESS ASHEVILLE, N. C. BILTMORE LECTURES ON SYLVICULTURE By C. A. SCHENCK, Pu.D. f Director of the Biltmore‘ Forest School, and Forester to the Biltmore Estate, N. C. ALBANY BRANDOW PRINTING COMPANY Srare LEGISLATIVE PRINTERS 1905 BILTMORE LECTURES ON SYLVICULTURE By C. A. SCHENCK, Pu.D. Director of the Biltmore Forest School, and Forester to the Biltmore Estate, N. C. ALBANY BRANDOW PRINTING COMPANY Stare LEGISLATIVE PRINTERS 1905 Paragraph. g<48eU XXV. XXVI. XXVII. XXVIII. SYNOPSIS OF PARAGRAPHS. CHAPTER I. Foundations of Sylviculture. . Introduction. . Ecological factors and their influence on the sylva, . Influence of the sylva on the ecological factors. . The North American sylva. . General definitions and explanations. . Light demanders and shade bearers. VII. . Dr. Henry Mayr’s fundamental principles of sylviculture. Pure versus mixed woods. CHAPTER II. The High Forest. . Genesis of the high forest and its methods. . The seed. XI. XII. XII. . Season for planting seeds on open ground. XV. XVI. XVII. XVIII. XIX. . Age, size and number of seedlings used. XXI. XXII. XXIII. . Special methods and tools used for planting seedlings in Preparations for planting seed on open ground. Securing and preparing the seeds. Actual planting of seeds on open ground. Auxiliaries to seed planting. Planting seeds of the broadleaved species. Planting seeds of the coniferous species. Actual planting of seedlings: Introductory remarks. Criteria of good seedlings. Lifting seedlings from nursery bed. Transportation of seedlings. Common methods of planting seedlings in the open. the open. Season for planting seedlings. Cultivation of plantations. Prairie planting in particular. Methods of obtaining plants for planting. 3 , XXIX. XXX. XXXL XXXIL XXXII XXXIV. XXXV. XXXVI. XXXVII. XXXVIII. XXXIX. XL. XLI. . XLIL XLII. XLIV. XLV. XLVI. XLVII. XLVIIL. | XLIX. L. LI. LII. LII. LIV. LV. LVI. LVII. LVIIL. LIX. LX. LXI. SYLVICULTURE. Permanent nurseries in particular. Seed planting in seed beds. ‘Transplanting an. transplanting: ‘beds, ' Protection of nurseries. Nursing in nurseyies? Special nursery methods proclaimed by renowned sylvi- culturists. . Raising and planting hardwood seedlings on open ground. Raising and planting softwood seedlings on open ground. European results of planting experiments with American hardwoods. European results of planting experiments with American softwoods. : Difficulties of natural seed regeneration (Enesar). Age of trees fit for natural seed regeneration (Enesar). Methods of natural seed regeneration (Enesar), Types in which lumbering precedes natural seed regenera- tion. Cleared compartment type. Cleared strip type. Cleared group type. Cleared selection type, Types, in which lumbering coincides with natoral seed regeneration.: Shelterwood eneiaetiant type., Shelterwood strip type. Shelterwood group type. Shelterwood selection type. : Types in which lumbering follows natural seed regenera- tion. Advance growth compartment type. Advance growth strip type. Advance growth group type. Advance growth selection type. Regeneration of valuable species by natural seed regenera- tion with, amongst and into companions of weedy character. Pedagogy of the high forest. Cleaning in high forest. Weeding in high forest. Improvement cutting in high forest. 4 SYLVICULTURE. LXII. Thinning in high forest. LNIII. Pruning in high forest. LXIV. Underplanting in high forest. LXV. Key to the forms of high forest. LXVI. Critical remarks on high forest. LXVII. High forest by species. CHAPTER III. The Coppice Forest. LXVIII. Genesis of the coppice forest. LXIX. Pedagogy of the coppice forest. LXX. Key to the forms of coppice forest. LXXI. Critical remarks on coppice forest. LXXIT. Coppice forest by species. CHAPTER IV. The Coppice Under Standards Forest. LXXIII. Genesis of coppice under standards. ~LXXIV. Pedagogy of coppice under standards. LXXV. Key to the forms of coppice ‘under standards. LXXVI. Critical remarks on coppice under standards. LXXVII. Coppice under standards by species. CHAPTER V. Propagation of Forest Products Other Than Wood and Timber. LXXVIII. Raising of forest by-products. LXXIX. Combination of sylviculture and agriculture. LECTURES ON SYLVICULTURE. CHAPTER I. FOUNDATIONS OF SYLVICULTURE. Paragraph I. Introduction. Sylviculture means the raising and tending of forest products (wood, bark, deer, stock and other by-products). Sylviculture was practiced by the ancients only for park or erchard purposes. The first writings on Sylviculture proper appear in the so-called “House Father Literature.” Sylviculture as a discipline was developed by George L. Hartig, Henry Von Cotta and Christian Hundeshagen. European standard books on Sylviculture of more modern tenure are those of Charles Heyer adapted by Schlich) and by Charles Gayer. European Sylviculture in word and work has, in the course of years, petrified into a set of recipes. It is high time for Sylvicul- ture to be taught and practiced on the basis of Plant Ecology. For America, European Sylviculture at the present moment is of no more use than Chinese Sylviculture, owing to the great eco- nomic differences separating the old from the new country. The ecological principles underlying Sylviculture are, obvicisly, identi- cal for all countries. The planting of trees on a large scale is, in this country, now out of the question, since the expense of planting an acre of land usually exceeds the value of an acre of forest. The modern owners of woodlands are not far sighted enough—possibly not credulous enough—to anticipate the arrival of European stumpage prices for a time at which plantations now started will have developed into mature trees. : If we can assume that stumpage in this country will be as valuable in 1980 as it is now in Germany, France and England, then forest planting must be, at least, as remunerative here as it is in the old country (small soil value in the United States). 7 SYLVICULTURE. Sylviculture as a discipline comprises the following themes: A. Ecological principles, facts and definitions. B. The genesis of the forest. C. The pedagogy of the forest. D. The sylvicultural forms. In the discussion of themes B, ©, and D, a distinction is made between the treatment of: 1. High forests. 2. Coppice forests. 3. Coppice under standards forests. Paragraph II. Ecological factors and their influence on the sylva. A. Definition—Plant ecology is a branch of botany showing the dependence and adaptation of plant forms and plant life of and to the surrounding local factors (climate, soil, ete.). B. Natural laws govern the organization of the species and regu- late the communal life (symbiosis) and messmateship (commen- salism) of individuals with their own kin, with relatives and with other plants belonging to the same household and feeding at the same table. C. The most important ecological factors are: I. Air. Oxygen, nitrogen and carbonic acid, the main coni- ponents of air, are essential for plant life. The relative proportion of the two integral parts, 79% N., 21% O., varies very little with altitude, latitude and elevation. Salt particles in the air near ocean and sulphuric acid in the air near melting works are very injurious to plant life. II. Light. Intensity depends on: Season. Latitude. Altitude. Direct insolation is said to be on the whole of less importance than diffused light (excepting polar regions). Light is not required for germination of seeds. Without light, however, there is no assimilation, and hence no possibility of tree life. Assimilation increases with increasing intensity of insolation; excessive insolation is, however, destructive. For each species, and for each stage of its growth, there exists a certain optimum, mini- mum and maximum of insolation with reference to the possibilities of its success. The damaging influence of excessive. insolation is prevented by the inner organization of the plant. 8 SYLVICULTURE. The duration (number of days) of insolation is as important as the intensity of insolation. Within the individual tree the lower branches are killed gradually, being overshadowed by new upper branches. Without light no bud; without bud no leafing branch; without new leaves annually fermed no limb can live. Within one and the same species a tree once acquiring superi- ority over its neighbors is apt to retain superiority until death. Since it enjoys more light, it assimilates better. Within rival species, owing to greater sensitiveness of chloro- phyll and thanks to more favorable inclination, form and position of leaves, some species exceed others in assimilation and vitality under the same influx of iight. Shade bearing are such leaves as assimi- late sufficiently (so as to bear buds at the axils) in spite of the fact that only little diffused light chances to strike them. Many dicotyledonous trees form a so-called “leaf mosaic,” the lower tiers of leaves fitting themselves into the interstices of light left in the upper tiers. Many leaves alter their inclination toward the sun according to the hourly degree of insolation (photo-metric movement). The epidermis of light demanding and sun-exposed leaves is heavy, leathery. The leaves of shade bearers are thin and wither quickly when picked. Light demanding leaves are often shin- ing, reflecting and whitish, so especially in tropical countries, and the leaf stomata are deeply sunk into the surface. On the same tree leaves growing in the shade are darker than those growing in the light; old leaves darker than young ones. The formation of spines and thorns indicates a sun plant; hair or down are usually found in light demanders more than in shade plants. IIT. Heat. For each plant and for each step of its development can be de- termined a minimum, optimum and maximum of heat required or allowed. Without heat growth is impossible, since cell division is impossible. The formation of chlorophyll, breathing, assimilation, germination, flowering, fruiting and transpiration depend on heat. The distribution of the genera is governed, pre-eminently, by heat. For some polar plants, life is possible below 32 degrees Faht. As a rule, however, plant activity begins to be observable at 50 degrees Faht. The maxima of heat compatible with plant life generally lie be- low 115 degrees Faht. Excess of temperature over’ maximum is more disastrous: than deficiency of heat below minimum. Plants, however, temporarily fortify themselves against periodical extremes: 9 SYLVICULTURE. 1. By non-freezing cell contents. 2. By reduced water contents (seed, rosin). 3. By lignification. 4. By dropping leaves during winter or during period of exces- sive drought. 5. By adequate covers (bark, hairs, bud scales, layers rich in ait cells, reddish color, wrappings formed by last year’s leaves). These covers, at least, allow the plant to escape rapid changes of tempera- ture. Short periods of vegetation and Jong periods of rest result froin deficient heat. Hence no annual plants in polar regions. Short shoots, evergreen leaves, preparation of flowers in year preceding fruit are characteristic of a polar flora. In tropical countries there are no periods of rest unless determined by periods of drought. IV. Moisture of air and precipitations. Water is at hand. a. to increase the toughness of wood (imbibition water cf cell walls) ; b. to allow of solution of cell contents (cell sap) ; ce. to serve as plant food, through assimilation; d. to allow of osmotic movement of sap; e. to assist in photometric movement of leaves (through swell- ing and irritation) ; f. to reduce rapidity of change of temperature by evaporation. ,, Only some lichens survive a process of absolute drying. Lack of moisture causes crippled growth, and frequently subterranean forests (mesquit). After Henry Mayr, the minimum of moisture compatible with tree growth is two inches of rainfall and fifty per cent. of relative humidity during period of vegetation. Phanerogamous plants are unable to absorb water directly through the epidermis, obtaining it instead through the spongiolae of the roots and, in gaseous form, through the stomata of the leaves. Mosses and lichens, however, absorb water directly through the epi- dermis. The hygroscopic power of a dead cover of mosses on the ground equals that of a live cover. Wet climate creates evergreen woods (Pacific coast and Ant- arctic forests of South America). A dry climate gives rise to annual species, to a distinct period of rest, to rapid flowering and fruiting. Precipitations equally distributed over the twelve months of an entire year and precipitations falling during a few weeks result in 10 SYLVICULTURE. entirely different floras. Rain in summer stimulates growth much more than rain in winter. De Candolle divides our globe according to moisture and heat and on the basis of floral differences resulting therefrom, into five regions in the fourth of which we are living. 1. Hydromegathermal region (water great heat). Mean annual temperature over 68 degrees Faht. (Amazon river region, wet tropi- cal zone). : 2. Xerophilous (Dry loving) region. The region and borders of arid deserts, prairies, sunny slopes, etc., exhibiting a flora very modest in moisture requirements. 3. Mesothermal (medium heat) region, having mean tempera- ture of 59 to 68 degrees Faht. (northern Florida, etc.). 4. Microthermal (little heat) region of 32 to 59 degrees Faht. 5. Hecistothermal (least heat) region of less than 32 degrees Faht. The most important representative of a Xerophilous character is the Yellow Pine. The hecistothermal zone shows Spruces, Birches, Cottonwoods. V. Wind. Wind brings moisture and drought, heat and cold; it covers or uncovers vegetation with sand or snow drifts, tumbling, at prior geographical eras, whole mountains into the valleys (Loess formation). Severe wind dwarfs tree growth and forces branches to grow in leeward direction only. ‘The influence of a slight obstruc- tion, preventing the access of wind at high latitudes, is splendidly illustrated by the growth of Spruce and Fir on Pisgah Ridge. On high mountains tree growth is often entirely determined by wind (slope of Little Ball). Species resisting wind best in. Pisgah Forest are Red Oak, Chestnut, Locust. Picea alba and dwarf pines like Pinus pungens and montana show great strength in resisting wind. In the west Tsuga merten- siana, Pinus albicaulis, Pinus monticola, further western Juniper rank first among the trees braving severe storms. Wind is essential for the breathing and for the perspiration of leaves and bark; for driving pollen on stigma to fertilize the seed; for trimming the branches, thus forming clear boles; for dis- tributing seed. The investigations conducted by Fliche (French Forester) have, however, yielded the astonishing result that winged seeds travel much slower than heavy seeds covetted by birds. Fliche gives the following number of years as required by trees traveling from Nancy to Paris, a distance ‘of 160 miles: ll SYLVICULTURE. BOQCH snide ceed enka ee ee TGE NSS REE 18640 years. CHEStHUE node: taal canis terete eenes 12920 years. PANG et ayia aieeha aue a cmea audits eeatuaase ae apne ey 48680 years. RAVVIS: sc ycgingy hacia ws domes ws 1330 to 2000 years. VI. Structure of soil. Soil consists of natural rock; or of rock disintegrated under the influence of water, frost, heat, oxygen, carbonic acid, lichens, bacteria; or of washings deposited by water, wind or glaciers. The components of soil are: a. Soil skeleton, large grains, principally quartz and stones. b. Soil flesh, minute semi-soluble particles—the mud of the rivers. ce. Soil fat, the humose particles giving the soil-a dark color. d. Soil blood, the air and water, filling the pores of the soil. The size of the pores determines the capillary capacity. According to the resistance which soil offers to spade or plow, we distinguish the following classes: Light soil; Loose soil; Binding soil; Heavy soil; Stiff soil. VII. Air in the soil. Roots require oxygen for breathing. Like fish, they die from lack as well as from superabundance of oxygen. Subterranean air is rich in carbonie acid exhaled by roots, fungi, bacteria, animals. Swamp soil contains little air. Hence such species only find a living in swamps which have large inner air ducts (Cypress knees, Nyssa root, bamboo, cane breaks, sour grasses). Prairial soil is naturally so compact that it contains little oxygen. VIII. Water in the soil. It occurs: a. Chemically bound to minerals and salts. b. Absorbed by the hygroscopicity of soil. e, Raised by the capillary power of soil. d. As ground water—lakes, swamps, brooks being merely areas of open ground water. The size of the pores and the presence of humus govern the intensity and rapidity of water obtention and retention. Sand, for instance, allows water to enter its large pores quickly, but gives .it. up rapidly as well. Wet; moist, fresh, dry and arid soil are: distinguished. 12 SYLVICULTURE, . ,The degree.of wetness of soil is of the utmost importance fur tree grow th. . At its southern limit, a species grows only in swamps or along watercourses, The water in the soil dissolves the mineral salts so as to form sap and, seems tc be of great influence. on the bacterial life in the soil. IX. Heat in the soil. ‘It is derived from the earth’s own temperature, from: chemical processes in soil (notably fermentation) and from sun rays. In the latter case, the angle of insolation, the duration of insolation, the heat ‘capacity of soil, the color of soil, the porosity of soil and its vegetable cover serve as influencing factors. Jf A. cold root has no pumping power. Fine root fibres die from temperatures which fine branches easily withstand. The actual influence of the heat in the soil on tree growth is practically un- known. The opening of the ‘buds in spring and the fall of leaves in autumn are probably connected with the thermic changes occur- ring in.the various strata of the soil. “' X.Depth of soil.’ Flat, rooted species easily obtain the superiority over tap- ‘rooted species on shallow soil. Tree roots, however, are not apt to penetrate to a depth greater than six ‘feet. Shallow soil in- creases danger from fire, drought, storm. A tap rooted species, planted on shallow soil, produces only a stunted form. Shallow ‘soil is well adapted to the coppice system, in case of broad Jeaved tap rooted species. XI. Food in the soil. A tree, like a crystal, is composed of various chemica] elements. The available amount of that necessary element which happens to occur in the relatively smallest degree determines in both crystal and plant, the rate of. growth actually. taking place (Liebig’s law). -The Superabundance of one component, even: of a necessary com- ponent, prevents, on the other hand, ane local existence of many -Species. The ten necessary elements found within a plant in solid, liquid or gaseous condition are O, H; C, P, Fe,-K, Mg, Ca, N, 8S. “Roots search food as if they had eyes,”—a rule easily proven dn any nursery. XII. Species of soil. a. Rock. Most important rock formations are: Granite, gneiss, -limestone, sandstone, slate and trap. 13 SYLVICULTURE. Vertical stratification facilitates decomposition and tree growth. The various species of rock differ in hardness, porosity, heat con- duction, and above all in soluble mineral contents. b. Quartz sand. Quartz.sand is unfertile when. pure,.since. silicic acid fails to be digested by the roots and fails to react with the acids usually found in the soil. Quartz sand is loose, has small hygroscopicity, small capillarity and small heat-retaining capacity. It is hot during the day and cold at night. ce. Lime. Lime when pure is a poor soil, although not quite as dry and hot as sand. Lime, however, mixed with loam and clay (so-called marl) forms an extremely productive soil. d. Clay. Clay has great absorbing and hygroscopic power. It is wet and cold. Main components are aluminum-silicates. e. Loam. Loam is a mixture of sand and clay—the usual soil in agriculture and forestry. It is usually colored by iron (red loam at Biltmore). We speak of a sandy loam or of a loamy sand according to the prevalence of one or the other component. Loam soil exhibits a happy medium of qualities favorable to tree growth. f. Humus. Humus results from the decomposition of vegetable and animal matter under co-operation of bacteria, fungi, rain worms (Darwin), larvae. Humus forms a solvent of mineral plant food. A bad conductor of heat and cold, it prevents rapid changes of temperature in soil, has great hygroscopicity and great water- retaining power and is a preventive to evaporation of soil moisture. Mild forest humus shows a basic reaction, whilst the sour humus of the swamps shows an acid reaction. Unfavorable is the dust humus formed by many- Ericaceae. XIII. Physical versus chemical qualities of soil. Agriculture withdraws food only from the top layer of soil. It deprives that top layer of its rarest and most valuable com- ponents, by the annual crop of grain excessively rich in nitrates, phosphates and potash. The porosity, and through it the water capacity and the heat capacity of soil, are readily controlled on the field by the plow. It is necessary in agriculture, in the long run, to return to the soil in the shape of fertilizer annually as many pounds of nitrates, phosphates and potash as have been removed in the shape of crops from a given acre of land. The productiveness of agriculture depends, above all, on the chemical qualities of the soil tilled. A crop of trees, on the other hand, takes from the soil very little, since the tree consists mainly of C, 0, H, or since wood is nothing but air solidified by sunshine. The phosphates, nitrates and potash absorbed by the tree are 14 SYLVICULTURE. returned to the soil by the fall of branches, leaves, seeds, flowers, ete. The traces of chemical fertility locally removed in the shape of logs are, in addition, counterbalanced by the decomposing influ- ence on the rock exercised by roots and root-bacteria. Hence it is not likely that a rotation of crops, as is required in fields, has any advantages in the case of forestry. In primeval woods, we know that Nature allows a species to succeed itself, The physical qualities of the soil preeminently influence the tree species and the rate of its growth. The chemical qualities of the soil play the most potent role in the case of agricultural species. Soil fit for agriculture is not necessarily good forest soil (prairies). Soil fit for forestry (strong north slopes) is often utterly unfit for farming. XIV. Soil covers. Soil covers are either dead or living. Dead soil covers are snow, debris of leaves and twigs. Living soil covers consist of mosses, grasses, ete. Snow keeps the soil warm, prevents rapid changes of tempera- ture, prevents young plants covered by it from perspiring, prevents lifting of plants by frost. The debris on the ground feed millions of animals and fungi; they harbor, on the other hand, mice, larvae and other enemies of plant growth. Debris frequently prevent reproduction from self- sown seed and increase the severity of forest fires. Living as well as dead soil cover influences evaporation of moisture, porosity of soil and water drainage. : XV. Life in the soil (Compare Swiss L. F. F. 1904, May and June). The soil lives like a plant or an animal, since it shows con- tinuous changes of form and of composition. Very little, however, is known of the life and the interdependence of millions of live indi- viduals found in the soil. Certain it seems that tree growth is bound on the presence of certain fungi and bacteria living on the roots (Mycorrhiza). Most important are the bacteria capable of digesting the nitrogen of the subterranean air. Leguminous plants (Clover, Black Locust) are beset with root knobs, containing bacteria. busily engaged in the assimilation of. nitrogen. The. hyphae of a fungus called Frankia play a similar role on the root knobs of Alder and Sweet Fern. After P. C. Mueller, Spruce will grow on poor sand lacking nitrogen if Pine is. mixed with it, furnishing nitrogen through its mycorrhiza. 15- SYLVICULTURE. The maximum number of bacteria is said to be found two feet below the surface of the ground, and none exist below six feet. The number of bacteria per pound of soil varies from one hundred million to two hundred and fifty million. / Important, too, in plant ecology is the life of the larger animals (worms, insects, centipeds) changing the vegetable matter of the soil into manure proper, mixing mineral soil and vegetable matter, increasing the porosity, drainage and aeration and neutralizing the acids of the soil: Shade, protection from wind and sufficient moisture . are beneficial to animal life in the soil. Paragraph III. Influence of the sylva on the ecological factors. , The influence exerted by the forest on local climate (heat, air, precipitations, etc.) is dwelt upon in the lectures on forest policy. Whilst the ecological factors shown in the previous ‘paragraph exhibit the important influence which the soil has on the tree, there exists ‘at the same time, although to a lesser degree, an influence of the tree on the soil. This influence is invariably such as to facili- tate life to the tree itself and to its progeny. The production of humus is the main source of that influence. : ‘Governing factors are: A. Leaf canopy overhead. Evergreen as well as deciduous woods annually return to the soil by the leaf fall a large amount of dead matter readily assiniilable. Shade bearers furnish a better humus than light demanders, excluding, at the same time, intensive insola- ‘tion, so that the decomposition of the leaf carpet and the evaporation of the soil moisture is favorably retarded. A humus formed by Beech, Maple and Chestnut is considered especially good. Beech is justly ‘called abroad the “Mother of the Forest,” owing to its soil-improving qualities. The leaf canopy is particularly dense during the thicket aud the pole-wood stage. Even light demanders, whilst young, improve the fertility of the soil. At a higher age, when the light demanders place themselves far apart one from another (say less than 100 trees per acre), the humus on the ground is destroyed, being replaced by a dense and impermeable matting of grasses or shrubs. Amongst the conifers, Yellow and White Pine seem to furnish the best humus. Spruce humus is too waxy. B. Rate of disintegration of leaves. This rate depends on insolation, on heat capacity of soil (sand versus clay), on atmospheric humidity. Uusually, decomposition of leaf fall takes place within two or three years. The thin leaves of the shade bearers decompose quicker than the heavy leaves of the 16 SYLVICULTURE. light demanders. The high atmospheric moisture of high altitudes causes accumulation of large quantities of leaves. In the tropics there is little litter on the ground. C. Root system. It is the decaying root which allows the precipitations to trickle down to the lower strata of soil. Hence tap rooters seem more efficient than flat rooters in converting a rapid surface drainage into a slow underground drainage. Decomposing the rock by chemical action, the tap root forces it to yield its soluble salts. D. Soil improvement through root-bacteria and fungi. The upper layers of forest soil are densely peopled with the hyphae of basidiomycetes, living on humus. Leguminous trees (Locust, Kentucky Coffee tree, ete.) by their root-bulbs increase the fertility of the soil, and the Alders seem to act in a similar way. Qn abandoned fields in Pisgah forest the soil is improved by Su- mac, Sassafras, Locust, etc. These species act as ushers for more exacting forest growth, improving the physical conditions of the soil. Very little is known about the nature of the improvements. Paragraph IV. The North American Sylva. The northern limit of the forest coincides with the isothermal line, 30 degrees Faht., which lies on the west side of the continent at 70 degrees latitude in Alaska (under influence of the Japan cur- rent), and on the east side at 55 degrees latitude in Labrador and at the Hudson Bay. The rainfall and, consequently, the existence of forest depends on the moist sea winds supplied by the Pacific, the Atlantic, the Gulf and the Great Lakes. A cross-section through North America at the latitude of Lake Michigan and Portland, Oregon, shows the inter-dependence between the lowest gaps in the mountain chains and the forest on the next mountain chain lying to leeward. For in- stance; lowest gap in Coast Range at 3,000 ft. above sea level; no forest in Cascades below 3,000 ft.; lowest gap in Cascades at 4,000 ft. above sea level; no forest in Blue Mountains below 4,000 ft.; lowest gap in Blue Mountains at 5,000 ft. above sea level; no forest in Rockies below 5,000 ft. The east slope of the Coast Range, Cascades, Blue Mountains and Reekies shows little or no forest, and the lowlands to the east of the mountain chains are deserts and prairies. 17 SYLVICULTURE. Moist sea winds, after passing one chain allow the forest to grow on the next chain only above the altitude of the gaps in the first chain. ; The following table shows the composition of the forest of the United States and of Canada, under the influence of the climate: Percentage of forest area occupied by: In United States. In Canada. Tropical forest ......-. esse cece eee reece ere eee W% U% Sub-tropical forest ........ 04 cee eee eee eee 15 % 0% Forest of the moderately warm zone..........- 75 % 10% Forest of the moderately cold and alpine zone. . 914% 90% The United States contain two big and one minor forest region, namely the Atlantie forest region; North Mexican forest region; Pacific forest region. The Atlantic and the Pacific forest join under the influence of the Hudson Bay winds at 52 degrees latitude, in Assiniboia. There are no prairies proper north of this latitude. The tropical forest shows no seasons. Its species are evergreen. In the United States it is found only at the extreme southern point of Florida. The sub-tropical forest is characterized by the evergreen broad- leaved trees, and is the zone of rice and oranges, extending in east- ern North America to 35 degrees, in western North America to 40 degrees, latitude. The moderately warm forest region is the zone of the broad- Jeaved deciduous trees, of corn, vine and wheat. The moderately cold forest region is that of the evergreen ecnifers too cold for the production of corn. In North Carolina a trip from the coast to the high Balsams leads the traveler from the northernmost limit of the sub-tropical through the moderately warm forest region into the southernmost limit of the moderately cold forest region which sets in at about 6,000 ft. elevation. ’ A. The Atlantic forest. I. Eastern tropical forest. Mahogany occurs only as a small tree; Palms and other tvpically tropical orders (Sapotaceae, Ebon- aceae, Euphorbiaceae, Verbenaceae) compose the forest. It must be remembered that Southern Florida exhibits only the extreme northern occurrence cf the tropical forest. 18 SYLVICULTURE. II. Eastern sub-tropical forest. It shows evergreen Oaks, Mag- nolias, Persea, etc., besides the Pines, the soil being too poor for the formation of a large wintergreen broad-leafed forest. The winter temperature averages 53 degrees Faht.; precipitations are heavy; relative humidity is 75 degrees. Sabal palmetto is a characteristic weed. Bald Cypress and Cuban Pine are characteristic trees of the region. Among the other Pines, the Long Leaf Pine is the most important, associated in the north and west with Pinus clausa, echinata, taeda, serotina, glabra. Liquidambar, Nyssa and Fraxinus platycarpa occur in swamps at the edge of which southern White Cedar frequently appears. Ii. Eastern winter bald forest of the moderately warm zone. It is fringed at the south, north and east by a broad belt of Pines, which belt connects this region at the south with the sub-tropical forest, at the north with the Fir and Spruce forest of the moderately eold zone. It is divided into a northern and a southern half by the 39th degree of latitude. Each half shows an Atlantic, a central and a prairial sub-region. a. South Central sub-region. Traversed by the Mississippi, the sub-region is characterized by high temperatures, large precipita- tions and fine soil, which allow of the best development of broad- leaved woods found in the world. Twenty-three Oak species, eight Hickory species, two Walnuts, Buckeyes, Chestnut, Gums, Cotton- woods, Yellow Poplar, Sycamore, Beech, Maple, Elm, Red Cedar, etc., stand in a dense undergrowth formed by Dogwood, Kalmia, Rho- dodendron, Hazel, Cherries, Hawthorn, Buckthorn, Witch Hazel, ete. In this sub-region the heavy seeded broad-leaved trees obtain the maximum of size, quality and number of species at altitudes running up to 3,000 ft. Higher up the number of species diminishes. At 5,000 ft. only Red Oak, Chestnut, Beech, Buckeye, Sugar Maple (resembling north central subdivision) are found, and at 6,000 ft. the Spruces and Firs (southernmost sentinels of moderately cold zone) set in. b. South Atlantic Sub-region. It comprises the Eastern foot- hills of the Alleghanies (Piedmont Plateau) and part of the Coastal Plain. Temperature 3% degrees Faht. less, soil poorer, precipita- tions less abundant than in the South Central Sub-region, hence much Pine (taeda, mitis, rigida, virginiana). Only ten Oak species; White Cedar swamps; broad-leaved flora otherwise as in South Central, but of rather inferior development. e. South Prairial Sub-region. Extending from the 92nd to the 102nd degree of longitude, the forest appears poorer than the annual 1) SYLVICULTURE. temperature and the annual rainfall seem to indicate; a discrepancy between cause and effect, possibly due to forest fires. West of the 95th degree of longitude, Oak, Ash and Walnut occur along rivers, especially on Eastern banks. Oak also appears scattered through the depressions. d. North Central Sub-region. Precipitations very abundant from South as well as North. Average winter terhperature 30 de- grees Faht. Quick change of temperature. The light-seeded, broad- leaved species reach maximum in this section, also White Pine an! Hemlock. Six Maples, five Birches, Elms and Lindens, further Ash, Buttérnut, Red and White Oak compose the forest. e. North Atlantic Sub-region. Plenty of moisture, the moun- tains being close to the sea-shore, but not so much as in Lake states. -Average winter temperature 34 degrees Faht. at seashore. Pinus rigida and mitis, Beech, Birch, Chestnut, Maples, often replaced by Poplar and Willow. Spruce sets in at altitude exceeding 1,000 ft., accompanied by Hemlock, White Cedar, Red Cedar, White Pine and Tamarack. f. North Prairial Sub-region. Dry summers, blizzardy winters and more sandy soil. No Hemlock. Red Pine and Jack Pine intrud- ing fom North. Scrub Oak openings. On best soil still good develop- ment of Linden, Maple, Elm and Birch. White Pine of poorer quality than in sub-region “ d.” IV. Eastern Evergreen Forest of the moderately cold zone. The majority of this zone lies in Canada, in northern Lake states, Maine. It occurs in North Carolina at 6,000 ft. elevation; in the Adirondacks at 2,000 feet; in Maine at sea level. , The region occupies a big belt stretched across the continent, so that western and eastern flora joins hands in it. A typical tree of this region, the White Spruce, often forms large pure forests, Other species of the zone are Red Spruce, Black Spruce, Balsam-fir, Cotton- woods, Cance Birch, Hemlock, White Cedar and Tamarack, the latter here optaining its optimum. B. The North Mexican forest. The North Mexican Flora intrudes, coming from Mexico, Arizona and New Mexico. It is different from the Pacific flora, unimportant commercially, interesting only botanically. Forest possible only at altitudes exceeding 5,500 feet. Forest proper—dense forest—only at 8,000 feet. I. North Mexican sub-tropical forest. Characterized by Cactus, Yueca, Agave and Mesquite (Prosopis). Evergreen Oaks in moist valleys. Madrona (Arbutus), a beautiful 20 SYLVICULTURE. tree, on sunny slopes often mixed with Manzanita (Acrostaphylos pungens). II. North Mexican forest of the moderately warm zcne. This zone, very narrow, should contain winter-bald broad-leaved species. The dryness of the soil and of the air, however, allows of their occurrence only on moist ground along rivers. Western Walnut, Mexican Ash, Poplars and Willows. The Pines are the leading species of the zone, forming huge forests at altitudes exceeding 6,000 feet elevation. Some of these Pines are northern sentinels from Mexico, others outposts from the States. Most important is Pinus Chihuahuana, in Mexico largely used for timber, up to 80 feet high, three feet in diameter, three needles. Pinus Arizonica, a five-needled pine, occurs at 6,000 feet elevation. Pinus reflexa, locally known as White Pine, occupies moist dells at 8,000 feet elevation. Nut pines at lesser elevations as low brush, notably Pinus edulis, monophylla. osteosperma. , C. The Pacifie forest. Typical difference from Atlantic forest lies in the relative lack of broad-leaved woods—not in species, but in area. Tropical forest is absent, possibly due to’lack of moisture at low elevations in “outhern California. I. Pacific sub-tropical forest. é Occupying Southern California. This zone is devoid of dense forests, the northern edge excepted. Evergreen Oaks, or rather Winter Green Oaks (Quercus densiflora is leafless during dry sum- wer) dot the ground in park-like groves. California Laurel (Um- bellularia californica) is a characteristic tree of this region, growing up to 100 feet high. Impenetrable bush thickets cover hot aspects, fermed by Leguminosae, Labiatae, Compositae, Rosaceae, etc. The rare and beautiful Montery Cypress along the seashore. Sequoia sem- pervirens is the biggest. tree of the zone, found only at its edge in the Coast Range. Pinus insignis known as Montery Pine is valu- able on sand dunes. Pinus tuberculata (attenuata) occurs most frequently in even- aged woods. Pinus sabiniana, Nut or Digger Pine, valuable for the Indians, of Olive-like appearance, is mixed in the Oak parks and in the Chaparal thickets. Another Nut Pine is Pinus parryana, grow- ing 30 feet high. Pseudotsuga macrocarpa on St. Bernardino range. Eucalyptus and Accacia were successfully introduced from Austra- lia, Oranges and Figs from the Orient. II. Pacific forest of the moderately warm zone. 21 SYLVICULTURE. This zone covers the major part of Oregon and Washington and the mountains of Northern California. It is characterized by very even annual temperature and high precipitations. Here the winter bald broad-leaved species should rule supreme. The winter bald Oaks are represented in Oregon by Quercus garryana (White Oak), in California by Quercus Kellogii (Black Oak), Fraxinus Oregona, Acer macrophyllum, Populus trichocarpa (Black Cottonwood, the biggest Cottonwood of the world) occupy the bottom land along the rivers; further Sorbus, Amelanchier, Crataegus, Prunus, Salix, Aes- culus, Alnus, Acer, Platanus, Negundo, Betula. All of these latter species unimportant commercially. In strict contrast with the Atlantic forest of the same zone, the conifers rule in importance, foremost among them the Douglas Vir (Pseudotsuga taxifolia) which stands temperature of 15 degrees Faht. easily. Best development on west slope of Coast Range. In the Rockies, it forms only summer shoots and short boles, owing to shorter growing season and lack of atmospheric moisture. In Colo- rado, Arizona, New Mexico occurs a gray variety. In the Sierras it appears only as a dependent species. Pinus ponderosa (Yellow Pine, Bull Pine). Height and timber quality depend on proximity to Pacific Ocean. Optimum in Sierra Nevada, where trees 300 feet high are frequently found. Very heavy sap-wood. Name ponderosa undeserved. No tree of the United States occupies a larger territory or shows greater adaptabil- ity. Chamaecyparis lawsoniana (Port Orford Cedar) occupies only a very small territory close to the Pacific Coast. Does not ascend mountains to over 1,500 feet. Heavy shade bearer, splendid repro- duction. Thuja plicata (Red Cedar of the West) up to 170 feet high. Rare in California. Best development in Oregon and Washington and Northern Idaho, where it occupies only the moister coves. Boles very tapering; shade bearing; thin bark. Libocedrus decurrens (White Cedar, Bastard Cedar) on west slope of the Sierras at medium elevations, where the tree is mixed with Abies concolor, Yellow and Sugar Pine. Regeneration easy, often in places previously occupied by the Pines. Pinus lambertiana (Sugar Pine), a White Pine since it has five needles in a sheath. Specific gravity even less than that of Eastern White Pine (Pinus strobus). The biggest Pine of the world. Very large cones. Optimum in Sierras at 5,000 feet elevation; occurs often with Sequoia, Libocedrus, Abies concolor, Yellow Pine, Pinus Jef- 22 SYLVICULTURE. freyi. The latter, a very close relative to ponderosa and distin- guished from it by bluish shoots and needles bent towards the shoots, occupies the lower Sugar Pine belt. It prefers moist ground and reaches only one-half the size of ponderosa. Mayr groups the above trees as follows, according to their de- mands on moisture: : Demands on soil moisture: 1. Libocedrus decurrens, 2. Pinus jeffreyi, 3. Abies concolor, 4, Pinus lambertiana, 5. Pinus ponderosa. Demands on air moisture: 1. Abies concolor, 2. Pinus lambertiana, 3. Pinus jetfreyi, 4. Libocedrus decurrens, 5. Pinus ponderosa. Abies grandis (White Fir of Northern Pacific Coast). The only fir on Vancouver Island. Optimum at coast in Oregon where it grows up to 300 feet high, standing alongside gigantic Cottonwoods; extends eastward across the Northern Rockies, and is the first Pa- cifie fir met by the traveller going west on the Northern Pacific. Requires moist soil. Abies concolor (White Fir of Colorado and of the Sierras). Running south to the San Bernardino mountains, where it occupies elevations of up to 10,000 feet. Traversing Nevada, it occurs in Colorado (gardener’s variety glauca). It accompanies Sugar Pine and Bigtree. After Muir, always mixed with Abies magnifica, occur- ing at altitudes ranging between 5,000 feet and 8,000 feet. Abies bracteata (Santa Lucia fir of high mountains) occurs in Southern California in moist cool dells. Tsuga heterophylla (Black Hemlock of low elevations). A fine tree, the progeny of which forms a dense undergrowth underneath Douglas fir. Heavy shade bearer, requiring plenty of moisture, oc- curring in Alaska, Coast range and Cascades. Picea sitchensis (Tideland Spruce). Along coast on very moist soil in Washington, on dryer soil in Alaska, very shade bearing and branchy. Stinging needles. Up to 200 feet high. Sequoia Washingtoniana (Bigtree). Occurring only in the Sierras in scattered groups at elevations ranging from 4,000 to 7,000 feet. 23 SYLVICULTURE. Enormous seeding capacity and sprouting capacity. Average di- ameter 20 feet, height 275 feet, age up to 4,000 vears. III. Pacific forest of moderately cold zone. This zone is economically of no importance, although it is the forest zcne proper, owing to the impossibility of agriculture within this zone. It is “The Canadian Forest Zone.” It lies in the Sierras at 8,000 feet, in the Cascades at 4,000 feet, and in Alaska at seashore. The forests of the Northern Rocky mountains belong to it preferably. Pinus murrayana (Lodgepole Pine). Shade bearing, in close stands, very branchy, very sappy, retaining cones, easily destroyed by fire, closely related to the Jack Pine of the east. Frequent on old burns, typical for Yellowstone Park, going south to Arizona, Larix occidentalis (Western Tamarack). : Splendid lumber tree, often in pure forests, optimum in Montana, natural regeneration easy, rapid height growth, little sap wood, timber equal to Long Leaf Pine. ‘ Pinus flexilis (Limber White Pine). More branchy and much shorter than eastern White Pine; forms open forests on south slopes of Sierras and in Nevada at 7,000 feet elevation; from Montana it extends southward to Colorado. Pinus monticola (Mountain White Pine). In Cascades, British Columbia, Idaho, Montana, in the latter state more on slopes drain- ing westward. Abies nobolis, amabilis, magnifica, the Red Firs of the west. Magnifica known in California,as Larch. The two first named often associated with Abies grandis and more frequent in Washington and Oregon than in California. Amabilis.extends into Alaska. Red Firs are lacking in the Rockies. Needles are dark. Picea engelmanni (White Spruce). At home in middle and southern Rockies, on northern slopes at altitudes averaging 10,000 feet. Picea parryana (Colorado Blue Spruce). Needles very pointed and stinging, of a bluish tint. Occupies moist ground. IV. Pacific forest of the Alpine region. Typical trees are: Pinus albicaulis (Dwarf White Pine). Occurring in the Cascades and the Rockies (Utah). Pinus balfouriana and aristata (Fex-Tail Pine). White Pine found in California at 8,000 feet to 12,000 feet elevation; twigs thin, retaining needles for many years. ; 24 SYLVICULTURE. Abies lasiocarpa (Balsam). At edge of tree growth only a shrub. In Colorado at lower, warmer situations a valuable tree. Occurs in all states of the west. Larix lyallii (Larch of British Columbia). Occurs here and there in Washington, Idaho and Montana, at very high altitudes. Tsuga mertensiana (Hemlock). A storm-battered hemlock, at high altitudes in Sierras, Cascades, Montana. A branchy tree up to 100 feet high, inaccessible and hence of no value. Peragraph V. General definitions and explanations. A. In Europe, under the term “ Wood” is understood an aggre- gate of trees of such uniform character that it can be subjected to the same manner of treatment. In the American virgin forests, “woods” are rare. As a matter of fact the term “ woods” as well as the term “forests ” has no definite meaning in America. A fores- ter should keep in mind, however, that a plantation or a natural regeneration, whatever its age and its condition, must be classed under the heading “ forests.” A “group ” of trees consists of even-aged specimens of the same species and is larger than a bunch, clump, or cluster. No recog- nized definitions of the term “group” and “clump” are at hand, un- fortunately, based on the space or the acreage covered by them as units. Groups, as understood in the following pages, are distinct aggregates cf trees covering ~; ‘o 4 acres. B. Pure forests, pure woods, pure groups or bunches are such as contain one timber species only, 5 per cent. admixture being permissible. Species able to form pure forests are termed gregari- ous or ruling species, sub-divided into distinctly ruling species, which are usually found in pure stands, and conditionally ruling species, which are occasionally found in pure stands. I. After Drude, the participation of a species as a mess-mate at the forest table is expressed by the following terminology: a. Social species, denoting the main character, the striking feature (in numbers and volume) of the forest; the rank and file cf the forest. b. Gregarious species, occurring in clumps and groups, island like; “8 ce. Copious species, interspersed with others, the degree of fre- quency being interpreted by exponents, f. i., copious’, copious’, copi- ous’; d. Sparse species, occurring isolated and in single specimens; e. Solitary species, very isolated and very rare. 25 SYLVICULTURE. II. It might be preferable to express the ratio of the participa- tion in per cent. Social, forming 60% and over of growing stock. Gregarious, forming 40% and over of growing stock. Copious, forming 20% and over of growing stock. Sparse, forming 1% and over of growing stock. Solitary, forming less than 1% of growing stock. Intermediate stages might be indicated by a union of the given designations, f. i., “* social-gregarious.” III. The configuration of the ground and the rapidity of its change vitally influence the possibilities of a species as a component of the forest. : IV. Species which are not, or which are locally not, “ruling” species are called “ dependent ” species. A species might be ruling in North Carolina, while it is depend- ent in South Carolina. The distribution of the species is limited by its demands on soil and climate. Far away from the center of distribution a species is likely to be dependent. V. The ruling species in the south are: Long Leaf Pine, Bald Cypress, Loblolly Pine, Short Leaf Pine, Sweet Gum, Post Oak, Cottonwoods, Chestnut. The ruling species in the west are: Lodgepole Pine, Pinus ponde- rosa, Douglas Fir, White Fir (Abies grandis), Engelmann’s Spruce, Western White Pine, Port Orford Cedar, Redwood, Sitka Spruce. VI. Obviously the meek species are those that conquer the globe. With the inroads of civilization on the fertility of the soil, and especially on the water capacity of the soil, these meek species obtain additional chances to supersede the exacting species. C. Weapons of the species in the struggle for existence are: I. Shade-bearing qualities. II. Modesty as regards the fertility of soil, the moisture and the heat during the period of vegetation. III. Power of resistance to storm, sleet, snow, late and early frosts, droughts, fire, etc. IV. Immunity from forest insects and forest fungi. V. Longevity. Oak lives longer than Beech; Sequoia longest of all. VI. Reproductive power, especially reproductive power from stumps, frequency and richness of seed years. VII. Portability and sensitiveness of seeds; number of enemies of seeds; germinating percentage of seeds. VIII. Rapidity of height growth in early youth. 26 SYLVICULTURE. D. Density of stand. Every ruling species shows a particular density of cover and a particular ramification during every stage of its life, when grown in pure forests. I. Density of leaf cover overhead. a. The form of the crown of the individual depends on side- shade, topshade, neighborly friction and quality of soil. b. Natural regeneration causes a greater density of cover than artificial regeneration, certainly during the thicket and pole staze. Other influencing factors are: quality of the soil, age of the forest, inroads by snow break, wind fall, fire, deer, fungi, insects. ce. A dense canopy overhead produces clear boled timber and allows of a heavy layer of humus on the ground. The method of regeneration distinctly influences the value of the timber to be formed. II. Number of trees per acre. Under normal conditions an acre of pure forest contains the more specimens of equal height or diameter, the better the quality of the soil and the better the climate; and the more specimens of the same age, the poorer these factors are. For example—Yellow Pine Forests: Number of trees per acre. Soil. Boles 75’ long. Diameter 12.” Age 60 yrs. I quality... 320 240 380 II quality... 240 215 460 II quality... 190 190 540 During the pole stage and tree stage shade bearers exhibit per acre of ground about 50% more trees than light demanders. The following curve illustrates the interdependence between age and number of trees per acre: 10,000 *, 5,000. : Number 2,500 * of trees per acre 1,000 . 900 : 800 - 700 . 600 . 500 - 400 Sos 300 . 200 w. 100 5 0 0 10 20 30 40 50 60 70 80 90 100 120 130 140 150 160 170 180 Number of years old. se . i ee ee SYLVICULTURE. III. Growing space of a tree. In their early youth all species stand or even desire a dense cover overhead. When the food supply stored in the seed shell is consumed, however, the seedling requires light to digest its food. With increasing age, the tree boles getting longer, the crowns rub and beat one another intensely, swaying pendulum fashion in the wind. As a consequence each crown is surrounded with an air space, the relative width of which depends largely on the length and-the flexibility of the bole. It might be stated that the growing space of a tree is a function of the square of the gradually lengthening bole. Trees differ in the ease with which warring neighbors lose their kuds and shoots. Oak, for example, loses its May shoots easily, whilst Beech, struggling with Oak, loses a few leaves only along its flexile swaying twigs. In heavy storms Yellow Pine often loses whole branches. White Pine, on the other hand, does not easily lose its shoots. The top shoots of the taller individuals are immune from harm. Thus a tree, once in the lead of its competitors, has a good chance to retain the lead over: them. IV. Grades of density of cover are: Pressed cover, Close cover, Light cover and Open cover. No strict definition of these terns can be given. Obviously the number of stems under pressed conditions is very large. Indications of a normal cover are: u. Relation between length of crown and length of bole. b. Normal diameter growth and height growth. v. Proper participation of the various diameter classes in‘ the volume of wood at hand. The normal participation in a pure, even- aged wood is for the Ist. Diameter class—40% of total volume. 2nd, Diameter class—24% of total volume. 3rd. Diameter class—17% of total volume. 4th. Diameter class—12% of total volume. 5th. Diameter class— 7% of total volume. If cover overhead is too dense, the first class shows over 40% of volume and vice versa. V. In nature, the same causes necessarily have the same result. The causes of timber production are soil and atmospheric food “ fall- ing ” onto the soil in the shape of sunshine, moisture and air. Hence, whatever the species are, it seems as if the acre of ground, fully stocked, must produce on the annual average the same weight of timber—not the same volume of timber. Thus, ceteris paribus, 28 SYLVICULTURE. species of light specific gravity are the best volume producers. Since, however, shade-bearing species are better digestors of atmospheric and terrestrial food, the largest growth per acre per annum is obtained from shade bearers of light weight (Hemlock, Spruce, Fir, White Pine). In the virgin forest the annual production of wood fibre is exactly offset by the annual death and decay of wood fibre. The virgin forest is a forest seemingly in economic stagnation. VI. The sectional area of-a tree usually measured chest high (4% feet above ground), inclusive of bark, is the area of the circle corresponding with the diameter measured chest high. The sectional area of an acre of forest is the sum total of the sectional areas of the trees standing thereon. It rarely exceeds one- half per cent. of the acreage of the ground, or 218 square feet per acre. E. Rotation. Under rotation is understood the number of years which a seed- ling requires to reach maturity. For a second growth in America, rotations will vary in length from 60 years to 160 years, according to the species and local conditions. During a rotation a wood lot may pass through the cleaning stages, thinning stages, the stage of pre- paratory cutting, the seed-cutting stage and the stage of final removal. F. Size classes and age classes. I. Pinchot adopts the following seven age classes or size classes of trees in his “ Primer:” a. Seedlings, up to 3 feet high. b. Small saplings, from 3 to 10 feet high. c. Large saplings, 10 feet high to 4 inches diameter. d. Small poles, from 4 inches to 8 inches diameter. e. Large poles, from 8 inches to 12 inches diameter. f. Standards, from 12 inches to 24 inches diameter. 2. Veterans, over 24 inches diameter. II. During the sapling stage, the specimens form a thicket; dur- ing the pole stage, they form a polewood; and during the standard and veteran stage, a tree forest. III. During the thinning stage (pole stages) of trees in an even- aged wood, the following classes of mess-mates might be distin- guished: a. After Schlich, “Dominant,” “Dominated,” “Suppressed, yet * alive,” and “Dead.” b. After Pinchot, “ Dominant,” “ Retarded,” and “ Overtopped.” 29 SYLVICULTURE. e. The usual classification, adopted by German foresters after Krafft is: 1. Predominating trees, having crown strikingly well developed. 2. Dominating trees, with well-developed crowns, forming the main cover overhead. 3. Condominating trees, with crowns of a fairly normal form, but of somewhat poor vigor, carrying, however, their crowns within the level of the main canopy. 4. Dominated trees with crowns more or less crippled or pressed from the sides, subdivided into two sub-classes, viz.: _a. Most of crown free from cover overhead. b. Most of crown underneath cover overhead. 5. Trees absolutely suppressed, standing entirely under the cover of others. G. Eyen aged woods: Woods, the components of which differ in age by less than 25 years, are called “even-aged woods.” In America, even-aged woods and hence the advisability of thin- ning is mighty rare. The struggle for existence between even-aged comrades can readily be alleviated by the forester’s interference. In America, even-aged woods are formed, for instance: I. By Long Leaf and by Cuban Pine. Il. By Jack Pine and Lodgepole Pine. Ill. By Bald Cypress. IV. By Douglas Fir. V. By Pinus echinata, taeda, strobus, ponderosa, virginiana on abandoned fields. H. Distribution of species. The horizontal distribution of species depends on the latitude and the proximity of the ocean, or better on sea winds, and pro- ceeds parallel with the vertical distribution. In the neighborhood of Biltmore, the following altitudes may he given: Spruce and Fir—5,500 ft. Beech—2,000 to 6,000 ft. Hemlock—2,000 to 3,800 ft. Chestnut—2,000 to 5,000 ft. Chestnut Oak—2,000 to 4,000 ft. Pignut Hiekory—3,000 ft. Bitter-nut Hickory—3,800 ft. Black Cherry—3,500 to 5,000 ft. Pinus virginiana—2,000 to 2.500 ft. Pinus strobus—2,000 to 3,500 ft. 30 SYLVICULIURE. Yellow Poplar—2,000 to 4,000 ft. Buckeye—3,000 to 6,000 ft. Red Oak—2,000 to 5,500 ft. White Oak—2,000 to 5,000 ft. Spanish Oak—-2,000 to 3,800 ft. Post Oak—2,000 to 3,000 ft. Black Oak—2,000 to 3,600 ft. Echinata—2,000 to 2,600 ft. Rigida—2,000 to 3,500 ft. Pungens—4,500 ft. Locust—2,000 to 5,500 ft. Black Gum—2,000 to 4,000 ft. Every species thrives best in certain centers, which are few in the case of the exacting and numerous in the case of modest species like yellow Pine, both east and west. Aside from vertical and horizontal elevation, the influence on distribution exercised by storm, snow and sleet is very marked. Paragraph VI. Light demanders and shade bearers. A. A plant is termed the more shade bearing or tolerant of shade, the less light it requires for the functions of assimilation, breathing, perspiration, flowering and fruiting. Only parasites live without light, and hence without chlorophyl. B. The following characteristics, in their aggregate and not singly, may lead the observer to classify a tree as a shade bearer: I. Dense leaf canopy. II. Leaves thin, dark, fiat, more numerous, not glossy, not downy, not bunched at the ends of the branches, with blades spread horizontally, withering quickly after separation from the branch. III. Thin bark. IV. Thick sapwood. V. Branches persistent, spread flat or pointing downward, com- paratively thin and interlacing. Crowns long. VI. Little live soil cover, and a heavy layer of dead humus underneath leaf canopy. VII. Dense stand of trees. C. Factors influencing the relative demand for light within one and the same species are: I. Latitude and hence intensity of insolation. II. Exposure. III. Fertility of soil, and hence digestive power. IV. Age of plants. 31 SYLVICULTURE. V. Distance between the crown levels of the shaded and of the ‘shading trees. Instances for I and III. White Pine is, in the south, almost shade bearing; in the north it is almost light demanding. Yellow Poplar on fertile soil stands heavy shading overhead. D. Woody species in their relative order of resistance against heavy shading might be arranged as follows: I. Relative order for the southern Appalachians: Witch Hazel. Dogwood. Fir. Hemlock. Hard Maple. Chinquapin. Black Gum. Spruce. Soft Maple. White Pine. Pinus virginiana. Linden. Chestnut. Red Oak. White Oak. Chestnut Oak. Ash. Spanish Oak. Black Oak. Finger Oak. Post Oak. Pinas rigida. Black Locust. Poplar. Hickory. Pinus echinata. Sassafras. Unfortunately, at Biltmore, shade bearers are usually weeds interfering with the valuable species. If. Pinchot gives the following schedule for the Adirondacks: Hard Maple. Beech. Hemlock. 32 yy SYLVICULTURE. Spruce. Balsam. Soft Maple. Birch. White Pine (intermediate). Black Cherry. Black and White Ash. Bird Cherry. Cottonwood. Tamarack. . The trees above White Pine Pinchot calls “tolerant” and those below White Pine “intolerant of shade.” III. The leading species of the United States; classed according to light or shade-demanding qualities are: a. Eastern Conifers: Long Leaf Pine—distinctly intolerant of shade. Echinata—light demander. Taeda—intermediate. Virginiana—intermediate. Rigida—not so much as virginiana. Bald Cypress---light demander. Chamaecyparis spheroidea—shade bearer. Spruce—fair shade bearer. Balsam—intense shade bearer. Hemlock—intense shade bearer. Tamarack—light demander. Arbor vitae—shade bearer. White Pine—intermediate. Jack Pine—light demanding towards intermediate. Norway Pine—light demander. b. Eastern hardwoods: * Beech—shade bearer. Hard Maple—shade bearer. * Silver Maple—shade bearer. Red Maple—shade bearer. Black Gum—shade bearer. Sourwood—light demander. Locust—light demander. Yellow Poplar—light demander. Chestnut—intermediate. Oaks—light demanders (White and Red Oak stand lots of shade when young). SYLVICULTURE. Elm—shade bearer. Birch—light demander or intermediate. Black walnut—intermediate. Linden—shade bearer. : Umbrella tree—less light demanding than Yellow Poplar. Cucumber—less light demanding than Yellow Poplar. Sycamore—medium shade bearer. Willows and Cottonwoods—light demanders. Liquidambar—light demander. Hickories—light demanders. ce. Western Conifers: Douglas Fir—intermediate. Ponderosa—light demander. Nut Pines—intense light demanders. Lodgepole Pine—intermediate. Sugar Pine—intense light demander. Lawson Cypress—intense shade bearer. Tide-land Spruce—shade bearer. Redwood—shade bearer. Western Hemlock—intense shade bearer. Western Firs—intense shade bearers. Larch—intense light demander. Engelmann’s Spruce—shade bearer. Colorado Blue Spruce—shade bearer. Paragraph VII. Pure versus mixed woods. A. Conditions inviting pure woods and mixed woods. Conifers are more apt to grow in pure forests, owing to their greater modesty. Abroad, up to a very recent time, the desire of the forester was to raise mixed woods, but quite recently the “Danish propaganda ” has turned the minds of some foresters back to pure woods. Severe climatic conditions and poor soil conditions invariably give one species the preponderance, for example: Bald Cypress rules in the swamps of the South, Tamarack in those of the North; Nut Pines prevail in the semi-arid regions of the Southwest; Long Leaf Pine on poor sand in the South; Cuban Pine in half swamps of the South; Red Spruce on the “Black Slopes” of the Adirondacks; White Spruce in Northern Canada; Lodgepole Pines on old burns; Jack Pine on poor sand in the Lake States. Pure forests are sometimes in the interest of the owner, for: example: Pure Spruce near paper mills; Hickory near carriage works;' Tan Bark Oak near tanneries. 34 SYLVICULTURE. A high rotation often leads to a pure forest, a short-lived admixture being gradually pressed out. Abroad the forester is required to maintain the fertility and productiveness of the soil. Since light-demanding species allow the soil to be baked by the sun during the pole and tree stage of the forest when grown purely, admixture of shade bearers under such conditions is advisable, obtained, for instance, by underplanting Yellow Pine with Beech, when Pine is 50 years old. B. Kinds of mixture. A mixture may be temporary or permanent; a mixture may be even aged or uneven aged; the species may or may not differ in height growth; the mixture may be composed of single indi viduals; of strips, rows, bunches, groups; or it may show an irregular character. In the course of time the original character of the mixt ve might be changed entirely by the forester or by nature. C. Advantages of mixtures. Mixed forests take advantage of differences of soil qualities; the moisture-demanding species gradually claiming the dells ani more modest kinds obtaining preponderance on the dry plateaus or spurs. 2 A mixture may form a preventive against late frost. A mixture is better protected against damages by fire, insect~, fungi, storms, snow, ete. A mixture produces « better quality of humus (Pine and Oax humus is better than pure Oak humus or pure Pine humus). A mixture produces a larger quantity of timber for the above reasons in addition to the fact that «a mixture allows its com- ponents to more fully utilize the productive factors of the air as well as those of the soil through a. Difference of crown formation, crown levels, crown density. b. Difference in root system (tap and flat-rooters mixed). ce. Difference in mineral and light requirements. A mixture also tends to produce cleaner timber—certainly so for the benefit of light demanders when placed in mixture with shade bearers. For all these reasons a mixed forest may be said to produce a larger and safer revenue than a pure forest. Valuable species might be raised beyond the limits of their habitat in mixed forests. D. Objections to mixed forest. ox ne SYLVICULTURE.' The administrative and the sylvicultural management of mixed woods is more difficult and hence more expensive than that of pure woods. In America logging expenses are much increased where only one species can be utilized in mixed forests. Logging for Spruce on “Black Spruce Slopes” in the Adirondacks is relatively cheaper per thousand feet board measure than logging for Spruce where Spruce forms only one-third of the growing stock. This objection does not hold good, of course, where all species are marketable at the same time. E. Rules-governing the composition of a mixture and rules for treating mixed forests (holding good for artificial and semi-arti- ficial forests) : I. Species selected for a mixture must improve one another, II. Each species should oceupy that section of ground on which it thrives best. : III. The mixture should at least maintain the productiveness of the soil. IV. A light-demanding species mixed with a shade bearer must either be given an advance in age or else must naturally possess an advantage in rapidity of height growth; otherwise it soon disappears. This relative height growth is not a fixed quantity; it usually differs according to the soil and to the climate. V. The denser the forest cover is, the earlier. and the morc intense must be the help given to the species likely to be suppressed (Sassafras: and Locust in mixture with Chestnut). After Henry Mayr: species which are botanically different from the most natural mixture (Oak and Pine at Biltmore; Birch and Spruce in Balsams; White Pine, Linden and Elm in Michigan). ‘The exceptions to this rule are many (Norway and Jack Pine in Michi- gan; Red Firs and White Firs in the Pacific Coast States). Paragraph VIII. Dr. Henry Mayr’s (Munich) fundamental prin- ciples of Sylviculture. A. Forest is possible only where the mean temperature of the four months of most active growth averages 50 degrees Faht. or over B. A mean summer temperature (May to August) of 53 to 59 degrees Faht. produces the Fir and Spruce zone of Europe, Asia and America. A mean summer temperature of 59 to 64 degrees is productive of Beech, also of White Oak, Maple, Hemlock and Cham- aecyparis. A knowledge of the summer mean is essential when introducing exotics. A -knowledge of the possibilities of forest 36 SYLVICULTURE. growth in a given country implies a knowledge of the mean summer temperature. Some very modest trees are unreliable as indicators or ther- mometers (i. e. Pinus echinata, Pinus ponderosa). C, A species may be grown far from its original habitation, provided that the local climate of the new region is ana:ogous to that of the old. If the exotic comes from a warmer climate, it should be placed on south slopes with plenty of sun; if it comes from a colder climate it should be placed in moist soil and on cool aspects. There is no such thing as adaptation of trees to a different climate, or as acclimatization of trees. Walnut, Peach, and Black Locust have been grown in Germany for centuries, be- cause the climate of naturalization was and is essentially identical with that of the natural habitat of the trees. D. Tree specimens of a cold climate do not possess in them- selves any special power of resistance to frost. It is useless to import seeds from colder climates in the hope of obtaining greater hardiness (Douglas Fir from Oregon and from Colorado differ, how- ever, in hardiness). , E. Species of trees growing in hot localities or else in open stands place comparatively small claims on the fertility of the soi. All species bear shade better when brought to a warmer climate and require more light when brought to a colder one (White Pine). F. In level countries, at not over 500 ft. elevation, the habita- tion of a species depends on latitude considerably modified by sea winds. In many countries, away from the ocean, that modification is so strong as to create a dependence of the habitation more on longitudes than on latitudes. In high mountain regions, altitude may produce effects similar to those of latitude: it is, therefore, a mistake to label one species as a mountain species and another as a plains’ species. In Eastern North America Picea rubens, in Western North America Douglas Fir, also Abies grandis and ama- bilis, bear witness to this truism. G. The climatic needs of a species are better characterized by the forest zone than by the latitude or the altitude at which or up to which it grows. Even a knowledge of altitude and latitude combined furnishes insufficient information relative to such cli- matic needs. H. If, in a given climatic zone, there are found two neighbor- ing species of the same genus, it is safe to assume that these two species were not mixed originally, but that each had its dis- tinct habitation and that the mixture is due to the action of man. 37 SYLVICULTURE. I. In primitive forests the species which harmonize are those which differ botanically. J. When two species are so alike as to be almost varieties but have, nevertheless, different climatic needs, then they are, in reality, true and distinct species (Douglas Fir in Colorado and Oregon). K. Frest injury is always due to the death of the plasmodium killed by the direct action of the frost. The plasmodium is most sensitive during the time of cell formation and of active growth. The plasmodium in the inert stage, as in seeds, is actually insensitive. L. All species become more hardy as they grow older. This is simply due to the trees rising above the cold layers of temperature near the ground and to the greater thickness and mass of the trunk, resisting rapid changes of temperature. : M. The degree of moisture in the air required for forest growth is 50% relative humidity during the growing season. The broad- leaved trees and the two and three needled Pines are the species best adapted to regions of extreme dryness or of sudden changes in atmospheric moisture. N. The association of trees into a forest has the effect of increas- ing the relative humidity by not to exceed 10%. Hence the neces- sity of maintaining forest in regions where the tension of watery vapor is close to 50%. The partial destruction of a forest may entail the death of the remainder rendering reforestation impossible unless it is started from the nearest adjoining forest. Inside a forest the greater atmospheric humidity acts as beneficially as a moist ocean wind, lacking, however, the latter’s violence. O. It is in moist, cool localities (mountains and northern cli- mate) that climatic variations are the least extreme during the growing season. It is here that the annual rings are equal, the grain fine and regular, and the timber of the greatest commercial utility. P. The moister the climate, the easier becomes forest culture, and the forester is apt to make the least mistakes in thinnings, regeneration, fellings, etc. Air moisture seems to exercise a favor- able influence on the straightness of the stems. Q. It is known that a failure of rain for several days may be fatal to young plants. The faculty of persistence increases with age, and the grown trees can endure long periods of drought. If, however, the lack of rain is such as to bring the sum total of precipitations during the four months of the growing season below the two-inch mark, then the forest disappears, even if the humidity 38 SYLVICULTURKE. of the air remains above 50%. Exception—immediate neighborhood of lakes and rivers with their sub-soil percolation. R. A fairly moist soil is the best for all species in their optimum climate. In hotter places the locality must be more damp, while in colder ones it may be dry without hindering growth (White Pine in the Pink Beds in swamps, in Canada on dry soil; Sitka Spruce in Washington in swamps; in Alaska on dry land). S. Snow protects those parts of a plant which it covers; it increases the danger, however, for the parts just above the snow level. Snowy winters are, therefore, useful to low plants, but harmful to trees (except broad-leaved trees). T. As regards the winds, the most dangerous are those which follow the direction of the barometric minima, which in Eastern America travel from east’ to west; in Europe from west to east: in East Asia from south to north. Next dangerous are the winds traveling in the opposite direction, whilst those from other points of the compass are more harmless. Every mountain, however, cre- ates a deflection of the current and possibly a return in the oppo- site direction. U. In their youth trees are almost indifferent to the quality of the soil; with increasing age their exigencies increase. Thus plantations on poor soil may thrive well for a number of years, only to-be suddenly arrested at the beginning of the pole stage. V. In their most suitable situation (natural optimum) a species succeeds on soil of any mineral description. In a less favorable climate the soil requirements .of the species increase. W. The light most favorable to activity of the chlorophyll is not the light of the blazing sun, nor is it the diffused light coming through rain or fog, but that light which is reflected by brilliant white clouds. Leaf cover overhead is favorable when it filters the rays of a burning sun and unfavorable when it excessively reduces the intensity of insolation. Under a continental climate, cloudless days are more numerous than near the coast. The infiu- ence of thinnings and removal cuttings on the remaining growth consequently depends on the continental position of a forest—not solely on species and soil. X. The regeneration of forests approaching exploitable age is easiest in their optimum climate. If the climate is too warm, seed will be more abundant, and the young plants will endure cover better. The moisture of the air, however, is wanting, and the 39 ‘ SYLVICULTURE. denser cover overhead may intercept too much of the needed rain- fall. If the climate is too cold, the moisture of the air indeed increases; but the production of seeds and the persistence under cover decrease. Y. In mixed forests artificial regeneration is more difficult than natural regeneration. A clean felling results in a capricious com- plication of natural laws and phenomena whose contrary actions are not easily understood. Natural regeneration, a mixture of species suitable to the locality, a crop resembling as closely as pos- sible the primitive state, such are the conditions which the forester should seek to realize for the avoidance of dangers as well as fur the greatest possible yield of the most valuable produce. No method of treatment harmonizes better with nature’s laws than the so-called selection system, when each tree is placed in a con- dition most favorable to its development, and when no single tre is removed for a purpose other than that of regeneration or im- provement of the crop. 40 CHAPTER II. THE HIGH FOREST. Paragraph IX. Genesis of the high forest and its methods. Wood crops can be started either naturally (from stump shoots, root suckers and self-sown seed) or artificially (by planting seeds, seedlings or cuttings). Forests starting from stump shoots, root- suckers and cuttings are called “coppice forests.” Forests start- ing from seeds or seedlings are termed “high forests.” A. Planting in Europe. "i Up to 1830 seed planting only was practiced to start high forests artificially. Since then seedling planting has gradually con- quered the European field, especially in the case of Yellow and White Pine, Spruce, Ash, Maple and Larch. Beech and Fir are invariably regenerated abroad from self-sown seed; also Oak in France, while in Germany acorns are usually planted. B. Advisability of planting in America. Excepting the case of the prairies and, possibly the case of fields abandoned by farmers in the Eastern States, the idea of artificial propagation of forest crops (by planting) seems preposterous in America. As long as an acre of virgin forest can be bought for a lesser sum of money than is required, in the same locality, for the successful re-forestation of an acre of ground, the chances for a re- munerative outcome of planting seem very slim. However, the fol- lowing points should not be lost sight of: I. The stumpage prices apt to prevail in America in the year 1960 are likely to equal those now prevailing abroad. Hence the same practice which is now remunerative abroad must prove paying in this country; possibly more paying for the reason that the value of the soil on which the growing crop must yield an annual dividend is abroad about ten times as high as it is in the United States. II. An expense for taxes and administration is incurred annually by the forest owner, whether the forest ground is kept fully or only partly stocked; hence it seems a remunerative venture to—at least— reinforce natural regeneration by artificial planting. III. The growth of weeds naturally plentiful in primeval con- ditions cannot be overcome unless radical artificial remedies are adopted. 41 « SYLVICULTURE. C. On the other hand, the following objections to planting must be considered: ce IAs long as the American forest is much endangered by fire, it is unwise to invest any money in young growth for which the danger of destruction by fire is excessive. II. Trees of a condition now considered “ weeds” may gradually attain a stumpage value (as Chestnut at Biltmore). III. Even European forestry is now reverting to a natural propa- gation of forests owing to the dangers usually inherent to artificial planting. D. Definitions. The word reforestation is used if the area to be planted has been previously occupied by tree growth. The word afforestation is used if there was no tree growth on the plot for a number of years beforehand. : Paragraph X. The Seed. The quality of seeds is shown by their size, weight, color, scent. A tree standing in an open position, not too young and not too old, produces the best seeds. = A. Seed years: f The atmospheric conditions of the year or year’s during which the seed is formed further influence the quality of the seed. Drought in summer and early frosts in fall cause the seeds to drop immature. Black Oaks and Pines require two years for the formation of seeds. Juniper three years. It seems as if all trees require a number of years for the preparation of seeds, inasmuch as the medullary rays before u seed year are found full of starch, and after a seed year de- void of starch. This phenomenon may explain the periodical occur- rence of seed years in Bamboo and Canebrakes, in Chestnut, Oak, Teech, Pine, ete. ; The length of the period elapsing between seed years depends on the local climate and the position of the trees, being short for trees standing in orchard-like positions on warm and sheltered ground where abundant heat allows of the rapid accumulation of starch. B. Rest: After dropping from the tree, all seeds undergo a period of rest in our climate. This rest is very short in the case of Cottonwood, Willow, Elm and Soft Maple. In the majority of cases, in Eastern North America, it lasts from November to April. In rare cases (German Ash, German Linden, Red Cedar, Hornbeam) the period of inactivity covers about seventeen months. Seeds which get too dry 42 SYLVICULTURE. while stored, often show a prolonged period of rest. For White Oak seed the period of rest is only two months; for Red Oak five months. The assumption that frost is required during the resting period for the benefit of the seed is erroneous. The germinating percentage is greatest immediately at the conclusion of the period of rest. C. Tests: Germinating tests are made with from 50 to 200 grains. I. Water test applicable to large seeds. Thrown in water the good seeds will sink, and the bad seeds will float. II. Cutting tests, made with a knife, used for testing acorns, chestnuts, nuts of Nutpines, also seeds of Ash, Yellow Poplar, Beech, ete. III. Hot-pan tests for conifers, which causes good seeds to jump and burst, poor seeds to burn and char. IV. Pot tests made in the following manner: Fill the lower halt of a flower pot with sawdust, the upper half with sand in which the seeds are embedded: Place the pot in a basin partially filled with water, in a warm room. V. Flannel test: Place the seeds between two strips of flannel kept moist by running their ends into a bowl of water standing at a lower level. VI. Test in the commercial-test apparatus, which consists of a bottom plate (glass or china), a bell-shaped top (same material) and a clay disk containing 100 small grooves, which fits into the bottom plate. All three parts are open in the center. The clay disk is burned in such a way as to retain good hygroscopic qualities, and is boiled for a number of hours (in water) before using, to kill adherent spores of fungi. Moist sand is kept between the disk and the bottom plate. The grains are inserted into the grooves. Paragraph XI. Preparations for planting seed on open ground. The germinating bed must offer the seed « proper, constant and equal supply of heat, oxygen and moisture. The actual amount of heat, oxygen and moisture required has not been ascertained scien- tifically. Observation in the woods is the best teacher of the condi- tions securing the largest possible germinating percentage for any given species. The preparaticn for seed-planting may extend over the entire area to be planted; or only over certain strips which may be inter- rupted or continuous; or it may merely involve the grubbing of plots or spots. Where the ravages of game or mice are feared, irregular working is advisable. 43 SYLVICULTURE. A. Removing the soil covers, such as briars, Kalmia, Chinquapin, mosses, dead leaves, humus. A plow and grubber (cultivator) or a harrow can usually not be used for the purpose; the hoe (a strong make) is largely used abroad; weeds are removed with brush hooks or seythes or machetes or are, if possible, killed by deadening. In certain cases an iron rake might do. Often it is necessary to remove the cover by fire; fire, however, produces a heavy growth of weeds on fertile soil (as in Pisgah forest). B. Loosening the soil. Just after logging, the soil has enough porosity to allow of the development of a second growth. On aban- doned fields or in prairies thorough working with the plow, often continued for a number of years, may or must precede the act of planting. Paragraph XII. Securing and preparing the seeds. A. European tree seeds are usually bought from reliable dealers, who rival in furnishing the best seed at the lowest price, guarantee- ing a certain percentage to germinate. In America, the forester must secure seeds himself, collecting them by contract, or preferably, by day work. Some European sylviculturists insist that seeds should be taken only from the best and strongest trees. Mayr considers special care superfluous. B. Under “coning ” is understood the method of obtaining seeds of coniferous species from their cones. Coning of Spruce, Pine, Fir and Larch on a commercial scale is practiced in Europe by Henry Keller, Appel & Co. and A. Lecoq, all of Darmstadt, Germany. Certain Pine species (Nutpines) have wingless seeds. The wings of other Pine seeds hold the grain in a claw. The seed of Spruce lies in the wing as in a spoon; the seed of Larch and Fir is attached to the wing and is not easily separated. Among the broad-leaf cone bearers—Alders, Birehes and Magno- lias—the coning of Magnolias only offers some difficulties. I. The methods of coning are as follows: a. Coning by insolaticn, the oldest and safest method. Trays, the bottoms of which contain cpen lath work cr wire netting, are placed in the sun and removed to a shed if rain threatens to fall. The cones are spread on the trays in layers not over two cones deep and are stirred with a rake. In place of trays, drums might be used ta good advantage. In a cold climate the sun process allows of obtaining the seeds only at a time too late for seed planting. The germinating percentage of seeds obtained by the sun process is, otherwise, superior to that of seeds coned by other methods. b. Coning by stove heat. 44 SYLVICULTURE. It is essential that the heat in the coning room should not reach 110 degrees. Thorough ventilation is required to prevent sweating and moulding of cones. The cones are spread in the coning-room in thin layers on shelves or screens, through the interstices of which the seeds drop. The cones are stirred three or four times a day. It is unwise to have the stove in the coning-room. An American hot-air furnace in the basement is well adapted to furnish the heat. Many of the large European forestry administrations have such or similar establishments for coning. ce. Commercial method. In the commercial establishments, heat is supplied by steam pipes, controlled by automatic devices. The trays or drums are kept in a constant rocking motion by machinery. The seeds, after falling through the crevices of the trays, are at once conducted to a cool room. II. Separating seeds from their wings. In the case of Pine and Spruce seeds, flailing is sufficient. It is not advisable to wet the seeds before flailing. For Larch, rubber millstones are used, the distance between the stones being equal to the smallest diameter of the seed. III. Cleaning the seed from dust, needles and wings. The seeds are freed from admixtures by fanning, shoveling, centrifuge or any grain-cleaning machine. The large commercial establishments drop the seeds on endless rolls of cloth, which are moving on an incline. The heavy seeds slide down, whilst dust and wings are carried uphill. IV. Statistical notes. a. Spruce in the Adirondacks (after Clifford R. Pettis). 1. Cost of picking cones 50c per bushel (green). 2. One bushel of green cones yields two bushels of dry cones, containing 1% Ibs. equal to 11% qts. of Spruce seeds. 3. One bushel of cones weighs 60 lbs., one bushel of seeds 40 Ibs. . One pound of seed contains 150,000 grains. 2 . It costs 95¢e to collect, cone and clean one pound of seeds. . White Pine at Biltmore. . 100 bushels of cones will weigh 2,200 Ibs. (a “long ton”). 2. One bushel contains 600 to 700 cones, and yields, on an average, % lb. of absolutely clean, wingless seeds. 3. One pound of such seed contains 25,000 to 30,000 grains. ec. Yellow Pine (ponderosa) in New Mexico (after Wm. H. Mast). 1. One bushel of cones yields 1.55 lbs. of clean seed. 2. The expense of collecting, coning and cleaning averages 23c per pound. eon, 45 ‘ SYLVICULTURE. d. Colorado Blue Spruce in New Mexico (after Wm. H. Mast). 1. One bushel of cones yields 1.2 lbs. of clean seeds. 2. The expense of coning, collecting and cleaning averages 23¢ per pound. : e. Shortleaf Pine at Biltmore (Pinus echinata). One bushel of cones yields one pound of clean, wingless seeds at an expense of $1.00 per pound. C. Seeds stored beyond the duration of their natural period of rest show a reduced percentage of germination. The percentage might be increased by the use of slightly acid solutions, lime water or hot water. Coniferous seeds are often placed in cold water for from three to seven days previous to planting; seeds thus treated, however, must be supplied with moisture artificially after planting if drought sets in. D. The “ malting ” of seeds (placing the seeds in heaps, moisten- ing them and stirring them in a warm room) is a rather dangerous procedure. After Weise, Douglas Fir and White Pine seeds should be mixed with moist and fertile soil and stable manure, to be then exposed to a hot-house temperature until the germs begin to show. S. B. Green recommends to pour boiling water on the seeds of Locust, Honey-Locust and Coffee-tree, and to allow the seeds to remain in the water until it is cold, planting immediately there- after. Paragraph XIII. Actual planting of seeds on open ground. Seeds should not be planted on rainy days, especially not on clay soil. For broadcast planting, the area to be planted and the seed are divided into equal lots. The quantity of seed allotted to the unit of space is subdivided into halves. Each half is sown separately by going over the ground crosswise. Broadcast planting is rare nowadays. Rough nursery beds (either running full length of the area or interrupted beds), furrows or banks are frequently provided. Nar- row trenches may be pressed into the beds or banks with the help ef a board, a hoe handle or a wheel. The seed is usually sown by hand, possibly with the help of a beer bottle, a so-called seed horn and, rarely, with a seed- planting machine. The machine should only be used on ground as well prepared as a wheat field (prairies or abandoned fields). On land newly cleared, roots and stumps prevent the use of a machine, 4G ‘ SYLVICULTURE. “Covering” purports to place or rather press the seeds into contact with the mineral soil on all sides; to prevent sudden changes of air temperature from striking the seed; to prevent the seeds from drying out under excessive exposure to the air. The cover must be such as to allow a young germ to push its cotyle- dons easily through the cover. The seeds keeping their cotyledons below ground (Oaks, Sassafras, Chestnut) allow of a heavy cover. In the case of coniferous seeds, a proper cover is secured with the rake or with a brush drag; or by marching the planters, a band of sheep or a herd of cattle over the plantation. Heavy seeas are often strewn on the ground without any preparation and then covered with a shovelful of dirt. In America seed-planting in the open is an unadvisable measure as long as the prices of seeds maintain their present figure. “Planting of cones” was the leading method used a hundred years ago by European foresters. The cones were strewn on the ground and stirred periodically by sheep, with good results. Seeds more than one-quarter inch thick, especially nuts, are usually dibbled with dibbling hammer, wedge, knife, hoe, spade, etc. The hole made should place the seed at the best depth. The hole is closed by side pressure, by the foot or the hammer, or by allowing a lifted sod to drop back in place. The common planting spade often puts the seeds too deep. , A. The quantity of seeds used per acre depends on: Price of seed. Density of stand desired. . Tenderness, sensitiveness and rate of growth of species. Local damage from late frost, drought, weeds, insects, mice, squirrels, rabbits, game, birds, etc. Quality of both soil and seeds. Fineness of prepared soil. Method of planting by hand or machine, regular or irregular, broadcast or in patchwork. Planting seeds in bands or strips only requires two-thirds or three-fourths of broadcast amount; planting in patches one-half, in holes one-fourth of the same. B. Figures adopted at Biltmore for broadcast planting are, per acre: White Oak and Chestnut Oak, 12 bu. Red Oak and Black Oak, 8 bu. Ash, 40 Ibs. Beech, 130 Ibs. Maple, 40 Ibs. 47 SYLVICULTURE. Elm, 24 Ibs. Birch, 32 lbs. Firs, 45 Ibs. Spruce, 10 Ibs. Larch, 10 lbs. Yellow Pine, 8 Ibs. White Pine, 12 lbs. C. Small seeds: Number of seeds in one pound (approximately, all coniferous seeds without wings): INGE: nade cae etled Seaptad HERES Coes eee Mey eS 6,200 NY © cents Radiesse oa ee alent dee dae A hanes 8S 55,000 Silver Fir? a,c carina ace nate oad yale 9,000 Tamarack seceavaniicas danger ds odin sas eee 70,000 White Pine ..s2¢¢0s sadegadevegesaa douse 30,000 Maple space edmueied aN E toca bE Ree DS 5,000 Bitchy -+ saccectesactdd des poaeeiat ou bet namaeneet 80,000 SPIUGE sawn yang eomenire can eine wees ee 56,000 Yellow Pine susnissaee ais dyes ceceeeua es 70,000 D. Large seeds: Number of seeds in one bushel are: White Oak, 8,000; Red Oak, 3,000; Walnuts, 800. Paragraph XIV. Season for seed planting on open ground. For Cottonwoods, Elms (excepting Red or Slippery Elm), Soft Maple, Black Birch and Mulberry, the best time of planting is nature’s time,—immediately after the fall of the seeds—in early summer. In the case of the species enumerated, the period of rest is very short and the seedlings starting rapidly have time to lig- nify before winter. In all other cases the forester can plant either in fall or in spring. Planting in winter is usually prevented by the condition of the soil. A. Planting in fall invites: I. Inroads of animals in winter. II. Washing of seed when snow melts. III. Damage from late frost, since planted seeds sprout early in spring. B. Spring planting necessitates: I. Expense for seed storage over winter. II. Checks during storage, injurious to germinating percentage. Ii. Higher expense for planting, planting taking place at 2 time when labor is scarce. Spring planting forms the rule, except with Fir, Beech, Chest- nut, White Oak. 48 SYLVICULTURE In semi-tropical regions or places of periodical drought, the best planting time is the fortnight preceding the rainy period. On dry soil seeds are planted as early in spring as possible so as to profit from the moisture left by melting snow. ; Seeds which naturally germinate 18 months after maturity (Red Cedar, Hornbeam, some Ashes, some Basswoods) require strati- fication: Place seeds, in dry soil, in a ditch ten inches deep and ten inches wide, to a depth of five inches. Cover seeds with straw and dry weeds, and finally with dirt. After the lapse of a year the seeds are ready for planting. Paragraph XV. Auxiliaries to seed planting. A. Means to protect species needing shade in earliest youth. I. Plant seeds with oats, barley or summer rye, planting the grain seed in quantities not to exceed 75% of the normal. Cut grain crops high. This method was used regularly 100 years ago, for European Pine and White Oak, possibly with a view to early returns, possibly to distract ravages of field mice and birds. II. Certain species, tender and shade demanding in early youth like Beech and Fir, cannot well be raised in the open, unless an usher growth 12 to 15 years older (of Yellow Pine, Sassafras, Black Locust, Birch) is previously started on the ground. The usher growth is gradually removed when the seedlings underneath want “skylight.” In semi-arid parts such usher growth is perhaps doubly advisable; further in prairies, where Poplars and Willows, Box Elders and Soft Maple might serve as ushers (also Locust). B. Means to protect the seed plantation from animals and weeds. , 1. Against seed-eating animals. Planting in late spring offers some protection. Planting in sprouting condition protects heavy seeds from rodents; slight coating of red lead protects conifers from birds. A watchman might be kept on large plantations, to scare the birds away. By coating large seeds with tar, crows might be kept away. II. Light cover of weeds is no disadvantage. Where weeds are heavy, seedlings should be planted, rather than seeds. Mowing (with seythe) weeds and fefns, crushing briars—preferably before weeds are seeding---is recommended. Where seeds are planted in rows or furrows on abandoned fields, cultivation checks weeds. IIL. Pasture is not allowed in seed plantations before the thicket stage is past. C. Reinforcing. Bare spots where seed planting has failed are 49 SYLVICULTURE. usually reinforced by planted seedlings. The latter are taken fron: adjoining dense spots. In broad-leaved species, the blanks where planting has failed, had better be marked during the preceding summer. Paragraph XVI. Planting seeds of the broad-leaved species. A. Acorns. The germinating acorn leaves the cotyledons below ground. If the first shoot is killed another forms at once. ‘ods hse Een 1 eee ree 158 Two-storied high forest..... 2... 5. sees ee eee e eect e eee ees 138, 141 Y AO, 126, 173 Transplanting iM NUMSCTICS. 0. ee eee nee 78 Trimming in nurseries .......... 6-02 seer reer eee e teenies 79 Types of enesar.... 00.5.6 +. sees tener eee e teen eee e eee eees 97 es 181 v8 ; U PAGE Underplanting ................ cle Maia tAlawle Siunniiel palate aeteR 127, 130 Underwood. sicicnsscexesinetes Ae arate nwa Regine NBER oe Reg eon 161 Ushergrowtht: 3.0.4 scien dace ta meee nadie eas Fay Secaais teomneal dices 49 S04 v Vendibility influencing the form............... esses eee ners 137 WwW Wagener thinnings ................ eee eeue pth Gea ence eaten kee 133 Walnut, high forest 0f.........0.. 002s cece cence nee tenes 148 Walnut, planting of seedlings............... 0c e eee eee 84, 87 Walnuts, planting of seeds....... 6... ce eee eee eee eee eee 51 Wartenberg’s planting iron..........--... 0 eee eee eee eee 67 Water in: 0il wisccescaderdenahies gent dtm angee heres ak sae 22 Weapons of species in struggle for existence................... 26 ‘Wedded: forms! ic.cator pouines ima naeo ine os Senet eSee ks 137 WSU i. sc iiceis seiazecsioseiecs: avsun sv caveneieceaess 4s aseutuds gud ucptbiaas 127, 128, 156, 165 Weeding in nurseries.......... 0.0: c cece eee cence eee eens 79 White Pine, high forest of...........00 0000 cece cucu eee eeeees 152 White Pine, planting of seedlings.............. 0. cece eee eeeee 85 White Pines, planting of seeds........... 0c cece e eee eee eee 58 Willow coppice: 224 cess. sew ceeetins beers wensr neces ess 160 Wind anid tree: erowthtiasisiieid cic ccna: sce. eneitaae aceudlaiie a mvenn ene wood 11, 39 Wintering of acorns... 0.0.0... cece cece eee teen eee 51 Y Yellow Pine, planting of seedlings.................0 esses 84, 90 Yellow Pines, high forest of........... 00... cece cence eens 152 Yellow Poplar, planting of seedlings................ cee eees 83 Yellow Pines, planting of seeds............ 0.0.0 cece cece e eee 57 Yellow Poplar, high forest of............0 00.0.0 cece eee eee 149 Yellow Poplar, planting of seeds.............. 20... e eee eee 56 182 et Asaeats Sess i SOLED ESE. 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