U. S. DEPARTMENT OF AGRICULTURE, DIVISION OF ENTOMOLOGY— BULLETIN NO. 34, NEW SERIES. L. O. HOWARD, Entomologist. Principal Insects Liable to be Distributed on Nursery Stock. Prepared Lender the Direction of the Entomoi OGIST, NATHAN BANltS, A msta nt Entom olog ist . WASHINGTON: GOVERNMENT PRINTING OFFICE. 1902. Digitized by the Internet Archive in 2012 with funding from University of Florida, George A. Smathers Libraries with support from LYRASIS and the Sloan Foundation http://archive.org/details/cipalinOOunit LETTER OF TRANSMITTAL U. S. Department of Agriculture, Division of Entomology, Washington, D. C., April 29, 1902. Sir: I have the honor to transmit for publication a manuscript pre- pared by Mr. Nathan Banks, of this office, in which are considered the principal insects liable to be distributed upon nursery stock. The inspection of nursery stock under State laws has become so general throughout the United States that the desirability of some publication of this sort has become very evident. I had the matter in mind last autumn, and at a conference of the official horticultural inspectors for the United States, held at Washington October 11-13, 1901, a resolu- tion was unanimously passed requesting this Department to prepare and publish an article on those nursery pests of the country which are capable of transmission on nursery stock to the injury of the pur- chasers. Since it is desirable that this manuscript shall be put in available shape for distribution to all horticultural inspectors and to all nurserymen and others immediately interested, I recommend that it be issued as Bulletin No. 34, new series, of this Division. Respectfully, L. O. Howard, Entomologist. Hon. James Wilson, Secretary of Agriculture. CONTENTS. Page. Introduction 9 Tabular statement of insects upon the tree in winter 1 9 Tubular statement of insects feeding on the buds and young leaves in early spring 10 Hemiptera (bugs, scale insects, plant-lice) 10 Family Coccidse (scale insects) 11 Table of scale insects 11 The peach lecanium 11 The oyster-shell bark-louse 12 The scurvy bark-louse 14 Aspidiotus ( circular or round scales) ; 14 Table of Aspidiotus 15 The San Jose scale 15 The European fruit scale 18 Putnam' s scale 19 The cherry scale 19 The walnut scale 19 The greedy scale 20 The grape scale 20 The peach scale 21 The rose scale 23 Family Aphid;e (plant-lice) 23 Table of plant-lice 23 The woolly apple aphis 24 The black peach aphis 25 Apple plant-lice 26 The plum plant-louse 26 The cherry aphis 27 Family Psyllidse 27 The pear-tree psylla 27 Family Membracidse. 28 The buffalo tree-hopper 28 Lepidoptera (butterflies and moths) 29 The apple-tree tent caterpillar 29 The fall web worm 30 The browm-tail moth 31 The leaf-crumpler 32 The white-marked tussock moth 32 The gipsy moth , 33 Cankerworms 35 The peach-tree borer 35 The peach twig-borer 36 The bagworm 37 Other caterpillars 38 5 Coleoptera (beetles, weevils) 38 The round-headed apple tree-borer 39 The flat-headed apple tree-borer 40 The sinuate pear-borer 40 The fruit-tree bark-beetle. 42 The apple twig-borer 43 Acarina (mites) 43 The pear-leaf blister-mite 43 Insects infesting fruits .... = „ 45 ILLUSTRATIONS. Page. Fi(i. 1. Lecanium nigrofasciatum 12 2. Mytilaspis pomorum 13 3. M ytilaspis pomorum 13 4. Chionaspis furfurus 14 5. Aspidiotus perniciosus, on branch 16 6. Aspidiotus perniciosus, female 17 7. Aspidiotus perniciosus, on fruit and branch 18 8. Aspidiotus ostraeformis 19 9. Aspidiotus juglans-regire 20 10. Aspidiotus rapax 21 11. Diaspis pentagona 22 12. Aulacaspis rosrc . . 22 13. Eggs of plant louse 23 1 4. Schizoneura lanigera 24 15. Schizoneura lanigera, work on roots 24 16. Aphis persicpe-niger 25 17. Psylla pyricola 27 18. Ceresa hubalis 28 19. Clisiocampa amerieana 29 20. Hyphantria cunea 30 21 . Euproctis chrysorrhea 31 22. Orgyia leucostigma 33 23. Porthetria dispar, moth 33 24. Porthetria dispar, larva 34 25. Porthetria dispar, chrysalis „ 34 26. Alsophila pometaria, moths 35 27. Alsophila pometaria, stages _ . 35 28. Paleacrita vernata, moths 35 29. Paleacrita vernata, stages 35 30. Sanninoidea exitiosa 36 31. Anarsia lineatella 36 32. Thyridopteryx ephemeneformis, cases 37 33. Thyridopteryx ephemeneformis, insects 37 34. Tmetocera ocellana, larva 38 35. Tmetocera ocellana, work of 38 36. Saperda Candida 39 37. Chrysobothris femorata 40 38. Agrilus sinuatus, stages 40 39. Agrilus sinuatus, work of 41 40. Scolytus rugulosus 42 41 . Amphicerus bicaudatus 42 42. Rhagoletis pomonella 44 43. Rhagoletis cingulata 45 7 THE PRINCIPAL INSECTS LIABLE TO BE DISTRIBUTED ON NURSERY STOCK. INTRODUCTION. In preparing this descriptive catalogue of the insects liable to be transported upon nursery stock, it has appeared that there is a great disparity of views as to what insects should be included. To include only such as are known to be very destructive would exclude a great many species that will be found by anyone who examines a tree in the fall or early spring. To include all the species that are known to be found in any stage upon fruit trees in winter would make the list too bulky. Therefore, all species known to be of more than local interest have been treated. Notes on the species infesting fruits are added at the end. The insects have been arranged according to their natural orders, and in the Hemiptera (bugs, scale insects, plant-lice) according to the families. In the Coleoptera (beetles, weevils) and Lepidoptera (but- terflies and moths), such an arrangement did not seem desirable. No account of the remedies to be recommended or used is given, as these differ greatly, according to locality and conditions, and the various State laws specify certain treatments. It will be a great help to those interested in the growth and sale of young fruit trees to be able to recognize the appearance of the various insect pests during the winter; therefore, much attention has been paid to this phase of the subject. In using this bulletin one should remember that, besides the insects here treated, there may be upon a tree other insects of )ess importance. TABULAR STATEMENT OF INSECTS UPON THE TREE IN WINTER. Insects upon the roots: Forming swellings on apple roots "Woolly aphis. On peach and plum roots Black peach aphis. Insects upon the bark of trunk or branches: Plant-lice or aphids Woolly aphis. Small brown clear-winged insect in the crevices of bark Pear psylla. Scale insects or bark-lice See Coccidse. Caterpillars in cases or cocoons Fall webworm, bud moth, apple Bucculatrix, codling moth, pistol-case and cigar-case bearers. In nests or bunches of shriveled leaves attached to branches Leaf-crumpler, and brown-tail moth. 9 10 Insects upon the bark of trunk or branches — Continued. In a case or bag hanging from twigs Bagworm. Clusters of eggs on bark Cankerworms, tussock moth, and gipsy moth. A belt of eggs around twigs Apple-tree tent caterpillar. Single small blackish eggs often in groups on twigs or branches Plant-lice. Smaller reddish eggs Clover mite. Insects beneath the bark: Tiny holes usually near a crotch, each covered by a bit of frass Peach twig-borer. Small brown beetle within the twig Apple twig-borer. Small holes in bark of trunk or larger branches Fruit-tree bark-beetle. A gummy exudation of sap at base of tree Peach tree-borer. Discolored spots or cracks and evidences of frass Round-headed and flat-headed apple tree-borers, and sinuate pear borer. TABULAR STATEMENT OF INSECTS FEEDING ON THE BUDS AND YOUNG LEAVES IN EARLY SPRING. Feeding on the buds or young shoots Bud worm, peach twig-borer, leaf-crumpler, brown-tail moth, pistol-case and cigar-case bearers. Feeding upon the leaves: Plant-lice Apple plant-lice, plum plant-louse, and cherry aphis. Caterpillars in tents Apple-tree tent caterpillar. Hairy caterpillars Tussock moth, brown-tail moth, gipsy moth. Bare caterpillars Canker worms. A blister or gall upon leaves Pear-leaf blister-mite. Small caterpillars within little cases Pistol-case bearer, cigar-case bearer, leaf-crumpler, and bagworm. HEMIPTERA (BUGS, SCALE INSECTS, AND PLANT-LICE). The members of this order obtain their food (which is liquid) by sucking it up a slender tube into the mouth cavity. This tube or beak is composed of several needle-like pieces so shaped and arranged that they inclose a minute channel up which the liquid food is drawn. The beak is inserted in the plant often to some distance beneath the surface. The members of this order do not pass through a pupal or chrysalis stage like the butterflies and moths, but there is an approach to it in the males of the scale insects. The insects of this order to be treated are arranged in four families, which may be separated, for our purposes, as follows: The insect from above apparently without legs, antennae, or wings, and fixed to the host plant; the adult male (not often seen) usually has two wings Coccidae. ( scale insects) . The insect shows distinct legs and antennas, and often four wings. Most of the specimens wingless, and provided with two small tubes or cornicles (see fig. 16) near tip of body; not hopping when disturbed Aphididae (plant-lice). Adult always winged, without the cornicles; hopping when disturbed. The prothorax not enlarged, with hyaline wings. Psyllidse. The prothorax greatly enlarged; wings obscured Membraeidse. 11 FAMILY COCCIDiE (SCALE INSECTS). The scale insects, or bark-lice, are readily known from most insects in that the stages commonly seen are immovably fixed to the bark or leaf, and show no outward sign of legs or other structures. For a short time after birth they are active, crawling creatures, and distribute themselves over the surface of the plant. Having selected a location, they push their long and thread-like beaks deep into the tree and pro- ceed to suck up the sap. As they grow the protected or covered bark- lice secrete a waxy substance that hardens and forms the scale. When the insect molts the old skin or exuvium remains attached to the scale. The shape, color, and position of this exuvium is of great value in identifying the specie-. Their small size and similarity of appearance makes their determina- tion difficult, and it is rarely safe to determine the species by a few individuals, but on a moderately infested branch one is apt to find some specimens that are quite characteristic of the species. The unprotected bark-lice, such as the Lecaniums, secrete no cover- ing scale. TABLE OF SCALE INSECTS. 1. Soft scales, without a shield-like covering, very convex, on peach or plum. Lecanium nigrofascUitnni , 2. Armored scales, with a shield-like covering and showing an exuvial spot, much less convex than Lecanium 3. 3. The exuvium shows as a circular spot situated near the center or at least remote from the edge of the scale; the adult female scale more or less circular, rarely whitish in color Aspidiotus. 4. The exuvium showing as a more or less ribbed, elliptical spot at the end or close tooneedge of the scale; scales usually whitish in color; if not, then of an oyster- shell shape : 5. 5. Scale brownish; the female of an oyster-shell shape, male ovate. Mytilaspis pomorum. 6. The scale whitish, female not oyster-shell shaped, male scale elongate 7. 7. The female scale plainly ovate, much longer than broad; the male scale having three longitudinal keels (see fig. 4, nmi in diameter, of a uniform drab or yellowish-brown color, the exuvial spot showing reddish, but not commonly exposed rapax Comst. Scale of the adult female large, nearly 3 mm in diameter, Hat, and pale-grayish in color; the exuvium reddish or orange jugktns-regix Comst. In identifying scale insects by means of the above table, scales should be examined from bark or fruit as clean as possible, and where the scales are not crowded and have room to normally develop. When thickly massed they lose their characteristic shape and appearance, and on sooty or dirty bark they are discolored and abnormal. THE SAN JOSE SCALE. [Aspidiotus pemiciosus Comstock — figs. 5, (>, and 7.) The San Jose scale is known to every orchardist by hearsay, but few, however, can distinguish it from allied scales, such as ancyhis, y brbesi, and osi/reaefonnis. On badly infested trees the scale presents the appearance of dark gray, scurfy patches. The individual scale is about 2 mm in diameter, usually nearly circular in outline, of a grayish color, with the central darker nipple surrounded by one or more quite distinct yellowish or pale grayish rings. When the scales are crowded the outline is more or less distorted. In none of the allied forms is the adult female scale as nearly circular as in the San Jose scale. When on fruit or young twigs there is often a reddish discoloration around the scale. Putnam's scale and the cherry scale have a brighter colored exuvium, situate one side of the center. The cherry scale is often much paler than the San Jose scale. The European fruit scale has an exuvium similar to the San Jose, but lacks the darker nipple; 16 moreover, the exuvium is plainly not at the center of the scale. The male of the San Jose scale is about two times as long as broad; broader at one end than at the other, with a large, dark exuvium, showing a central nipple. It is situated toward the small end of the scale. The male of the European fruit scale is not so elongate, and the exuvium is but little darker than the scale and nearer to the small end than in the San Jose scale. The male of Putnam's scale is as elongate as that of San Jose, but has an orange exuvium. The male of the cherry scale is in shape much like that of the San Jose scale, but the exuvium is of a brighter yellow, the scale usually being paler than the San Jose. CL Fig. 5. — Aspidiotus pemiciosus: a, infested twig; b, view of infested bark magnified. Marlatt. ) (Howard and In general the adult female of the San Jose scale may be distin- guished from its allies by the more circular scale, with yellow exuvium, when exposed, more centrally located, otherwise with dark nipple; the male by similar characteristics of exuvium and nipple. But the San Jose scale is most easily recognized by its immature scales, which are almost black, circular, and with a central nipple surrounded by one or two depressed circular rings. Such a character is not found in any other of the allied scales. 17 The San Jose scale attacks all of our orchard trees, but appears to be most destructive to pear and peach. The insect is represented in winter by partly grown specimens whose development was stopped by the cold weather. They resume growth in the early spring; the males soon appear, mate with the females, and the latter give birth to living young. At Washington, D. C, this time is about the middle of May, and the young continue to appear for about six weeks. The larva crawls off a little way. settles, and within two days begins the Fig. 6.—Aspidiohts pernicio&us: a, female; b, margin of pygidium magnified. (Howard and Marlatt.) secretion of its scale. This young scale is at first white with a swell- ing in the center. If it is situated on green tissue it is apt to pro- duce a redness. In a few days the pale scale becomes nearly black, with a central nipple surrounded by one or two depressed rings. This form is very characteristic of the species. In about twenty-five days another brood of males appears, and in thirty days the females become adult. At about thirty -five or forty days of age the females begin to give birth to living young. Since one of these mother scales may have been born six weeks before another, it results that there is a 24842— No. 34—02 2 18 confusion of generations throughout the summer, breeding constantly going on until late fall. The number of broods will thus depend upon the lenp'th of the season. YiG.l.—Aspidlotaspcrniciosus: Infested fruit and branch, and enlarged scales. (Howard.) THE EUROPEAN FRUIT SCALE. (Aspidiolus ostrefeformis Cnrtis — fig. 8.) This species can usually be readily separated from the San Jose scale by the characters mentioned under that species, but it is practi- cally impossible, without making a microscopic mount, to distinguish it from Putnam's scale and the cherry scale. The cherry scale, espe- cially when on cherry, is more shining and often shows a grayish margin. The European fruit scale occurs on all orchard trees, but only, so far as known, in certain Northern States. The winter is passed by the partly grown specimens, which become mature toward the last of June, and soon begin to give birth to living }^oung. The young continue to appear for several weeks. There appears to be but one brood a year, at least in the Northern States. 19 PUTNAM S SCALE. (Aspidiolus ancylus Putnam, i This scale is widely distributed and attacks all orchard trees. In general appearance it is like the San Jose scale, but at once known by the exposed orange exuvium, the less circular scale, and by the half- grown young having- no depressed ring around the nipple. It can be separated from the European fruit scale and from the cherry scale only by a microscopic examination of mounted specimens. It is usu- ally much darker than the cherry scale, the exUvium usually a brighter orange, and the scale more conical than that species. Specimens vary, however, a great deal in these points. The insect winters in a nearly full- grown condition. The males appear in April, soon pair with the females, and the latter deposit eggs in the late spring or early summer. The } r oung begin to hatch early in July and continue dur- ing the month. There is but one brood a } T ear. THE CHERRY SCALE. (Aspidiotus forhesi Johnson. ) This scale is similar to Putnam's and to the European fruit scale, but some- times, especially on cherry, it is more shining, and presents a gray rim around the scale, which is commonly flatter than the allied species. It attacks all orchard trees, but is rarely com- mon. It winters partly grown, like its allies. The male issues in April. The eggs are laid in April or earl} r May, the young hatching during May and part of June. There appears to be two broods a year, the males of the second brood issuing during the latter part of July and the young during August and September. Fig. 8. — Aspidiotus ostrexformis: a. scales on twig; b, natural size; c, immature stage: hi* persicae-niger. B. Plant-lice on the leaves: With bluish-white mealy powder; on plum Hyalopterus pruni. Dark brown ; on cherry Myzus a rasi. Green, or faintly reddish; on apple Iphis mali and A. sorbi. 24 THE WOOLLY APPLE APHIS. (Schizonrura lanigera Hausmann — figs. 14 and 15.) One often notices on the trunk or larger branches of the apple Fig. li.—Schizoneura lanigera; a, agamic female; &, larva; c, pupa; d, winged female. (Marlatt.) small, bluish-white, ilocculent patches of a woolly substance, which indicate the presence of this insect. This cottony substance is a wax-like excretion clinging to the posterior parts of a small, reddish -brown wingless aphis. It is not, however, this form on the trunks that causes injury. This aerial form is but the indication that there are other speci- mens, under the ground and feeding on the roots of the tree. It is the latter form that seriously affects the vitality of the tree. Upon the trunk the lice often cause a roughening of the bark, especially on the new growth around scars made by prun- ing. On the roots the lice cause hard and large knots, which eventu- ally produce a "club-footed" con- dition of the roots. Such trees usually show their weakness by the fewer and duller colored leaves. The woolly aphis is practically confined to the apple, but there are a few varieties, such as the Northern against its attacks. The lice com- Fig. 15. — Schizoneura lanigera; a, b, work on roots; c, a louse. (Marlatt.) Spy, that appear to be immune 25 inonly found on the trunk and roots in summer are the wingless, agamic females. They give birth to living young, and continue to do so, possibly for several years. In spring some of the root-lice 4 will crawl up the trunk and continue to breed there till fall. The colonies of lice on the trunk give rise to winged and migratory females. These, when they locate, give birth to wingless male and female lice, and each female deposits a single winter egg in a crevice of the bark. This egg will, in the spring, hatch into a female which will start a new colony of wingless lice on the trunk. Some of these will, in the summer, crawl down upon the roots and continue to breed there. In the north the colonies on the trunk are apt to be killed out by the severe cold weather, but in warmer latitudes many of them live through the winter, particularly if they are protected by a piece of bark. THE BLACK PEACH APHIS. {Aphis persicse-7iiger E. F. Smith — fig. 16.) This insect, like the woolly apple aphis, does its great injury under- ground. Its ravages on the roots of peach give a sickly appearance to the foliage of the affected tree, the leaves often being light green or Fig. 16.— Aphis persicx-niger; winged specimen. (J. B. Smith.) yellowish in color, and their edges somewhat rolled. The wingless lice on the roots are of a dark-brown color. They breed there con- tinuously without producing males or eggs. Early in the spring some of the root-lice crawl up the trunk of the tree and locate on the young twigs. Here the winged form develops and migrates to other trees to found other colonies. The winged insect is of a shining black or very dark brown color, the tibia? of the legs being mostly yellowish. 26 Toward midsummer many of the lice on the twigs crawl down into the ground and locate upon the roots. APPLE PLANT-LICE. The foliage of apple trees, particularly of young trees, often appears curled, and sometimes discolored. This curling is produced by colo- nies of plant-lice. These lice secrete a sticky liquid known as honey- dew, which falls on the leaves below. A black fungus grows upon the leaves covered by the honey-dew, and this checks their growth. There are several of these plant-lice that attack the leaves of apple; two of them are greenish in color, another has a reddish tinge. The commoner of the two green species is known as Aphis mali Fitch, (probably Aphis annum Oest). Its life history is about as fol- lows: The eggs are laid on the tree in the fall, partly hidden in crev- ices of the bark; the young hatch from these eggs in early spring, and grow into wingless and sexless lice, known as "stem-mothers," which produce living young; these young become winged, and, in the early summer, migrate to grasses, where they increase during the summer. In the fall they develop a set of winged, sexless lice, which migrate back to the apple and give birth to sexed individuals; these pair, and the female lays her eggs. The other green species is Aphis mali Koch. It passes its entire life history upon the apple. The eggs are laid in the late fall. They are black, and occur generally on the trunk and branches. In early spring the young hatch from these and grow into stem-mothers. These produce living young for a number of generations. Many of these of the first two generations become winged, fly to other apple trees, and there start colonies. In October sexed specimens are produced, and the female lays the eggs that are destined to pass the winter. The other apple plant-louse is A. sorbi Kalt. It is distinctly tinged with red, and the wingless forms have a whitish powdering on the body. This species has a life history similar to that of Aphis mali Fitch., but it is not known what plants serve as its summer hosts. THE PLUM PLANT-LOUSE. {Hyaloptevus pruni Fabr. ) This insect winters in the egg state. The young on hatching in spring go to the under surface of the leaf and there multiply rapidly. Their bodies are covered by a bluish-white mealy powder. Winged specimens are occasionally developed which migrate to other trees. They feed on the plum all summer, but some specimens are said to migrate to grass in early summer. In the fall the winter egg is attached to a plum twig, usually at the base of a bud. At times they do considerable damage to young plum stock. 27 THE CHERRY APHIS. ( Myzus cerasi Fabr. ) This aphis often causes the leaves of the cherry to become crumpled and rolled, and on young trees sometimes does serious damage. The winged and wingless insects are both of a dark brown color, and look much like the black peach aphis. The c^^ are laid in the fall on the branches at the base of buds and in crevices of the bark. The young hatch from them in the spring when the buds begin to swell. crawl out upon the buds and growing leaves, and develop into stem- mothers, which give birth to living young. This is kept up all sum- mer until the fall, when the sexes appear and the female deposits her eggs. A number of winged migrants are developed in the spring generations, which serve to spread the species. The insects usually become very abundant by June, but in midsummer they are not as common. FAMILY PSYLLIDiE. THE PEAR-TREE PSYLLA. (Psylla pyricola Forster — fig. 17.) This insect is closely related to the plant-lice, but readily known by its longer antenna 1 and its ability to hop. Its color is reddish, with Fig. 17.— Psylla pyricola; greatly enlarged. ( Maria tt.) some black markings, and with clear wings laid roof -like over the body. When disturbed, it hops and flies away. 28 The insect is widely distributed in the East, but usually is not abun- dant enough to seriously injure the ttree. When they become excess- ively abundant they cause the leaves and fruit to dr}^ and fall. The adult insect hibernates in crevices of the bark. These overwintering specimens are brownish-black in color, with bronzy eyes. The}^ emerge from their hiding places in the early spring, mate, and the female begins to lay eggs before the leaves are out. The eggs are placed singly or in groups in crevices of the bark of the twigs or in old leaf scars, and, when the leaves have unfolded, upon the leaves themselves. The larvae hatch in about two weeks and begin to suck the juices from the leaves and petioles. They at once commence to excrete hone} r -dew, and when the insects are extremely numerous the amount of liquid secreted is enormous and fairty rains from the tree. A black fungus grows on the honey-infested leaves and tree, so that the whole soon has a smoked appear- ance. In about thirty days the larva becomes adult. Development contin- ues all through the summer, and there may be as many a live broods if the season be long enough. It is only known to attack the pear. FAMILY MEMBRACIDiE. THE BUFFALO TREE-HOPPER. (Ceresa bubalus Say — fig. 18.) Upon young fruit trees, particularly the apple, one sometimes sees a series of oval or elliptical scars that disfigure and weaken the branches and render them liable to other insect attack. These scars are the results of the work of a curious insect, the buffalo tree-Lopper. It is a grass-green, triangular insect that hops and flies away when disturbed. The pronotum of the thorax is enlarged, as with others of this family, to cover the head and most of the abdomen. The anterior corners of the pronotum project laterally into acute angles. In August and September the adult insects ma}^ be found on the trees engaged in oviposition. The female cuts the bark with her ovipositor in two nearly opposite curved slits, so that the bark between is cut loose. Beneath each slit she deposits a series of from 6 to 12 eggs. These eggs hatch in the spring. The dead piece of bark falls out and leaves the elliptical scar, which enlarges with the subsequent growth of the twigs and becomes an inviting point for the attack of other insects. There is but one brood each year. Fig. 18.— Ceresa bubalis: a, insect; b, recent punctures; c, eggs; e, old scars. (Marlatt.) 29 LEPIDOPTERA (BUTTERFLIES AND MOTHS). The caterpillars and cocoons of these insects are known to all. The caterpillars differ from the grubs of beetles in that they have on the under side two rows of pro-legs — fleshy, wart-like structures that serve to support the posterior part of the body. The injuries caused by these insects are made by the caterpillar. These have biting mouth- parts that nip out tiny pieces of the leaf or wood, which is then chewed and swallowed. The more injurious forms that are liable to be transported on nursery stock may be arranged as follows: 1. Feeding within the trunk. Peach-tree borer. Feeding within the twigs <>r leaf-shoots Peach t wig-borer. Feeding upon the leaves 2. 2. The insect covered by a case Bagworm, leaf-crumpler, pistol-case bearer, cigar-case bearer. The insect not covere< 1 by a case 3. 3. Making tents or nests Apple-tree tent caterpillar, fall webworm, brown- tail moth, leaf-crumpler, and bud moth. Without tents 4. 4. Hairy caterpillars Tussock moth, gipsy moth. Bare caterpillars Cankerworms. THE APPLE-TREE TENT CATERPILLAR. (Clisiocampa americana Ilarr — fig. L9. I %v ; ■ ^ ~ -r^mim? -P. ■ -~M{ tm HP e r- */ Fig. 19.— Clisiocampa americana: a, b, caterpillars; c, egg-mass, d pupa; e, female. /. male. I Riley.) The webs or tents of this caterpillar are frequently found on orchard and nursery trees in May and June. The caterpillars use this tent as 30 a common home, where they retire at night and remain during cloudy days. Each clear morning, at about 8 o'clock, they go out along the branches to the leaves for feeding. The amount of damage done will depend a great deal upon the number of tents upon the tree. The eggs are laid in masses of 200 or 300 arranged in a broad belt around the twig. (See fi.g. 19, c.) Each end of this belt tapers off to the twig, which character serves to distinguish it from similar egg-clusters of certain other moths. Each mass is covered with a glistening sub- stance that protects it from the rain. The }^oung caterpillars hatch during the- latter part of April or earty in May, at about the time when the leaves are expanding. They immediately begin to feed on the leaves near by and to unite them into their tent, which is enlarged as the caterpillars grow. The full-grown larva is nearly 2 inches long, hairy and black, with a white stripe along the back. On each side of this is a row of short, yel- low streaks; there are also pale lines on the sides of the body. The under side is nearly black. When ready to pupate the caterpillar seeks some protected spot and there spins its yellowish cocoon, and soon changes to a brown chrysalis. The moth, which is brown, with oblique white bands across the forewings, emerges in a week or so and deposits her egg-mass and dies. There is but one brood a year. THE FALL WEBWORM. (Hyphantria cunea Dru. — fig. 20. ) During the summer and early fall webs or tents sim- ilar to those of the. apple- tree tent caterpillar are often seen among the terminal branches of fruit trees. These are the work of the fall webworm. The eggs of this moth, 300 to 500 in num- ber, are laid in patches on either side of the leaves in June. The larvae issue from June to August, and at once begin their web. They eat only the upper surface of the leaf, leaving the veins and the under surface untouched. The young caterpillar is pale yellowish, with dark spots along the sides and covered with scattered hairs. The full-grown Fig. 20.— Hyphantria cunea: moths and cocoons. (Howard). 31 caterpillar is velvety black above, the sides have two yellow stripes, and between them are many blackish patches and dots. The yellowish or brownish hairs are mostly in tufts which arise from tubercles or warts. Some specimens are quite pale; others very dark. In Septem- ber or October the caterpillar is ready to pupate, and descends to the main branches or trunk of the tree. Here it makes a delicate cocoon, within which it changes to a chrysalis. The insect passes the winter in this stage, and the moth emerges the following spring. The latter has white, sometimes spotted wings, and expands about an inch and a half. There is but one brood each year in the North, but from New York city south there are two broods, the caterpillars of the second making their appearance in August. THE BROWN-TAIL MOTH. (Euproctis chrysorrhea Linn. — fig. 21.) This insect, at present confined to certain parts of eastern Massa- chusetts, is such a dangerous pest that all interested in nursery trade Fig. 21. — Euproctis chrysorrhea. Moths, larvae, and cocoons. (Howard.) should be able to recognize it. During winter their small but very compact webs or nests attached to the terminal twigs are very promi- nent objects and will aid in distinguishing the species. In midsummer the eggs may be found in patches of two or three hundred attached to the under side of a leaf near the tip of a branch. The o^ mass is covered by a dense Uryer of brown hairs from the tip of the abdomen of the female. The young hatch in August and eat the surface of the leaf. As soon as it is devoured thev draw another leaf to it, until 32 in the fall the}^ have quite a tent. On the approach of winter they strengthen their tent and use it to shelter them during the winter. In spring they come out, eat the unfolding buds and tender leaves, and thus do great damage. The full-grown caterpillar is about 1^ inches long, dark brown, mottled, and spotted with orange, and clothed with reddish-brown hairs and two rows of dense tufts of white hair along the upper side of the body. By the middle of June the cater- pillars are ready to pupate, and each makes a cocoon attached to a terminal branch, or sometimes elsewhere on the tree, or even on some other object. These cocoons are often close to each other, so as to form quite a mass. The moths emerge in a few weeks. They have white wings, and the females a brown tip to the abdomen. There is but one brood each year. THE LEAF-CRUMPLER. (Mineola indiginella Zell.) The presence of this insect is easily recognized in winter by the clusters of brown, shriveled, and partly eaten leaves fastened together and to the twigs by silken threads. Within each cluster of leaves is a curved tube, usually sinuate at the small end, and within this tube is the small, brownish caterpillar of this moth. This caterpillar is but half grown. In early spring the larva cuts loose from its fastenings, crawls with its case out upon the branches, and attacks the developing buds and young leaves, thus causing a great deal of injury. The cat- erpillar becomes full fed by the middle of May, and is then of a green- ish color. It pupates in the larval nest, and the moths issue in June or early July. The eggs are deposited in July, singly on the leaves. The young larva, upon hatching, starts to make a little case for itself, which it enlarges when necessary. They feed on all fruit trees, but are partial to apple, and there. is but one brood annually. THE WHITE-MARKED TUSSOCK MOTH. (Orgyia leucostigma S. & A. — %, 22.) The caterpillar of this moth, which does great damage to shade trees in cities, sometimes attacks apple and other fruit trees. The adult insect is a light-grayish moth, the female wingless, the male with ash- gray wings, expanding about li inches, and the antennae are feathered. The eggs, 300 to 500 in number, are laid by the wingless female in the fall within a frothy substance, which on drying becomes hard and brittle. The whole is a very prominent whitish mass, often situated partry or wholly upon the old cocoon. In Ma}^ the } r oung larvae hatch and begin eating the foliage. The larvae are full-grown in July, and spin their slight silken cocoons, attached to any convenient spot. The full-grown caterpillar is a very handsome insect, about li inches in 33 length, yellowish, with three blackish stripes along the body, and a bright-red head. It is clothed with long, scattered hairs, four white HEIDEMflN S.t Fig. 22. — Orgyia U ueostigma. Various stages; eggs at h and k. ( Howard.) tufts on the anterior part of the body, and three long black plumes, two in front and one at the tip of the body. In the North there is but one brood a year, but from New York city south there are usually two broods, the caterpil- lars of the second appear- ing in early August. THE GIPSY MOTH. (Porthetria dispar Linn — figs. 23, 24, and 25. ) Although practically confined to certain parts of Massachusetts, this insect is quite liable to spread, and all interested in orchards and nurseries should be able to recognize this caterpillar. 24842— No. 34:— 02 3 Fig. 23. — Porthetria dispar: female moth. (Howard.) 34 The eggs to the number of 400 to 500 are deposited in clusters attached to trees, fences, etc. Each cluster is covered with yellow hairs from the body of the female, which causes the mass to resemble a piece of sponge. The caterpillars hatch from April to June, and feed vora- ciously on the leaves, mostl} T at night. The full-grown caterpillar is about 2 inches long, of a grayish, mottled appearance, with the tuber- Fig. 24. — Porthetria dispar. Larva. (Howard.) cles on the anterior part of the bod}^ blue, and those on the hinder part of the body red, all giving rise to long yellow and black hairs. When the caterpillars are about half grown they begin to crawl down the tree to the ground in early morning, and ascend again for feeding in the evening. B3 7 July they are ready to pupate in a thin cocoon fastened Fig. 25. — Porthetria dispar. Chrysalis. (Howard.) to the trunk of the tree, to a fence, or other convenient object. The pupal period is about ten days, and the moths issue in August. The female moth has whitish wings with several black spots, notably around the outer margin. The male is brownish, with darker undu- late lines and spots. The gipsy moth attacks almost every sort of tree, and there is but one brood a year. 35 CANKERWORMS. (Figs. 26, 27, 28, and 29.) These .slender, bare caterpillars appear on apple and other fruit trees in early spring and eat holes in the leaves. As they crawl they loop up the body, and are thus called "measuring worms" or "inch worms." There are two species of the cankerworms, their habits, how- Fig. 26. — Alsophila pometaria: a, male; b, female, C, '/, details. (Riley.) Fig. 27. — Alsophila pometaria: a, I) /, larva; c, d, segments of same; (Riley.) '. eggs; v. pupa. ever, being similar. The eggs are laid in clusters on the tree in the fall and early winter, with the fall species {AlsojphUa pometaria Harr.); in March or April with the spring species (Paleacrita vemata Peck). The eggs of the former are flattened on top; those of the latter are rounded. The larva 1 hatch in early spring and at once feed on the Fig. 28. — Paleacrita vemata: a, male; b, female, c, d, c, details. (Riley.) 6 (£ Fig. 29. — Paleacrita vemata: a, eater- pillar; h, egg; c, d, segment of caterpillar. (Riley.) leaves. When full grown they descend to the ground and pupate therein, the moths issuing in late fall or wry early spring. The females are wingless, and obliged to crawl up the tree to deposit eggs. The males have large, thin, gray wings. There is but one brood each year. THE PEACH-TREE BORER. {Sanninoidea exitiosa Say — fig. 30.) This destructive insect is readily discerned by the presence of a gummy exudation mixed with frass and excrement at or near the base of the tree. The parent moth lays the egg^ singly (from May to July, according to latitude) on the bark of the tree, usually near the base. The young larva burrows into the bark and mines between it and the 86 sapwood during the .summer and fall. It is quiescent during- the winter, but resumes feeding in the early spring, reaching full growth by May or June. The caterpillar is then a little over 1 inch in length, soft, and pale yellowish in color, with a shining, dark-brown head. It transforms to a chrysalis within an elongate cocoon just beneath or sometimes outside of the bark. The moths emerge in May Fig. 30. — SSanninoidea exitiosa: a, female; b, male; c, larva; d, e, female and male pupse; /, cocoon. (Marlatt.) or June. The female has dark-blue fore-wings; the male has clear ones. It primarily attacks peach, but sometimes cherry and plum. There is but one brood each year. THE PEACH TWIG-BORER. (Anarsia linealella Zell. — fig 31. ) The presence of this insect in the winter is quite readily known by bits of frass attached to the bark, often at the crotches of branches or twigs. Each bit of frass covers the entrance to a small burrow lined with silk, within which the young larva of this insect passes the winter. It is now of a yellow- ish color, with the head and thoracic segments, as well as the last seg- ment, almost black. Early in spring, when the leaves are coming out, the larvae abandon their bur- rows and attack the tender leaf shoots, boring into them from a point a little below the apex, and when one shoot commences to dry the larva leaves it and attacks another. In about two weeks the larva is full grown, and pupates in a slight open cocoon attached to the bark or among the shriveled leaves. The tiny, grayish moth issues in May. Two broods follow this, the larvae boring in the young twigs Fig. 31.— Anarsia lineatella: a, infested twig b, same enlarged; c, larva in case, d, larva en larged. (Marlatt.) 37 or sometimes in the immature fruit. The larva from the second brood makes the little burrows in the bark in which the insect passes the winter. The peach twig-borer feeds on all stone fruits. THE BAGWORM. (Thyridopteryx ephemerssformis Haw. — figs. 32 and 33.) The winter cases or bags of this insect, 1^ to 2 inches long, are often seen hanging from the branches of shade trees, particularly arbor- Fig. S2.—Thyrulopteryx-ephemerseformis. Cases; d, one cut open. (Howard.) vitae, locust, and basswood, but are not so common on fruit trees. The adult insect is a moth; the female winffiess: the male with four Fig. 33.— Thyridopteryx ephemerseformis: a, larva; 6, head of same; c, male pupa; d, female pupa, e, adult female;/, adult male— all enlarged. (Howard.) transparent wings and a black body. The female never leaves her case alive, but in the fall deposits her eggs therein, drops out and dies, 38 Fig. 34. — Larva of bud-moth. (Slingerland.) the case remaining attached to the tree all winter. In May the young hatch, and at once start to make little cases for themselves, which they enlarge as they grow. When read}^ to pupate, the caterpillar fastens its case to a twig and transforms to the chrysalis. The male moth appears in August. There is but one brood a year. OTHER CATERPILLARS. On the apple tree in winter one may find several other caterpillars in various stages of development. One of them, the pistol-case bearer (Coleophora malivoreila Riley), is a small larva with a dark head. It carries with it a case the tip of which is curved over, the whole about one-eighth inch long. It feeds on the buds and leaves in spring. In the fall it fastens itself securely to the twig, and thus passes the winter in an immature condition. Another is the cigar-case bearer (Coleophora Jletc her ella Fern.). It has a life history similar to the preceding, but its case is straight, not curved. Both feed on the pear and quince. Small, elongate, white, ribbed cocoons, nearly one-fourth of an inch long, often in clusters, are sometimes seen on apple bark in winter. They indicate the presence of the apple-leaf bucculatrix (B. pomifoliella Clem.). In spring the tiny, delicate moths issue from the cases. The larvae mine the leaves. There are two broods an- nually. Small, inconspicuous cases, covered with particles of dirt and bark, are, at times, found on the bark of the apple and pear. These con- tain the half -grown larva of the bud-moth (Tmetocera ocellana Schif., figs. 34 and 35). In spring the larva feeds on the buds and young leaves, webbing the leaves in a bunch or nest. They pupate within this nest. The moth issues in Jul}^, and is a grayish insect with a creamy white patch on each fore-wing. During the summer the young larvae partially skeletonize the leaves, feeding beneath a thin silken web. As winter approaches they migrate to the twigs and form their hibernating cases. There is but one brood a 3^ear. COLEOPTERA (BEETLES, WEEVILS). Beetles are easily known by the hard, coriaceous fore-wings that cover and protect the back of the abdomen. Both in the larval and the mature conditions they have biting mouth-parts, and injury is Fig. 35.— Work of bud-moth larvse in opening twigs. (Slingerland.) 39 sometimes done by both the grub and the beetle. The grubs, to reach the adult condition, pass through a complete change or metamorphosis, like caterpillars, but do not spin a silken cocoon. The grubs do not have the prolegs that are found in caterpillars. The forms to be noticed below may be arranged as follows: 1. Boring in the twigs Apple twig-borer. Boring in the trunk or larger branches 2. 2. .Making tiny circular holes in the bark Fruit-tree bark-beetle. Making a sinuate crack or depression Sinuate pear borer. Discolored spots on the bark Round-head ami flat-head apple-tree borers. THE ROUND-HEADED APPLE-TREE BORER. (Saperda cr