INJURIOUS INSECTS AND USEFUL BIRDS BY F. L.WASHBURN M.A, 'The first farmer was the first man, and all historic nobility rests on possession and use of land." — EMERSON. LIPPINCOTT'S FARM MANUALS EDITED BY KARYC. DAVIS, PH.D. (CORNELL) PROFESSOR OF AGRICULTURE, KNAPP SCHOOL OF COUNTRY LIFE GEORGE PEABODY COLLEGE FOR TEACHERS, NASHVILLE, TENNESSEE; AUTHOR OF PRODUCTIVE FARMING, ETC. INJURIOUS INSECTS AND USEFUL BIRDS SUCCESSFUL CONTROL OF FARM PESTS BY F. L. WASHBURN, M.A. (HARVARD) PROFESSOR OF ENTOMOLOGY, UNIVERSITY OF MINNESOTA; ENTOMOLOGIST TO THE MINNESOTA EXPERIMENT STATION, AND STATE ENTOMOLOGIST. FELLOW IN A. A. A.S., MEMBER OF AM. ASSOC. EC. ENT., AM. ENT. SOC., AM. SOC. OF NATURALISTS, ETC. LIPPINCOTTS FARM MANUALS Edited by K. C. DAVIS, Ph.D. SECOND EDITION REVISED PRODUCTIVE SWINE HUSBANDRY BY GEORGE E. DAY, B.S.A. PROF. OF ANIMAL HUSBANDRY, ONTARIO AGRICULTURAL COLLEGE, CANADA. 96 illustrations. xiii-{-j6j pages. $1-75 net. SECOND EDITION REVISED PRODUCTIVE POULTRY HUSBANDRY BY HARRY R. LEWIS, B.S. POULTRY HUSBAND RYMAN, NEW JERSEY AGRICULTURAL EXPERIMENT STATION. 330 illustrations. xxi + 536 pages. $2.00 net. SECOND EDITION REVISED PRODUCTIVE HORSE HUSBANDRY BY CARL W. GAY, B.S.A. PROF. ANIMAL HUSBANDRY, CHAIRMAN ANIMAL HUSBANDRY SECTION, DEPARTMENT OF AGRICULTURE, UNIVERSITY OF MINNESOTA. 176 illustrations. xvi +JJJ pages. $1-75 net. PRODUCTIVE ORCHARDING BY FRED C. SEARS, M.S. PROF. OF POMOLOGY, MASSACHUSETTS AGRICULTURAL COLLEGE. 157 illustrations. xiv -\- 314 pages. $1.75 net. PRODUCTIVE VEGETABLE GROWING BY JOHN W. LLOYD, M.S.A. PROF. OF OLERICULTURE, UNIVERSITY OF ILLINOIS. 1 94 illustrations. xiii -f- 339 pages. $1-75 net. SECOND EDITION REVISED AND ENLARGED PRODUCTIVE FEEDING OF FARM ANIMALS BY F. W. WOLL, PH.D. PROF. OF ANIMAL NUTRITION, UNIVERSITY OF CALIFORNIA. 106 illustrations. xii -f- 375 pages. $l'75 net. SECOND EDITION COMMON DISEASES OF FARM ANIMALS BY R. A. CRAIG, D.V.M. PROF. VETERINARY SCIENCE, PURDUE UNIVERSITY. 124 illustrations. xii + 334 pages. $1-75 net. PRODUCTIVE FARM CROPS BY E. G. MONTGOMERY, M.A. PROF. OF FARM CROPS, CORNELL UNIVERSITY. 204 illustrations. xix +507 pages. $1-75 net. PRODUCTIVE BEE KEEPING BY FRANK C. PELLETT STATE APIARIST OF IOWA. JJ5 illustrations, ' xiv +302 pages. $1.75 net. PRODUCTIVE DAIRYING BY R. M. WASHBURN PROF. OF DAIRY HUSBANDRY, UNIVERSITY OF MINNESOTA. 132 illustrations. xii + 432 pages. $i-75 net- 10 I In L. WOOD, DEL. Plate 1. CUT WORMS, ARMY WORMS, AND OTHERS. RIOUS INSECTS USEFUL BIRDS vM Pi- iolo9 ni 8iioiJj;ni;Y janiwoiia bus .sra-Ba 9f(J lo tfooM— .£ .jp^ lo '{.iiuioiv sdi ni bs^oslloo ,8fmow-tuD ^nsieBiG — .7 bnB ,8 ,5 ^ .esi'il imow-tuO ^88^10 sri ,1 bnjs ,6 ,8 .egi'5! •;/s9b iwta 'Jnifi1! 10 (i£[fiqi.3teO fndsS 9iiT — .11 ba& 01 .831^ .(aineH otoiq; mSaajwolll) siii E« nwoojl irr i, 399. A Cottontail Rabbit 414 400. Nest of Young Rabbits 415 401. Apple Tree Protected by Wire Screen 417 402. Tree Guard Made of Wood Veneer 417 403. A Tree "Bridge-grafted". . 418 404. Pocket Gopher 419 405. Outline of Head of Pocket Gopher 420 406. An Effective but Unsafe Gopher Gun 420 407. Diagram of Burrow of Pocket Gopher 421 408. Thirteen-lined Ground Squirrel, or "Striped Gopher" 422 409. Gray Ground Squirrel or "Gray Gopher" 410. Another Species of Ground Squirrel 423 411. The Common Mole 424 412. A Successful Mole Trap 425 413. Field Mice 426 414. Woodchuck .431 A hair line in connection with a figure indicates the natural size of the insect. INJURIOUS INSECTS AND USEFUL BIRDS CHAPTER I LOSS TO AGRICULTURE DUE TO INSECTS AND RODENTS INSECTS comprise fully four-fifths of the animal kingdom. Nearly 400,000 species have been named and described, and an enormous number, several millions, are probably in existence. Deciduous fruit interests lose, according to Quaintance, over $66,000,000 annually through the work of insects. The Mexican Cotton Boll Weevil in Texas alone has caused a loss of $25,000,000 annually, and when all southern states which produce cotton are infested with this insect, the country will lose $250,000,000 every year. In 1906 our hay crop was valued at $600,000,000, but might have been $60,000,000 more had it not been for the inroads made by in- sects. About $150,000,000 is sacrificed every year to the Hessian fly, and between the years 1894 and 1909 the chinch bug destroyed $350,000,000 worth of crop. The codling moth (Fig. 1) alone levies an annual tax in the United States of $12,000,000. FlG' l-Codl™* moth> enlar*ed- Farm and forest products (Fig. 2) each year in the United States probably average more than $8,000,000,000, and these same products suffer a loss annually of $900,000,000, approximately, through the attacks of insects. Of this the wheat crop alone suffers a loss each year of about $100,000,000. In 1908 a cut-worm, attacking corn over a limited area in Indiana, caused a loss to that crop of $200,000. The work of cattle ticks entails a loss of from $40,000,000 to $100,000,000 each year. Briefly, about ten per cent of all of our crops are sacrificed every year to insect ravages. The work of the economic entomologists is to restore to the agricultural classes as much as possible of this loss, and, by their 1 TO AGRICULTURE WORK OF ECONOMIC ENTOMOLOGISTS 3 researches, to place citizens on their guard against insect enemies. That their work is appreciated is shown by the large appropria- tions for this work made by federal and state governments. Massa- chusetts, for example, has used, in the past, $150,000 annually to combat the gipsy moth, to which must be added approximately $100,000 spent by private citizens in that state and $10,000 con- FIG. 3. — A portion of a wheat field badly "down" as a result of the work of the Hessian fly (Original.) tributed by the United States Government. New Jersey is on record as spending $350,000 a year in fighting mosquitoes alone. Losses from the San Jose scale, codling moth, Hessian fly (see Fig. 3), chinch bugs, and grasshoppers have been materially re- duced through the work of our entomologists, who have also lessened by nearly or quite half the $100,000,000 loss on stored 4 LOSS TO AGRICULTURE products, such as mill stuffs, fruit, cotton, woollens, etc., suffered each year in the United States. Squirrels, gophers, and prairie dogs destroy every year some- thing like $10,000,000 worth of agricultural products. In the winter of 1901-1902 nurserymen near Rochester, New York, sus- tained a loss of $100,000 through the work of field mice. In the case of prairie dogs, conservative estimates place the annual loss in Nebraska, due to this rodent, at $80,000, and ground squirrels in one ranch in Nevada, in one season, caused a loss to the grain crop of $10,000. QUESTIONS 1. What losses have been sustained by farmers in your neighborhood, caused by grain insects? 2. What injury have you seen done to trees by insects? 3. Are there any valuable forest areas in your state? 4. Have they been injured by insect pests? 5. What is your state doing to protect its forest areas? 6. What orchard insects are troublesome in your vicinity arid what is being done to combat them? CHAPTER II FARM PRACTICES TO LESSEN INSECT AND RODENT INJURIES MODERN methods in farming have much to do with the con- trol of farm pests. Fall plowing and the use of tooth and disk harrows are helpful in destroying or exposing to their enemies such insects as pass the winter in the ground. In parts of the country where it is practical, summer fallowing, by keeping down all weeds, starves out insects which normally would feed upon them. Cleaning Up in Autumn. — Corn shocks afford hibernating quarters (Fig. 4) for chinch bugs and field mice; and cabbage and ___. - .„ -,,-~ FIG. 4. — Shocks of corn left in the field over winter afford shelters for chinch bugs and field mice. cauliflower stalks — melancholy objects in the field — harbor the pupae of cabbage maggots over winter; old melon and cucumber vines may afford retreats for insects infesting cucurbits, and volun- teer plants and weeds, both along fence rows (Fig. 5) and in other places, add to the number of Hessian flies, chinch bugs, joint worms, field mice and other pests. Clean farming, therefore, which means the cleaning up and destruction by burning of this rubbish, should be the rule. A neglected orchard is a breeding place for scale and borers; broken branches, dead or dying, invite the presence of hosts of minute beetles which bore in bark and wood (see Fig. 6). 5 6 FARM PRACTICES TO LESSEN INJURIES The modern orchardist does not permit these things to exist, and in his orchard there is to be found no tangle of matted grass to afford a hibernating place for mice and countless insects. Intelli- gent pruning will not only shape a tree, but the burning of the branches cut will destroy many eggs of aphids and of other insects. Systematic spraying of trees with the proper compounds is a necessity for one who would produce marketable fruit, and fre- quently protects an orchard, not only against insects which eat the leaf and fruit, but against other pests as well (Fig. 7). FIG. 5. — A weedy fence row harbors many insect pests. (Bull. 77, U. S. Bu. Ent.) Early mulching of trees or of any crop should be avoided, for field mice that work all winter look, in the fall, before freezing occurs, for snug nesting places for the winter. A field of timothy which has been in sod for a number of years is likely to become infested with army worms. Intelligent rota- tion, therefore, is practiced to-day by the wide-awake farmer, care being taken not to follow one crop with another equally as attract- ive to the insect he seeks to exterminate. Sod land is the natural abode of wire worms and cut-worms, and corn or grain or some truck crops following sod are likely to be injured. SOD LAND FIG. 6. — Branches left lying on the ground under a top-worked tree. The fruit tree bark beetles breed in these branches. (After Brooks, U. S. Bu. Ent.) FARM PRACTICES TO LESSEN INJURIES Early or late planting of certain crops may result in these escaping injury; for example, from the cotton boll worm, Hessian fly and others. The early cutting of clover leaves the second crop less subject to injury from the Clover-seed chalcid. Heavy fertilization or intensive cultivation, or both, may so force a crop as to enable it to outgrow insect injury. Resistant Plants. — The grower may also buy resistant stock — fruit trees on roots resistant to borers — or he may plant strong ~] stemmed wheat which will not ! readily break as the result of Hessian fly injury. Occasion- ally a choice in varieties will help, as in the case of the strawberry weevil, which attacks only staminate varie- ties of berries. Protection of all birds known to be useful, and judicious treatment of those thought to be injurious should be the program of a wide- awake farmer, and one should be cautious in condemning any bird, since an injurious trait may be a temporary one, due to unusual conditions, and may be more than balanced by a bird's good qualities exercised at another season. One should, in particular, hold the right attitude toward hawks and owls — a group formerly re- garded with unjust suspicion. With the exception of Coopers Hawk, and at times other large hawks regarded as "hen hawks/' and the sharp-shinned hawk which feeds largely on small birds, all of the hawks and owls are more or less useful, some of them decidedly so, since they feed upon insects, field mice, gophers, rabbits and ground squirrels (see Chapter XX). It is believed that the large increase in field mice in parts of the Middle West may be accounted for very largely by the war of destruction waged against hawks and owls, and animals such as FIG. 7. — Portion of an orchard showing trees well covered with a dormant spray. (Dean, in Kansas Bull.) COOPERATION le common skunk, weasels, and foxes. The natural food of the skunk is not chickens or eggs, but insects, mice, and young rabbits. A weasel, having acquired the habit, may at times kill poultry; yet normally they eat meadow mice, rabbits, and squirrels. Foxes — occasional depredators — cannot injure chickens which are properly housed at night. In the open, they feed upon rabbits, chipmunks, field mice, crickets, grasshoppers, white grubs, and May beetles. The ruffed grouse and the quail, also, suffer through their attacks. Hogs in an orchard pick up wormy windfalls; and hogs or sheep, or both, turned into an insect-infested field after crops are removed, are helps to the orchardist and agriculturist. Neglect of active measures at the beginning of an attack frequently means loss; plant lice, for example, increase with marvellous rapidity, and individuals should be destroyed by thorough treatment at the very beginning of their work. Certain questions, however, should present themselves to the thoughtful farmer or orchardist before attacking an insect which is apparently causing him a loss. He should first of all ask himself whether the insect in question is really the cause of the injury observed; secondly, is its attack lasting, thus making it necessary to take action, or is it temporary and not of great importance? thirdly, is the insect subject to attacks from birds or predaceous or parasitic insects (not always readily determined) which will make it unnecessary for one to wage war upon it? and, finally, if its extermination is practical, which is the best and most economi- cal way to attack it? — is it a sucking insect or one which eats the surface of the plant? If it is a sucking insect, employment of in- ternal poisons, like arsenic, Paris green or arsenate of lead, would be absolutely useless. Stop Rodents in Time. — One pocket gopher, in a nursery or young orchard, may, by working on roots, put many trees out of commission. This can be prevented by early attention. Mice and rabbits, in situations subject to their presence, will in winter work havoc on unprotected young apple trees. Cooperation. — Finally, there should exist in a farm community a spirit of cooperation in up-to-date farming methods and in general protection which spells success in agriculture. One farmer's effort against grasshoppers or Hessian flies is of little avail if his neighbors are not equally active. A striving to attain a certain high standard of excellence on the part of all members of 10 FARM PRACTICES TO LESSEN INJURIES a farming community should replace efforts on the part of indi- viduals to excel their neighbors. Attention to the precept of gen- eral helpfulness means success for every individual. QUESTIONS 1. Discuss, in general, modern methods of farming which tend to discourage the activities of insect pests and injurious rodents. 2. What points in farm practice are to be avoided by an up-to-date farmer? 3. What relation to the farmers' interests is borne by skunks, owls, hawks? 4. What questions would naturally present themselves to a farmer before taking action against an insect? 5. Discuss the value of cooperation among farmers as it applies to fighting insect pests. CHAPTER III EXTERNAL STRUCTURE OF INSECTS; ORDERS; METAMORPHOSIS ONE Branch or Phylum of the animal kingdom is called Arthro- poda ("jointed-footed") and includes all animals without a back- bone, which have segmented bodies, some or all of the body segments bearing jointed appendages of various kinds. Some of these animals live in water or moist places, are covered with a shelly crust, and are called Crustacea — the crayfish, lobster and crab, and barnacles, for example. Most of the other sub-groups under this Phylum live on land, when adult. But some are worm-like, with many legs, the centipedes and millipeds, class Myriapoda; and some have the head and thorax (second division of the body) in one piece, and have in the adult stage eight legs. This group includes the scorpions, mites, ticks, and spiders. The Class Insecta or Hexapoda ("six-legged") includes all the insects, and if we were asked to give in a brief way the character- istics which would include all insects, and exclude all other animals, we would say: Insects are Arthropods, which in the adult stage have six legs and no more: they breathe air directly through a system of tubes (trachece) opening on the surface. In their life history they pass through, from the egg stage to the adult, more or less changes or metamorphoses: they have one pair of antenna (feelers), two compound eyes, and frequently one or more simple eyes. They generally have wings in the adult stage (Fig. 8). Differences among Insects. — It will be seen from the above that neither a spider nor a tick is an insect. In looking over this enor- mous class, comprising at least four-fifths of all known species of animals, we note that there are some great differences between them; a squash bug is widely different from a butterfly, though agreeing with it in the above general characteristics, and a beetle does not resemble a mosquito. Hence the class is divided into a number of groups called Orders (see page 14). These Orders are largely characterized by differences in mouth parts and in the nature and number of the wings when present. The mouth parts 11 EXTERNAL STRUCTURE OF INSECTS in the typical insect, intended for biting, may be modified to form a sucking apparatus, the maxillae and mandibles being lengthened and frequently enclosed in a sheath formed by the labium. The stages of an insect's life are commonly the egg stage, the larval stage, the pupal or resting stage, and the adult or imago. In insects without a complete metamorphosis, the larval and pupal stages are both active, and frequently referred to as the nymphal stage, or "the nymph." All growth during an insect's life occurs in the larval or nymph stage, and is accompanied by several moultings of the larval skin. Each moult is called an "ecdysis." Kyea — 1st pair of Legs •'— 1st pair of Wings — •• 2nd pair of Leg9 — 2nd pair of Wings -.-—... 3rd pair of Legs Thorns Abdomen Tibia Tarsus •«»• 1 FIG. 8. — Dissection of a locust or grasshopper to show divisions of the body. The parts of a typical insect consist of a head, thorax, and abdomen. The head bears antennae, a pair of large compound eyes (see Figs. 8 and 9), and a few simple eyes. On the under side of the head occur the mouth parts, viz., the labrum, then a pair of strong mandibles; following these a pair of maxillce, each with palp at- tached, and lastly the labium and labial palps. These typical structures are, as intimated above, modified in some of the orders ; in fact, they are to a certain extent the fundamental cause of some of the groups given below. These variations adapt the possessors SPECIAL SENSES 13 to their different modes of life. In the sucking forms, such as mosquitoes and squash bugs, the insects suck the blood of animals or the juice of plants, piercing the surface with the mouth parts. The thorax or middle part of a typical insect's body really con- sists of three sub-parts: the prothorax, bearing the front pair of legs; the mesothorax, bearing the front pair of wings and second pair of legs, and the metathorax, from which spring the hind pair of legs and posterior pair of wings (Fig. 8) . The leg of a typical insect consists of the following joints: a small globular joint next to the body called coxa, then a long joint, generally the larger, called the femur* then a slender, long joint known as the tibia, and finally the tarsus, consisting typically of five joints, the last bearing two tiny claws. Between these claws is a pad-like appendage called the pulvillus (Fig. 10). FIG. 9. — Surface view of the facets of a FIG. 10. — Two types of the last tarsal compound eye, much enlarged. joint. The pulvillusin figure on right is pad- like; in the figure on left it is represented by a bristle. The abdomen. — Behind the thorax is the abdomen of a vary- ing number of segments. On the sides of the abdomen and the sides of the thorax occur the spiracles, openings leading into the trachea! system through which the adult insect obtains its supply of oxygen. It is to be noted, however, that insects will live a long time without oxygen. The posterior end of the abdomen may exhibit appendages, notably the ovipositor in the female grass- hopper or the sting (modified ovipositor) in wasps or worker bees. The hard, outer part of an insect's body (called exoskeleton) is composed of a horny substance, called chitin. Special Senses. — The sense of sight in insects is probably very primitive, as are also the other special senses. The sense of hearing exists in pits in the antennae, or in special organs on the first seg- ment of the abdomen, or in the tibice of some Orthoptera. That insects can hear is evidenced by the fact that we find sound-produc- ing mechanisms, which would not exist unless there also existed the means of hearing the same. The sense of smell is located in olfac- *A very small segment, sometimes well marked, between coxa and femur, is called the trochanter. 14 EXTERNAL STRUCTURE OF INSECTS tory pits in and on papillae or the antennae. The function of taste is located in some of the mouth parts, and minute hairs on the body are connected with nerve endings within and form part of a mechan- ism affording a delicate sense of feeling. The sense of touch is doubtless most highly developed in the antennae, hence these are often called the "feelers." Reproduction in Insects. — The two primary forces directing animal life are the need of nutrition and the instinct of reproduc- tion. Normally we find among insects, as in many other animals, mating and egg-laying, the egg hatching and producing the larva which later gives rise to the pupa. Agamic Reproduction. — In a few forms, however, notably among the plant lice, we have agamic reproduction, that is, several generations produced without mating, and the phenomenon is so striking and at such variance to the rule that we give here a brief outline of reproduction of plant lice, which, in a general way, is similar in practically all of the genera. From an egg which has passed the winter on the favorite food plant of a species, there hatches in the spring a female called the "stem-mother." This insect in a few days gives birth directly to other females; each one in its turn does the same, averaging five or six young a day for several days before the mother's activity is ended by death. This process, known as parthenogenesis, endures throughout the summer. During the summer and particularly towards fall winged females are born called "migrants," who fly to other parts of the tree or plant, or to other trees and plants, and start new colonies. In the fall, true sexual males and females ap- pear, mate, and the eggs are laid which produce the stem-mothers in the following spring. The enormous number of descendants resulting in the autumn from even the one stem-mother can be estimated approximately, and one can readily realize how destruc- tive plant lice may be and how difficult to exterminate. ORDERS OF INSECTS As already stated, the class Insecta is divided into a number of main divisions called orders. Entomologists recognize nineteen of the main orders, besides several sub-orders. These orders are here briefly described. Order Thysanura. — Wingless insects without metamorphosis, the larval form being retained by the adult. True compound eyes rarely present. Examples, fish moth and spring tails — the former ORDERS OF INSECTS 15 (Fig. 11) a household pest, and the latter minute and occurring in swarms in moist situations. Order Ephemerida. — This includes the delicate May flies so abundant in spring and early summer. They have four delicate wings, and live but a short time as adults. The young stage, nymph, is found in the water (Fig. 12). Order Neuroptera. — This group is characterized by the pres- ence of four delicately veined wings. Representatives of the order are the Golden-eyed Lace-winged fly, whose larva consumes plant FIG. 11. — -A "silver fish or "fish moth." FIG. 12. — May-flies. Nymph and imago in foreground. lice, and the "ant-lion, " whose larva digs pits in sandy soil, wherein it lies in wait for other insects (Fig. 13). Order Mecoptera. — A very small group containing the scorpion flies. Order Trichoptera. — Caddis-flies or Caddis-worms. Four- winged with a complete metamorphosis. The larvse construct cases of sand, gravel, and frequently of leaves, etc. In these cases they pass their larval life, crawling about on the beds or bottoms of streams. The mouth parts of the adult are rudimentary (Fig. 14). Order Odonata. — The dragon flies and damsel flies, with four wings of nearly equal size, biting mouth parts, and large compound 16 EXTERNAL STRUCTURE OF INSECTS eyes. The metamorphosis is incomplete. The larval or nymph stage is passed in the water (Fig. 15). Order Plecoptera. — Insects with four membranous wings, hind FIG. 13. — Ant-lion with larva, enlarged and natural size. wings much larger than fore wings, and when not in use folded in plaits. Wings lie flat upon the abdomen when the insect is at rest. Biting mouth parts frequently poorly developed. Metamorphosis incomplete, nymphs living in water. Example, stone flies. NA* FIG. 14. — A caddis-fly, showing c, larva, removed from its case; b, adult; e, pupa. On the right is a case made of stems. Order Isoptera. — Social insects, colonies including queens, kings, and workers, only the first two casts being winged, and then only temporarily. Mouth parts formed for biting; incomplete ORDERS OF INSECTS 17 metamorphosis. Example, white ants or termites (these must not be confused with true ants). Order Corrodentia. — Small four-winged insects; biting mouth parts; incomplete metamorphosis. Winged species feed upon lichens. A well-known wingless form is the tiny book louse. Order Mallophaga. — The so-called bird lice (not true lice, which are sucking insects), feeding upon feathers on birds and fur on mammals; wingless parasites with biting mouth parts; meta- morphosis incomplete. Order Euplexoptera. — Earwigs found in the South and on the Pacific Coast; rare in northeastern United States. The name ear- FIG. 15. — Dragon fly: below, nymph; on left, pupal skin. wig is given them because of a popular and erroneous belief that they creep into the ears of people when asleep. The wings are rudimentary. Posteriorly the abdomen has a pair of appendages resembling forceps. The metamorphosis is incomplete (Figs. 16 and 17). Order Thysanoptera. — (Thrips.) Minute four-winged insects. Many are especially injurious to agriculture. The mouth parts are evidently used for sucking. The metamorphosis is incomplete. Some species can be found by pulling apart blossoms of clover or daisies (Fig. 18). Order Orthoptera ("straight- winged"). — Here occur the 2 18 EXTERNAL STRUCTURE OF INSECTS locusts, which we commonly call grasshoppers (Fig. 19), the true grasshoppers (Fig. 20), and katydids (Fig. 21); crickets, "walking- sticks" (Fig. 22), and cockroaches. These insects have, for the most part, four wings, the foremost pair being really wing covers, or tegmina; the second pair are thin and gauzy, the mouth parts are formed for biting, and the metamorphosis is incomplete. The FIG. 16. — Earwig with wings FIG. 17. — Upper figure, fe- expanded. male earwig; below, end of abdomen of male, showing appendages. Both much enlarged. FIG. 18. — A specimen thrips. of grasshoppers, locusts, crickets and katydids have hind legs adapted for jumping. This order is at times very injurious; the Rocky Mountain locust or grasshopper, which normally lays its eggs on the slopes of the Rockies, frequently breeds on the plains east of there, and has at times swept down upon portions of Kansas, Nebraska, Dakota, Minnesota and other states, leaving no living FIG. 19. — A locust, commonly called grasshopper. Fiu. 20. — A true grasshopper. \ FIG. 21. — A katydid laying eggs. FIG. 22. — A walking-stick. 20 EXTERNAL STRUCTURE OF INSECTS plant behind it. Locusts and grasshoppers lay their eggs in the soil, and fall plowing generally serves to keep our native forms in check. Order Coleoptera ("sheath-winged"). — This name refers to the fact that the insects of this group have the fore wings hardened and horny, or modified to form covers for the second pair of wings, the true wings, when they are present. They have biting mouth parts, and a complete metamorphosis. The group includes the beetles. The potato beetle (" potato bug"), most of our wood borers, the May beetle which comes from the white grub, blister FIG. 23. — A ground beetle. FIG. 24.— A buprestid beetle. beetles, plum curculio, weevils, and many others occur here (Figs. 23 and 24). Order Hymenoptera ("membrane- winged"). — Members of this group of insects have four membranous wings with but few veins therein. The front wings are the larger. Mouth parts adapted for biting and sucking. The abdomen of the female is usually fur- msl cor clu< ORDERS OF INSECTS nished with a sting, piercer or "saw." The metamorphosis is complete (Fig. 25). The honey-bee is a good example of this order, which also in- cludes the true ants, the wasps, hornets, and sawflies. A large number of parasites which attack injurious forms of insects are also found here. Order Hemiptera. — This order includes all the plant lice, the true parasitic lice, all the scale insects, and the true bugs (Fig. 26). The name Hemiptera, which means " half-winged," is given the entire order because the anterior half of the first pair of wings in FIG. 25. — Hornets, with larva, pupa and cells. the true bugs is thickened, only the posterior part being wing-like. The mouth parts are formed for sucking, and they have an incom- plete metamorphosis. This is probably our most destructive order, for here occur scale insects, plant lice, leaf hoppers and tree hop- pers, squash bugs, Cicadids or harvest flies, and the true lice which affect man and animals. It is interesting to note that the word "bug," which is frequently employed to designate any insect, is rightfully applied only to that division of the Hemiptera which are "half -winged," sub-order Heteroptera. Sub-order Homoptera.— Scale insects, plant lice and mealy bugs belong to the sub-order Homoptera. At some stage these have gauze-like wings. 22 EXTERNAL STRUCTURE OF INSECTS Order Diptera ("two-winged").— These are the true flies, such as the house-fly, mosquito, horse flies, etc., characterized by the possession of only two wings, the second pair being represented by a pair of small knobbed projections, the halteres or balancers; they have mouth parts adapted for sucking, lapping or stabbing. They have a complete metamorphosis, the larva being referred to as a " maggot," and the pupa or resting stage is enclosed in a brown skin called puparium. Figure 27 illustrates a type of the order. Order Siphonaptera. — These are wingless, degraded insects, with no compound eyes, but having a complete metamorphosis. The mouth parts are adapted for sucking. Here occur the dog and cat flea, human flea, and others. FIG. 26.— A true bug. FIG. 27. — House-fly on lump of sugar. (After Brues.) Order Lepidoptera ("scale-winged"). — The butterflies, moths and skippers are characterized by the presence of four wings, cov- ered with tiny scales which easily rub off if the insect is handled roughly. To these minute scales is due the color of the wings. The mouth parts of these insects are modified for sucking. They have a complete metamorphosis. The larva is spoken of as a "caterpillar," and tent caterpillars and cut- worms are familiar objects in the country. Caterpillars have six true legs, and a varying number of temporary fleshy projections called "pro-legs," or "prop-legs." The moths are generally, but not always, night fliers; their antennae are usually either thread-like or feather-like. When at rest they rarely hold their wings elevated as do butter- flies. The skippers are day fliers, and dart rapidly from place to ORDER OF INSECTS FIG. 2j. — The parsley butterfly, male above, female below; caterpillars also shown. Fia. 29. — A small moth. FIG. 30.— A chrysalis. (After Riley.) 24 EXTERNAL STRUCTURE OF INSECTS place. Butterflies (Fig. 28) are day fliers; their antennae or feelers are thread-like, with a knob on the end. Injurious forms in this order are the codling moth (Fig. 29), currant borer, cut- worms, army worm, and others. The pupal stage of butterflies is naked and called a "chrysalis" (Fig. 30). The pupa of a moth is inclosed either in a silken cocoon or in a cell below the surface of the ground. Other Groups. — Insects in an order are divided into families; each family is divided into genera; each genus into species, and we frequently have varieties of a species. These groups and sub- groups are used in classification. QUESTIONS 1. What is the place of insects in the animal kingdom? 2. Give a comprehensive definition of an insect. 3. Name the three parts of an insect's body. Does each part bear appendages? 4. Name mouth parts of typical insects in order of their occurrence, beginning with the most anterior. 5. Are they the same in all insects? 6. What are the parts of an insect's leg? 7. Are all of the legs alike in the grasshopper? 8. Compare the legs of a caterpillar with those of a moth or butterfly, which produces the caterpillar. 9. What is meant by a "pro-leg" or a "prop-leg"? 10. What insects fly? Name a few which never fly. Do beetles fly? 11. Give, in general, the life history of a butterfly. 12. Of plant lice. 13. Name the orders of insects and give example or examples under each order. 14. Describe complete and incomplete metamorphosis in insects. Give . examples. 15. What is the difference between the pupal stage of a moth and that of a butterfly? 16. How does an insect see, feel, smell, and hear? 17. Name, in proper order, the divisions and sub-divisions used in classifying insects. CHAPTER IV COLLECTING AND PRESERVING INSECTS THE young collector has probably provided himself or herself with some insect pins and some sheet cork, which can be pur- chased for a small sum from retail dealers, though he can substitute slices of cork stoppers for his sheet cork, or pith from corn stalks, or corrugated paste-board packing, at no expense whatever, gluing the same to the bottom of a cigar box. Good insect pins of various sizes he can hardly get along without if he purposes to pin his specimens. The late spring and summer months naturally offer the best opportunities for collecting. When he goes into the field he should take a good insect net, one or two cyanide bottles, a few vials for holding delicate insects (some vials half full of alcohol for killing larvae), and some paper pill boxes, or tin salve boxes. These and the vials will hold living larvae, which the collector may desire to take home. A pair of FIG. 31. — Small forceps. forceps (Fig. 31) is not necessary, but sometimes very convenient in handling very small insects and those that sting. A box (cigar box will do) and some envelopes or folded papers are desirable to safely hold butterflies with wings folded until the return home. A cyanide bottle (Fig. 32) is made by placing two or three small pieces of cyanide of potassium,* pieces to be a little bigger than peas, or one large piece, in the bottom of a large-mouthed vial, and covering the same with plaster of Paris, to which water has first been added. This mixture should be of such consistency that it will just pour into the bottle, covering the cyanide half an inch. Leave the bottle open for a few hours until the plaster is set. If liquid gathers on the top of the plaster, dust in more dry plaster, and later a piece of blotting paper can be placed over the plaster to absorb moisture, and occasionally removed. As cyanide of potash is deadly poison, it is well to put the word "POISON" on the bottle. A tight cork should be provided, and care should *Or sodium cyanide, if easier to obtain. 25 26 COLLECTING AND PRESERVING INSECTS be taken not to leave the bottle open, after it is in use, for any length of time, lest it should lose its strength. A very useful style of bottle is shown in figure 33. This is provided at one end with a metal cap, which can be removed, and either cyanide or chloro- form placed on cotton in the lower end. A small straight-side vial made into a cyanide bottle is useful for very small insects, and takes up but little room in the pocket. In fact, one should take more than one cyanide bottle into the field to forestall any accident which might befall one, and to have one to use before insects are Fia. 32. — Home-made cyanide bottle. FIG. 33. — A more elaborate killing bottle. dead in the other. It is well to leave specimens, except delicate moths, over night in the cyanide bottle, or at least for several hours. Strips of paper in a cyanide bottle prevent undue rattling about of insects, and serve to absorb injurious moisture. A serviceable net can be made out of mosquito bar (or, better, of bobbinet), strung on a wire hoop fastened to a pole about five feet long. It is a very good plan to fasten a narrow strip of cloth to the wire hoop, and sew the net to that. Better nets and jointed poles can be purchased. Figure 34 shows a folding net, which can be packed in a small space. One may prefer a net which tapers KILLING SPECIAL INSECTS 27 considerably, but not to a point. Some insects are best caught when they are on the wing; others should be allowed to alight. A quick pass is made with the net, forcing the butterfly or moth, or grasshopper, as the case may be, to the bottom, and a turn of the wrist folds the net upon itself, preventing the captive from escap- ing. In sweeping for grass or clover insects, the net is passed back and forth as one walks along, striking the tops of the plants, and by its continued and rapid motion the captured specimens are kept safely in the bottom of the net until the collector stops, when a rapid turn doubles the net and holds all the contained insects securely. In beating brush or shrubbery a "beating net," made of stout cloth, is used. FIG. 34. — A convenient collecting net. Killing Special Insects. — The writer sometimes lulls stinging insects to unconsciousness by placing the point of the net in the bottle, and holding the cork over the mouth for a minute, when the bee or wasp can be taken out safely, and dropped into the killing bottle to complete the operation. Butterflies and moths should not be permitted to flutter about in a cyanide bottle, thus denuding the wings of their beautiful scales. They may be pinched between thumb and finger while still in the net (Fig. 35), or a drop of chloroform may be placed on the thorax and abdomen, and then the insects transferred to the cyanide bottle. Plant lice are best killed by dropping into vials of alcohol. 28 COLLECTING AND PRESERVING INSECTS Jarring. — Some insects may be knocked off of shrubbery or branches of trees by jarring, the net being held below. Water insects, such as "water boatmen/' skippers and " whirligig-beetles/' can be captured by using the net. Some larva can be found under stones, in ponds and streams. Those that frequent the bottom can be obtained by the use of a metal sieve-scoop, transferring the material — small sticks, mud, leaves, etc. — to a jar, whence the specimens can be separated later. Where to Look for Insects. — Insects of various kinds are found in a host of localities, upon flowers, upon shrubbery, along the edges of woods, in the woods themselves, in pastures and meadows, along the banks of streams, lakes and ponds and in the waters of the same; in rotten logs and stumps, under logs and rubbish, under bark, in fruits, and in nuts, etc. The collector who has the keenest eyes is the one, other things being equal, most likely to succeed. Baiting and Night Collecting. -While broad daylight and bright sunshine are the best con- ditions under which to collect the majority of insects, many are best collected at twilight, and night collecting by the use of baits is fascinating. FIO. 35.— Method of handling butterflies An acceptable bait is made of caught in net. (After H br()wn sugar ^ ^^ forming quite a thick syrup, and adding a goodly amount of stale beer or rum ; put this on, say, twenty trees (it may also be used on fences or stumps) in the woods, just after sundown, spreading it with a brush over a space about three by eight inches, and noting care- fully the baited trees, so that they can be found in the dark. If one starts out between nine and ten with a lantern, preferably a dark lantern, or electric flashlight, and several cyanide bottles, and visits the treated trees, flashing the light carefully on the anointed portions, one will probably discover moths and other insects at work sipping the attractive mixture. A collect- ing bottle is placed cautiously over one of these insects and moved to right or left slightly, thus loosening the insect from its hold, whereupon it falls into the bottle, the latter is tipped quickly and corked, placed in one's pocket, and a second bottle used for another insect. These insects are later united in one bottle, leav- ing one or more bottles free for use in capturing. Warm, still nights are best suited for this work. PINNING AND SPREADING 29 Lights in an open window, or, better still, the electric lights in :he streets of our towns and cities, offer excellent opportunities for light collecting. Pinning and Spreading. — In pinning insects a Comstock spac- ing block will be found useful. Its construction is easily under- stood by a glance at figure 36. Each layer from which the block FIG. 30. — A block used in pinning insects, spacing block. is made is one-fourth as thick as an insect pin is long. The hole on each step is large enough to admit the head of the pin. Each insect should be, when pinned, just one-fourth of the length of the pin from the head. This is brought about by inserting the head of the pin, after the pin has been pushed through the insect, into the hole of the lower step — the back of the specimen should rest FIG. -57. — The proper way to pin a grasshopper. FIG. 38. — A bee properly FIG. 39. — The proper pinned. way to pin a beetle. on the step. By reversing the pin and using the first and second steps the proper spacing of labels is secured, and when small in- sects are mounted on points the hole in the highest step receives the point of the pin. The German insect pins appear to be the best, and are made in several sizes. Perhaps sizes 0, 1, 3, 5, and 9 would be those most commonly used by the amateur collector. The thing to be sought is uniformity in height of insects and labels in the box, that the collection may present a neat appearance. 30 COLLECTING AND PRESERVING INSECTS Grasshoppers, bees and flies, butterflies and moths, etc., are pinned through the thorax, as shown in figures 37 and 38. Beetles are pinned through the right elytron, or wing cover, as shown in figure 39. Bugs are pinned through the median point of the scu- tellum (Figs. 40 and 41). Fia. 40. — A true bug correctly pinned. FIQ. 41. — Labels, showing species and locality. Fia. 42. — A spreading board for moths and butterflies. FIG. 43. — Microscopic insects mounted on pith block. Butterflies and moths should be spread on a spreading board as shown in figure 42. They are transferred to the collection when dried. Frequently the wings of other insects are spread if a col- lector has time to go into such niceties. Two dissecting needles, made by pushing the blunt ends of needles into round sticks 4 inches long, of the diameter of lead pencils, will be found useful tools in spreading. PRESERVING BOTTLES 31 Mounting on Pith and Cardboard Points.— Small moths and also other small insects are sometimes mounted on pith by the use of tiny wire, the pith being first fastened to an insect pin at proper height (Fig. 43). Again, a small beetle or fly, or other Fio. 44. — Microscopic insect mounted on cardboard point. FIG. 45. — A punch for making points. FIG. 47. FIG. 46. insect, may be mounted by being gummed to a cardboard point, as shown in figure 44. These points are made with a triangle punch illustrated in figure 45. Pinning forceps are desirable accessories in order to hold the pin upright, and to keep it from bending when it is being forced into the cork bottom of the collection box. Figures 46 and 47 represent these forceps, the first used with lighter pins, and the latter where large butterflies, etc., are being placed in position in the collection. A cheap pair of pliers will answer fairly well if one does not care to go to the expense of the regulation forceps. Very delicate insects, such as plant lice, minute flies, etc., which have first been in 90 per cent alcohol, are frequently mounted on glass slides, with appropriate labels (Fig. 48) for identification and study with the microscope. Magnifying Glass.— In studying and FlG- 46'-^ec?as .for pinning handling small insects a watchmaker's glass FlQ- 47t~^ceea^y Pinning (Fig. 49) is sometimes quite useful. This lies in the fact that it can be held in one eye, leaving the hands free. A pocket lens (Fig. 50) of some kind is very desirable. Preserving Bottles. — Figure 51 illustrates a home-made rack for holding vials, containing alcoholic specimens to be studied. 32 COLLECTING AND PRESERVING INSECTS Figure 52 shows the Comstock insect bottle, used by many ento- mologists for the permanent storing of insect larvae, pupae, etc. Inflating and Mounting Caterpillars. — Frequently one wishes to preserve a caterpillar in the dry state for mounting by the side of the imago. Kill the specimen in the cyanide bottle; make a small slit with a fine pair of scissors at the extreme posterior end NO. f SUB. t FIG. 48. — Insect mounted on glass slide, with labels. of the caterpillar. A better way, perhaps, is to insert the point of a pin about one-eighth of an inch into the anal opening at the posterior end of the caterpillar, and move it carefully around in order to cut through the intestinal wall, thus freeing it from its attachment to the body wall. Place the larva on blotting paper, and, placing a round pencil FIG. 49. — Watchmaker's glass useful in entomological work. FIG. 50. — Coddington hand lens. upon it just back of the head, roll it backward gently, pressing out the viscera. Care must be taken to move the caterpillar about during this in order to keep the hairs dry. Then insert a straw or a glass tube drawn nearly to a point, about one-fifth of an inch, into the opening. If a straw is used, push a fine pin through the specimen close to the posterior end and through the straw. This will hold it in place while inflating. If REARING LARVAE 33 one uses a glass tube, it should be held over a flame until the speci- men is dried to it at the point of contact. Should there be any openings between the straw or tube and skin of the caterpillar, a drop of glue will seal them. The actual inflating is done by hold- ing the specimen in a warm place for a few moments, keeping it inflated to natural size until dry. This may be accom- plished by the use of a simple apparatus and one's breath, as shown in figure 53. The lamp chimney rests upon an iron saucer filled with sand. One may prefer to purchase an inflating outfit, one of which is illustrated in figure 54, in which case the air is forced into the caterpillar from two bulbs. Care must be taken not to scorch the specimen. When thoroughly dry it may be pushed off the tube with a sharp knife. A mount for the caterpillar has been previously prepared. This will be understood by a glance at the accompanying illustration (Fig. 55), which shows a piece of cork at the proper height on an insect pin, and some fine wire (preferably the covered wire used FIG. 51.— Stand for bottles. FIQ. 52. — A Comstock bottle for alcoholic specimens. by milliners) wrapped about it as shown. The two ends are left twisted together, and upon these the caterpillar is thrust, a drop of liquid glue having first been placed on the wires' ends. The specimen is then ready for the label. Rearing Larvae. — A collector may be uncertain about the iden- tity of a captured larva, or he may wish to procure the imago for his collection, or he may desire to study its life history, observe its 3 34 COLLECTING AND PRESERVING INSECTS moults, etc. This is easily accomplished, whether it be the young stage of butterfly, moth, beetle, fly, or bug. The specimen or specimens are confined in some form of breeding jar with an abundance of food. If the food be a plant, a flower pot containing the same may be placed in the cage as shown FIQ. 53. — Home-made apparatus for inflating larvae. FIG. 54. — A more expensive apparatus for inflating larvae. in figure 56, which illustrates a home-made outfit in use. Or a lamp chimney, or lantern glass, with cheesecloth over the top, may be placed over small plants upon which the insect feeds, the glass being pushed into the soil of the pot about an inch. Water insects can be studied in the same way by making an aquarium, as shown in figure 57, in which a few water plants are grown, and the water of which is kept fresh. FlQ. 55. — An inflated larva properly mounted. The development of larval stages, wire worms, for example, which infest roots, can be studied in a Comstock root cage (Fig. 58). This, as shown in the illustration, consists of two plates of glass held a short distance apart by a supporting frame. This narrow space is filled with soil, and seeds of young plants placed therein. Careful and frequent observations should be made of insects CAREFUL AND FREQUENT OBSERVATIONS 35 Fia. 50. — A simple form of breeding cage. FIG. 57. — A home-made breeding jar for aquatic insects. FIG. 58. — Corn growing between two FIG. 59. — A, vertical section of moist glass plates for study of root forms. (After chamber used in relaxing dried specimens. Comstock.) B, partition of brass or copper gauze, sup- ported at o, upon which insects are laid. 36 COLLECTING AND PRESERVING INSECTS in breeding cages, and notes made of dates of capture and condi- tion of specimen, moults, pupation, emergence of imago, etc. Frequently, what appears at the time to be a trivial fact may be an important contribution to the science of entomology, particularly if the specimen be a pest to agriculture. Relaxing Dried Specimens. — Any insect which has become dried in storage, before being pinned, has to be relaxed before it is handled. We, for years, made use of a relaxing box shown in the accompanying illustration (Fig. 59), and found it very satisfactory. It shows the box and lid in section, A marking the point at which FIG. 60. — A Schmidt insect box. the wire gauze forms a false bottom a few inches from the floor of the box. B shows surface view of the gauze, the opening in the corner affording an opportunity to pour water into the bottom of the box. A little carbolic acid is placed in this water to prevent mould. The insects are left on the gauze over night, with the cover on the box. This will generally cause them to be so relaxed that they can be handled with safety. The box may be made of gal- vanized iron, and this particular box is 9 x 14 inches and 5 inches high, the gauze being placed two and one-half inches from bottom. A glass fruit jar containing some wet blotting paper is a simple relaxing chamber. MAILING AND STORING 37 A light dust-proof and insect-proof box is necessary to hold a permanent collection. Ideal boxes are seen in either the Schmidt box, illustrated in figure 60, or in a Comstock box. Collections should be examined every few months to prevent dermestids or other pests from working injury. If evidence of their presence is observed, the box and its contents should be subjected to the fumes of carbon bisulfid in a closed receptacle for several hours. Two treatments, with ten days' interval between, may be necessary. Most entomologists keep naphtha- line cones (Fig. 61) in their insect boxes as repel- lents. It is not safe to store insects permanently in unprotected cigar boxes. Mailing and Storing. — In mailing insects in vials, round mailing boxes (Fig. 62) are made use of, the vial being wrapped in cotton. Figure 63 shows the method of cutting and folding papers for butterflies and moths, either when they are to be mailed (in which case they would be packed flat in boxes), or when they are to be kept in storage. Avoid moisture in packing FIG. 61. — A naph- thaline cone. FIG. G2. — Mailing box for vials. away insects, and protect them from the attacks of mice and mu- seum pests. Specimens of a miscellaneous nature may be mailed or stored in boxes between layers of cotton, a piece of tissue paper being placed below and above them to keep them from actual contact with the cotton. This is a good method to be followed by students making small collections, required for a school or college course. 38 COLLECTING AND PRESERVING INSECTS Keeping Records. — Some form of entomological bookkeeping is desirable for any one wishing to make an extended study of the subject. Observations in the field or in the insectary can be made upon small sheets of perforated paper, temporarily bound in leather covers of a size suitable for the pocket, care being taken not to FIG. 63. — Showing method of making envelopes for butterflies. write an observation upon two or more insects on the same sheet. These sheets can later be removed from the temporary cover, and each one filed in a box devoted to a special insect or a special set of observations. Accessions to the collection may be entered in a Fia. 64. — A convenient form of card index and container. book, the accession number referring to a special collection or set of insects, and the sub-numbers placed on the side referring to the individual specimens in the collection. In this case the insect would bear a label showing its accession number and sub-number, as in figure 48. A card index (Fig. 64) is found to be a very valuable aid, by KEEPING RECOR] 39 forming a handy record of literature, illustrations, lantern slides, cuts or special lines of work, and can well be used as an accession index also. The necessity of having specimens in a collection care- fully labeled, and all data where they can be referred to, cannot be too strongly emphasized. QUESTIONS 1. Describe the making of an insect killing bottle. 2. Describe some special methods in collecting insect specimens. 3. Describe the form of net which you prefer. 4. Tell how to manage butterflies and moths to prevent fluttering. 5. How would you manage to collect water insects? 6. What are some of the best places to look for insect specimens? 7. Describe some methods of baiting insects. 8. Give important points in pinning insects. 9. Describe a good spreading board and give details of how to use it. 10. Give directions for inflating and mounting caterpillars. 11. Give important points in rearing larva;. 12. How may dried specimens be relaxed? CHAPTER V INSECTICIDES AND SPRAYING FOR the purpose of combating insects the farmer, orchardist and gardener, disregarding scientific classification, need consider only two groups: A. Biting insects, or those which devour leaves, stems, stalks of grain, grasses, and fruit. Examples of these are seen in grass- hoppers, caterpillars of all sorts (including cut-worms and army worms), and in beetles and so-called " slugs, " the larvae of saw flies. B. Sucking insects, those which pierce the surface of leaf or fruit, skin of animals, and suck the sap of plants or the blood of animals from below the surface. Manifestly two entirely different classes of insecticides are necessary in combating the two groups. Internal Poisons. — Group A calls for internal poisons, poison sprays or poison baits, which taken internally result in the death of the insects in question. Such poisons are found in a number of forms. 1. White arsenic or arsenious oxide (As2O3) is soluble in water, and is dangerous to both plants and human beings and hence not desirable. 2. Paris green is a combination of arsenic and copper with a certain amount of free arsenic occurring in the compound. Some states limit it by law to 50 per cent arsenious oxide and 3^ per cent water-soluble arsenic. This insecticide costs from 25 cents a pound up, depending upon the copper market and the avaricious- ness of the dealer. Care has to be exercised in its use, otherwise sprayed foliage is apt to be burned. It should never be used on evergreens. A few simple tests are available to the farmer buying Paris green. It should not be purchased at retail from open sacks or other open containers where it is kept in bulk. It should be bright green in color, not pale green. A small amount taken on a knife blade, deposited on a piece of glass, and the glass then inclined and gently tapped should leave on the glass a green streak ; if decidedly pale green or whitish the Paris green is adulterated. Another test is to add a small amount (J^ teaspoonful) to a 40 . ARSENATE OF LEAD PASTE 41 small glass of ammonia; the Paris green should completely dis- solve. If it does not it is evidently adulterated. If a microscope is available and a little pure Paris green is examined it will appear made up largely of regular, more or less spherical, bodies with smooth edges (Fig. 65); if adulterated many irregular-shaped particles will be observed mixed with the more spherical bodies (Fig. 66). The fact that there is some free water-soluble arsenic in Paris green, which amount may be illegally excessive, makes it more or less dangerous to use in the hands of a careless grower, for, as intimated above, it is very likely to burn tender foliage. At the same time some crops can stand a large amount of this insecticide •*«»< * rfi ».c va & i^ml&7v&fvE& i *«*»* ?** c te^iteN^ss :g$® H •f *ft 4 FIG. (55. — Good Paris green, as it appears under the microscope. FIG. 66. — Poor Paris green as seen with the microscope. without injury. Cabbage plants, for example, when good-sized, show no serious effect when sprayed with soap and Paris green at the rate of five pounds of the latter in fifty gallons of water. Less than one-half of those proportions would burn the leaves of apple trees. Use Lime with Paris Green. — This burning quality of Paris green can be restrained by the use of two pounds of quicklime for every pound of Paris green used. Since the larger part is not soluble in water, but is held in suspension simply, there should be constant agitation of the liquid while spraying. 3. Arsenate of Lead Paste. — This contains less than 1 per cent of free or soluble arsenic and about 15 per cent of arsenic oxide. It is a much safer and more satisfactory poison than the 42 INSECTICIDES AND SPRAYING foregoing. It rarely injures foliage and has the property of stick- ing to leaf and fruit much longer than Paris green. It is always used at a greater strength than Paris green is used, and with per- fect safety. Its effect is not always so marked as the latter and in at least one instance requires the addition of a little Paris green to be really effective. The adult potato beetle is referred to, which will hardly yield to arsenate of lead, although the latter is sufficient to kill the larvse. Potato growers are advised to use two pounds of arsenate of lead and one pound of Paris green in fifty gallons of water. Arsenate of lead paste may be made at home, but with diffi- culty, and the commercial article is preferable. Directions for use of this and most other insecticides and fungicides are printed on the can label. A powdered form of arsenate of lead may be purchased, which can be mixed with water, but is perhaps not as satisfactory as the paste. It is quite effective if it is mixed with air-slaked lime and dusted on plants after a rain or when wet with dew. 4. London purple is a by-product in the manufacture of aniline dyes. It contains so large and such a varying percentage of soluble arsenic that it is not a safe agent. It is little used at present, but its cheapness is attractive. 5. Combined Insecticide and Fungicide. — Orchardists' needs frequently require that fungous diseases and insect pests may be treated in one spraying. Arsenate of lead may be safely and effectively added to commercial lime-sulfur. Potato growers, however, should combine Paris green with Bordeaux mixture. The last-named fungicide is made by combining four pounds of copper sulfate or blue vitrol, four pounds of quicklime, and fifty gallons of water as follows: Making Bordeaux Mixture. — The four pounds of copper sul- fate are suspended in a cloth sack in twenty-five gallons of water in some wooden receptacle. It will take several hours for this to dissolve. In another wooden receptacle (a barrel, for example) four pounds of quicklime are slaked in just enough water for this purpose, and enough more water gradually added to make twenty- five gallons. These two solutions may be then united or equal portions taken from each container as desired. This compound, like all other spraying mixtures, should be carefully strained before beirig placed in the spray pump reservoir, barrel, or tank. Bor- deaux mixture should be used as soon as made; it changes on stand- POISON BAITS 43 ing. Several commercial mixtures of prepared Bordeaux combined with arsenate of lead are on the market. 6. White Hellebore is not poisonous to human beings, but deadly if eaten by insects, and is very useful if used fresh. It loses its strength rapidly when exposed to the air. It is a product of the white hellebore plant and is generally used in the dry form, by dusting it over the plant. It may be made into a decoction (one ounce in two quarts of water) by steeping, and used as a spray. 7. Proprietary Insecticides. — Under this head are classed quite a number of compounds with attractive names, but of questionable utility. Many of them are valueless, or, if of any merit, cost three or four times as much as a farmer need pay. 8. Poison Baits. — Attractive baits may be made which con- tain poison: Poison Bran Mash. — This is very effective against cut- worms, army worms, and grasshoppers. It is made as follows : Paris green is mixed with dry bran until the latter becomes quite green. Pro- portions approximate one pound Paris green to 20 or 25 pounds of bran. To this dry mass are then added water and about two quarts of cheap syrup or molasses and the mixture stirred. It should be of the consistency of chicken feed, not sloppy. For cut-worms a tablespoonful of this is placed near a plant, perhaps eight inches away. If placed too close, a copious rain may wash the Paris green onto the roots, destroying the plant. For both cut- worms and army worms covering large areas, it is broadcast among plants, or, from a tub on a stoneboat, over fields infested with grasshoppers. Dean, of Kansas, recommends, for grasshoppers, adding the juice and pulp of three oranges or lemons to a mixture of one pound Paris green, twenty pounds wheat bran, two quarts of syrup and three and one-half gallons of water. Some workers, however, claim that the addition of the fruit does not make any material difference in the attractiveness 'of the bait. For cut-worms, where Paris green is too expensive or not pro- curable, ten pounds of bran may be poisoned with one pound of arsenic, mixed into a dough with water and where practicable with molasses or cheap syrup. A bait made of alfalfa or clover, freshly cut and dipped into a solution of arsenic and water and distributed in small bunches at sundown or after, is quite effective against cut-worms. It may also be used against prairie dogs. When dried by the sun this bait is not attractive. 44 INSECTICIDES AND SPRAYING Poisoned Grain. — Corn may be soaked in a strychnine solution, rendering it poisonous to crows, squirrels or gophers, and may be scattered about in fields where crows are working. The method of making and using this solution is as follows: One ounce of sulfate of strychnia is dissolved in two quarts of boiling water. This is sufficient to treat a bushel of grain, which should soak over night. The poison should be prepared and mixed with the grain in a metal container and the latter thoroughly cleansed after the operation. Wheat is used when mice or gophers or prairie dogs are to be poisoned. Crushed or rolled oats form a good basis for a poison bait. Seed corn may also be safely treated with this preparation. The United States Department of Agricul- ture (Farmers' Bulletin 670) recommends for field mice the adding of two tablespoonfuls of laundry starch in one-half pint of cold water to either of the above poisons, pouring the starch into the solution and boiling for a few minutes, then pouring it over the grain. Care should be taken to prevent stock or poultry having access to poison baits. Tarred corn can be prepared in such a way as to enable it to pass easily through the planter (see under Crow, page 405). This treatment also renders it distasteful to wire worms, squirrels and gophers which sometimes attack the planted seed. 9. Arsenite of Soda. — One-fifth ounce of arsenite of soda, one- half pint of New Orleans molasses and one gallon of water sprayed on young cabbage, cauliflower, onion plants and radishes attract and poison the adult flies which produce the destructive maggots. To be effective they must be applied early, before egg laying begins. Bait for Sow-bugs. — Paris green or arsenic on slices of potato is claimed to be a successful bait for sow-bugs (not insects) in greenhouses. We have successfully used a mixture of Paris green and sugar. The Florists9 Review advises for sow-bugs, two parts rye flour, two parts sugar, one part Paris green, kept dry and frequently renewed. Insecticides for Sucking Insects. — Contact insecticides are in- tended for such insects as do not eat the surface of plant, but suck the sap from below it. Entomologists formerly believed that soap, oil, or oil mixtures killed by stopping the spiracles and thus "smothering" the insect. This theory appears to be, in part at least, disproved, since insects can live a long time without access to oxygen. It is now thought that their death is due to volatile substances in oil or soap. SOAP SOLUTIONS 45 Kerosene Emulsion. — This compound has been largely super- seded by soap solutions and tobacco extracts, because to be a safe agent it must be made and used correctly; if not, the kerosene, separating from the emulsion, gathers at the top of the mixture, and when the spray pump draws this layer off and applies it to foliage severe burning is the result. The approved formula for kerosene emulsion is: One pound soap, dissolved in two gallons of hot soft water. When boiling hot this is taken from the fire and four gallons of cheap kerosene added, the mixture being at once churned by means of a force pump until a creamy, white emulsion is formed. This is the stock solution. For summer spraying add thirty-four gallons of water to this; for dormant or winter spraying add from ten to fourteen gallons of water. Keep the liquid well agitated while spraying. Avoid any mechanical mixture of oil and water; and never use pumps advertised as mixing oil and water mechanically. In using any dormant or winter spray it should not be applied in severe weather; mother words, freezing of the spray on the tree should be guarded against. Crude Oil Emulsion. — Made in the same way as the above, employing crude petroleum in place of kerosene. A 20 per cent solution is used as a dormant spray against scale insects. Distillate Emulsion. — Thirty pounds whale oil or fish oil soap dissolved in twenty gallons of water by boiling. Add twenty gallons of distillate and churn while hot. When wanted for use, add 20 gallons of water to every 1 gallon of stock. Lime-sulfur. — While this may be made at home, it is one of the few proprietary compounds which can best be purchased. Com- plete directions for use are given on containers. Primarily a fungi- cide, it forms an excellent insecticide for scale insects and many other pests. It can be used both as a dormant spray and, much reduced by the addition of water, as a summer insecticide or fungi- cide. Combined with arsenate of lead, it affords a means of preven- tion for both codling moth or curculio injury and the apple scab. It is to be regarded as one of the most useful agents in the work of the orchardist. The stock solution will stand a very low temperature, possibly five or ten degrees above zero without freezing. Soap Solutions. — It is doubtful if true whale oil soap is on the market at this time. If so, the price must be prohibitive. It would be safer to assume that soap advertised as whale oil soap is 46 INSECTICIDES AND SPRAYING made from fish oil. Ordinary laundry soap and ivory soap are both efficacious against lice and harmless to foliage or fruit. A five-cent cake of ivory soap dissolved in five or six gallons of hot water or one pound of laundry soap in the same amount of water is an excellent remedy for plant lice, and will not injure the most tender foliage. It is best used warm, and a little tobacco decoction, either made from stems or purchased, if added to the soap solution increases its efficiency. Tobacco Extracts. — While a fairly efficient extract may be made by steeping tobacco stems or other waste forms of tobacco, it is better to rely upon the commercial extract at present on the market. " Black Leaf 40," a nicotine sulfate solution, gives excel- lent results. The commercial form may usually be used in place of the patent preparation. It is expensive, but can be effectively used hi such extreme dilution that the final cost is slight. For example, one or two tablespoonfuls in a gallon of water are most effective against plant lice, and if this solution is poured several times at intervals around the base of melon vines it forms an exceedingly helpful remedy for the larvae of the striped cucumber beetle working on the roots. Nicofume is another tobacco solution. It is vaporized in greenhouses; and a prepared paper (Nicofume paper) is burned as a fumigant against lice on melons and in greenhouses. It is pre- pared by soaking porous paper in tobacco extract or nicotine sulfate. After drying it may be burned, causing the desired fumes. Tobacco Dust. — This is finely powdered product, used on young radishes against root maggot, and on dahlia and aster buds against tarnished plant bug. It is also of practical use in greenhouses. Flowers of Sulfur. — This material is dusted on steam pipes in greenhouses, but is only fairly effective against the " white-fly." Mixed with air-slaked lime it is used for control of red spider and mite. Pyrethrum, Buhach, Persian Insect Powder. — This is made from the pulverized heads of a species of chrysanthemum. Must be used when fresh to be effective. Harmless to human beings and to foliage. It is either dusted on plants or steeped for several minutes in water, one ounce of pyrethrum to three quarts of water. Air-slaked Lime. — This is an excellent and cheap deterrent and insecticide for many insects. Dusted on leaves of fruit trees, it is deadly to the leaf -eating "slugs." It saves to a large extent DUST SPRAYING VERSUS LIQUID SPRAYING 47 potato vines from attacks of flea beetles. It drives striped cucum- ber beetles away from melons and cucumbers. Road dust is used effectively against slugs on foliage. Crude Carbolic Acid. — Dissolve one pound of hard soap1 in one gallon of water by boiling, add one pint of crude carbolic acid and churn by forcing it with a spray pump over into itself until emulsion is formed. The stock solution should be diluted with about thirty parts of water when wanted for use. It is employed against root maggots, but the arsenite of soda spray appears to be more effective and easier to prepare. Diluted one part of stock carbolic solution to twenty parts of water, it is used in California, as a spray against mealy bugs, plant lice and soft brown scale. Fio. 67. — A hand dust sprayer at work in a nursery. Hot Water. — Boiling hot water, poured upon plants from a watering pot held above the plants, has sufficient heat to kill caterpillars (green cabbage worms, for example) without injuring the foliage. Dust Spraying Versus Liquid Spraying. — This subject is one of some controversy between workers, with most of the evidence in favor of the latter process. However, where water is scarce, or when orchard trees or other crops are on steep hillsides where liquid cannot well be hauled, the dust spray appeals to one strongly. 1 Wherever hard soap is mentioned in the above suggestions it can be replaced with soft soap by using twice as much of the soft soap as directed for the hard soap. 48 INSECTICIDES AND SPRAYING Other advantages of the dust method are as follows: The cloud of dust envelops immense numbers of trees, one barrel of dust, it is claimed, under proper conditions, being sufficient to cover five hundred trees; one cannot get on too much of the dust; it com- mends itself for small plants such as cabbages, currants, and straw- berries; it is somewhat less expensive, both in labor and material, than using the liquid spray ; one hundred large trees can be dusted in one hour at an average cost of about one cent per tree (Figs. 67 and 68). Its disadvantages lie in several facts: When a strong wind is blowing it cannot well be used, because one is obliged to keep to windward side of trees constantly; it is best used when the dew is FIG. 68. — A larger dust sprayer on wagon. on the trees or plants, thus relegating the work to the early morn- ing hours; it is not especially effective against the codling moth; on account of the clouds of dust it settles on horses and workmen much more readily than liquid spray; is not nearly as effective against sucking insects as the recommended liquid sprays. In connection with the subject of dust spray it is interesting to note that one barrel of quicklime will make two • and one-half barrels of dust (air-slaked lime) ; five pounds of Paris green to every barrel of lime is the proper proportion to be used against biting insects; it should be repeated several times. For canker worms, however, one should use ten pounds of Paris green to every barrel of lime; and for potato beetles and green cabbage worms twenty- five pounds to every barrel. MECHANICAL MEASURES AGAINST INSECTS 49 In using a liquid spray, apply until the liquid drips from the tree. Never spray a tree in bloom, because of danger to visiting bees. MECHANICAL MEASURES AGAINST INSECTS 1. Trap Crops. — A crop not desired by the farmer may be used to attract insect pests which might otherwise attack a valuable crop. For example, millet planted about a corn field will protect the latter crop from chinch bugs, which prefer the millet and may be destroyed thereon. 2. Lantern Traps. — A lighted lantern suspended at night over a tub partially filled with water covered with a film of kerosene will attract large numbers of May beetles or "June bugs" (Fig. i FIG. 69. — A lantern trap for catching June beetles. 69). This remedy should be used at the very first appearance of the insects, before the females have laid their eggs. 3. Bands of burlap or other material about apple trees afford a nesting place for larvae of codling moths. The larvae or pupae under the bands may be destroyed at intervals. Traps for encircling trunks of trees, preventing the ascent of canker worms, are on the market. 4. Tree Tanglefoot. — This is a manufactured sticky compound used as a band on trunks of trees to prevent ascent of wingless moths and caterpillars; when used on young and tender-barked trees, these must be protected by paper or cloth so that the tangle- foot will not come in direct contact with the tender bark. This paper or cloth should not be tied on young trees with a tight string and left during the growing season for fear of girdling the tree. 4 50 INSECTICIDES AND SPRAYING 5. Hopperdozers. — Various forms of these may be constructed to combat grasshoppers or other jumping insects (Figs. 70 and 71). 6. Ditches may be dug around a threatened crop to prevent inroads by chinch bugs, army worms, field mice, gophers, etc. (see discussion of these pests). 7. Dust furrows may be used against an advancing army of chinch bugs. 8. Oil barriers are also used to check chinch bugs where dust furrows are not practicable. 9. Tarred Paper or Tarred Felt Disks. — These are placed on cabbage or cauliflower plants when set out, to prevent eggs of cabbage maggot being placed thereon. Fio. 70. — Working against grasshoppers with a "hopperdozer." 10. Covering of Seed Beds and Plants. — Cabbage and other plants in coldframes are protected by screens. Melons and cucum- ber plants may be guarded against insect attack until well started, by wooden frames covered on top with cheesecloth. Wash for Tree Trunks and Limbs. — Several washes for pro- tection of trees against borers are in use. They act as deterrents and some of them as poisons for the young grubs entering the tree. All are more or less effective, but must not be relied upon absolutely. The following is an example: Two quarts of strong soft soap (or one pound hard soap) dissolved in a bucket of water. Add one-half pint of crude carbolic acid and two ounces of Paris green. Then add lime or clay, or both, to make it a thick paste (O'Kane). Probably two applications of this wash during the year would be necessary. Never use an oil paint — white lead, for example — or any form of boiled linseed oil on trunk or limbs. SPRAY PUMPS AND SPRAYING 51 12. Jarring trees is useful to dislodge beetles and let them fall on sheets below. 13. Hand Picking. — Large caterpillars and other insects may be easily picked off of trees and .plants. 14. Burning of Caterpillar Nests. — Tent caterpillars and the fall web worm may be burned by touching their nests with a burn- ing rag and saturated with kerosene wired to a pole. This should be done at a time when the caterpillars are "at home." FIG. 71. — Removing dead >perdozer. SPRAY PUMPS AND SPRAYING Cheap spray pumps should be avoided, and a high price should not be paid for an inferior article, which is not dependable. A hand atomizer or sprayer for use in flower gardens or where only a few plants are concerned can be bought for from $1.00 to $3.00; a bucket pump (Fig. 72) used in connection with bucket or pail may cost from $6.00 to $7.00, while knapsack sprayers (Fig. 73) cost from $10.00 to $14.00, and a barrel pump, most serviceable and satisfactory for a medium-sized orchard, will cost from $14.00 to $16.00, without the barrel. Power sprayers, run by gasoline, will amount in price from $125.00 to $300.00. The essential points are that all valves are of the ball type, and 52 INSECTICIDES AND SPRAYING working parts of brass or bronze. Leather or rubber valves are not used in the best pumps. Cylinders lined with porcelain are not desirable. A farmer or fruit grower with a medium-sized or- chard should be willing to pay anywhere from $12.00 to &20.00 FIG. 72. — Bucket pump. FIG. 74,— A barrel spray pump, showing agitator. FIG. 73. — A knapsack sprayer. for a good pump. A pur- chaser should insist on see- ing the inside of a pump before buying. In getting the more expensive pumps, several growers might unite, thereby being enabled to purchase a good article with comparatively small expense to the individual. Some Good Types of Sprayers. — Figures 74 , 75 and 76 illustrate types of barrel piimps, and figure 77 a double-action pump. Figure 78 is a combination barrel pump and cart, and figure 79 a one-man outfit, 54 INSECTICIDES AND SPRAYING which has been found most serviceable in experimental work. It is an excellent apparatus for a few small trees, garden vegetables, and other plants and shrubbery. Tall trees may be sprayed from a home-made tower as shown in figure 80, or with a more modern apparatus, run by gasoline power, shown in figure 81. Low plants in acreage amount, like large fields of strawberries, for example, are well handled with an outfit as shown in figure 82, or its equivalent. Hose and Extension Rod. — Connections of good hose are im- portant, and poor hose should be avoided; three-ply and four-ply FIG. 78. — Barrel pump with cart. are generally used, but where great pressure is to be needed, five- or even six-ply is desirable. Hose can be bought of any length. Where trees of some height are to be sprayed, extension rods are necessary (Fig. 83). These extension rods can be bought of various lengths, and consist either of metal pipe alone or the same encased in bamboo. To the ends of this the hose and nozzle are attached. Drip guards which encircle the extension just below the nozzle, or just above the point where it is held, will add to the comfort of the man spraying. These guards catch liquid which would other- wise run down the pole upon his hands. A nozzle which can be readily cleaned is important, and one FIG. 79. — A very serviceable outfit Fia. 80. — A home-made tower. 56 INSECTICIDES AND SPRAYING which applies the liquid in a fine spray and with force. The Vermorel type is the most desirable, and of recent years the nozzles known as the " Friend" and the "Mistry" ap- pear to give best results. When Bordeaux mixture or whitewash is to be used, a "Bordeaux" noz- zle is best. A nozzle with sharp angles or projec- tions is apt to catch on twigs and branches while in use. Figures 84, 85, 86, 87 and 88 illustrate different types of nozzles. FIG. 81.— A sensible outfit for power spraying, rpi J- +_._« ~f ,,/U^V, where large trees have to be treated. (Courtesy of ine Q1SC lYPe> OI WHICH the Gould Mfg. Co.) the "Mistry" is an ex- ample, shown in figure 87, B, B1 and C, and in figure 88, 2, receive most favorable comment in connection with tree spraying. F - FIG. 82. — Three-row sprayer at work in a field of strawberries. Never spray plants or trees when in bloom. Protect men and horses from lime-sulfur. The Spray Itself. — Closely connected with the subject of a nozzle is consideration of the spray itself. The liquid must be AGITATORS 57 applied in the form of a mist, or very fine spray, and must strike the fruit, leaf or twig with force. A nozzle which will not do this is, with the exception noted below, of little or no value, so far as treatment against insect pests is concerned. Do not think that a mere sprinkling is going to do the work. Note, in this connection, that the old-fashioned field sprinkler which used to be employed in putting Paris green solution on potato vines has been replaced by the modern cart, geared to pump automatically, and fur- nished with nozzles which apply the liquid in a fine spray and with force. This is economy, for when there is but a coarse spray, or if the nozzle " dribbles, " the liquid is wasted. It is economy, too, while seeing that every leaf and every part of the fruit or twig is well covered, not to waste the liquid by spraying too much; that is, the liquid should not drip off or run off the tree or plant to any great extent while being treated. Strainers. — All compounds used for spraying should be strained before or while being poured into the barrel or other receptacle from which they are to be drawn by the pump. If possible avoid using burlap for this purpose, as lint is bound to be carried into the pump, and is likely to give trouble by clogging the nozzle. Brass strainers are the best. They are made to fit the opening through which one pours the liquid. In addition to this, every good pump has a strainer in the lower end of the suction pipe or suction hose through which the liquid is drawn into the pump. Agitators. — Most pumps — all good pumps — are equipped with agitators which, as a rule, the working of the pump handle keeps in motion (Figs. 74, 75, 76). These are generally paddles which keep the liquid in the barrel or other receptacle constantly stirred. Paris green, being heavier than water, sinks if the liquid is not kept constantly in motion, the result being that the poison is unevenly distributed, and a part of the tree or a portion of the plant will be injured or killed by receiving an unnecessarily large FIG. 83.— A amount of the green, while other parts will receive j££bo° exten~ FIG. 84. — Nozzles of Bordeaux (left) and Vermorel type. FIG. 85. — Double Bordeaux nozzle. FIG. 86. — Double Vermorel nozzle with Y connection. A. Bordeaux. B1. Disc type adjustable. C. Two B type attached to a Y, adjustable to any angle. D. Fine spray. E. Coarse spray. F. Solid stream nozzle. FIG. 87. — Collection of nozzles. DUST SPRAYERS 59 little or none. Should one be using Paris green in a liquid from a bucket, this should be borne in mind, and the liquid almost constantly stirred. Tanks for Field Use. — These can be made of galvanized iron or pine, cypress or cedar. The last is said to be the best of the woods for this purpose where obtainable. When made of wood, the inside should be painted. Tanks vary greatly in size. Two horses cannot comfortably draw more than 250 gallons of liquid over the field. FIG. 88. — 1. Bordeaux nozzle. 2. Disc type of nozzle; and 3. Double Vermorel. Britton and Clinton. Report of Conn. Station, 1911 Knapsack Sprayers. — These are machines intended to be car- ried around on the person's back, or lifted about by hand when desired. They are excellent for work with shrubbery or in garden where too much ground is not to be covered. The writer speaks from personal experience when he says that after several fillings, the weight tells upon one's back and shoulders (Fig. 73). Dust Sprayers. — The simplest form of dust sprayer is found, perhaps, in the little bellows sold at drug stores, and used to dis- 60 INSECTICIDES AND SPRAYING tribute pyrethrum in cracks and crevices which might conceal fleas or bedbugs. A larger bellows is made for use with plants, and a still more complete machine for field use is shown in figure 67. With these one can distribute lime or a mixture of lime and Paris green, dry Bordeaux and like material. More recently, at least two firms have manufactured dust sprayers on a larger scale, to be placed on wagons, and intended for use in large nurseries or orchards. One called the " Cyclone Sprayer," and made in Kansas City, is shown in figure 68. This machine and a smaller one made by the same firm are shown in use on pages 47 and 48. A dry Bordeaux and certain caustic compounds are used with these sprayers, or a combination of dry Bordeaux and Paris green is manufactured, though directions are given to purchasers whereby many of these compounds may be made at home. QUESTIONS 1. What two practical divisions of insects can be made by the farmer and orchardisi;, independent of scientific classification, and what bearing have these upon the use of insecticides? 2. Describe Paris green and its uses. How can*one distinguish between good and bad Paris green? 3. Describe and discuss the use of arsenate of lead. 4. Why is the use of London purple undesirable? 5. How can we treat a tree for a plant disease and insect pest at the same time? 6. Describe poison baits and their uses. 7. Name in order of importance three insecticides for use against sucking insects. 8. What are some of the leading mechanical measures against insects? 9. Enumerate the uses of tobacco derivatives in sprays. 10. What is the chief objection to the use of kerosene emulsion? 11. Give a recipe for a preventive wash to apply to the trunks and branches of fruit trees. 12. Compare liquid and dust spraying. 13. WThat points are to be desired in a spray pump, and what features are to be avoided? 14. Discuss nozzles, good and bad. CHAPTER VI FUMIGATION FUMIGATION, in entomology, consists of the application of poisonous gases to kill insects. Disregarding a discussion of ben- zine derivatives, the use of which is yet in the experimental stage, we find available for use in fumigation the following: Tobacco — discussed before ; sulfur, either in powdered form or in the shape of " candles"; formaldehyde — of little or no value against insects; carbon bisulfid, and hydrocyanic acid gas. The last two deserve most careful consideration as being of the greatest economic importance. Carbon Bisulfid. — A cheaper grade is known as Fuma. The commercial grade is excellent for use against clothes moths, buf- falo beetles, and insects infesting stored grain or seeds. It has a most striking odor, that of the pure article reminding one of ether, the poorer grade like that of decaying eggs. The gas generated, when mixed with air, is highly inflammable; it is heavier than air, and is thus adapted to sinking down among furs, woollens and grain. If breathed for any length of time, it gives rise to unpleasant symptoms, and may, if inhaled to excess in a closed room, cause sickness and even death. It is not, however, as dangerous in this connection as hydrocyanic acid gas. It is evident that no light of any kind should be brought near bisulfid of carbon when employed as a fumigant. How to Use. — Commonly, it is used at the rate of two pounds of the liquid for every 1000 cubic feet of space when the tempera- ture is about 70° F. In actual use against the Angoumois grain moth it has been found that six pounds for each 1000 cubic feet are necessary. The granary, bin, room, chest, barrel, or jar must be made as nearly tight as possible, and when the liquid is used in quantity it should be placed in shallow dishes or pans to facilitate evaporation. The higher grade will not injure clothes, and in any form it will not affect the germination qualities of seed or render any product unfit for human food. Its various uses are discussed in the following chapters, under the heads of the insect pests against which it is employed. Treating Grain in Bins. — In using this on stored grain, the 61 62 FUMIGATION liquid may be poured directly on the grain. The bin or warehouse is to be first made as tight as possible; heavy sackcloth may be placed on top of grain in the bin. If the bin is very deep, a gas pipe with the lower end plugged, and with holes drilled in the side to allow escape of liquid, may be thrust down into the grain. This aids in distributing the insecticide at different levels. Two pounds of liquid for every one hundred bushels of grain, or two pounds for every one thousand cubic feet of space are advised. The process should last over night. The building or bin should be well aired afterward. Workmen should be cautioned against using lighted cigars or pipes, or lights of any kind, during their work with this agent or while ventilation is in progress. Hydrocyanic Acid Gas. — -This is made by uniting cyanide of potash or cyanide of soda with sulfuric acid (H2SC>4) . Unlike the preceding, this gas is lighter than air. It is not inflammable nor explosive at the strengths used by entomologists, but is most deadly in its effects upon man or animal if inhaled. In the hands of an expert, it is a safe agent, for knowledge of its dangerous qualities results in intelligent precautions in its use. The odor of the gas is much like that of peach pits, and the slightest trace of such an odor constitutes a warning. As an insecticide it is far superior to bisulfid of carbon, in that it is fatal to all stages of most insects, including the egg stage. Only the chemically pure cyanide should be used (98 per cent), and sulfuric acid of a specific gravity of 1.83 or over. Cyanide of sodium may be used in place of cyanide of potash if the latter cannot be obtained, but should be fresh, and it calls for one-half more acid than does potassium cyanide. For example, the standard formula for every one hundred cubic feet is one ounce cyanide of potash, one fluid ounce of commercial sulfuric acid, and three fluid ounces of water ; if cyanide of soda is used the formula would be: Cyanide of sodium, one ounce; sulfuric acid, one and one-half fluid ounces; water, four fluid ounces. For the fumigation of orchard trees with hydrocyanic acid gas, see Chapter XI. Fumigating Scions and Other Nursery Stock. — Many states require that nursery stock sold therein or brought within the state boundaries be fumigated. Nurserymen, therefore, should know how to conform to these requirements. In fumigating nursery stock, an air-tight box or room should be constructed, cubical contents of which can be easily figured. For every one hundred cubic feet of space use one ounce cyanide of potassium, two ounces FUMIGATING HOUSES 63 sulfuric acid, and four ounces of water. If cyanide of soda is employed, use three ounces sulfuric acid. The cyanide should be broken into lumps about two inches in diameter and placed in manila paper bags. Workmen should use gloves. Water should be placed in earthen crocks, large enough to prevent the liquid from boiling over, the acid added, pouring it gently into the water. The acid should never be poured into the jar before the water. This crock is placed in the center of the room or box, the trees or scions lying on racks above it. When everything is ready the proper charge of cyanide — contained in a paper bag — is dropped into the liquid and the box or room tightly closed. Exposure to fumes should last about one hour, the fumigation chamber then opened and allowed to air for fifteen minutes. Stock to be fumi- gated should not be wet. Fumigation of nursery stock is far pref- erable to "dipping." Where not practicable, however, stock may be dipped in oil emulsion or lime-sulfur, avoiding wetting the roots, or, better, it may be planted out and sprayed with these scalecides. The greatest care must be observed in handling this poison and during the operation. In cleaning up, every particle of cyanide should be accounted for, and all tools and utensils employed made scrupulously clean. One should avoid inhaling the dust in break- ing up the cyanide, and it should be kept out of sores or cuts in the hands. (For the fumigating of mills with hydrocyanic acid gas, see Chapter XVIII.) Fumigating Granaries and Grain Bins with Hydrocyanic Acid Gas. — This is described on page 353. It is useful if bins are empty. For full bins carbon bisulfid should be used as directed under that head. Both processes may be resorted to for the same building, one following the other. Fumigating Houses with Hydrocyanic Acid Gas. — This process is very effectual against bedbugs, fleas and ants. At the same time it is very dangerous, and every precaution must be taken to prevent accident. It should not be resorted to if other effective measures are available. The same general method is followed as given under fumigation of mills. All polished metal must be protected, rugs and carpets safeguarded against the boiling over or breaking of jars, and the house must be left unoccupied during the fumigation and ventilation. All moist foods should be removed. Fumigation of one apartment of a double house or apartment house would be attended with grave dangers to occupants of the other apartments. As pointed out elsewhere, in working with this gas, one should 64 FUMIGATION keep below it, i.e., begin to fumigate on the top story and work down, while in the use of bisulfid of carbon the reverse is necessary, and one can work for quite a long period in the fumes of the latter gas — until dizziness is felt. Fumigation of Greenhouses with Hydrocyanic Acid Gas.— Excellent for mealy bugs, white fly, and aphids, but not practical for red spiders and scale insects. William Moore, of the Minnesota Station, has done some excellent work in this direction, and we are privileged to quote from his report as well as from results attained by Whitmarsh, of Ohio, and Davis, of Illinois. In the fumigation of greenhouses, there are a number of factors to be taken into consideration. The most important feature is to FIG. 89. — Diagram of greenhouse with two sides of roof equal. have the greenhouse accurately measured, so that one can deter- mine the exact dose of chemical which is necessary to kill the insect pests and not destroy the plants. Contents of House. — Figure 89 shows a view of a greenhouse which has both the slanting roofs equal and the height of each side equal. Such a house is very easily measured and the number of cubic feet determined. In a house of this kind, the height AB is multiplied by the width AE and the result multiplied by the length AH. This gives the number of cubic feet of space in the rectangular portion ABDE-H. The upper portion is still to be estimated. For this purpose, take the height CG and subtract from itAB, the height of the side. This will give the height of the line CF. Multiply CF by the width FB (which equals GA or half AE). This will give the number of square feet in the section BCD. The number of square feet in BCD is multiplied by the length AH, FUMIGATION OF GREENHOUSES 65 giving the number of cubic feet in the upper portion of the green- house, which, added to the number of cubic feet in the lower portion, gives the capacity of the greenhouse in cubic feet. Many greenhouses have the sides unequal and the slopes of the house unequal, as shown in figure 90. In such a- greenhouse, one must multiply the height AB by the width of the rectangular portion A BIG, which width is AG, G being a point immediately underneath the highest portion of the roof. The same is done for the rectangular portion DEGF. We then have two triangular portions still to compute. Multiplying CI by IB and dividing by two gives the number of square feet in the portion CIB. The same is done for the triangle DCF: that is, DF is multiplied by CF and divided by two. The number of square feet in these four sections are then added together to give the sum-total of square feet in the end of the FIG. 90. — Diagram showing roof with unequal sides. greenhouse. This sum is now multiplied by AH to get the cubic feet in the house. Amount of Chemical. — After having carefully estimated the number of cubic feet, the next point to determine is the amount of the chemicals to be used. This varies according to the plants which are present. Some plants are more susceptible to cyanide gas than other plants, and where there are a number of different plants in the same house the amount of material to be used should be such that it will not injure the most tender variety. Two other factors which are most important are the tempera- ture and the humidity in the house. Plants are always more readily injured in a house where the temperature is low, say 60 degrees, than they are when the temperature is high, as, for example, 70 to 80 degrees. The more moisture in the house the more apt the plants are to be injured, so that the house should be just as dry as is possible, considering the plants which are in it. 66 FUMIGATION Some plants can never be fumigated, or have never been suc- cessfully fumigated. Roses, carnations, and chrysanthemums can be successfully fumigated to kill aphids and white fly under proper conditions. The plants may even be in full bloom. Plants should not be watered just before fumigation. In fact, it would be well if the plants had not been watered for twenty- four hours before the process. The temperature should be about 68 to 70 degrees, and the fumigation must be done at night; even on a cloudy day it is apt to burn the foliage, while some entomolo- gists seem to think it advisable not to fumigate on a bright moon- light night. However, the moon does not seem to affect results. The materials used in fumigation with cyanide are potassium cyanide, sulfuric acid, and. water. The usual formula is: One ounce potassium cyanide, two fluid ounces sulfuric acid, and three fluid ounces water. Some prefer to use as much as six fluid ounces of water to one ounce of sulfuric acid. The more water that is used, the slower the gas is generated and the more evenly it is probably distributed. The sulfuric acid is slowly added to the water, which is contained in an earthenware jar, constantly stir- ring. The earthenware jar is necessary, inasmuch as metal will be acted upon by the sulfuric acid. The resulting mixture will be hot, and the broken cyanide is added to it while still hot. The dose which is in general use is from one ounce to five ounces of potassium cyanide per thousand cubic feet. It would be well to first try the lighter dose, and if the insects are not killed and the plants are uninjured, a stronger dose should be used. For overnight fumigation use one-quarter to one-half ounce per thousand cubic feet rather than a heavy charge for a short time. Under these con- ditions there will be no danger in airing out the following morning. It would be well to advise the use of not more than one-quarter of an ounce for the first dose to each thousand cubic feet for over- night use, and not more than three ounces per thousand cubic feet for fumigation for a half hour. If either of these doses is used, and the insects are not killed while the plants show no injury, the amount of cyanide per thousand cubic feet could be increased, but not exceeding five or six ounces per thousand cubic feet as a maximum quantity. Precautions. — The gas is extremely poisonous, as is also the case with the potassium cyanide. For that reason it is best not to be in the house at the time that the cyanide is to be placed in the jars. This can be arranged by putting the cyanide in bags tied to a string suspended from the ceiling, end of the string to be HEATED ROOMS 67 extended to the outside of the house, so that the cyanide can then be lowered into a jar while the person is on the outside of the house. When a large greenhouse is to be fumigated, it would be well to have several jars, so that the gas will be thoroughly distributed throughout the greenhouse. If heavy bags are used for the cyanide, the jars can be placed in order and a bag placed beside each jar. When all is ready, move rapidly along the row of jars, placing the bags in the acid, and leave the house at once. Ventilators should be arranged in such a way that they can be opened from the outside to air the house. One should be careful to remove cats or any other pets from the house before the fumigation is started. If the cat is forgotten, one should not go into the house to get it after the cyanide is started; in fact, under no circumstances should the house be entered after the fumigation is started until such time as the house has been thoroughly ventilated. Directions for Using Sulfur. — Rooms should be made tight by stuffing all cracks or pasting paper over them. Iron, steel and nickel are also attacked by sulfur fumes. Nickel fittings and gilt frames, copper, silver and steel utensils should be removed, though metal may be protected by smearing it with vaseline. Use two to three pounds of sulfur for every thousand cubic feet. Place vessel holding sulfur in a larger dish of water. A half pint of wood alcohol mixed with the above amount of sulfur will cause same to burn freely; or sulfur candles may be used. Heated Rooms. — Most insects, particularly those in mills, will succumb if exposed to a temperature of 123 to 125 degrees F. for several hours. Dean, of Kansas, first demonstrated this with mill insects, and where such temperature can be safely maintained in mill, warehouses, or dwelling it is recommended. QUESTIONS 1. Describe the method of fumigating grain or seed with carbon bisulfid. What precautions must be observed? 2. Describe methods of fumigating a greenhouse with hydrocj'anic acid gas and tell what precautions should be observed. 3. How is nursery stock fumigated? 4. Give directions for the use of sulfur as a fumigant. 5. Enumerate the dangers in the use of hydrocyanic acid gas and tell what precautions should be observed in its use. 6. In what ways is fumigation with bisulfid of carbon dangerous and what precautions are to be observed? 7. What are the qualifications of a good spraying outfit? 8. What precautions are necessary in preparing and applying a liquid spray? 9. What are the objections to spraying fruit trees while in bloom? CHAPTER VII INSECTS INJURIOUS TO THE APPLE THE apple is so universally grown and is such a valuable addi- tion to our food supply that conditions surrounding its growth have been perhaps more carefully studied than those of any other tree, and the various insect pests attacking it have been the subject of careful investigation on the part of entomologists. The results of some of this work are given in this chapter. INSECTS ATTACKING THE TRUNK AND BRANCHES The Flat-headed Apple Tree Borer.— The adult is a broadly- flattened, metallic bronze-colored beetle (Chrysobothris femorata Fab.). It is about two-thirds of an inch in length, with short antennae, conspicuous eyes, and a more or less ornamented back. The males are smaller than the females (Fig. 91). It is fre- quently seen during the spring and summer months, first ap- pearing in May or June upon the trunks of the trees. Life History and Habits.— The female oviposits in cracks or under the bark. Diseased or dying trees are preferred. It attacks both fruit and forest trees, notably young trees. Sometimes maple trees may be infested. The eggs are yellow and usually several are grouped together. The larva is large, legless, and with a broad, flat head. It works into the wood, digging irregular flat channels, sometimes completely girdling a tree. Its presence is often indi- cated by sawdust-like excrement on the bark. The winter is spent in the larval stage, possibly occasionally as pupa. Ordinarily it pupates in the spring, just under the bark — the pupal stage being very short, approximately three weeks. When the adult beetle emerges from the trunk, it leaves an elliptical hole in the bark, while the hole left by the following borer is round. 68 FIG. 91. — Flat-headed apple-tree borer. (U. S. Bu. Ent.) ROUND-HEADED APPLE TREE BORER 69 Control. — Encourage the presence of woodpeckers. Cut borers out when discovered, if possible, without seriously injuring the tree. Place limbs in the sun around the orchard to attract the beetles during the egg-laying period. Burn this infested wood the following fall or winter. Practice clean culture and proper pruning. Plant healthy stock. See also remedies for round-headed borer. The Round-headed Apple Tree Borer. — (Saperda Candida Fab.) . —The adults have two dorsal white lines on the back (Fig. 92). Life History and Habits. — Adults appear in spring and summer. Females oviposit in incisions in the bark made with the mandibles. FIG. 92. — Round-headed apple tree borer; a and b, two views of the larva; b, pupa, c, adult. (U. S. Bu. Ent., U. S. Ag.) The puncture is then closed with a gummy fluid. The pale- brownish eggs are placed singly. The time required for hatching is in doubt. The larvae work inward and feed on the sap wood, working up and down the tree. After resting during the winter, they resume action in the spring. They work into the heart wood during the second season, spending their second winter as larvae, and entering the pupal stage during May and June. They emerge as adults about two weeks later. Two years, therefore, are re- quired to reach the adult stage. Control. — Cut out larvae when possible. To prevent egg- laying in the bark, paint the trees in the spring with a mixture of soft soap and carbolic acid. Boil one quart of soft soap or one pound hard soap in two gallons of water; then add one pint 70 INSECTS INJURIOUS TO THE APPLE of crude carbolic acid. A little Paris green and lime will make the mixture more valuable. Wrap the tree-trunks with paper in the spring. Paint the trunks with strong whale oil soap wash; or paint with good, so-called "tree paint" which is made up with water, not oil. A very good wash for tree-trunks on larger branches is the "government whitewash." The recipe is as follows: Government Whitewash.— Slake half a bushel of quicklime with boiling water, keeping it covered during the process. Strain it and add a peck of salt, dissolved in warm water; three pounds of ground rice put in boiling water and boiled to a thin paste ; half a pound of Spanish whiting and a pound of clear glue, dissolved in warm water; mix these together well, and let the mixture stand for several days. Keep the wash thus prepared in a kettle or port- able furnace; and when used, put it on as warm as possible, with painters' or whitewash brushes. The San Jose Scale (Aspidiotus perniciosus Comstock). — This very destructive scale attacks all parts of the tree above the ground. The scale is frequently seen on fruit or young twigs accompanied by a red discoloration around each scale. It imparts a grayish, roughened appearance to the bark when very abundant. Life History and Habits.— This insect spends nearly all of its life under the scale ; is active only as a young larva and as a mature winged male. Both sexes hibernate when half grown under the scale. Males reach maturity early in the spring, fertilize the females, and disappear. Later, the latter give birth to living young. There are probably four generations in a year in favorable localities. The young larva, yellow in color, moves about to find a suitable place to attach itself. When about to become stationary, the scale is formed — the insect becoming covered with it in two days. The young scale is whitish, turning darker with age. The scale of the female is convex, with a yellowish and shining nipple in the center. The first moult occurs when the scale is twelve days old, after which males and females take different form. The scale of the male is smaller than that of the female and somewhat elon- gated, the nipple being near one end. The females pass the second moult when about twenty days old, becoming adult at the age of thirty days (Fig. 93). This pest spreads quickly on nursery stock by blowing from tree to tree, and is also carried upon the feet of birds and on the bodies of large insects. The English sparrow has been recently shown to be a prominent means of dispersal. FIG. 93. — San Jos6 scale. 1, female scales, nipples lateral; 2 and 4, adult females with young; 3, male scale; all much enlarged. 5, adult female scale, natural size on apple; 6, dis- coloration of fruit by growing scales. (After Hall, Lowe and Parrott, N. Y. (Geneva) Bull. 193 and 194.) 72 INSECTS INJURIOUS TO THE APPLE Control. — Spray the trees twice — once as soon as the leaves are fallen, and, second, in the early spring, as soon as the buds swell. Use lime-sulfur wash each time. The old rough bark on the trunk of the tree should be scraped off before applying the winter spray, so that every portion may be wet with the liquid. Lime-sulfur Wash. — Lime, four pounds; sulfur, three pounds; water, ten gallons; or, better, purchase commercial lime-sulfur and use according to directions on can. FIG. 94. — Oyster-shell scale or bark louse: a, female scale from below filled with eggs; b, same from above; c, infested twig; d, male scale; e, twig infested with male scale. (U. S. Bu. Ent.) Summer sprays are hardly effective and should be resorted to only when winter spraying has been neglected. Dilute lime-sulfur (see directions) or whale oil soap (one pound to four or five gallons) or dilute miscible oils may be used at this season. The Oyster-shell Scale (Lepidosaphes ulmi Linn.). — These have been introduced from Europe. The scales are one-sixth of an inch long, brownish in color, and are somewhat like the shell of the oyster in shape. The white eggs are found under the scales in winter. SCTKFY SCALE 73 Life History and Habits.— They hatch in May or early June. Like the preceding species, the young seek new locations on the same tree, and, becoming fixed, insert their beaks in the bark. The complete scale excreted from the body of the insect gradually covers it. By the middle of August the female scale has become transformed into a mass of eggs under the scale, and, day by day, as these are laid, her body shrivels until, finally, it becomes scarcely noticeable at the end of the scale. Male scales are smaller than the female and are seldom seen (Fig. 94). The young scale retains the power of motion only a few days after hatching, and does not spread far, if nothing intervenes to help it. It may be spread by being carried on the feet ^ A, ? of birds or large insects, and nursery stock should be care- ^ fully examined for it. It is a striking fact that a tree may be thickly covered with this scale and yet not seri- ously suffer, while a half or a quarter of that number of San Jose scale insects, if present, will cause the death of the tree. Control. — Use lime- sulfur spray in the dormant season as with the San Jose scale. The Scurfy Scale (Chionaspis furfurus Fitch). — This scale is quite common on apple trees. The female's scale is oblong, taper- ing to almost a point at one end; grayish white in color and about one-tenth inch long. The male scale is much narrower and smaller (Fig. 95). There is only one brood a year. The eggs are purplish- red in color. They remain under the old female scale during the winter and hatch in early spring. The young move a short distance on the trees and settle down permanently. The scale covering begins to develop soon after. Control. — The lime-sulfur should be applied in late winter or early spring. The lime-sulfur solution does not appear to kill the eggs of this insect, and its application should be made just before the buds open in spring in order to catch the young larvae. Or FIG. 95. — Scurfy scale: a, twig infested with female scale; 6, twig infested with male scales; c, female; d, male. 74 INSECTS INJURIOUS TO THE APPLE we may use whale oil soap, one pound to four or five gallons of water. In June use the same remedies as given for San Jose scale. For any scale, pruning of fruit trees should be practiced before winter or early spring treatment with sprays, in order that all parts of the tree may be better reached by the liquid. It is desir- able to burn all prunings from infested trees. The Putnam Scale (Aspidiotus ancylus Putn.). — This is not a serious pest, but is of considerable importance, because it resembles the San Jose scale so closely. In color it is dark gray. The female is circular and about one-twelfth inch in diameter. This differs from the San Jos£ scale in being slightly larger. It usually has a conspicuous or orange nipple a little to one side of the center, surrounded by a concentric de- pression less conspicuous than in the San Jose scale. Dis- persal of this scale is less rapid than the Iast-named> and the injury caused is less severe. The young cluster more about the parent, thus making a more uneven infestation. The insects pass the winter in the immature stage on the bark, completing their growth in the spring, at which time the two-winged males emerge. The females lay from thirty to forty FIG. 96. — Buffalo tree hopper (a), infested twig eff£S late in the Spring, Under and eggs (c and d). (After U. S. Bu. Ent.) * the scale. The fact that they are oviparous instead of viviparous is another mark distinguishing them from the San Jose" scale. There is supposed to be but one generation. Control. — Use lime-sulfur spray when trees are dormant. The Buffalo Tree-hopper (Ceresa bubalus Fab.). — This is a jumping insect capable of strong flight. It is about one-third inch long, light-green in color, with whitish dots and a pale yellow- ish streak along each side. A sharp point upon each side of the front is seen jutting out horizontally, reminding one of a horn and suggesting the name. The body is three-sided and has been BUFFALO TREE-HOPPER 75 FIG. 97. — Branches of apple tree broken by over-bearing. In these the fruit-tree bark-beetle was found breeding in great numbers. (After Brooks, U. S. Bu. Ent.) 76 INSECTS INJURIOUS TO THE APPLE likened to a beechnut. The insect lives by sucking the sap through a sharp-pointed beak. Life History. — Adults appear about the middle of May and continue egg-laying through August and September. The eggs are laid in two nearly parallel slits, each containing from six to Fia. 98. — Woolly aphis on branch of young apple. twelve eggs. These slits run lengthwise of the branch and are about three-sixteenths inch long, separated by about one-eighth inch of bark (Fig. 96). This provision is important, as the tips of the slits meet and cause a deadening of the wood, which prevents the eggs being crushed. Cold weather kills the adults, but the eggs winter in the branches, hatching in spring or early June. Control. — Spraying specifically for this insect has not proved effective, even against the young hoppers, since these infest vege- WOOLLY APHIS 77 tation in proximity to the apple trees, but proper spraying for other insects would be of some service in checking attacks. Clean cultivation of the orchard is one of the best preventives. The Fruit Bark Beetle (Scolytus rugulosus Ratz).— (Fig. 97.) See chapter on Plum, Peach and Cherry Insects, page 113. The Woolly Louse or Woolly Aphis (Schizoneura lanigera Hausmann). — Bluish - white, flocculent, or cottony patches, wrapping clusters of the lice, are noted on the lower part of trunks or on branches of young trees (Fig. 98), particularly abundant on water - sprouts. There is a root form, also, which is more injurious (Fig. 99) . This insect causes gall-like swellings in cracks of which it lives in clusters. A winged form also occurs during the season. The wingless lice are one-tenth inch long; reddish- brown, covered with character- istic cottony or waxy secretion. Life History. — The woolly aphis lives over winter on the trunks and branches when the season is not too severe. The exact length of life of the adult is not known. Females give birth to living young for an indefinite period. The larvae, when first born, have not the white secretion which soon appears when they begin to feed. Injury. — As a result of the work of this pest, the bark becomes deeply pitted, or large cavities are formed. The tree ceases to grow at the point of attack. On roots it produces gall-like swell- ings. If abundant, the tree loses its vitality on account of the loss of sap, coupled, perhaps, by transmission of a poison by the insect. This insect is likely to be extremely abundant on any injured por- tion of the tree. FIG. 99. — Woolly aphis, root form: a, deformed root; 6, root covered with aphids; c.rootlouse, female, much enlarged. (Marlatt, U. S. Bu. Ent.) 78 INSECTS INJURIOUS TO THE APPLE Control. — Dig up and burn badly infested trees, using ground for another purpose for a time. For the bark form of louse, use any of the washes recommended for plant lice, such as kerosene emulsion, strong soap wash, tobacco extracts, resin wash, etc., applied with sufficent force to penetrate the cottony cover. Sprays are best applied warm. Bands of tanglefoot about the base of trunk in early spring may keep many of the root forms from ascending. The New York Weevil (Ithycerus noveboracensis Forst.).— This is one of the largest of our snout beetles or curculios; at least a half -inch long; ash-colored, marked with black, with four whitish lines on each wing-cover, interrupted by black dots (Fig. 100). Three smaller whitish lines on the thorax; a yellowish spot on the back, at the junction of wing case and thorax. The larva or grub is footless, pale yellow, with a tawny head. Life History. — The adult appears in May or June, the female depositing her eggs usually in oak or hickory trees. She usually makes a longitudinal incision with her jaws, eating under the bark; then turns and deposits her eggs in the opening. The larval stage is passed in the oak or hickory, and damage to orchards is naturally greatest near woodlands. Injury. — The adult injures apple and other 100.— New York fruit trees by eating the buds and bark of twigs. Later, leaves are eaten off at the base. The beetle is active at night and prefers the tender, succulent shoots of the apple, but also feeds upon pear and plum, as well as peach in localities where the latter is grown. Control. — Practice jarring of the trees as for plum curculio (which see). Spray with arsenicals early in the spring, just as the buds are swelling. The Apple Twig Borer. — This insect is commonly found attack- ing the small twigs of apple trees. See the discussion under grape insects, pages 155 and 157. INSECTS INJURING THE LEAVES The Apple Tree Tent Caterpillar (Malacosoma americana Fab.). — The adult insect is a dull, reddish-brown moth with stout FIG. weevil, infested twig (a), larva (6), adult (c). APPLE TREE TENT CATERPILLAR 79 body; and in the female a wing expanse of one and one-half to two inches; in the male, about one and one-half inches. In each sex there occur two nearly parallel, whitish lines running obliquely across the front of the wings. The larva or caterpillar is two inches long when mature, cylin- Fia. 101. — American tent caterpillar (Lugger). drical, deep black with white stripe along the back and also with lateral markings; on each side, a row of oval, blue dots occur (Fig. 101). The body is sparsely clothed with fine yellowish hairs. The larvae live in conspicuous nests made of layers of silk, fre- quently with room for the caterpillars between the layers. 80 INSECTS INJURIOUS TO THE APPLE Life History. — One generation is produced each year. The sexes mate soon after emergence and eggs are deposited on limbs and twigs. The female deposits from 150 to 200 eggs in early midsummer, the eggs encircling the smaller twigs (Fig. 102). These eggs stand on end and are covered with a waterproof coating secreted by the female. The caterpillars develop, but remain within the egg until the following spring. Upon the arrival of warm weather, they gnaw through the shells, often before the leaves come out. In that event they feed upon the glutinous cover- ing of the egg mass (Fig. 102). As stated above, the caterpillars live in silken nests or webs and feed on foliage at regular intervals — morning, afternoon, and night. The older caterpillars wander away from the nest and feed upon such plants as they find. They pupate approximately six weeks from the time of hatching, in any secluded place, under loose bark, in grass, or brush, under trees, along fences, and on the sides of sheds, houses and in other similar situations. The pupal case or cocoon is composed of white or yellowish-white webbing, and the pupal stage lasts about ten days. Control. — Remove all useless trees, such as wild cherry and worthless apple trees, growing along road- sides or fences. Destroy egg masses during dormant FIG. 102.— period of trees by pruning and burning the cuttings. Egg mass of ~ .,, , * ., „ . f American tent Caterpillars, when they first appear, may frequently caterpillar. be kmed by crughmg ^ftfo the j^^ Later the nests may be burned. Arsenical sprays such as arsenate of lead are very effective against these and all leaf -eating forms of insects. Use two or three pounds of arsenate of lead in fifty gallons of water. This poison, when used as a spray against the codling moth or combined with a fungicide, easily keeps this pest in check. The Tentless Caterpillar or Forest Tent Caterpillar (Mala- cosomadistriaJIlm.). — This pest in the caterpillar stage somewhat resembles the previously discussed insect, with which it might be confounded. It does not, however, form a nest. The adult moth is yellowish-brown, with a wing expanse of one and one-half inches. It has two oblique, brown lines on the fore wings, enclosing a darker space. The caterpillar is slightly smaller than the apple tent cater- pillar. The general color is a pale blue, tinged with green on the FOREST TENT CATERPILLAR 81 sides and everywhere sprinkled with black dots or points. There is a row of white spots along the middle, an orange-yellow stripe on each side of this row of spots. Below the yellow stripe is another cream-colored stripe, all stripes being edged with black. Each segment of the caterpillar has two elevated black points in the back from which arise a bundle of coarse hairs. The back is clothed with whitish hairs. The head is dark blue, freckled with black dots, also clothed with black and rufous hairs. The legs are black with whitish hairs (Fig. 104). Life History and Habits. — The eggs are laid in the fall in rings around the twigs. The clusters of eggs are cut off squarely at the ends, differing from the egg-clusters of the tent caterpillar, which taper to the twig. There are from 200 to 400 eggs in each cluster, whitish covered with a brown, varnish- like substance. They hatch so early in the spring that the caterpillars have to wait for green food and have been known to live three weeks in quite cold weather without eating. When the leaves appear, they grow faster, and march over the tree in regular order. They feed twice a day. Wherever they go, they spin a thread, but do not make webs, nests, nor tent. Although gregarious when young (Fig. 105), the individ- uals spread when older and are seen wandering along fences, houses, roads, etc., in search of suitable shelter in which to change to pupae. After two or three days, they transform to reddish-brown pupae covered with short yellowish hairs. Moths appear about ten days later, deposit eggs, and die. This occurs in midsummer and only a single brood is produced in a season. 6 FIG. 103. — American tent caterpillars just hatched. Also egg mass on right. (Lugger.) 82 INSECTS INJURIOUS TO THE APPLE This insect eats foliage of apple, plum, fruit trees, and several of the forest trees. Control. — Gather and destroy egg-clusters in winter. The larvae are easily kept in check by poison sprays, preferably arsenate of lead. Spray with this compound as for the codling moth. The Apple Leaf Aphis (Aphis mali Fab.). — This is a serious pest, particularly on young trees. The leaves, when attacked, curl up and may drop off. Description and Life History. — The black winter eggs of these lice are frequently seen on the axils of the buds in late fall and win- ter. These eggs hatch in early spring, each egg producing what is FIQ. 104. — Forest tent caterpillar: a, egg mass (compare with egg mass of American tent caterpillar) ; 6, moth, enlarged; c, top of enlarged egg; d, side view of three enlarged eggs. (After Riley.) known as the " stem-mother," dark green in color. These stem- mothers work into the folds of the opening leaves, insert their beaks into the tissues, and feed upon the sap. In favorable weather they become adult in about two weeks and give birth to living young at the rate of from three to twelve a day for about three weeks, each stem-mother producing from 75 to 100 individuals. These first insects are always wingless females. The fol- lowing generations during the summer are all viviparous females. The second generation is slightly larger than the first. A small percentage of individuals of this generation are winged. Many of the third generation are winged, scattering to nearby trees to start new colonies. The wingless forms are larger and somewhat APPLE LEAF HOPPER 83 more injurious than the winged forms. Late in the summer, winged forms become less numerous. True sexual males and females are developed about September —the males being smaller than the females and both sexes smaller than the summer stages. After mating, the eggs are deposited on exposed surfaces of stems of apple trees. When first laid, the eggs are light green, later turning black, and remain unhatched until the following spring. Control. — Late fall and early spring sprayings will help to destroy the eggs. Use lime-sulfur mixture according to direc- tions on can; or use tobacco extracts. For summer sprays on living aphids, dissolve a five-cent cake of Ivory soap in five gallons of water; or of black leaf, No. 40, two table- spoonfuls, in a gallon of water; or one pound of whale oil soap in four gallons of water. When pruning, in the late winter or early spring, burn the cuttings to destroy the eggs thereon. The Apple Bud Aphis (Aphis avence Fab.). —This is another louse, like the former in- troduced from Europe, found upon the apple. The eggs hatch in early spring on apple trees. The first generation or stem-mothers are deep green, wingless, and give birth to living young when mature, continuing to reproduce for three weeks. A few winged forms are found in the second generation, and a large proportion of the third generation are winged and migrate to grasses, grain, or oats. Sev- eral generations are produced on the grasses during the summer. Early in the fall the winged migrants go back to the apple trees Fl«- 105.— Forest tent i • i • 1 1 , -IP caterpillars crowded to- and give birth to true sexual forms, the eggs gether, greatly reduced, being laid on the apple twigs. Control. — Use the same remedies as for Apple Aphis. The Apple Leaf Hopper (Empoasca mali LeB.). — This insect is not a serious pest in orchards, but retards nursery stock. It occurs in large numbers on plum, maple, burr oak, black oak, 84 INSECTS INJURIOUS TO THE APPLE thorn apple, basswood, hazel, box elder, blackberry, and many other trees and shrubs, but is particularly injurious to young apples. Description and Life History. — The young form or nymph, when first hatched, is almost colorless, becoming pale-orange or greenish-yellow. It crawls to the under side of the leaves, is extremely active, and moves quickly when disturbed. It always walks, except in the last nymph and adult stages. The adults are about one-eighth inch long (Fig. 106). This pest is apparently two-brooded, the number of broods probably varying with the latitude. The nymph emerges from the winter egg soon after the leaves open. It has five nymphal stages, twenty-two days being required to reach the adult stage. The adults lay summer eggs in petioles of clover, apple, and probably many other plants which furnish food during the summer. The adult stage lasts from two to four weeks. Where there are but two broods, the second brood deposits winter eggs under tender bark of apple tree or nursery stock. The presence of this egg is denoted by a blister-like swelling on the bark — less than one-twenty-fifth inch in diameter. Control. — Collect the first brood with some sort of hopper- dozer on a shield smeared with tanglefoot. One pint of nicotine sulfate in one hundred gallons of water will control the young or nymph stages. Periodical dippings of affected tips of nursery stock, when insects first appear, in the same solution, are effective. Soap adds to the value of the above extract. Where convenient one should grow nursery stock as far as possible from orchard, as orchards seem to be infested yearly. Scions cut from infested orchards may help to spread the pest. The May Beetle or "June Bug." — The adult beetles feed at night on leaves of fruit and shade trees, and the immature form or white grub frequently attacks the roots of the apple. See White Grub, under strawberries, page 135, for life history and control measures. The Tarnished Plant-Bug (Lyjus pratensis Linn.). — This in- sect begins its work in spring, feeding upon young buds, from which it sucks the sap. Its puncture seems poisonous and causes the leaves so attacked to wither and dry. Sometimes this bug attacks the fruit, causing deformities of the latter. It feeds upon almost all garden crops, small fruits, tender shoots of fruit and nursery trees, many flowering plants, and most of the common weeds. Description and Life History. — The adult is brownish; about TARNISHED PLANT-BUG one-fifth of an inch long. It varies somewhat in color from a dark- brown to a greenish- or yellowish-brown, the male being generally darker than the female. The head is yellowish, with three narrow, reddish stripes on top. The beak is about one-third as long as the body, folded underneath the insect when not in use. The thorax is yellow, margined with several yellowish lines running length- wise. Upon the thorax is a yellow V-shaped mark. The wings are a dusky brown; and the legs are a dull yellow (Fig. 107). The young bugs or nymphs resemble their parents, but they lack wings and are more or less greenish in color. The female deposits her eggs on leaves in the early spring, and later both young and old bugs are found together. The winter is FIG. 106. — Apple leaf hopper: 1, 2, 3, nymphs; 4, adult. FIG. 107.— The tarnished plant bug. (Lugger.) passed in the adult stage among rubbish, etc. There may be two or three generations of this insect. Injury. — This destructive bug attacks most garden plants, small fruits, tender shoots of fruit trees, nearly all of the flowering plants, and many weeds. It also punctures the young fruit of strawberries. Development is arrested when the bug sucks the sap. Control. — Contact insecticides, such as tobacco extracts, soap solutions, etc., are used for the young nymphs. The adults are too active for effective treatment and, being sucking insects, are not affected by arsenical poisons. Clean cultivation and complete cleaning up of all rubbish and crop remnants are suggested. When the adults are plentiful they may be collected from the 86 INSECTS INJURIOUS TO THE APPLE trees with a net in the cool of the early morning. Lime-sulfur and Bordeaux mixture both form fairly good repellents. The Lesser Apple-leaf Roller (Alceris minuta Rob.). — The caterpillars of this little moth fold tender leaves along the midribs or fold over the margins of older leaves and seek protection in the enclosure thus formed. Several young larvae may tie up the tender unfolding leaves at growing tips and work inside, boring through the tender tissue and riddling it with small holes. Again, they may fasten two leaves together by their flat surfaces. The insect fre- quently injures young nursery stock. Life History. — There are two forms of this species, an orange- colored moth, seen during spring and summer, and a slate-colored form observed late in the fall. The species has two broods. The wing expanse is about a half -inch. The larva is about a half-inch long, with yellowish head. In June, in many localities, and again in August, orange-colored adults appear. Pupation occurs on the leaves. The third brood, consisting of slate-colored adults, appears in October. The late forms hibernate among fallen leaves. Control. — Pick off or pinch affected leaves on small trees or on nursery stock. Spray with arsenate of lead when the larvae are very small or before they are hatched. If sufficient time is given them to fold their leaves, they are then protected from arsenical spraying. When moths are seen flying about, use this spray and repeat the same in ten days or two weeks. The Bud Moth (Spilonota ocellana Schiff.).— The black-headed, greenish caterpillar — the young of this moth — feeds on the epider- mis of the leaf, leaving a network of veins. It spins a small silken case just above the winter bud and hibernates therein when half- grown. In spring, when the buds open, it eats into the buds and young leaves, webbing up buds and clusters of leaves to make nests. The insects pupate in these clusters, the pupal period lasting about ten days. The adult moths appear in June, the transparent eggs being placed singly or in clusters. This insect is especially injurious to nursery stock. Control. — Collect and burn the nests in spring or crush them with the hand. Early spraying with arsenicals as used for codling moth will help in their control. (See page 98.) The Cigar Case-bearer (Coleophora fletcherella Fernald).— The insect hibernates as a half-grown larva in a case attached to a twig, emerging in April or May and attacking buds, leaves, and fruit. The case is built larger as the larva increases in size. In SPRING CANKER WORM 87 this stage the insect mines a leaf and, discarding the old case, makes a new one from the upper and lower layers of the leaf. It becomes full grown in June or July, fastens the case to a twig, and pupates within. The pupal stage lasts ten days, after which the adults appear as minute gray moths. Control. — Spray with arsenate of lead as in the treatment of codling moth. Repeat for five days. Kerosene emulsion used in place of arsenical poisons is effective. In connection with kerosene emulsion, note caution given in the chapter on insecticides. The Spring Canker Worm (Palecrita vernata Peck). — The pale grayish female moth with dark brown stripe down middle of back and • dark head is wingless ; somewhat fancifully referred to as resembling a spider. The male is winged with a wing expanse of about an inch; wings semi-transparent; brownish-gray; three indis- tinct dark lines around the forewings. When full grown, the larva is three-fourths of an inch long, cylindrical, with but one pair of pro-legs on middle of abdomen, and it walks by " looping." The color of the larva varies from ash-gray to green or yellow; the predominating color, however, is dark-greenish olive or blackish. It is marked with narrow, pale lines down the back and has a light stripe along each side. Life History and Injury. — The moths emerge from their pupal cells in the ground in March and April. The wingless females then climb the trunks of trees. After the mating, the eggs are deposited in irregular masses of about fifty each on or under scales of bark, in cracks, crevices, and crotches of limbs and twigs. They hatch in approximately a month. The young caterpillars begin to feed on the expanding leaves, the larvae when first hatched eating holes in the leaves and later eating the entire leaf except the midrib. They may drop from the tree and hang suspended upon strands of silk when disturbed. The caterpillar becomes full grown in four or five weeks; enters the soil to a distance of two to five inches, hollowing out a cell in the ground, which it lines with silk. It then changes to a pupa which is about one-third of an inch long and light brown. The summer is passed in this condition. Control. — Thorough cultivation during summer will largely destroy the pupae. The caterpillars are easily destroyed by a spray of arsenate of lead, three pounds in fifty gallons of water. The first spraying should be given as soon as the trees leaf out, and the second as soon as the blossoms drop. The first is the more 88 INSECTS INJURIOUS TO THE APPLE important, and one good spraying is usually sufficient. The remedial measures recommended for the codling moth will also control these caterpillars. The wingless females may be prevented from ascending trees by a tanglefoot band three or four inches wide. These bands should be applied late in March for the spring canker worm and FIG. 108. — The fall canker worm attacks trees other than apple. A basswood defoliated by attacks of this insect. (Original.) in late September for the fall canker worm. Before applying tanglefoot bands, the rough bark should be slightly scraped in order that no cracks are left untouched by this sticky mixture and that the compound may not be wasted. Personal observation leads us to believe that on very young trees it is safer to wind paper bands, two or three inches in width, about the trunk and apply tanglefoot bands on that, in order to avoid injuring the young bark. Do not tie these bands tight. Tanglefoot bands. FALL CANKER WORM 89 should be kept sticky during seasons of infestation by "combing" with paddle or brush or adding new material. The Fall Canker Worm (Alsophila pometaria Harris). — This measuring worm or "looper" also feeds on the foliage, sometimes stripping a tree completely. It not only attacks apple, plum, and other fruit trees, but is at times destructive to basswood and elm (Fig. 108). Description. — The adult male moth, grayish or whitish in color, has fore-wings crossed by two light bands, the outer one indented on the front margin so as to form a distinct spot. This outer band is also seen on the hind wings, but less distinct. The female of this species is wing- less and of a uniform, ash-gray color without markings. The segments are about as broad as long, without hairs. The full-grown larva is from three-fourths to an inch in length, slender, cylindrical, with two pairs of pro-legs on the abdomen, which dis- tinguishes it from the spring canker worm, the latter hav- ing only one pair. The color varies from ash gray to green J FIG. 109. — The fall canker worm. Above: a, Or yellow, but the predomi- 6, single eggs, much enlarged; c, d, joints of cater- ,. i'ii • i pillar, much enlarged; e, egg mass; /, caterpillar; Dating COlor IS dark greenish ff, pupa of female. Below: a, male moth; b, female yellow or blackish. It is moth; d' one joint ° marked with narrow, pale lines down the back and a whitish stripe along each side. Life History. — The moths may emerge from the middle of September to as late as the middle of November, or even later — depending apparently upon climate and season — the eggs being laid in clusters of about one hundred in rows. These eggs are fastened on end on the bark of smaller branches or on the trunk. They are brownish gray, each something like a flower pot in shape, with a spot in the center and a ring on the outer end (Fig. 109). They hatch the following spring, in April, May, or early June. The caterpillars when full grown, in midsummer, pupate in the soil beneath the infested tree. Control. — They are easily controlled by the usual arsenical 90 INSECTS INJURIOUS TO THE APPLE sprays or by the same mechanical barriers as advised for spring canker worms. Mechanical barriers, whether they consist of tanglefoot bands, or cotton, or wire netting, should be put in posi- tion as early as the middle of September for this species. The Red-humped Apple Tree Caterpillar (Schizura concinna S. and A.). — These caterpillars are often found in great numbers on apple trees. When not feeding they are generally in groups. They feed on the leaves. Description. — The larva of this moth, when full grown, is striped with yellowish white and dark brown or black lines and a double row of black spines extending along the back, which is marked with five narrow black lines. The first three segments are spotted black and white. The sides of the fifth to the tenth seg- , ments are whitish with black lines and five black points, and last segment is spotted with black. There is a promi- nent hump on the fourth segment, and this, with the head, is bright coral red, giving the caterpillar its name (Fig. 110). The caterpillar is one and one-fourth inches long when full grown, tapering towards the ^as^ seSments, which are usually held in an elevated position. Life History. — Caterpillars appear FIG. no.— Red-humped apple tree in August, feeding upon the leaves, caterpillar. (Lugger.) . ° ° and in September they descend to the ground and construct a cocoon of silk mixed with particles of the surrounding rubbish. Here they pass the winter and emerge as moths in the spring or about the last of June. These moths have a wing expanse of about one and one-fourth inches. The general color is dark brown. The eggs are laid on the under side of leaves in late June or July, and there is one brood each year. Control. — These caterpillars may be hand-picked or the colonies destroyed by swabbing them off the limbs with rags or waste satu- rated with kerosene. The tip of the limb containing a colony may be cut off and burned. The usual arsenical sprays as applied for codling moth would control this as all other forms of leaf-eating caterpillars. The young forms are more susceptible to poison than the mature insects. The Yellow-necked Apple Tree Caterpillar (Datana ministra YELLOW-NECKED CATERPILLAR 91 Drury). — These caterpillars when young eat the under side or soft parts of leaves, leaving the veins. The older caterpillars devour all of the leaf. Description and Habits. — When full grown, these caterpillars are two inches long; and are often seen in clusters on the twigs of the trees. They have jet-black heads. The head segment, which is often termed the "neck," is a bright orange yellow, and from this fact the insect is named. A black stripe runs down the middle of the back, and on either side of the body are three black stripes, alternating with four yellow stripes. The body is thinly clothed with long, soft, white hairs. If a limb upon which these cater- pillars are found is jarred, the insects throw the head and tail in the air and may remain several minutes in this position (Fig. 111). FIG. 111. — Yellow-necked apple tree caterpillar, larva, eggs, and imago. (After Riley.) The female moth is reddish brown, has a wing expanse of about two inches, and lays from seventy-five to one hundred eggs in a cluster upon the surface of a leaf. The eggs hatch during the latter part of July and first part of August. Control. — The colonies may be picked by hand and destroyed or swabbed off the limbs with rags or waste saturated with kero- sene, as recommended for the red-humped caterpillar. If infesta- tion is very serious, the tree may be sprayed with arsenicals while the larvae are still small. The Cecropia Moth (Samia cecropia Linn.). — This insect is a minor pest, but is conspicuous on account of its large size. It is easily controlled; yet a couple of caterpillars on a young tree, if unchecked, will strip it bare in a short time. This prevents the proper ripening of the wood for winter. Appearance and Life History. — The full grown caterpillar is three or four inches long, is bluish green, and is covered with 92 INSECTS INJURIOUS TO THE APPLE tubercles. These tubercles on the third and fourth segments are red, while the others are yellow; and each tubercle bears a bunch of short, black spines. The tubercles on the last segment are blue. The adult moth is one of our largest species, the wings having a spread of from five to seven inches. The body of the moth is furry. The head and thorax are rust red. The abdomen is red, with bands of white and black. The wings are grayish, inclined to brown, with cross-bands- of white, black, and red. On the fore- j FIG. 112. — Cecropia wings there is a purplish patch. A crescent of white bordered with red and black is on each wing. The wings are edged with clay brown, and are grayer on their under side (Fig. 112). The female moth lays lead-colored eggs on the upper side of the leaves in short rows. The caterpillars, when first hatched, are black, with shining black knobs on their bodies, these knobs bearing black hairs. Their growth is very rapid and there are several moults. AMERICAN SILKWORM 93 Control. — Hand-picking of these large species is probably suf- ficient. They may also be controlled by arsenical sprays. In this connection, it might be noted that a fruit raiser, employing modern methods and spraying his trees in season with the proper com- pounds for the leading and most injurious pests, will control these minor pests at the same time, and hence the latter need no special consideration on his part. The grayish cocoons (Fig. 113) are easily seen on the bare trees in fall or winter, and should be destroyed. The American Silkworm (Telea polyphemus Cram.). — This, like the preceding insect, is of minor impor- tance as a pest, but its immense size makes it well known by many people. It is popu- larly known as the polyphemus moth. The larva attacks not only the apple and plum, but also such shade trees as maple, oak, elm, basswood, and others. Description. — This large moth has a wing expanse of from five to six inches. It is buff- colored, but is sometimes inclined to pale gray or cream and again almost brown. The wings toward the base are crossed by irregu- lar, pale, white bands margined with red. Near the outer margin is a stripe of pale purplish white, bordered with one of rich brown. About the middle of each wing is a transparent eye-like spot, with slender line across the center. The front edge of the forewings is gray. The moth flies only at night and is often mistaken, in the dusk FIG 113.__Cecropia co_ of the evening, for a bat by the uninitiated coon frequently seen on bare ,_. ^ .. trees in winter. (Fig. 114). The caterpillar, when full grown, is over three inches long, with a thick, yellowish green body, having seven oblique pale yellow lines on each side. Its segments are well marked, and each is ornamented with tubercles, which may be tinted with orange, and each has a silvery spot in the center, and bears a few hairs. The head is pale brown. The terminal segment of the body is bordered by an angular point resembling the letter V (Fig. 115). Life History. — When this larva is mature, it spins a silken cocoon inside an enclosure formed by drawing together a few 94 INSECTS INJURIOUS TO THE APPLE leaves. The cocoons may drop to the ground with the falling of the leaves or may remrin on the trees during the winter. The FIG. 114. — The polyphemus moth and cocoon, reduced. (Lugger.) FIG. 115. — Caterpillar of polyphemus moth. (After Riley.) cocoons of this species and also of the previous insect are conspicu- ous objects upon the leafless trees in winter. The adults emerge FRUIT-TREE LEAF ROLLER 95 from the cocoons late in May or in June, and the female, a few days after emergence, lays from two hundred to three hundred eggs on the under side of the leaves, usually only one or two on a leaf. From ten to twelve days are required for hatching. FIG. 116. — A leaf-roller. . 117.— Larva of leaf-roller on leaf. (Herrick and Leiby, Cornell Bull., 367.) Control. — Hand picking of the larvae is probably sufficient. Insectivorous birds attack the larvae. Parasitic insects, both Ichneumonids and Tachinids, are natural enemies. The Fruit=Tree Leaf Roller (Archips argyrospila Walk.). —This insect is a gen- eral feeder on apple, pear, plum, cherry, and a host of other trees (Fig. 116). It has become one of seri- ous importance. Pri- marily it is a pest of the apple, folding the young leaves and ty- ing them together with silk, the larva feeding without this nest (Fig. 117). Then the bios- crvm «tAm« «nffpr onrl FIG. 118. — Work of leaf-roller larva on aoples. (Herrick er> ailC and Leiby, Cornell Bull., 367.) later it gnaws the young fruit (Fig. 118). Much of this injured fruit never matures; that which does is deformed and is unmarketable (Fig. 119). Life History. — Eggs are deposited during the summer on bark of twigs. The caterpillars emerge the following spring. Pupation takes place within a folded or rolled leaf, the pupa lasting about eleven days. The moth, measuring about one inch from tip to 96 INSECTS INJURIOUS TO THE APPLE tip of expanded wings, is reddish, with two bright grayish spots on the front margin of each fore-wing. The insect is single brooded. Control. — Miscible oils (one to fifteen gallons of water) sprayed once on trees in early spring, when the temperature is above freezing, will destroy the eggs. Two or more later sprayings of arsenate of lead (six pounds to 100 gallons of water), or of lime- sulfur solution, as directed for codling moth, and also directed against the latter insect, would be effective. The Oblique-banded Leaf Roller (Archips rosaceana Harr.). — This small green or reddish caterpillar, three-fourths of an inch FIG. 119.— Appl deformed by leaf-rollers. Bull., 307.) (Herrick and Leiby, Cornell long, rolls up the leaves of the apple and lives and feeds inside. The adult is a bnyvvnish moth which emerges from the pupal form within the rolled leaves (Fig. 120). It is believed that the winter is passed in the egg stage — the eggs hatching in spring, with perhaps a second brood during the summer. The eggs are laid in clusters on the bark and are green in color. About one hundred and twenty eggs are laid by one female. Control. — Lime-sulfur at the strength used for scale in the dormant spraying will prevent eggs from hatching. Trees may be sprayed also with arsenate of lead, three pounds to fifty gallons of water, when buds are swelling and again before the flower buds WELL-MARKED CUT-WORM open. These sprayings would also catch the bud moth larva, which is a serious pest. The Apple-leaf Skeletonizer (Canarsia hammondi Riley). — This is a small, brown caterpillar, about one-half of an inch long when full grown. It feeds on the tissues of the leaves beneath the silk web, causing the leaves to look corroded and rusty. The larva is marked by four black dots just back of the head, two on the first segment and two on the second (Fig. 121). The pupal stage is passed on the leaf, and there are probably two or three broods during the season. The adult is a grayish moth with a wing ex- panse of one-half inch. Control. — These caterpillars are easily killed with arsenical sprays. They are also attacked by several parasites. The Well-Marked Cut-Worm (Noctua clandestine, Harr.). — De- scription: The caterpillar of this species resembles somewhat other cut-worm caterpillars and its life history is more or less like that L_ -_J FIG. 120.— Oblique-banded leaf roller. FIG. 121. — Apple-leaf skeletonizer: a, larva; b, segment of same, enlarged; c, anterior segments, enlarged; d, adult; hair lines below show actual size. (After Riley.) of other representatives of the family. When full grown, it is from one and one-half to two inches long. It is dull brown, gray, or blackish, often tinged with greenish, and is more or less marked longitudinally with dots and dashes. These markings are inconspicuous so that the caterpillars harmonize with the color of the soil. The head and thorax-plate are horny, and are reddish brown in color. The moth has dark fore-wings, gracefully marked with darker or lighter spots and narrow bands, and has lighter hind-wings. The moths, unlike others of this group, fold their wings over the back when at rest. Life History and Habits. — The female deposits her eggs in July 7 98 INSECTS INJURIOUS TO THE APPLE or August on grass land or where a crop has grown up to grass. They are placed on stems or leaves of grass or on weeds, or even on stones or twigs. The caterpillars hatch in August and Septem- ber, feed on whatever is available until frost. The caterpillars climb trees at night and attack the foliage, as well as living on the roots of various crops in the soil. They pass the winter in the caterpillar stage, and become full grown hi the early summer of the year following; they then pupate and the adults emerge in July or August. There is usually but one generation a year, Control. — Thorough cultivation of orchards is recommended. Clean up and burn all rubbish. Place cotton bands or tanglefoot around young trees to prevent climbing by the worms. Drop poisonous bait, such as poisoned bran mash (see chapter on Insec- ticides), hi little bunches near base of trees. These caterpillars succumb to arsenical sprays. Young trees are the chief sufferers, but occasionally old trees are infested. Their attacks on young trees appear to be a strong argument against allowing sod in a young orchard. The Bud Moth (Spilonola ocellana Schiff.). — The larva of this pest destroys young foliage and fruit buds, hibernating in small, oval, silken cases on bark of twigs. When the buds swell, the caterpillars bore into them and are thus protected from in- secticides. Later they form nests by tying leaves together. Life History. — They become full grown in June, transforming to pupse in silk-lined nests. After ten days the dark ash gray moth appears, laying eggs singly or in small clusters on the under side of leaves. The eggs hatch and the young caterpillars feed on the epidermis of the lower side of the leaf, protected by a silk web. In the fall they migrate to twigs and there form cases in which they hibernate. When full grown the caterpillar is half an inch long, with a light chestnut brown color. (See also page 86.) It is believed that this pest was introduced from Europe at least one hundred years ago. Control. — Spray with Paris green or, better, with arsenate of lead just as the buds burst and again before the trees are in blos- som. Here again the usual codling moth sprayings are effective. The Leaf-crumpler (Mineola indigenella Zell). — Caterpillars of this moth build cocoons of silk, mixed with the dried excrement and borm gs of the worm . During winter crumpled leaves a re found fastened to the twigs which, when separated, reveal the horn- shaped cocoons. Early in spring, when buds commence to ex- CODLING MOTH 99 pand, the caterpillars — not yet full grown — emerge and draw new leaves toward the cocoons. When full grown the reddish brown caterpillar is a little more than half an inch long. It matures a few weeks later, changes to a pupa in its case, and emerges as a moth two weeks later. There is but one brood annually. Injury. — The caterpillars attack young apple trees in nursery and orchards, which are often seriously injured by the destruction of the leaves as they emerge from the buds. Green fruit and young bark are sometimes attacked. Other trees affected are quince, peach, plum, cherry, and sometimes pear. Control. — Pick off and burn conspicuous cases in the dormant season. In extreme infestation, an early application of arsenate of lead, two pounds to fifty gallons, would be of value. Codling moth sprayings easily control this pest. ATTACKING THE FRUIT The Codling Moth (Carpocapsa pomcnella Linn.). — This well- known pest is believed to cause an annual loss in the United States of about $12,000,000; it originated in England. Description and Life History. — The grayish brown moths, which fly only at dusk, have wings expanding about three-fourths of an inch. When closely examined, numerous lines of tiny gray and brown scales are observed. Near the rear angle of each fore- wing is a large, dark brown or coppery spot marked with streaks of brown and gold. The hind-wings are somewhat lighter, growing darker toward their margins (Fig. 122). The larva or caterpillar is the well-known, pinkish, somewhat fleshy " apple worm," three- fourths of an inch long when mature. It passes the winter in a cocoon in crevices of the bark, or in fruit cellars or fruit houses, wherever infested apples were found in the late summer and fall (Fig. 123). Before the time of blossoming, the larvse turn into small brown pupae, the moths emerging in two or three weeks. In from three to nine days the females deposit eggs, mostly on the foliage or in the calyx end of the small apple, each female averag- ing from eighty to ninety eggs. Hatching occurs in from five to ten days, depending upon the temperature, and the larvse become full grown in from three to four weeks. Some of these larvse may pupate and cause a small or partial generation. Most of them, however, hibernate during the winter and pupate in spring. The young larva feeds at first either on the tender parts of the leaves or enters an apple. Those of the early brood, for the most 100 INSECTS INJURIOUS TO THE APPLE part, enter through the blossom end, and bore into the core (Fig. 124). The seeds appear to be very attractive to this pest. In three or four weeks the caterpillar is full grown and issues from the side of the apple, seeking a place for spinning its cocoon. If the FIG. 122. — Codling moth, much enlarged. apple is still on the tree, the larva lets itself down to the ground by a silken thread. Control. — In the winter time woodpeckers seek out and devour the larvse and cocoons beneath the old bark scales. These birds FIG. 123. — Codling moth larva, much enlarged. (After Slingerland.) should be attracted to orchards by hanging up suet in the winter. All fallen fruit should be disposed of by the use of stock or gathered and destroyed in other ways. The chief measure of control consists, of course, in spraying with arsenate of lead or with arsenate of lead combined with a fungicide, in order to control fungous diseases at the same time PLUM CURCTJLlO 101 (Fig. 125). Two or three pounds of arsenate of lead in fifty gallons of water or in fifty gallons of fungicide is recommended. Spray with commercial lime-sulfur, one part to forty parts of water. Use two or three pounds of arsenate of lead for every fifty gallons of the mixture as soon as the first blossom buds begin to show pink. Repeat as soon as all petals have fallen (Fig. 126) and again three weeks later. A later spraying should be given, toward the end of July. This treatment should control not only the codling moth but also the plum curculio attacking the apple, and all leaf-eating insects, as well as the apple-scab. For oyster-shell scale a dormant spray (one part lime-sulfur to eight of water) might well be given earlier, when leaf buds are swollen, just before they open. FIG. 124. — Proper time for first spraying for codling moth. The right-hand calyx closed; no chance to get poison in this. The Palmer Worm (Ypsolophus ligulellus Hbn.). — This cater- pillar may be primarily a leaf-eater, but, since it attacks fruit as well, it is included among the fruit insects. It injures apple trees in June and July, skeletonizing the leaves and fastening a few to- gether by a web within which it feeds. It also eats irregular holes into the growing fruit and spins a web across the opening. It is extremely active, rapidly wriggling backward or forward and frequently hanging suspended by a web. The pupa is suspended by a web from the posterior end or rests between a few folded leaves. It changes to a moth in about ten days. Control. — Spray trees with arsenate of lead as for codling moth. The Plum Curculio (Conotrachelus nenuphar Hbst.). — This familiar beetle, more destructive to apples in some localities than the codling moth, is characterized, like other curculios, by the 102 INSECTS INJURIOUS TO THE APPLE presence of a prolonged beak or snout. It is about one-fifth of an inch long ; color, mixed black, brown and white, with darker shades predominating. Several humps occur on its back, giving the dorsal surface a roughened appearance and affording it some protection on account of its resemblance to the bark on which it rests. The curved snout is about one-third the length of the body (Fig. 127). FIG. 125. — First spraying for codling moth forcing the liquid into calyx cup. Note that there are two cavities in the calyx cup, an upper and a lower (1 and 2 in b), separated by stamen bars (61). A few days after the petals fall, while the apples are still erect, these bars wither and separate (c 1), allowing the poisoned liquid to enter the lower cavity of the calyx, (a after Slingerland, remaining figure after Ball.) Life History. — This beetle is sometimes called the "Little Turk," because the female, when the apples are no larger than peas, punctures them with her beak, introducing an egg into the puncture, and then cutting a crescent in the fruit at one side of the egg, pre- venting, it is believed, the growth of the tissue and the consequent crushing of the egg by so doing. This act on the part of the female beetle causes a distorted growth and the fruit would rank as imperfect. The beetles leave their hibernating quarters in the spring, before PLUM CURCULIO 103 blooming time, seeking quarters in the trees. Egg-laying occurs during spring and early summer, when the old beetles die. The eggs, numbering anywhere from one hundred to five hundred from a single female, hatch in from three to seven days, and the grub normally feeds for from fifteen to twenty days in the fruit, at which time it leaves the apple or plum and enters the ground. It hollows out the soil and transforms into a pupa, in which stage it remains for about a month, then emerging as a beetle, going to trees and feeding on fruit, but does not lay eggs in the fall. Beetles FIG. 126. — Blossoms from which the petals have fallen; in good condition the spray. It is too late to apply calyx spray to two apples on left Bull.. 210.) to receive (Gillette and List, Col. also feed to some extent on the young buds in the spring, before the blossoms appear. Its work and life history in connection with the plum is practically identical with that in the case of the apple. Apples or other fruits infested with the larvae, for the most part, drop to the ground. This allows the completion of the life history. It is claimed, however, that in much of the fruit which does not drop, the development of this pest is prevented. Many of the larvae die before the larval stage is half completed, leaving matured fruit with the sunken scars on the surface as above indicated, and streaks of hardened tissue in the flesh. 104 INSECTS INJURIOUS TO THE APPLE Control. — Spray thoroughly with arsenical insecticides before leaves expand. Spray ing for codling moth, after the petals fall, will aid in controlling the curculio. All fallen fruit should be de- stroyed. As an additional measure, the trees might be jarred every few days in the early morning, catching the beetles on a sheet FIG. 127. — Plum curculio, larva, pupa, adult. Hair lines show natural size. below and destroying them. The jarring is done before the adults lay their eggs on the young fruit. The Apple Curculio (Anthonomus quadrigibbus Say.). — This is a small, brown weevil or curculio which comes out from hiberna- tion quarters early in the spring, punctures the young fruit with 6 a FIG. 128. — The apple curculio, larva, pupa and two views of adult. (After Riley.) its beak, and deposits an egg in the puncture. The eggs are yel- lowish, oval in shape, and hatch in from four to five days. The period of greatest egg-laying is late spring and early summer. The native food is hawthorn and wild crab, but the insect is also fond of cultivated fruit, and from sixty to one hundred eggs are laid by a single female. APPLE MAGGOT 105 j FIG 129. — Apple n.aggot fly. The larva or grub is \\hite, legless, with a yellowish brown head and jaws, and is found burrowing and feeding near the center of the apple (Fig. 128). It becomes full grown in about twenty days, changing to a pupa in the center of the fruit and emerging as a beetle about ten days 5 — --- -^ •• \ •»*; — - later. This emergence oc- t / curs during June, July, and \ August, and, after emerg- ing, the insect feeds but \i little. The fall and whiter | are spent under leaves and f rubbish beneath trees. Control. — Use the same methods as for the plum curculio. The Apple Maggot (Rha- L gcletis pcmonella Walsh). — The adult of this insect is a two-winged fly (Fig. 129) . The general color is black, sides of head white, eyes green, antennae orange. It is about one-fourth of an inch long, and appears early in the summer. The eggs are laid only in matured fruit, hatching in a few days. The larvae make tunnels in the flesh of the fruit, working in all direc- tions (Fig. 130). It takes from five to six weeks for the maggot to complete its growth . As a result of inf es- tation, the fruit falls to the ground. The larva enters the soil, pupating about one inch below the surface. Fre- quently the maggots remain in the stored fruit. Adults appear the following spring, FIG. i3o.— Burrows of apple maggot in soft fruit, and there is but one brood (O'Kane, N. H. Bull, 171.) & year Control. — Gather and destroy windfalls as soon as they drop to the ground. Cultivate orchards thoroughly. Brown Fruit Chafer. — This brownish beetle is also called the 106 INSECTS INJURIOUS TO THE APPLE Indian Euphoria (Euphoria inda Linn.) . It is about one-half of an inch long and is heavy-bodied. The wing covers are yellowish brown, marked with irregular darker patterns. The head and thorax are blackish, or a dark copper brown, thickly covered with short yellowish hairs. The under side of the body is black and hairy (Fig. 131). The beetle moves slowly and is not easily disturbed. Eggs are deposited in manure heaps or decaying vegetable matter or in sod. In midsummer the grub changes to a pupa beneath the surface, the beetles emerging in the early au- tumn. There is one brood a year. The adults eat ripening apples and are sometimes also found on green corn. Control. — Where troublesome, hand-picking may be resorted to, or the beetles may be attracted to a pile of decaying fruit and destroyed. This is not regarded as a serious pest, but is fairly abundant in localities. Supplementary List of Apple Insects. — The following insects are more or less injurious to the apple. See page references. 131. — The Indian Euphoria. (Lugger.) Ash-gray pinion Blind-eyed sphinx Broad-necked Prionus Buck moth or Maia moth Cherry-tree scale, p. 127 Cottony maple scale, p. 287 Cucumber flea-beetle, p. 239 Emperor moth, p. 128 Eye-spotted bud-moth Eyed elater False chinch bug Fasciated Lithacodes Goat-moth Gray dagger-moth Hag-moth caterpillar Imbricated snout beetle Lime tree winter-moth, p. 284 Mottled plum-tree dagger-moth, p. 119 Oak primer, p. 281 Pear blight beetle, p. 116 Resplendent shield bearer Rose leaf -hopper Slug caterpillar Smeared dagger-moth Stalk borer, p. 248 Two-horned tree-hopper Thysbe clear-wing Tiger moth Trumpet leaf- miner Unicorn prominent Wild-cherry leaf miner Zebra caterpillar of cabbage, p. 236 QUESTIONS 1. Enumerate the principal insects found on the apple tree in the following situations: trunk and branches; leaves; fruit. 2. Give life history of flat-headed apple tree borer and remedial measures. Give the same for the round-headed apple tree borer. QUESTIONS 107 3. Give life history and remedial measures for San Jose" scale. What are methods of controlling the oyster-shell scale? 4. Describe life history and measures of control of the woolly louse or woolly aphis of the apple. 5. Give life history and remedial measures for the tent and tentless cater- pillars. What are the differences between these two species? 6. Give life history and measures of control for the apple-leaf aphis. 7. What remedial .measures are suggested for the apple-leaf hopper? 8. Give life history of the fall web worm. 9. Compare the spring and fall canker worms. Give difference in life history and remedial measures for each. 10. Compare the red-headed and yellow-necked apple tree caterpillars. 11. Describe and give life histories of the Cecropia moth and the American silkworm. 12. Name a cut-worm which is sometimes an orchard pest, and give reasors. 13. Give descript' n and life history of the tarnished plant bug. 14. Describe in detail the life history and habits of the codling moth, and best treatment for same. 15. Do the same regarding the plum curculio when it affects the apple. 16. In what way is the apple maggot injurious? CHAPTER VIII INSECTS AFFECTING THE PEAR AND QUINCE A NUMBER of insects attacking the pear and quince are injurious also in the apple orchard. The San Jose scale, the twig girdler, and the codling moth have already been described under apple insects. ATTACKING TRUNKS AND BRANCHES The Sinuate Pear Borer (Agrilus sinuatus Oliv.). — This is a bronze-colored beetle, nearly one-third of an inch long, whose larva bores in trunks and branches of the pear, making tortuous passages in the sap wood. The presence of these borers is frequently indi- cated by a discoloration of the bark above. Since these burrows, if numerous, may result in the girdling of a tree, a large tree may gradually die as the result of an attack, and a small tree may be killed immediately. The grub becomes full grown the second year, pupates in the tree, and emerges the following spring, the female at that time depositing her eggs in cracks of the bark. These beetles may fre- quently be seen basking in the hot sun on the trunks of the tree they attack. Control Measures. — Dying or dead trees or branches should be burned. Repellent washes may be used as in the case of apple- tree borers. The grub may be removed from the burrow with a knife or killed therein by the use of a wire. ATTACKING LEAVES AND FRUIT Pear-tree Psylla (Psylla pyricola Forst.). — This insect was in- troduced from Europe about 1830. It is a brownish hemipterous insect, barely one-tenth of an inch long. Its abdomen has black bands. It has two pairs of wings, which, when the insect is resting, are folded over the back and against its sides in such a way that the insect is made to resemble a very small harvest fly or cicada. Life History. — The adults hibernate under bark and rubbish, emerge in the spring, and lay their tiny eggs on bark or about buds. The scarcely visible yellow nymphs attack the petioles, fruit stems, and also the leaves (Fig. 132). It has several broods a 108 PEAR-TREE PSYLLA 109 FIG. 132. — Pear psylla: 1 and 2, nymphs; 3, eggs; 4, winter adult. All much enlarged. (Hodgkiss, Geneva Bull., 387.) 110 INSECTS AFFECTING THE PEAR AND QUINCE year, and may at times cause severe injury in an orchard by weakening the trees and stunting the fruit. A sweet " honey dew" is secreted by them, which drops upon the leaves below, much in the same way as in the case of the hop aphis, and woolly louse of the alder, affording a fine culture for a black fungus, which gives a blighted appearance to the foliage. Control Measures. — This insect may be kept in check by up- to-date orchard practice. Weeds and rubbish should be kept off the ground and the rough bark scraped from the trunks and larger branches. Spraying the trees on warm days in early spring with a tobacco extract will kill many. Use one pint of nicotine sulfate in fifty to seventy-five gallons of water, to which four pounds of soap are added. The dormant spray as used for scale will kill some, as well as the eggs of the first brood if present. Later, when nymphs are on petioles, the above spray of tobacco extract and soap may be employed, using it a little weaker (one pint of nico- tine sulfate in one hundred gallons of water). FIG. 133. — Blister mite. Greatly enlarged. (After Parrott, Hodgkiss and Schoene, Geneva Bull., 283.) Pear-leaf Blister-mite. — Pear leaves with rusty blotches upon them are likely to be found infested with this tiny mite (Fig. 133) (not an insect), which lives within the leaf tissue. It is some- times known as the plum gall-mite (Eriophyes pyri Pagen). See page 118.) The eggs of the mite are deposited within a raised blister or gall, which precedes the rust-like appearance above alluded to, the young migrating from one leaf to another. Young fruit may also be attacked. Control Measures. — Spray in winter with lime-sulfur as prac- ticed against scale insects. Pear Blight Beetle (Xyleborus dispar Fab.).— The adult of this insect is a very small brownish beetle, one-eighth to one- sixteenth of an inch long, the round head nearly concealed by the thorax (Fig. 134). The female bores in small branches and twigs, causing the tips to die and to present a blighted appearance, hence the name of the insect (Fig. 135) . The group of beetles to which PEAR THRIPS 111 this one belongs is of wide distribution and is interesting because both young and old beetles feed on a fungous growth in their burrows, which is referred to as " Ambrosia." Remedies. — If troublesome, an application of carbolic acid soap is said to give good results if applied in the spring. Use three gallons water, one gallon soft soap, one-half gallon crude carbolic acid. Pear Thrips (Euthrips pyri Daniel) . — These are minute brown- ish insects, which attack the buds of fruit trees, including the plum, FIG. 134. — Pear blight beetle (E. pyri); adults and enlarged antennae of female beetle. (Hubbard, U. S. Bu. Ent.) FIG. 135.— Gallery of pear blight beetle in poplar twig. Cross section above, longitudinal section below. (Marx, U. S. Farmers' Bull., 763.) peach, and cherry. The adults are winged, but the young are wingless. They are white and have red eyes. Transformation takes place in the ground beneath the tree. Eggs are laid in fruit stems and in leaves and hatch in four or five days. The punctures made for the eggs cause the young fruit of prune and cherry to yellow and drop to the ground. Remedial Measures. — From the above statement regarding its life history, it is evident that fall plowing and harrowing will 112 INSECTS AFFECTING THE PEAR AND QUINCE kill many of the nymphs in the soil. This treatment is said to be very successful in prune orchards of California. Two sprayings with nicotine sulfate, as recommended for the pear psylla, are advised. The first is made when the buds are on the point of opening and the second immediately after the petals fall. A white- wash spray is also used in California. Quince Curculio (Conotrachelus cratcegi Walsh). — Quince fruit is frequently made ill-shapen by attacks of this weevil. It works upon the quince in much the same way as the plum curculio works upon the plum and apple, but it does not make the crescent-like cut beside the egg puncture. Further, unlike its congener men- tioned, it will develop even when the affected fruit does not drop to the ground. The white, footless grub burrows into the soil and remains in the larval stage until the following spring, trans- forming then to a pupa; and in ten or twenty days it changes to an adult. The latter is about one-quarter of an inch long, and is brownish gray. Control Measures. — Destruction of windfalls and picking and destroying infected and misshapen fruit are recommended. Jar- ring beetles on to sheets spread below the trees is also practiced. The beetles are gathered up and destroyed. The False Tarnished Plant Bug (Lygus invitus Say). — This plant bug looks much like the true tarnished plant bug, and in- jures the fruit by puncturing it. A spray of nicotine sulfate as recommended elsewhere in this chapter, immediately after all petals have fallen, is efficacious. The Pear and Cherry Slug. — This slug attacks both the pear and the cherry. The discussion is given under cherry insects, page 129. QUESTIONS 1. What insects affect the pear which are also found on the apple? 2. Describe and give remedial treatment for the pear-tree psylla. 3. The same for the sinuate pear borer. 4. The same for the quince curculio. CHAPTER IX PLUM, PEACH, AND CHERRY INSECTS ATTACKING TRUNK AND ROOTS OF PLUM A NUMBER of the insects attacking the plum, cherry, and peach trees have already been described in the chapter on apple insects. Reference should be made to that chapter for discussions of the New York weevil, the American silkworm, the plum curculio, San Jose scale, and others. Peach-tree Borer (Sanninoidea exitiosa Say). — This destruc- tive borer may completely girdle a tree. If the attack is severe — its presence indicated by the foliage turning yellow — the tree may eventually die. Description and Life History. — The borer is the larva of a clear-winged moth. When full grown, it is about an inch long, and is light yellowish with brown head. The body is sparsely clothed with brownish hairs which arise from tubercles. The excrement thrown out of the burrow and observed on the bark indicates the presence of the pest. The caterpillar grows rapidly, hibernating during the cold weather, and resumes operations again in the spring. Its activities cause gum to exude from the tree. About two years are required for the life-cycle; the larvae hatching in late fall do not become moths until the second season. The moth itself, flying during the daytime, may be mistaken for a wasp. The female is deep, steel blue, with a broad, orange band across the abdomen. The fore-wings are opaque, covered with bluish scales, and expanding about one and one-fourth inches. The hind-wings are transparent, except the dark margin. The male is smaller than the female. Its wings are clear, except the margins and a line across the fore-wings. The abdomen is marked with three or four yellow stripes (Fig. 136). West of the Rocky Mountains, this form is replaced by S. opalescens. Control. — Dirt may be heaped in a mound high on the trunk, forcing the moths to lay eggs at a distance from the ground, where the borers are more easily found when they begin their work. Many are kept out of the trees in this way. This mound can be leveled in the early fall, and the larvae maybe destroyed, by careful use of the wire and knife, at that time. The laying of eggs on the 8 113 114 PLUM, PEACH, AND CHERRY INSECTS trunk may be largely prevented by wrapping the trunk with building paper. This paper should extend an inch or two below the surface of the ground. These wrappings should be applied before the moths emerge and should be removed after egg-laying is over. One can also resort to digging the borers out in the fall and again in the spring. This is a good plan for the South. A B FIG. 136. — Peach-tree borer (S. exitiosa): A, male; B, female. The Plum-tree Borer (Sesia pictipes G. and R.). — This borer is quite a common pest, injuring the inner bark and sap wood of the trunk and limbs of plum and similar trees. It works somewhat after the manner of the preceding species. It is found in both the cultivated and wild plum and also in wild cherries. It turns into a clear-winged moth, the two sexes resembling closely the male of the peach-tree borer — in fact, is hardly to be distinguished from that species. Control. — Cut out and burn in- fested parts of the tree. The Fruit-tree Bark Beetle (Scoly- tus rugulosus Ratz). — If it were not Ct & for various enemies this insect would FIG. is?.— Fruit-tree bark beetle; dorsal be verv injurious. The adult appears view and in profile. (U. S. Bu. Ent.) , . T, • j in early spring. Its presence is de- tected from the fact that the outer bark is penetrated by numerous small " worm-holes" or " shot-holes." From these holes the gum exudes, especially in the case of stone fruits. Weak or diseased trees are most subject to attack, but young, healthy trees may also suffer. Life History. — From the worm-holes the beetles emerge in April and May (Fig. 137). The female burrows through the bark to the sap wood, where she eats out a vertical brood-chamber. FRUIT-TREE BARK BEETLE 115 Along the sides of this chamber she gnaws out pockets, and in these places her eggs. The larvae, upon hatching, excavate little side galleries, which are widened as the larvae grow. Three weeks are required for them to reach full growth. The winter is spent in the adult form within the burrow. The beetle is black in color; about one-tenth inch long and about one-third as wide. The very tips of the wing-covers and parts of the legs are reddish. FIG. 138. — Peach-tree bark beetle: a, b, adult beetles; c, egg; d, larva; e, pupa. All greatly enlarged. (After Brooks, U. S. Bu. Ent.) Control. — All infested parts should be cut out and destroyed. All prunings and trimmings from the trees should be burned. A whitewash applied to the trunks and larger branches in the spring and midsummer and again in late fall acts ?,s a repellent. Or, better, apply a carbolic acid wash to the trunk and larger branches. Use one pint crude carbolic acid, one gallon of soft soap, then dilute 116 PLUM, PEACH, AND CHERRY INSECTS with five gallons of water. Orchards should be kept free from dead wood. A closely allied form, the peach-tree bark beetle, and its work are shown in figures 138 and 139. The Pear-blight Beetle (Xyleborus pyri Peck).— This beetle may infest plum, pear, apple, and apricot. It is commonly regarded as infesting only weak and unhealthy trees, but, as in the case of the two bark beetles, sound trees are known to be infested also. It may attack not only twigs but also the trunk. The twigs, as a FIG. 139. — Exit holes in peach limbs made by adults of peach-tree bark beetles, shown in figure 138. (Brooks, U. S. Bu. Ent.) result of attack, die, but this must not be confounded with the death of twigs due to the disease known as pear-blight or fire-blight. Life History. — The beetle deposits her eggs at the base of the buds. The young larva, upon hatching, works into the pith, causing the tree to wither. In the bottom of this burrow the larva changes to a pupa and later to the beetle. In June and July the adult emerges and lays its eggs before the end of August. The adult is a small, cylindrical beetle, one-tenth of an inch long; deep brown or black. PLUM SCALE 117 FIG. 140.— Divar- icated buprestis. (U. S. Bu. Ent.) Control. — Blighted trees or limbs should be cut off below the injured part and burned before the beetle emerges. The Divaricated Buprestis (Dicer ca divaricata Say). — The grub of this beetle, when full grown, resembles, in a general way, the flat-headed borer of the apple tree. It lives in the sap wood and destroys it by burrowing and feeding upon it. Pupation takes place just below the bark. The adults appear in June, July, and August, and at that time they may sometimes be seen in the bright sunshine on the trunks of the trees. The eggs are deposited in the crevices in bark of old plum and cherry trees; it also attacks the peach. The adult is a copper-colored beetle nearly an inch long, with brassy reflections. Its back is thickly pitted and also exhibits several depressed lines and small elevated spots. The posterior ends of the wing-covers are separated (Fig. 140). Control. — Control measures similar to those used for the flat- headed borer of the apple tree apply equally to this species. It is seldom very troublesome. The American Plum-tree Borer (Euzophora semifuneralis Walker). — This moth appears in early spring and deposits eggs on the larger limbs of the plum trees. Tl^e young caterpillars eat their way into the tree, feed- ing upon the inner bark, and re- maining under the bark until the following spring, when they emerge as adults. Control. — When possible, de- stroy this borer with a sharp wire. A strong solution of soap and crude carbolic acid may be ap- plied as a repellent. See also remedy fo*r round-headed apple- tree borer. The Plum Scale (Eulecanium sp.). — This is a large scale attack- ing the leaves and bark of the plum tree. The eggs are deposited in great numbers under the old scale in early summer. The young, when hatched, crawl about the tree, reaching the leaves and twigs, FIG. 141. — Lecanium scale on plum. 118 PLUM, PEACH, AND CHERRY INSECTS where they become attached. In the fall they migrate to the under side of the branches (Fig. 141). Control. — Commercial lime-sulfur may be used as a spray against this insect, applying it before the leaves appear. The spraying may be repeated in July, employing the summer strength. Directions for using this are found upon the can. ATTACKING THE LEAVES OF PLUM The Plum Gall-mite. — This is not an insect, but an allied form belonging to the branch of the animal kingdom known asArach- nida. Like other members of the group, it has, in the adult stage, eight legs instead of six. It is sometimes called the Pear- leaf Blister-mite. (See page 1 10) . It is barely visible, but is destruc- tive, in that by its work it causes the leaves to become distorted into the peculiar galls shown in the illustration (Fig. 142). Control. — The only method of control that can be suggested at this time is to pick off and burn the abnormal leaves, thus destroying the pests within. Commercial lime-sulfur is used ^ as a dormant spray to destroy the winter forms. The Plum-leaf Aphis (Hyo- lopterus arundinis). — The eggs of this aphis are laid on the plum twigs in the fall and hatch in the spring. Two or three genera- tions are developed in the early summer on the plum, and then the insect migrates to other food plants, returning to the plum in the fall. This migration is accomplished by winged generations. Injury. — This louse is extremely injurious in that it sucks the juices of the leaves and tender twigs, causing the leaves to drop prematurely, checking the growth of the tree and preventing the proper fruiting. If it occurs hi large numbers, the tree appears blighted. Control. — About a week before the buds open, spray the trees with one of the tobacco extracts, such as Black Leaf 40; or us'e whale oil soap, one pound to fifty gallons. Trees sprayed with lime-sulfur for the twig borer just before blossoming should not be troubled with aphids. This compound might also be used on MOTTLED PLUM-TREE DAGGER MOTH 119 the foliage if aphids become numerous. In spraying against aphids or plant lice, the spray must reach the insects under the curled leaves and strike them with some force. Dipping the affected tips of the branches in a pan of nicotine sulfate solu- tion and shaking the submerged twigs in the liquid is very effi- cacious and practical. For this use a tablespoonful to a gallon of water. The Plum-tree Sphinx. — The adult moth of this species (Sphinx drupiferarum S. and A.) lays its pale yellowish green eggs singly, on the leaves of the plum. These eggs hatch in six to eight days. The full grown larva is rich green with lateral dark spots; oblique bands appear on each side of the body. It enters the ground a few inches to pupate, forming an earthen chamber. The pupa is dark, reddish brown and the pupal stage lasts from fall until the following spring. Figure 143 illustrates the moth. -tree sphinx. (Lugger.) Control. — This insect seldom needs special attention. Four pounds of arsenate of lead in one hundred gallons of water is the usual remedy suggested. Hand-picking may be resorted to. Mottled Plum-tree Dagger Moth. — The larva of this moth (Acronycta super arts Guen.) is usually greenish, but may vary in color, showing a broad chestnut-colored stripe along the back. There are several tubercles bearing hairs on each segment, and other hairs are found along the side of the body. The caterpillar is one inch long, slightly compressed. The young caterpillars appear in June and again late in September. The larva feeds on the foliage of plum, apple, mountain ash, birch, etc. It is also often found on shadberry and many other similar plants. 120 PLUM, PEACH, AND CHERRY INSECTS Control. — It is seldom abundant enough to become a serious pest, and is held fairly well in check by an ichneumon fly. If a spray is necessary, arsenate of lead would be very effective. The larva, after pupating, turns into a grayish moth. The Plum-tree Catacola (Catacola ultronia Hubn.). — The lar- val form of this moth is a grayish brown caterpillar. It is about one and one-half inches long when full grown. The ninth segment bears a fleshy horn half an inch long, and an irregular grayish patch occurs on each side of the horn. There is a low, fleshy ridge on the twelfth segment (Fig. 144). The under side of the cater- pillar is pinkish, and a row of black spots occurs on the mid- ventral line. The adult moth has front wings of rich amber color, darker at the posterior margin. Several brown and white wavy lines cross FIG. 144. — Plum-tree catacola. the wings. The hind-wings are deep red, margined with a broad band of black. There is also a black band across the middle of the hind-wings. Life History. — The winter is passed in the egg stage, the eggs being deposited in cracks in the bark. They hatch in the spring, becoming full grown about the end of June. The moths emerge and are on the wing during the most of July and August, at which time eggs are deposited for the next brood. Injury by this insect is not often serious. Control. — Arsenical sprays would be effective if necessary. Jarring for plum curculio frequently causes caterpillars of this species to drop off. RUSTY-BROWN PLUM LOUSE 121 The Rusty-brown Plum Louse (Aphis setarice Thomas). — This rusty-brown aphid has the base of the antennae white, which color also appears on the legs and on the posterior end of the insect. It is first observed in early spring on tender shoots of the plum, secreting honey dew in abundance. Its secretion frequently causes the upper surface of the leaves below the lice to present a shiny, glistening effect. FIG. 145. — Plum gouger, adult, larva, and injured fruit. (Lugger.) These lice remain on the plum during the entire year, but grasses may be also attacked during the summer. As summer advances, many of these insects may become a deep black; in fact, the egg-laying females and the true males are strikingly black. The oviparous female is wingless, while the male is winged. Winged forms are produced at different times during the summer or fall. 122 PLUM, PEACH, AND CHERRY INSECTS Control. — As in treatment for all plant lice, tobacco extracts are recommended as sprays or as dips. Also use soap solution. (See under plum louse.) ATTACKING THE FRUIT The Plum Gouger (Coccotorus scutellaris Lee.). — This snout- beetle resembles somewhat the plum curculio, but lacks the humps on the back. The insect is one-fourth of an inch long, with a snout Fio. 146. — Plum curculio, adults, larva, pupa, and infested fruit. (Lugger.) Hair lines indi- cate natural size in each case. about half the length of the body. The wing-covers are lead gray, finely spotted with black and brown. Yellowish markings are on the thorax and head (Fig. 145). They feign death when disturbed. Injury. — The beetles puncture the calyx and feed on the ovary of the flower, destroying it. Later, for purpose of obtaining food and for egg-laying, they puncture the growing plum. These small holes made by the proboscis exude gum. The affected plums do PACIFIC PEACH-TREE BORER 123 not drop off as is the case with those injured by the plum curculio, but badly punctured fruit becomes gnarly and worthless. After the egg is placed in the puncture made by the female beetle, it is pushed down with the insect's snout. Life History. — The egg hatches in a few days, the grub working toward the kernel of the pit. It is single-brooded, its complete development requiring about three months. It hibernates in the adult stages, appearing on the tree at blossoming time. Control. — If this pest is unusually abundant, use a spray of two to three pounds of arsenate of lead in a barrel of water, just as the blossoms fall, and again three weeks later. The Plum Curculio. — Full treatment is given under apple insects, as in some localities it is a destructive pest of the apple. Figure 146 is an excellent representation of this insect in its various stages and of the injury it causes upon stone fruits. Supplementary List for Plum. — Many other insects besides those just described are less commonly found attacking the plum. In the following list the pages given are for the descriptions given in this book. Apple-leaf hopper, p. 83 lo emperor moth, p. 128 Banded hair-streak "June bug," p. 211 Blind-eyed sphinx Leaf crumpler, p. 98 Bud-moth, p. 98 Long-horned prominent Buffalo tree-hopper, p. 78 Oblique-banded leaf roller, p. 96 Brown fruit chafer, p. 105 Oyster-shell bark-louse, p. 72 Cecropia silk moth, p. 91 Putnam scale, p. 74 Cherry -leaf beetle, p. 132 Rose chafer, p. 156 Cherry-tree scale, p. 127 San Jose scale, p. 70 Cherry-tree thecla Scurfy scale, p. 73 Dominican case- bearer Tarnished plant bug, p. 84 Double-eyed sphinx Tent caterpillar, p. 78 Fall canker worm, p. 89 Thysbe clear wing Fall web worm, p. 265 Tree cricket, p. 140 Flat-headed apple-tree borer, p. 188 Unicorn prominent Grape flea beetle, p. 155 Viceroy Gray dagger-moth White-marked tussock moth, p. 269 Hop plant-louse, p. 214 ATTACKING TRUNK, BRANCHES, AND TWIGS OF PEACH For a discussion of the Eastern peach-tree borer which injures peach trees see page 113. And for a treatment of the fruit-tree bark beetle, see page 5. Pacific Peach-tree Borer (Sanninoidea opalescens Edw.). — This species is found on the Pacific coast, where it exhibits the same habits as its eastern congener, and resembles it closely. The steel- 124 PLUM, PEACH, AND CHERRY INSECTS blue abdomen of the female, however, lacks the yellow band seen in the eastern form. The same measures of control as employed against the eastern form are adaptable in the case of this west coast species. See treatment for peach-tree borer. The Peach Twig-borer. — This small gray moth (Anarsia lineatella Zell), barely one-half an inch from tip to tip of extended wings, is an importation from Europe and a serious peach pest in many of our states, particularly on the Pacific coast. The brownish larva is about one-half an inch long when adult. During its active life it bores in the pith of tender growth, causing the tips of branches to wither and die (Fig. 147). The insect at this stage is very active and voracious, and crawls from twig to twig, causing extensive injury. It pupates under scales of bark on large branches. The female moth lays her white eggs on the young twigs. About ten days are required for hatching. Fruit may be attacked by the second brood of caterpillars, and the third brood feed entirely on the fruit. A fourth brood of caterpillar gives rise to the moths whose eggs, placed in cracks in the bark, produce the caterpillars which winter over in bark close to the young FIG. 147. — The peach PTOWth. twig-borer. „... , Control Measures. — The best measure of combating this pest is by the use of frequent winter sprayings of lime-sulfur. Use one part commercial lime-sulfur to ten of water. In the spring, from the time of the swelling of the buds until the blossoms begin to appear, a little later, just as the blossoms show pink, arsenate of lead may be applied at the rate of five or six pounds in fifty gallons of water. Terrapin Scale or Peach Lecanium. — This is a turtle-shaped or terrapin-shaped scale (Lecanium nigrofasciatum Perg.) about one-eighth of an inch long when full grown. It is brownish or reddish in color; individuals may be found which are nearly black. The young hatch beneath the mother scale and attach themselves to the leaves later. After the females have been fertil- ized by winged males, they migrate to the twigs and branches. Control Measures. — Spray with miscible oils when the trees are dormant. Care has to be observed in using this spray on the peach. It should not be used in the fall, but is best applied in early spring. GREEN JUNE BEETLE 125 Miscible oils are commercial sprays known as "Scalecide" and "Kil-O-Scale." Other dormant sprays for scale insects would probably be equally effective. Tree Crickets sometimes inflict serious injury, directly and indirectly, upon peach trees, cherry trees, and many others. Figure 148 illustrates some of these. (See also page 140.) ATTACKING THE LEAVES AND FRUIT OF PEACH The Black Peach Aphis. — This is blackish or brownish larva of Aphis per sicce-niger Smith. It is found on leaves, and in the winter and summer wingless forms occur on the roots. Some of these later migrate to leaves when they appear. Their life history is, in a general way, similar to that of other aphids or plant lice, and, like other forms, they multiply with amazing rapidity. The yel- lowing of peach leaves is frequently due to the presence of the underground form, which, though unseen, is sucking the vitality from the tree. Measures of Control. — Frequent spraying with tobacco ex- tract is effective against the leaf form if applied with force to the under side of the leaves. Use two tablespoonfuls of nico- tine sulfate in one gallon of water with a little soap. For the root form remove some of the earth from about the roots and apply a liberal quantity of tobacco dust or tobacco stems, covering the same with earth. Trees received from an infested nursery may bring this pest into an orchard which would otherwise be free. If lice are observed upon the roots of such trees when purchased, dip the roots in a strong tobacco solution. The Tarnished Plant Bug or "Peach Sting."— This insect, discussed on page 84, frequently attacks young trees twenty to twenty-four inches high, causing the terminal bud to wilt. This may occur on both leader and lateral. Since a portion of the life of this insect is passed on various weeds and cultivated plants, clean cultivation in and about an orchard is recommended. The Green June Beetle. — These greenish beetles (Allorhina nitida Linn.) have yellowish markings on the side. They frequently feed upon the fruit of the peach. The clumsy, whitish grubs from which they develop in two years are found in the ground, particu- larly where it has been abundantly treated with manure or other dressing (Fig. 149). Repeated hand-picking and destruction of the beetles appears FIG. 148. — Peaches suffer at times from attacks of tree crickets; 1, scars in peach wood caused by epg-laying; 2, brown rot infection of peaches following feeding. Photo by Garman. (Parrott and Fulton, Geneva Bull., 388.) EUROPEAN FRUIT EULECANIUM 127 to be the only practical remedy. This beetle also attacks the fig, in which connection it is known as uThe Fig Eater." Supplementary list of peach insects. — Codling moth Peach saw fly Pear thrips Plum curculio Tent caterpillars White peach scale ATTACKING TRUNKS AND BRANCHES OF THE CHERRY The Flat-headed Cherry-tree Borer or Divaricated Buprestis is discussed on page 117; it attacks several of the stone-fruit trees. The Cherry-tree Scale or Bark-louse. — This black scale (Eule- canium cerasifex Fitch) is found on the lower side of limbs FIG. 149. — The southern June-beetle, or fig eater: a, adult; 6, grub; c, pupa in cell; d, empty cell. of the cherry tree. Egg masses are produced under the scale, and the young, upon hatching, in the early summer, spread over the tree, attaching themselves finally to the under side of tender branches, where they soon cover themselves with a scaly secretion. The adult stage is reached before the beginning of whiter. Control. — The usual summer and whiter treatment for scale applies in the case of this insect. The European Fruit Eulecanium. — This scale is somewhat similar to the preceding insect, and is a related species, E. corni Bouche. It injures the tree by sucking the sap therefrom and thus interferes with the growth. The adult scale is one-eighth of an 128 PLUM,. PEACH, AND CHERRY INSECTS inch long, nearly hemispherical; yellowish when young, becoming dark and shiny when older. The hard part of this and allied scales is really a part of the insect and not separable from the insect, as is the case with the oyster-shell scale, San Jose scale and some others. Control. — The life history and control is practi- cally the same as in the preceding species. The Dog Day Cicada. — This is a well-known insect in many latitudes (Cicada tibicen Linn.). It is seen and heard during August and September and is commonly called " locust." The upper side of the body is black, the head and thorax being mottled with olive green. The large, transparent wings are strongly veined; the more prominent veins have a greenish tinge. The under side of the body is coated with a whitish powder. The legs are greenish (Fig. 150). Not much is da?Scada?'7i5ig- known regarding the larvae. Probably both &er-) the larval and pupal stages resemble those of the periodical cicada or so-called " seventeen-year locust." Like other species, the adult often wounds the small limbs of the cherry and deposits eggs in the wounds. INSECTS ATTACKING THE LEAVES OF CHERRY lo Emperor Moth. — The male of this striking moth (Hyper- chiria io Linn.) is of a deep yellow color, with faint purple-brown markings. There are two oblique, wavy lines near the outer margin of the fore-wings and a zigzag line near the base. There are also other markings and blackish dots on the fore-wings. The hind- wings are of a deeper yellow color, shaded with purple next to the body and with a large blue eye-spot in the center. The wing expanse is about two and one-half inches. In the female, the hind-wings are somewhat like those of the male. The fore-wings are somewhat duller in color, and the wing expanse is from three to three and one-half inches. The larvae. — The dark-colored larvae keep together while young in small swarms, and when moving march in a procession, as it were. Later they lose this habit and spread, maturing late in the summer. When full grown, they are two and one-half inches long, approximately, pale green, the green becoming paler along the back, and there is a broad, dusky-white stripe on each side margined with lilac. The body of the larva is covered with CHERRY LOUSE 129 bunches of branching spines, tipped with black. These spines are capable of inflicting a painful wound on tender skin. The caterpillars feed not only upon cherry but also upon apple, willow, elm, poplar, oak, currant, clover, etc. Control. — If troublesome, the species may be easily controlled by hand-picking. Gloves should be worn for this work. As stated elsewhere, a spray of arsenate of lead controls all leaf- eating forms of bisects without injury to the most tender tree. The Pear and Cherry Slug. — This insect in its immature form is a small, dark green, slimy slug (Eriocampoides limacina Ratz). It later turns into a black, four-winged insect known as a saw-fly (Fig. 151). Life History.— The female lays eggs in the tissues of the leaves, at inter- vals during the summer, giving rise to several broods of slugs. This slug, when first hatched, is whitish. There are ap- parently four moults . After the last moult it loses its slimy appearance and becomes yellowish hi color, crawling or falling to the ground and forming a pupal chamber three or four inches below the surface, FlG' 151-~cherry alu« on leaf- emerging as an adult, four-winged saw-fly in two or three weeks. Injury. — This slug feeds on the upper side of the leaves of cherry, plum, etc., causing the foliage to wither and appear scorched as by fire. Control.— Spraying with a weak solution of arsenate of lead will prove effective. Use one pound to fifty gallons of water. Or use white hellebore, one ounce to three gallons of water. Air- slaked lime or even road dust thrown on this insect is fatal. Trees protected from other insects by arsenical sprays would not be injured by this pest. The Cherry Louse (Myzus cerasi Fabr.).— -These are black, shiny plant lice, working upon the young shoots and tender foliage of cherry trees. Description and Life History.— Like other plant lice, they multiply with great rapidity, giving birth to living young during the summer. Also, like other members of this group, they secrete a sticky honey dew which attracts ants, wasps, and two-winged flies. Winged generations appear during the summer. The last generation in the fall usually produces winter eggs. These, in turn, hatch into " stem-mothers," which, in the following 9 w/ 5-(w/i> 1 .( FIG. 152. — A. sorbi, 1, 2, 3, infesting apple. Myzus cerasi, 4, 5, 6, infesting cherry. (After Kirchner and Boltshauser.) CHERRY LOUSE 131 spring, start new generations. See figure 152, which also illustrates A . sorbi, occurring on apple trees. Control. — These insects may be controlled with any of the tobacco extracts. Special care must be taken to strike all the Fio. 153. — Cherry-le i; 3, pupa; 4, adult. (From Geneva Bull.) lice, which are concealed under the leaves, with the spray solution. A better way, where trees are in the nursery or not too large, is to bend over the affected branches and swash the infested tips in a pan of tobacco extract. Black Leaf 40, for example, may be used 132 PLUM, PEACH, AND CHERRY INSECTS at the rate of two tablespoonfuls in a gallon of water. This is the best way to handle all plant lice on the ends of branches upon trees not too high for such treatment. Cherry-leaf Beetle. — Ordinarily, attacks on the part of this insect (Galerucella cavicolis Lee.) are confined to wild cherry, but early in the summer these beetles freely attack cherries in orchards. Description and Life History. — The adults are small red beetles which lay their eggs in the spring in soil close to the trees, but they may be placed on the bark. About three weeks are required for hatching. The grubs are born with black head. When full grown they are about one-third of an inch long. The pupae are found in the ground during the latter part of July (Fig. 153). Remedial Measures. — Use arsenate of lead spray or nicotine sulfate. Supplementary List for Cherry. — The following are other in- sects which attack the cherry. See page references to those de- scribed in this volume. American tent caterpillar, p. 78 Forest tent-caterpillar, p. 80 Apple-twig borer, p. 157 Gray dagger-moth Canker worm, p. 87 Leaf crumpler, p. 98 Cecropia silkworm, p. 91 Oak pruner, p. 281 Cherry-tree leaf-folder Purblind sphinx Cherry-tree Thecla San Jose" scale, p. 70 Eye-spotted bud-moth, p. 86 Tarnished plant-bug, p. 84 Fall web worm, p. 265 Tree crickets, p. 140 FIG INSECTS The Fig Eater or June Bug. — For a description of this insect, see page 127. Fig trees attacked should be jarred, causing the beetles to fall on sheets below the tree, where they can easily be gathered up and destroyed. QUESTIONS 1. Give life history of peach-tree borer. Describe injury caused by same and enumerate protective measures and other methods of control. 2. Enumerate the injuries caused by the peach-twig borer. 3. Give life history of plum-leaf aphis. What measures would you take against it? 4. Describe the work and give life history of the plum curculio and methods of control. 5. Dp the same with the plum gouger. 6. Give life history of the black peach aphis and control measures. 7. Give life history of the flat-headed cherry-tree borer and remedial measures. 8. Give life history of the Dog Day cicada and describe its work. 9. Describe and give control measures for the pear slug. 10. Describe the lo emperor moth. 11. What are methods of controlling the cherry louse? 12. Describe and discuss the cherry-leaf beetle. Give methods of control CHAPTER X INSECT PESTS OF BERRIES AND GRAPES BERRY growers are found over a large portion of the United States, and in many sections berry-growing is the chief means of livelihood. Grapes, which' are really berries, botanically, are grown commercially in favored localities. The bisect pests affect- ing these plants are given in this chapter. INSECTS INJURING STRAWBERRIES Attacking the Roots of Strawberry Plants. The Strawberry Crown-borer. — The adult beetle (Tyloderma fragarice Riley) is wingless, about one-sixth of an inch long. It is brown, marked with several dark brown spots, as well as with lines and dots running lengthwise of the body (Fig. 154). When full grown the grub is white, with a horny, yellow head. a. I FIG. 154.— The strawberry crown-borer. (After Riley.) Life History. — It is first observed in June or July, at which time it deposits an egg on the crown of the plant. The grub, after hatching, burrows down into the crown, feeding upon the tissues. The pupal or resting stage is passed within the crown or root, the adult emerging some time hi late summer. Control. — Infested plants are almost sure to succumb. These should be dug and burned after the fruiting season and before the grub has time to complete its transformation and emerge as an adult. If strawberries are cropped only one year and if a bed is placed at a distance from the bed of the preceding year, the danger of serious injury from this insect is but slight. 133 134 INSECT PESTS OF BERRIES AND GRAPES The Strawberry Crown-miner. — The species here referred to is regarded by some as identical with Anarsia lineatella Zell, which was described under insects affecting peach. In the strawberry, the caterpillar becomes fully grown in early summer, changing to a small, reddish-brown chrysalis in one of the cavities excavated in the crown or in the dead leaves. The moth, upon emerging, lays eggs in the crowns of several plants, depositing usually but one egg in each. This is done during middle and late summer. These eggs soon hatch and the caterpillar bores into the heart of the plant, remaining in its excavated chamber during the winter, enclosed in a silken cell. Affected plants wither and die. Even if they survive the attack, the plants are weak and worthless. Control. — No practical remedy is known. Badly infested plants should be dug up, burned, and new ones planted. New beds should be set each year in new locations. The Strawberry Root-louse (Aphis forbesi Weed). — This species passes the winter in the egg stage. The eggs are black and clustered on the stems and leaves. They hatch in early spring. The young aphids attack the leaves and later the crowns of the plants. They become adult in about twelve days and then pro- 155. — The strawberry duce living young (Fig. 155). The second root-louse. (Original.) . & / . , rm • generation is wingless. This generation is generally taken to the roots by the corn-field ants, which are attracted on account of the sweet juice secreted by the lice. Many of the third brood are winged and are carried to other plants by the wind. Winged forms may also appear at any time when food is lacking. These winged forms start new colonies. The fourth generation appears in early summer and contains some winged forms. The sexual forms appear in the fall, the females then laying eggs, in which stage the winter is passed. Injury. — Frequently, as a result of the work of this insect, one sees portions of a strawberry bed wither, causing bare spots in the patch, and ants may be observed about infested plants. Control. — Avoid buying infested plants or using infested plants for starting new beds. If plants with infested roots must be planted, dip the roots in tobacco decoction before planting. If a new bed must be planted near an old infested bed, plow the old WHITE GRUBS 135 bed under the previous fall. If the aphids appear early in the spring, spray the strawberry crown with nicotine solution — one part to 1000 parts of water. Affected plants intended for shipment should be fumigated for ten minutes with hydrocyanic acid gas, made by using: Potassium cyanide, 1 ounce; sulfuric acid, 2 ounces; water, 4 ounces. This is for every one hundred cubic feet of space. (See page 62.) The deadly nature of this gas should not be overlooked, and precautions must be taken to insure safety. (See also methods of control given under strawberry crown-borer and strawberry crown miner.) White Grubs. — The larval forms of different species of Lach- nosterna are called June beetles, May beetles, or June "bugs." The larvae are commonly called grub worms. They are un- doubtedly the worst of the pests attacking strawberries. They feed also on potatoes, roots of young evergreens in nurseries, and roots of young apple stock. A strawberry crop following directly after sod is very apt to suffer, since the grubs, deprived of their natural food, turn their attention to cultivated plants. Life History. — Ordinarily, eggs are laid by the beetles in grass or sod lands some time in May or June. Grubs hatch in July and begin feeding on rootlets. They grow to less than one-half inch during the first season, retiring, so it is claimed, below the frost line when winter sets in. This statement is questionable where northern latitudes are concerned. The second season they continue feeding and grow to about one inch in length. Growth is completed the third season in midsummer, and the pupal stage is passed in a cell a few inches below the surface of the ground, the pupa gradually changing to an adult, and remaining below the ground until the following May, when it emerges. Control. — Where these white grubs are actually hi a strawberry field, there is nothing to do but dig them out when a plant shows injury. If it is necessary to use sod land for strawberries, such land should be plowed hi early September. This process tends to kill a portion of the brood ready to transform, but will not kill the younger grubs while hi the ground. A rotation of crops is desirable, and the sod should be followed with some crop other than straw- berries for two years or more. Clover is said to be ideal for this purpose, as these insects do not attack it severely. Cropping straw- berries for one year only is manifestly another way of avoiding injury. Where hogs can be used in infected land, they are a great help. Since the most severe injury from white grubs is periodic, 136 INSECT PESTS OF BERRIES AND GRAPES experiment station workers in the various states can generally advise their constituents of the probable occurrence in numbers of this pest and make suggestions regarding strawberry planting. Attacking the Leaves of Strawberry Plants. The Strawberry Leaf-roller. — This moth (Ancylis comptana Froehl.) appears in the strawberry fields during May, and, shortly after, eggs are laid on the under side of leaves. The small brownish or greenish larvae hatch in five to seven days and at once begin feeding on the upper surface of the leaves (Fig. 156). At first they are about one-eighth of an inch long and feed unprotected ; but they soon begin to draw the sides of the leaves together until they are concealed in a complete fold. Feeding continues within the shelter, and pupation occurs about four weeks later, within the leaf. The moth emerges nine or ten days later. There are three broods each season. ct t FIG. 156. — The strawberry leaf-roller: a, larva, natural size; b, anterior segments of larva, enlarged; c, adult, hair lines indicating length of insect and spread of wings. Control. — Old leaves should be burned on the patch in the late fall. When a strawberry patch is no longer useful, it should be completely plowed under in autumn or early spring. The patches, when bearing, call for a properly timed spraying with four pounds of arsenate of lead to one hundred gallons of water. This spraying should be made about a week after the moths are first noticed. By that time the eggs first laid will be hatching, but no leaves will yet be folded. The spraying should completely cover the upper surfaces of the leaves, but should never be used after the berries begin to color. One is further advised to avoid the use of plants from infested districts. The Obsolete-banded Leaf-roller. — The adult of this insect (Ar chips obsoletana Walk.) is a small, brown moth appearing in spring, and depositing eggs which overlap in clusters. The larvae, hatching in about ten days, are light yellow in color, with brownish heads. STRAWBERRY WEEVIL 137 Injury. — They feed on the under side of leaves, skeletonizing small areas. They roll the leaves and fasten them with fine webs. Broods. — When full grown, these caterpillars spin thin cocoons and remain in the pupal stage about ten days. The first brood of larvae appears in the spring, and a second brood early in the fall. Their method of hibernation is somewhat in doubt. Control. — A patch known to be infested should be sprayed with arsenate of lead just before the blossoms open in the spring. Spray thoroughly after the fruit has been picked. Or the strawberry tops should be mowed soon after the fruit is picked, and when dry burn them on the field. See also method of control given under the strawberry-leaf roller. The Strawberry Slug. — The adult is a four-winged fly (Empria maculata Norton) about one-fourth of an inch long, with a row of small white spots along each side of the abdomen. The larvae resemble small green worms. They feed upon the leaves for five or six weeks and then enter the ground to pass the winter in the pupal stage. Control. — If there is fruit on the plants, spray with white helle- bore ; use two ounces to three gallons of water. Dusting with Paris green and air-slaked lime is effective and may be used when there is no fruit present. After the last picking the tops should be mowed and the field burned over. Attacking the Fruit. The Strawberry Weevil. — This is a small, black or brown snout beetle (Anthonomus signatus Say) about one-tenth of an inch long. Life History. — After depositing its eggs in fruit buds, it gnaws the stem just below the bud, causing it to wilt. The young grubs feed on the wilted bud for a few weeks and then change to pupae. The adults later emerge from the dried buds and go to other flowers for feeding purposes. They disappear' about the middle of summer, at which time they probably go into permanent quarters for the following winter. There is only one brood. Since young and old feed upon pollen, pistillate varieties of strawberries — that is, strawberries lacking stamens — are exempt from attack. Late in the season the adult beetles feed upon the leaves. Control. — Clean culture is very essential in controlling this insect, since it passes the winter under rubbish in the field. Old 138 INSECT PESTS OF BERRIES AND GRAPES fields should be plowed as soon as the berries are picked. The leaves might be sprayed after the crop is gathered. Use arsenate of lead at the rate of three pounds in fifty gallons of water. Plant pistillate varieties as far as possible. Ground beetles at times cause injury by gnawing into the fruit of the strawberry. These insects (Harpalus pennsylvanicus DeG. and#. caliginosus Fabr.) are, for the most part, carnivorous, attacking injurious caterpillars, and hence are beneficial. They probably attack the strawberry for its seeds, but their fondness for seed has extended to the pulp also. Their work is done mostly at night, the beetles hiding under stones or clods of earth or mulch during the day. The larvae or grubs live in the ground. Control. — Experiments hi the control of these insects have never been fully worked out. The beetles are attracted to strong lights at night and may be trapped by lanterns or may be caught in traps with meat baits. Short pieces of boards also may be placed at intervals over the patch and offer favorable hiding places. The bisects gather under these boards and can be collected and killed during the day. English growers trap an allied form by the use of dishes with high smooth sides sunk in the ground and baited with meat. The tarnished plant bug is discussed on page 84, under the head of Apple Insects. Supplementary List for Strawberries. — Several other insects also attack the strawberry. Page references are given for those described in this book. False chinch-bug Stalk borer, p. 256 Glassy cut-worm Sulfur brown tortrix Greasy cut-worm Thread-bearing span worm Imbricated snout beetle Wavy-striped flea beetle Oblique- banded leaf-roller, p. 96 Wire worm, p. 206 Rusty-brown tortrix INSECTS ATTACKING RASPBERRY AND BLACKBERRY Attacking the Roots or Canes. The Blackberry Crown-borer or Raspberry Root-borer. — This is a clear-winged moth (Bembecina marginata Harris), shown in figure 157. Life History and Habits. — The adult moth deposits its eggs in midsummer on the leaves. These eggs are deep brownish red in color. Each female lays about one hundred and forty. The young, RED-NECKED CANE-BORER 139 white, grub-like larvse crawl down the stems and bore under the bark, eating into the pith. They feed downward in the pith during the fall, passing the winter in the roots. The next spring finds them working upward in other canes. When full grown they eat nearly through the stem walls a few inches above the ground level and there change to the pupal stage. At this time they are pale yellow with brown heads. Before the adult emerges, the chrysalis pushes itself part way through the unbroken skin of the cane, and when the adult escapes the chrysalis's skin remains in the opening. Injury. — These injurious insects may entirely girdle a stem at the ground. They are particularly destructive in that, in the spring, they abandon the old wood and at- tack the new. Plants attacked generally make a poor growth and may die if the roots have been badly affected. Infestation may come from wild canes in the vicinity. Control. — Infested canes should be pulled up or cut off below the work of the borer and destroyed by burning. Or the borer should be cut out as soon as its work is observed. The various pests attacking canes may all be controlled, to a large ex- tent, by a judicious pruning and cutting out every spring. In the middle and south- ern states, blackberry canes may be en- tirely mowed down after the crop is har- borer- vested. The canes are to be burned immediately. Young shoots will be sent up and become mature before fall. The Raspberry Cane-borer (Oberea bimaculata Oliv.). — The tips of young shoots of raspberries and blackberries sometimes wither and die, due to the attack of this pest, which tunnels through the center of the canes. The adult is a slender, dark beetle with a yellow ring back of the head, and with long antennae or feelers. The larva, when full grown, is one inch long, dull yellow, with a small brown head. Two years are required to complete the life cycle. Control. — Withered tips should be cut off below the point of girdling and burned as soon as cut. This pruning should be done before the larvae go into the crown off the plant to hibernate. The Red-necked Cane-borer. — Both blackberries and rasp- "• male; 6- female- 140 INSECT PESTS OF BERRIES AND GRAPES berries are attacked by this elongated, flattened, bronze-colored beetle (Agrilus ruficollis Fab.). It is about one-third of an inch long. The eggs are deposited near the ground in the axil of the leaf stalk. The young grub eats into the cane at this point and causes the formation of the raspberry gouty gall (Fig. 158). As the gall enlarges, the surface becomes rough and cracks. The larvae tunnel along in the sap wood in an irregular course. When mature, the insect is pale yellow or whitish, with a very small brownish head and black jaws. It is about five-eighths of an inch long. Several larvae may be found hi a single cane. They pupate in the pith; and emerge as adult beetles in early summer. FIQ. 158. — Red-necked cane-borer, adult, larva or grub, and gall. (After Riley.) Control. — Galls thus formed should be cut out and burned dur- ing the whiter, late fall, or early spring, while the larvae are hiber- nating. All wild canes in the neighborhood should be destroyed and clean cultivation practiced as far as possible. Infested canes in the berry patch should be cut out and destroyed before summer. The Snowy Tree-cricket. — This tree-cricket (CEcanthus niveus DeG.) is of a delicate greenish white color, lighter than the allied form 0. fasciatus, from which it is also distinguished by marks on the basal joint of the antennae (Fig. 159). It is quite musical and may even be heard occasionally within houses, where it acci- dentally occurs. SNOWY TREE-CRICKET 141 Life History. — The eggs are laid in the late fall, gashes being cut in the stems by the female for this purpose (Fig. 160). The canes are thus weakened, breaking down tinder the weight of snow or by the influence of the wind. The eggs hatch in late spring. Figure 161 illustrates interesting features in connection with the life history of tree crickets. Figure 162 gives a clear idea of the different stages in the hatching. Habits. — These insects, while harm- ful, should be credited with doing a large amount of good, in that they feed upon plant lice and other insects and rarely nibble the foliage, either in the adult FIG. 159. — A snowy tree-cricket, male and female. (Lugger.) Fio. 160. — Eggs of a snowy tree-cricket: a, twig showing punctures; b, twig split open to show eggs; c, egg and cap, enlarged. (After Riley.) or nymph stages. In the South the insect has two broods a year. As intimated above, the only damage by this insect is that caused by cutting gashes for the eggs. A long, ragged wound in the cane marks the point of egg-laying, and if this rough surface is cut away a series of longitudinal punctures will be found. Each punc- ture extends to the pith, and an egg is placed in the bottom of each. Infected canes, in many cases, if not broken down during the winter, fail to put out leaves in the spring. For a most excellent account of tree-crickets the reader is urged to see Bulletin 388 of the New York (Geneva) Station, 142 INSECT PESTS OF BERRIES AND GRAPES FIG. 161. — Snowy tree cricket. 1. Female feeding on thoracic gland of male at time of mating; 2. female ovipositing. (Parrott and Fulton, Geneva Bull., 388.) RED SPIDER 143 Control. — Examine canes as soon as the foliage starts, at which e the injured ones may be easily detected. These should be t out and burned. If the damage is slight, the work of this insect may be ignored, yet, if neglected, it may become injurious on account of excessive numbers. FIG 162. — Hatching of a tree cricket: A, position of embryo in egg; B, C, D, E, suc- cessive stages in emergence of nymph. (Parrott and Fulton, Geneva Bull., 388.) Attacking the Leaves. The Raspberry Saw-fly. — The adult of this insect is a four- winged fly (Monophadnus rubi Harris). It deposits its eggs near the veins of the leaves and beneath the epidermal layer. The body of the larva is nearly white and thickly covered with trans- verse rows of white spines. The head is greenish white, with a black eye-spot on each side. After feeding upon the leaves until late in the spring, the larvae become full grown and enter the ground to form pupal cases. They emerge as adults early the following spring. Control. — Spray or dust with white hellebore, using one ounce hellebore to one gallon of water. The Red Spider. — This is not an insect, but a mite (Tetrany- chus bimaculatus Harvey), as shown by the fact that the adult has eight legs, but the immature form has only six legs. It often 144 INSECT PESTS OF BERRIES AND GRAPES severely injures the productiveness of small fruits. The colorless eggs are laid in the spring on the under surface of leaves where the mites feed by sucking the juices. These mites are very small and are barely visible to an ordinary observer. The adults leave the plants in late summer and early fall and hibernate in the ground. The injury, however, is very evident, for the affected leaves become yellowish and shriveled, finally drying up completely. Control. — Spray the under sides of leaves with sulfur and water, in the proportion of one pound of flowers of sulfur to three gallons of water. To make the sulfur mix easily with the water, add one ounce soap to six gallons of water. A forceful spraying with a garden hose is frequently helpful. A cheap flour paste is also recommended. Use one pound of flour to a gallon of water for a stock solution. Mix the batter first, avoiding lumps, and then dilute to the above proportions. In preparing the spray, add one part of the stock solution to ten parts of water. The Long-horned Prominent (Schizura ipomoece Doubl.).— Another name of this larva is the dingy cut-worm. The cater- pillars of this species vary considerably. They are usually green, speckled with purple. Two rusty, wart-like projections occur on the top of segments four and eleven. Caterpillars feed upon oak, maple, birch, raspberry, and other plants, besides the blackberry. When the caterpillar is full grown it makes an earthen cocoon below the surface of the ground, in which it passes the whiter. The moths emerge in the spring. The adult moth (Fig. 163) is purplish gray, tinged with greenish at base and along the front edge of the fore-wings. The hind- wings are whitish in the male and grayish in the female. The expanse of the wings is a little more than one inch. Control. — As stated elsewhere, any arsenical spray will kill a leaf -eat ing insect. Poison baits are also recommended. Of the arsenical sprays, arsenate of lead is repeatedly stated as safer than Paris green and has practically replaced the latter. Attacking the Fruit of Blackberries and Raspberries. The Raspberry Fruit Worm (Byturus unicolor Say). — This is a small white "worm" slightly tapering at each end and nearly one-fourth of an inch long when full grown. Injury. — It feeds upon the leaves of raspberry and blackberry, and afterward locates inside the cup of the berry or on the recep- IMPORTED CURRANT BORER 145 tacle on which the berry is borne. Frequently, it is consumed with the berries at table. The adult is a reddish-yellow beetle (Fig. 164) about three- twentieths of an inch long, the female laying her eggs in or on the berry. Control. — Spray heavily with arsenate of lead, just before the emergence or at the first appearance of the beetles. Use six to seven pounds in one hundred gallons of water. This will naturally cut down the number of adults. Thorough cultivation late in the fall, close up to the bushes, is also advised, since this tends to de- stroy the pupae or expose them to the extreme winter weather and to the attacks of enemies. FIG. 163. — Moth of the long-horned prominent. (Lugger.) FIG. 164. — The raspberry byturus. Lower figure, natural size. Supplementary List for Raspberry and Blackberry. — A few additional bisects which attack raspberries and blackberries are here listed. Those described are referred to by page numbers. Apple-leaf hopper, p. 83 Blackberry flea-louse Blackberry-leaf miner Blackberry psylla Eye-spotted bud-moth, p. 86 Oblique-banded leaf roller, p. 96 Orange-striped oak worm Raspberry-leaf roller Raspberry geometer Stalk borer, p. 256 Strawberry weevil, p. 137 Tarnished plant-bug, p. 84 INSECTS INJURIOUS TO CURRANTS AND GOOSEBERRIES Attacking the Canes. The Imported Currant-borer. — The adult of this borer (Sesia tipuliformis Linn.) is a clear-winged, wasp-like moth (Fig. 165). It was introduced from Europe about 1820, and is now widely distributed and destructive over practically all North America. Description and Life History. — The adult female is black, with three bands of yellow on the abdomen; the male is four-banded. These bisects appear hi early summer, at which time eggs are laid 10 146 INSECT PESTS OF BERRIES AND GRAPES on the bark. The caterpillar, on hatching, enters the stem and tunnels up and down the canes. This causes a yellowing of the leaves and death of the canes. They pass the winter, full grown, in the stem. At this time they are one-half of an inch long, with brown head. In the spring they transform to pupae just beneath the bark, and soon emerge, leaving the empty skins of the pupae projecting from the bark. Control. — Infested canes are always easily detected and should be cut off below the injured portion and destroyed by burning; this kills the borers within. Since the bearing qualities of currant and gooseberry are improved by cutting out old canes, FIG. 165. — The currant borer; larva, adult, and pupal case on left. (Lugger.) this yearly practice on the part of the growers would materially help to control this pest. These old canes should always be burned, even when borers have not been noticed. Attacking the Leaf. The Imported Currant Worm. — This insect is a saw-fly (Ptero- nus ribesii Scop.). The adult female is one-third of an inch long, light yellowish in color, marked with black. The male is smaller than the female and somewhat darker. The Eggs and Larvae. — Eggs are glued to the main ribs of the leaf, not inserted in pockets as is usual with saw-flies. They hatch in four to ten days and at first the larvae are whitish, with dark spots on each side. As soon as the caterpillars begin to feed, this color IMPORTED CURRANT WORM 147 changes to green. After the first moult the head becomes black and the black spots on the side of the body become more promi- nent. The full-grown caterpillar is three-fourths of an inch long (Fig. 166) . When full grown it descends to the ground, and spins a small, oval cocoon of a brownish silk among the leaves or rubbish, or even below the ground. Two Broods. — The adults emerge from these cocoons late in June or July, mate, and produce a second brood. The adults of FKJ. 1()(5. — The imported currant worm: a, a, male and female saw fly; b, b, b, larvse of differ- ent sizes; c, pupa; d, cocoon; e, eggs. (Lugger.) this latter brood do not emerge until the following season. Since the two broods overlap, larvse of all stages may be found during the summer. Injury. — These, perhaps, are the most destructive of the cur- rant pests. This is particularly so since they come in the busy part of the year and their depredations are not noticed until the currant or gooseberry bush is nearly stripped of leaves. Control. — If the worms are observed when they first begin to feed, control is easy. Simply dust the leaves with dry, white helle- bore when they are moist with dew. Or spray the foliage with the 148 INSECT PESTS OF BERRIES AND GRAPES same material, at the rate of one ounce of hellebore to three gallons of water. Before the fruit is set, and also after it is picked, arsenate of lead is cheaper and more effective as a spray material. The Native Currant Worm. — The greenish caterpillars of this saw-fly (Pristophora gossularice Walsh) appear on currant and gooseberry leaves in the spring. They feed on the leaves until full grown and pupate among the twigs. The adults are black, four-winged flies. The females deposit their eggs under the epidermis of the leaves. There are two broods a year. The control is the same as for the imported currant worm. The Four-lined Leaf-bug. — This bug (Pcecilocapsus lineatus Fabr.) is widely distributed in North America. Its upper surface FIG. 167. — The four-lined leaf-bug; a, adult; 6 and c, nymphs. (After Slingerland.) is green or yellowish, with four black stripes. The tips of the wing-covers are black. The body is a bright orange yellow (Fig. 167). The nymph, when newly hatched, is one-twentieth of an inch long; bright red, marked with blackish spots. When full grown this nymph is one-fifth of an inch long. Egg •. hatch in late spring. The nymphs require from seventeen to twenty days to complete their growth. Injury. — This insect preys upon a long list of plants, but is particularly injurious to currant and gooseberry. Attacked leaves appear spotted, turn brown, curl up, become brittle, and are torn and broken by the wind. Shoots bearing these leaves are checked in growth and frequently droop and die. Dahlias and roses are often injured; in fact, it is a marked enemy of these two plants. CURRANT PLANT LOUSE 149 Control. — The nymphs may be killed by spraying with kerosene emulsion. But the tobacco extracts are particularly recommended. It is to be noted that the adults are not susceptible to treatment. Both nymphs and adults will drop when disturbed. The Yellow-bear Caterpillar is injurious to berries, currants and gooseberries as well as to many other plants. See the discus- sion on page 160, under Grape Insects. The Currant Plant-louse. — This aphid (Myzus ribis Linn.) sucks the juices from the leaves of the currant, causing them « r • .JBBHHI FIG. 168. — Currant leaves infested with lire. (Lugger.) to curl and form incomplete galls, inside of which the lice stay. Their presence on the under side of the leaf is indicated by the striking red color on the upper surface (Fig. 168). In midsummer they migrate to some other plants for food or become greatly reduced in numbers by parasites and pre- daceous insects. Description. — The winter is passed in the egg stage, like many other aphids, these eggs hatching when the foliage appears. The wingless females are one-twelfth of an inch long; green or yellowish green, mottled with darker shades. The eyes are bright red. The winged females are slightly larger than the others. 150 INSECT PESTS OF BERRIES AND GRAPES Control. — When remedial measures are called for, the under side of the leaves should be sprayed with whale oil soap or other strong soap. Use one pound to six gallons of water. Or spray with tobacco extracts. The spraying must be done before the foliage becomes badly curled, or the insects will not be hit. Picking off curled leaves by hand and destroying them will keep the pests somewhat in check. The Spiny Currant Caterpillar (Polygonia comma Harr.). — The caterpillars, when full grown, are about one and one-fourth inches long. They vary from light brown to greenish yellow in color and are marked with black and yellow lines. Upon the body are numerous branched spines, varying in color from dark brown to a yellow. The spines are frequently tipped with black. The adult insect is the common and strikingly handsome butter- fly which hibernates in some sheltered spot and is frequently seen in warm places very early in the spring. The illustration (Fig. 169) serves to give a good idea of this species. The wings are quite irregular in outline, and there are many projecting points and notches. The surfaces of all four wings are reddish brown, bor- dered on the outer edge with darker brown. The color of the hind- wings varies considerably in intensity, and more so on the under side, which is usually dark brown, with many grayish lines and streaks. The butterfly may always be recognized by a plainly marked "C" on the lower surface of the hind-wing of a metallic silvery color. One's imagination might picture this mark as a comma. Life Cycle. — Eggs are laid singly on the leaves of currant and gooseberry, and here the solitary larvae are found. When full grown the caterpillar seeks a secluded spot to change to pupa or chrysalis. The chrysalis is frequently seen hanging from leaf or twig. It is brown in color. In ten days, from this formation, the butterfly emerges. There are generally two generations of caterpillars — one in late spring and another one in late summer or early fall. Injury. — The caterpillar is a general feeder, attacking not only wild and cultivated currants and gooseberries, which it prefers, but is also fond of elm, hop, nettle, basswood, and various other growths. Control. — Arsenical sprays or white hellebores are effective, if any remedy is needed. The hellebore is preferable if the fruit is ripe or nearly so. Recourse may also be had to hand-picking. RED SPIDER 151 FIG. 169. — Spiny currant caterpillar and two butterflies. (Lugger.) The red spider is a small mite seriously injuring many kinds of plants. For discussions and treatment, see pages 215, 221. See also greenhouse pests. 152 INSECT PESTS OF BERRIES AND GRAPES Attacking the Fruit. The Currant Fruit Fly. — This is a pale yellowish brown fly (Epochra canadensis Loew.) of medium size, with dark bands on the vvings. It deposits eggs in the skin of the half-grown fruit. The young maggots eat into the seeds, causing the berries to be- come discolored, to turn red prematurely, and fall to the ground. The full-grown maggots emerge from the fruit, pupating in the ground, and come forth as adults the following spring. Control. — Spraying is not effective for this insect. Where practicable, the ground should be worked early in the spring and late in the fall. If the bushes are not too numerous, the injured fruit might possibly be removed and destroyed. Poultry might be allowed to run among the bushes early in the fall and would scratch up and eat many insects in the hibernating stage. The Gooseberry Fruit Worm (Zophodia grossularice Pack.). — These worms cause fruit of both gooseberry and currant to become discolored and ripen prematurely. -The gooseberry fruit worm. jf ^ ^ attacked when quite young, the fruit becomes whitish and withers. Currants are not, ordinarily, large enough to hold this larva and therefore they are drawn together in clusters and the worm lives within the web- covered enclosure. Figure 171 gives a very good idea of the work of this pest of currant and gooseberry. Life History. — This pest (Fig. 170) is the young of a pale-gray moth, the wings of which expand one inch. The adult appears early in the spring, depositing eggs on the young currants or goose- berries shortly after the fruit is set. It changes to a pupa in the ground, spinning silken cocoons among the rubbish for the winter, emerging the following spring. Control. — The same remedies employed against the currant fruit fly are applicable to this pest. Supplementary List for Currant and Gooseberry. — The fol- lowing insects are also found attacking currants and gooseberries. The pages cited give full discussions of these. Apple-leaf hopper, p. 83 Saddle-backed caterpillar Cottony maple scale, p. 287 San Jose scale, p. 70 Currant scale "Stink" bugs lo emperor moth, p. 128 Tarnished plant bug, p. 84 Oblique-banded leaf roller, p. 96 Well-marked cut-worm moth, p. 97 IOOSEB] )RM 154 INSECT PESTS OF BERRIES AND GRAPES INSECTS INJURIOUS TO THE GRAPE Attacking Roots and Vines. The Grape Root Worm (Fidia viticida Walsh) . — This is one of the most serious pests of the grape in many parts of the United States. Grubs, by destroying the roots, may completely ruin a vineyard (Fig. 172). Description and Life History. — The adult of this grub is a small brownish beetle with hairy coat. The beetles emerge during the summer, beginning at once to feed, eating chain-like holes in the FIG. 172. — Different stages of grape root worm. (U. S. Bu. Ent.) grape leaves, apparently preferring young plants. They have also been reported eating the skin from the fruit. When disturbed, they endeavor to conceal themselves. The female deposits from sixty to one hundred eggs during the season, evidently at three different periods, from twenty to forty being laid at one time. These eggs are yellow and are placed in clusters under the loose bark or hi crevices on the canes. They hatch in from eight to ten days. The grubs, upon hatching, fall to the ground, entering the soil, and make their way to roots where GRAPE CANE-BORER 155 they feed. They are, for the most part, full grown before winter, reaching a length of about one-half inch. They come to the surface in spring, form earthen cells, pupate, and emerge as adults a few weeks later. Control. — Cultivate early to destroy the pupal cells. Spray for the adult with arsenate of lead. Use three pounds of lead arsenate in fifty gallons of water. Add one gallon of molasses or cheap syrup to sweeten the mixture. The adult beetles may ba jarred from the leaves on sheets placed beneath the vines. These measures may, for the most part, also be recommended for the moth known as the grape-vine root worm. Attacking the Leaves of the Grape. The Grape-vine Flea-beetle. — The adult of this insect (Haltica chalybea Illiger) is a steel-blue beetle appearing in early spring, feeding on the first-appearing buds. It is a voracious eater, and is most active during the heat of the day. When disturbed, it drops to the ground. Life History. — Eggs, according to Slingerland, are laid side by side, tucked into cracks in the bark, some in cavities eaten into the buds. They hatch about the time the young leaves are expanding. The small, dark brown grubs feed on the young leaves, eating irregular holes from the upper side. They become full grown after several moults, which require from three to four weeks. They then fall from the leaves and enter the ground about one inch, forming & smooth cavity in which they pupate. They remain in the pupal stage about one or two weeks, appearing as adults in midsummer, at which time they feed to some extent on grape leaves. The winter is passed under 'any protecting litter. Figure 173 illustrates this insect. Control. — Keep the vineyards free from rubbish in the winter. As soon as the work of the beetles is noticed on the buds, spray with arsenate of lead. Use six pounds to fifty gallons of water. Vineyards regularly sprayed with arsenicals and well cultivated show but little injury from this insect. Beetles may also be jarred on sheets or into large pans and then killed. Grape Cane-borer. — This widely distributed insect (Schisto- cerus hamatus Fab.) is also known to attack the twigs of apple. It was described by Say and named Amphicerus bicaudatus, as a distinct insect, but these are now shown to be identical. It tunnels and kills young shoots of grapes in the spring. It also works in peach and pear, and to some extent in shade trees. 156 INSECT PESTS OF BERRIES AND GRAPES Life History. — The eggs are probably laid in the spring. The full-grown grub transforms to a pupa within the burrow, the adult escaping by gnawing through the walls of its tunnel. The beetle (Fig. 174) is dark brown, not quite one-half of an inch long, with a head drawn under and below the thorax (Fig. 174). It may pass the winter in the adult stage within the burrow, emerging in the spring, or may issue from the twigs of the grape and hibernate in a tunnel which it makes in fruit trees. Control. — One should cut out and burn in spring all diseased and dying twigs. By fall pruning of the grape, and burning of all cuttings, affected vines may be relieved. FIG. 173. — The grape-vine flea-beetle, different stages (U. S. Bu. Ent.) Hair lines The Rose Chafer (Macrodactylus subspinosus Fab.). — This small beetle appears at times in swarms and attacks the grapes about blossoming time. It is awkward-appearing, yellowish and brownish, and more or less hairy. The eggs are deposited in the ground during spring and early summer. The larvae (Fig. 175) look somewhat like small white grubs. They feed on grasses; live over winter as larvae; turn into pupae in the spring, and soon appear as adults. A Toxic Principle. — This beetle is interesting in that for a long time it was supposed that the death of fowls after eating them was GRAPE-VINE PHYLLOXERA 157 due to spiny projections on the legs of the insect. It has now been demonstrated that the death of fowls and other animals, including trout, feeding upon these beetles, is not due to mechanical irritation, but to a toxic principle existing in the beetle. Control. — Poisons are not generally satisfactory, but the fol- lowing spray is quite effective. Use ten pounds arsenate of lead, twenty-five pounds cheap molasses or confectioners' glucose or FIG. 174. — Different stages of the grape cane-borer or apple twig-borer and its work. (U. S. Bu. Ent.) cheap syrup, and one hundred gallons of water. Jarring adults into a large sheet may greatly aid in destroying them. The Grape-vine Phylloxera. — This aphid or plant louse (Phyl- loxera vastatrix Planch.) was first discovered in eastern United States on wild grapes and was introduced into France early in the 1860's. There it became a most serious enemy to grape-raising. It exists in several forms and is found on both roots and leaves. The female is plump, orange yellow, wingless, and fills the gall in which she lives with her eggs (Fig. 176). The female root form 158 INSECT PESTS OF BERRIES AND GRAPES is one twenty-fifth of an inch long; light greenish yellow in summer, and darker in winter. When they are numerous on the roots there is an appearance as if the roots were dusted with mustard. Life History. — There are really four forms to be observed in the life history of this plant louse: (1) the leaf -gall form; (2) the root form, which is the most destructive; (3) the winged or coloniz- ing form; and (4) the sexual form. Winter eggs are deposited in the fall on bark or wood. They hatch in the spring, and the FIG. 175. — The rose-chafer or rose-bug; different stages, details of structure and injury to grape leaf. (U. S. Bu. Ent.) young, settling on the leaves, cause galls on the lower side. These are all females, which die after laying their eggs. In about eight days these eggs hatch into females like the parent, which migrate and form new galls. There may be six or seven generations during the season. Many migrate to roots during the spring and summer, and they all seek the roots at the approach of winter. The last generation takes no food, and each female lays one egg, which passes through the winter. The next spring the roots are attacked and the females multiply GRAPE-VINE P^VLLOXERA 159 upon them also. Some at this time develop into winged females, which escape from the soil and fly to neighboring vines and lay eggs which hatch into males and females. This is the only sexual generation in the whole life cycle. Injury. — This is a serious pest of the grape, as above intimated. The galls on the roots are frequently accompanied by a rotting of the plant tissue. It is not so destructive, by any means, in America as in Europe. Most varieties of grapes grown here are resistant, yet in California it is regarded as an important pest of the grape. Control. — The general recommendations are to use resistant vines. There is a marked variation in the resistance of different ft FIG. 176. — The grape-vine phylloxera, leaf form. (Alter Marlatt, U. S. Bu. Ent.) species and varieties. Not all varieties can be used as stock for desired scions. As is well known, the wild grape of America makes good stock for roots. On deep loose soils carbon bisulfid may be used against the root form, but not on clay nor on dry, rocky hillsides. This treat- ment is hardly practical and has met with only indifferent success. Treatment with carbon bisulfid is rather expensive, costing from $15 to $25 per acre. It is applied by pouring one-half to three- fourths of an ounce of the liquid into holes a foot deep. The holes are made from eighteen to twenty-four inches apart, and not nearer than one foot to the vine. 160 INSECT PESTS OF JERRIES AND GRAPES Submersion of the roots in water, if the latter is available, is effective. It is suggested that, where possible, an affected vineyard be flooded with six inches of water for from seven to ten days, as soon as the vines cease growing in the fall. Infested vines are benefited also by two days' flooding in midsummer, but are injured by any more. Vines on sandy soil are rarely injured by this pest. The Light-loving Anomala. — Beetles of this group (Anomala lucicola Fab.) attack leaves of grape and of Virginia creeper. They are yellowish or brown beetles about one-third of an inch long. There is considerable variation in color and markings of the adult. The larval stage is spent in the ground as a white grub, feeding on various roots. Another somewhat larger form, A. marginata, FIG. 177. — The yellow-bear caterpillar, moth, and pupa. (After Riley.) occurs in some sections. These beetles frequently destroy the leaves of the grape. Control. — Spray with arsenate of lead, four pounds to fifty gallons of water, when there is no fruit on the vines. The Yellow-bear Caterpillar. — The adult moth of this species (Diacrisia virginica Fab.) is often called "the white miller." It is of a white color, marked with a few dots. The expanse of wing is about one and three-fourth inches. Description and Life History. — There are two generations — the second brood of caterpillars appearing in late summer or early fall. When full grown, these striking caterpillars are two inches long, generally yellowish, but the colors vary from yellow to brown in the same brood (Fig. 177). The female places her round, yellow eggs in clusters on the GRAPE-VINE HOG CATERPILLAR 161 under side of leaves. These eggs hatch in a few days into small, yellow caterpillars, which, for a time at least, are gregarious, and eat only the under sides of the leaves. Later they scatter and feed on all parts of the leaf. When full grown the hairy covering of the body is worked into a silken cocoon in which the chestnut-browr. chrysalis is formed. The two broods intermingle so that the insect is present, in one form or another, from spring to autumn. It is a common and rather serious pest and something of a general feeder. Control. — When in moderate quantities it may be hand- picked. If numerous, use arsenate of lead spray as strong as four Fio. 178.— The hog caterpillar of the grape. (After Riley.) pounds to fifty gallons, since the caterpillars are thoroughly resistant. The Grape-vine Hog Caterpillar (Ampelophagus myron Cram). —These caterpillars are very destructive to foliage of the grape, and are also said to bite off stems of unripe grape clusters, causing them to fall. The chrysalis is formed in clusters of leaves which are bound together with a silken thread. The adult moth has long and narrow wings, expanding two and one-half inches. The front wings are olive green, crossed by bands of greenish gray. The hind-wings are dull red, shading to greenish gray next to the body. The caterpillar (Fig. 178) is two inches long, green in color, 11 162 INSECT PESTS OP BERRIES AND GRAPES covered with minute yellow tubercles or blue dots. There are seven oblique yellow spots on each side the body, margined with green. There is also a white stripe from the back of the head to horn on the posterior end, on each side ; a series of seven dots along the middle line, the color of dots varying from red to lilac and each dot set in a yellow patch. It is two-brooded, and pinkish indi- viduals are found in the second brood of caterpillars. Control. — These conspicuous caterpillars are not numerous. Hand-picking may be sufficient ; but spraying with arsenicals may be resorted to if thought necessary. The White-lined Sphinx. — This large, handsome moth (Deile- phila lineata Fab.) may be seen about twilight, hovering before flowers like a humming bird. Description. — The ground color of the fore-wings is a rich greenish olive, with a pale buff stripe along the middle of the wings from the base to near the tip. There is a gray band on the margin of the fore-wings, and the veins are margined with white. The hind-wings are small, crossed by a wide, rosy band. There is a line of white on each side of the body, from the head to the first abdominal segment. The abdomen is olive, with white and black spots. The wing expanse is about three and one-half inches (Fig. 179). The caterpillars vary somewhat in color, but are often yellowish green, with a row of prominent spots along each side. The breath- ing pores on each side are margined with black or black with yellow edges. Life History. — The adult moth appears in the spring and again in the fall, the insect being two-brooded. The caterpillars may be found on the grape, or more commonly, perhaps, on turnip, buck- wheat, and frequently on apple. When the caterpillar is mature, it buries itself in the soil in a smooth cavity and changes into a light-brown pupa. Winter is passed by the pupse of the second brood. Control. — This is not a serious pest, but the larvae are voracious eaters when present. Hand-picking is probably as practical as any method. They are held well in check by attacks of a tachinid parasite. The Grape-leaf Skeletonizer or American Procris. — The cater- pillars of this moth (Harrisina americana Guer.-Men.) are grega- rious, feeding with their heads all toward the margin of the leaf. They are black and yellow in color and six-tenths of an inch long GRAPE-LEAF SKELETONIZER 163 when full grown. When their growth is finished, they become yellow, with a transverse row of large spots on each segment, and are slightly hairy. In late summer, when ready to transform, they disperse. Each seeks a sheltered spot, where a tough, oblong cocoon is con- structed, in which the caterpillar changes to a shiny brown pupa for the winter season. The adult emerges the following spring. This insect has proba- Fia. 179. — Two sphinx moths which are enemies to grapes: above, Ampelophaya my run a,ii«J pupa; below, Deilephila lincata and larva. (After Lugger.) bly two broods in some sections. The female moth is about one- half inch long. It is bluish to greenish black, with an orange- colored collar. Its flight is slow and unsteady. Eggs are deposited on the outer side of leaves. Injury. — The caterpillars eat the soft tissues of the foliage, but not the veins. As they grow, the smaller veins are eaten, leaving only the larger ones not attacked. This insect may become quite injurious if occurring in numbers (Fig. 180). Control. — Hand-pick the leaves on which colonies are feeding. 164 INSECT PESTS OF BERRIES AND GRAPES Arsenate of lead may be used as a spray if the fruit is not too near the ripening stage. Grape-vine Leaf-hoppers. — There are three species of the genus Typhlocyba. Perhaps the most important is T. vitis Harr. The adults of these three species of leaf-hoppers are all similar in shape and general appearance, differing in minor markings. T. vulnerata is a reddish-brown insect, marked with white lines FIG. 180. — The American procris: a, caterpillar; b, pupa; c, cocoon; d and e, moths. Below, a colony of caterpillars feeding. (After Kiley.) and dots, with two prominent black lines at the margin of the upper wings. T. comes is of a translucent white color, marked with red lines and prominent black spots at tip of wings and two black lines at the margin. These nymphs hatch in midsummer or early fall, they hibernate as adults, and in spring attack the leaves of the vines as soon as the foliage appears. The life history as well as the occurrence of these species varies in different parts of the country. GRAPE-VINE LEAF-HOPPERS 165 Leaf-hoppers are regarded as among the most destructive of grape-vine pests, sucking sap from the leaves and thus greatly weakening the vines. A party in California has estimated his loss on one thousand acres at ten thousand dollars in one year (Fig. 181). Control. — Remove all rubbish in the field and rake or lightly cultivate the ground. The nymphs or young, being all on the under FIG. 181. — A grape-vine leaf-hopper, different stages. (Lugger.) side of the leaves and not capable of flight, may be sprayed with whale oil soap solution or the resin spray. Use one pound of soap to fifteen gallons of water in the former case. The resin spray is made by adding one pound of resin to fifteen gallons of hot water and enough lye or potash to completely dissolve the resin. This generally takes one pound of lye to eight pounds of resin. The 16J INSECT PESTS OF BERRIES AND GRAPES spraying should be done forcefully from below. It should be borne in mind that this treatment kills only those insects which are hit with the spray, the adults escaping by flight. FIG. 182. — The eight-spotted forester. (Lugger.) The Eight-spotted Forester (Alypia octomaculata Fab.). — This is a strikingly handsome moth (Fig. 182), with a wing expanse of from one to one and one-half inches. It is bluish black in color, EIGHT-SPOTTED FORESTER 167 marked with eight large light spots — two spots on each wing. Those on the fore-wings are pale yellow, while those on the hind- wings are white or whitish. The caterpillars are light brown in color, with many black lines and an orange band across each segment. The head and FIG. 183. — Larvae of eight-spotted forester. On black ground, a parasitized "yellow bear ' caterpillar. (Lugger.) dorsal shield of the first segment are shining bright orange, marked with dots. There are eight black conical, elevated tubercles on the orange band of each segment in the middle region. These caterpillars (Fig. 183) feed quite commonly on the grape and on the Virginia creeper. The species is commonly found throughout the United States and Canada. Control, — An arsenate of lead spray is the most efficient remedy. 168 INSECT PESTS OF BERRIES AND GRAPES Attacking the Fruit. The Grape Curculio (Craponius incequalis Say). — This beetle (Fig. 184) is black in color, sprinkled with grayish spots, and is one-tenth of an inch long. It hibernates in the adult stage, and eggs are laid on the young grapes in early summer. Injury. — The larva or grub, upon hatching, enters the fruit and feeds within. Its presence causes a discolora- tion of one side of the berry as of premature ripen- ing. The berry remains plump, but sometimes drops before becoming ripe. The grub, becoming full grown before the crop ripens, leaves the berry, drops to the ground, and buries itself a short distance below the surface. It changes to a pupa, FIG. 184.— The from which the beetle escapes some time in Sep- grape curculio. Control Measures. — Jar the vines occasionally in June, placing a sheet on the ground beneath to catch the weevils, which can then be destroyed. The Grape-berry Moth. — This insect is a serious pest in vine- yards, and the injury it causes resembles that of the grape curculio. FIG. 185. — The grape-berry moth: a, b, larva; c, pupa; d, case with empty pupal skins; all enlarged; /, grapes with worm, natural size, hair lines indicate size of a, b, c, and d. (U. S. Bu. Ent.) The pest when a moth (Polychrosis viteana Clem.) has fore-wings of a pale, dull bluish shade, and hind-wings dull brown. Injury. — The caterpillar enters the grape early in July, produces a discolored spot; and spores entering the grape at the puncture CRANBERRY LEAF-FOLDER 169 cause rotting of the fruit (Fig. 185). Sometimes several grapes are bound together by silken threads and fed upon by one insect. The first generation of caterpillars may also feed upon the blossoms. Transformations. — When the larva is full grown, and ready to pupate, it forms a cocoon on the leaves of the vines by turning over the edge of a leaf and lining the inside with silk. There are two broods of this insect, the spring brood being sometimes found on weeds. Control Measures. — Since the whiter is probably passed in the pupal cases attached to leaves, gathering and burning the leaves will materially diminish their numbers. All diseased and fallen fruit should be destroyed. Wormy grapes might be picked off the vines in summer at an expense of about two dollars per acre. Vineyards sprayed with a combined fungicide and arsenical poison before blossoms open are not seriously affected with this pest. Supplementary List of Grape Insects. — Besides the insects described in this section of the chapter, the following also attack the grape less seriously. Where page citations are given a dis- cussion of the bisect may be found. Abbot sphinx Mealy flata Achemon sphinx Pandorus sphinx Cottony maple scale, p. 287 Pyramidal grape-vine caterpillar False chinch bug Red-shouldered simoxylon Grape plume moth Saddle-back caterpillar Grape-vine leaf-folder Smeared-dagger-moth Grape-vine leaf-sewer Snowy tree-cricket, p. 140 Indian euphoria, p. 106 Spotted vine-chafer INSECTS INJURIOUS TO THE CRANBERRY Attacking the Leaves. The Cranberry Leaf -folder (Peronea oxycoccana Pack.). — This is a small moth, having a spread across the wings of only three- fourths of an inch. The fore-wings are reddish brown and the hind- wings glistening gray, the body being a dark slate color. The method of control employed in the New Jersey cranberry district is to keep the bogs covered with water until after the middle of May, compelling the moths to lay their eggs on other plants belonging to the same family. This practice aids greatly in con- trolling other cranberry insects. One spray ing with arsenate of lead will effectually destroy them if applied when the eggs of the second brood are hatching. Use five or six pounds in fifty gallons of water. 170 INSECT PESTS OF BERRIES AND GRAPES The Yellow Cranberry- worm (Teras vacciniivorana Packard). — This pale yellow caterpillar (Fig. 186) is about three-tenths of an inch long and feeds on the foliage of the cranberry. It draws leaves of the plant together with silken threads, feeding upon their upper surfaces. Control. — Flooding is recommended as the most effectual remedy. The vines should be kept under water for two or three days. Fires lighted in the Fia. 186. — The yellow cranberry worm, dorsal and side views of larva and two views of pupa. neighborhood will attract and destroy some of these moths. Where possible, a thorough. spraying with arsenate of lead, at the rate of five pounds to fifty gallons of water, at the time of hatch- ing of the eggs of the second brood will clear a badly infested bog for three or four years. The time for spraying varies with the season; usually it should be done about the middle of summer. The Cranberry Leaf-roller (Ar chips parallella Rob.). — This is another caterpillar which feeds upon the foliage of the cranberry. It is reddish in color, with a yellow head. It is about three- fourths of an inch long, with a number of prom- inent warts on the back. From each wart one or more rather long, stiff hairs project. The moth (Fig. 187) is a reddish orange; the fore-wings are crossed diagonally with numerous fine lines of a darker reddish brown. Control. — Apply the same remedies as given for the cranberry leaf-folder. The Cranberry Spittle Insect, — This is a small, soft, sucking FIG. 187. — The cran- berry leaf-roller. FIG. 189. CRANBERRY WEEVIL 171 insect (Clastoptera proteus Fitch) found in the spring in small masses of froth-like secretion growing upon the shoots of the cranberry. When mature the insect jumps like a flea. The vine is weakened by the loss of sap. Flooding is recommended. Attacking the Fruit. The Cranberry Fruit Worm.— The caterpillar (Fig. 188) of this moth (Mineola vacdnii Riley) is yellowish green in color. The injury caused by it takes place in late summer, when it enters the berries, eating the contents and causing Fia 188 them to turn prematurely red. In the fall it becomes fully grown and buries L itself in the ground, where a cocoon is 5 formed, covered with grains of sand. \! As with the preceding insect, flooding [i appears to be the only remedy. The Cranberry Weevil. — This is a C reddish-brown beetle (Anthonomus sutur- ' alis Lee.) with a dark-brown head and FlG- iss.— The ««nberry fruit- a beak or snout half as long as its body FlG- 189- ~ (Fig. 189). The complete length of the insect, including the beak, is a little over one-eighth of an inch. It selects an expanding blossom bud, drills a hole into it with its snout, and lays in the hole so made a pale yellow egg. The bud is then cut off by the beetle, and, lying upon the ground, furnishes shelter and food for the grub, which completes its transformation within. Finally the new beetle emerges from a round hole in the side of the decaying bud. Flooding with water is the remedy advised. QUESTIONS 1. What do you regard as the most injurious insect enemies of strawberry growers? 2. Give life history and remedies for the strawberry root-louse. 3. Discuss the work of white grubs in connection with strawberries. 4. Give life history and remedies for the strawberry weevil. 5. What insects, normally beneficial, sometimes injure strawberries? 6. Name three insects of importance which attack raspberries and black- berries; give life history and remedies for each. 7. Give life history and remedies for the imported currant worm. 8. What difficulties are met in combating the four-lined leaf-bug? 9. What striking feature indicates the presence in injurious numbers of the currant plant louse? What is the reason for this? 172 INSECT PESTS OF BERRIES AND GRAPES 10. Describe the work and methods of control of the currant fruit fly and the gooseberry fruit worm. 11. Give description, life history, and remedies for the grape root worm. 12. What new and interesting facts have been brought to light in connection with the rose chafer? 13. Compare the work of the grape-vine phylloxera in Europe and America. 14. Discuss the grape-vine leaf-hoppers. 15. Name three other insects not referred to above which you regard as injurious to the grape. 16. Mention four of the most injurious cranberry insects and give remedial measures therefor. CHAPTER XI PRINCIPAL INSECTS AFFECTING CITRUS FRUITS PROBABLY the worst pests with which orange and lemon growers have to contend are the various scales found on branches, trunks, twigs, and leaves, and in some instances on the fruit itself. But a number of other insects attacking citrus fruits are discussed in this chapter. FIG. 190. — The red scale: a, winged male; b, female scale; c, male scale. Scale Insects. — Among the scale insects may be mentioned the following: (1) The red or orange scale (Chrysomphalus auran- tica) (Fig. 190). (2) Yellow scale (C. aurantica var. citrinus). (3) The black scale (Saissetia olece) (Fig. 191), indirectly the cause of black fungous growth on the tree. 173 174 INSECTS AFFECTING CITRUS FRUITS (4) The soft orange scale or broad scale (Coccus hesperidum) (Fig. 192), everywhere very common. (5) The cottony cushion scale or ribbed scale (I eery a purchasi) (Fig. 193), one of the pests of citrus fruits, but now held fairly well in check by predaceous insects introduced from Australia. (6) The purple scale (Lepidosaphes beckii) (Fig. 194). (7) The long scale (Mytilaspis gloveri) (Fig. 195). FIG. 191.— Black scale. (8) In addition, growers have to contend with the circular scale (Aspidiotus ficus) (Fig. 196). (9) The greedy scale (A. rapax) (Fig. 197). (10) The white scale (A. nerii). There are also two or more troublesome varieties of mealy bugs (Pseudococcus sp.) (Fig. 198). Space hardly allows a detailed description of all of the above. They all yield to the same general treatment. Briefly, it may be said that under the chitinous covering referred to as a ' 'scale" REMEDIES FOR SCALE INSECTS 175 the insect is found; the female produces either living young or eggs, and the young scales crawl about for a time before becoming permanently located, after which they secrete their own covering scale. This group is subject to the attack of many parasites and pre- daceous insects. Among the latter, "lady beetles" or "lady birds" Fia. 192. — The broad scale. Fio. 193. — Cottony cushion scale on orange twig. (Quayle, Cal. Bull., 214.) are the most prominent and the most useful. Any effort to eradi- cate scale insects must naturally result also in the death of many beneficial forms preying upon them. But, inasmuch as citrus growers cannot depend upon the services of the latter, radical treatment must be resorted to. Remedies for Scale Insects. — Spraying has been largely super- seded by fumigation, but is still in use in many orchards. For citrus trees, kerosene emulsion is probably the safest of the various FIG. 194. — Purple scale; a, female scale, dorsal view; b, ventral view; c, male scale FIG. 195.— The long scale: a and c, dorsal and ventral view of female scale; 6, male scale. REMEDIES FOR SCALE INSECTS 177 compounds. This is made by dissolving one-half pound soap in one gallon of water by boiling. Remove from fire and add one gallon of cheap kerosene. Churn by forcing through spray pump and add fourteen gallons of water, mixing thoroughly. It should be used at once. This spray is intended to be employed when young scales are crawling over the trees. Fia. 196. — The circular scale. Fumigation is, on the whole, more satisfactory than spraying and is in more general use in citrus orchards. The chemicals most commonly employed are cyanide of potash and sulfuric acid. The most desirable proportions are one ounce of cyanide of potash to two fluid ounces of commercial acid and four fluid ounces of water. Canvas tents made of eight-ounce canvas should be used to cover the trees. These may be rendered more impervious to gas leakage by painting thoroughly with boiled linseed oil, or in other ways. 12 178 INSECTS AFFECTING CITRUS FRUITS FIG. 197. — Orange infested with greedy scale. (Quayle, Cal. Bull., 214.) Fia. 198.— Mealy bugs on orange. (Quayle, Cal. Bull., 214.) CRESPHONTES BUTTERFLY 179 The tents are constructed on various plans, according to the prefer- ence of the grower. Manifestly some standard of dosage must be followed to secure the desired results with safety, and the necessary charges have been well worked out by entomologists. A formula is obtained by multiplying the circumference of the tented tree by the distance over the top. Point off two places in the result. For example: a tented tree measuring twenty feet around and thirty feet over would require six ounces of cyanide of potash for the purple scale. Using the proportions given above, the formula would be: six ounces cyanide, twelve fluid ounces acid, and eighteen fluid ounces FIG. 199. — Larva of cresphontes butterfly. water for each tree. This, however, is for the purple scale only. For the red, yellow, and black scales the amount should be reduced about one-quarter. Since different methods of fumigation are practiced in different sections and different dosages are required for various scales, growers are advised to consult with their own experiment station authorities in undertaking this work for the first time. For remedies for the San Jose" scale see page 72. "The Orange Dog," or Cresphontes Butterfly (Papilio cres- phontes Fab.). — This conspicuous caterpillar, which feeds in the North on prickly ash and other plants, is at times a serious enemy to the orange, stripping the leaves from young trees. Description and Life History. — When full grown the larva is 180 INSECTS AFFECTING CITRUS FRUITS CRESPHONTES BUTTERFLY 181 about two inches long, dark brown, and marked with white or light areas spotted with brown. Between the fourth and fifth segments is a large white patch, and a more or less similar patch is found upon the posterior end of the larva. The most striking feature of the caterpillar consists of two long " horns," flesh colored, just behind the head, which may be extended, and which exude a bad-smelling fluid (Fig. 199). FIG. 201. — Work of thrips (Euthrips citri) on oranges. (Quayle, Cal. Bull., 214.) When the caterpillar is about a month old it forms a grayish or brownish chrysalis; is fastened to a twig by means of an attach- ment at the lower posterior end and by a silken thread which passes around the twig and around the middle of the insect. The butterfly (Fig. 200) is one of our most striking insects, its wings measuring nearly five inches across. The black ground color of the upper surface is marked by spots and bands of yellow. 182 INSECTS AFFECTING CITRUS FRUITS Below, the wings are yellow, with blue spots on the hind pair. Control. — Hand-pick the caterpillars and pupae. Orange Aphis. — This is a black or brownish aphid (Siphono- phora sp.) with yellowish legs. It sucks the sap from the twigs of the orange. Both winged and wingless forms may be seen on the trees at the same time, the winged form migrating to other trees. The life history of the orange aphis agrees in general with that of other aphids. Control. — A spray of strong soapsuds or tobacco extract, with soap added, is generally sufficient to control this pest. It is attacked by predaceous and parasitic insects. Orange Thrips. — Of the various species of thrips which work on the orange, this (Euthrips citri Moul.) appears to be the most injurious, for if it does not render the fruit unmarketable (Fig. 201), it at least obliges grocers to classify it as an inferior grade. In certain regions in California it is proving an injurious pest. Various species of thrips may be observed about the blossoms of orange FIQ. 202.— The cot- trees. They are blackish or yellowish insects ton stainer. . . which move rapidly. Control. — Spraying is the most effective method of controlling these insects, and the following is recommended by the United States Bureau of Entomology : Commercial lime sulfur, 2^ gallons; black leaf extract, 2 gallons of 2 ^4 per cent or 14 fluid ounces of 40 per cent; water, 200 gallons. Possibly three applications may be necessary at intervals of about ten days. The spray should be applied forcibly. The Rust Mite. — The rust often observed on the fruit of the orange is caused by the activities of a whitish mite (Phytoptus sp.) which is frequently found in large numbers on the skin. Control. — A strong soap solution is recommended for the ex- termination of this pest. The Cotton Stainer (Dysdercus suturellus H. Schif.). — This bug is not only a bad pest of cotton, but it also sometimes seriously injures the fruit of the orange by sucking the juice. As a result of its work the fruit may decay and fall. When adult (Fig. 202) its ground color is black, with red anterior markings. The margins of the body are pale yellow, and two white lines cross on the back when the wings are folded. It is bright red below. The eggs are FIQ. 203, — The angular-winged katydid. /, adult; la and 2b, eggs; Ib, nymphs; 2 and £a, female and male chalcid egg-parasites of this katydid. 184 INSECTS AFFECTING CITRUS FRUITS placed on the under side of leaves. The nymphs emerging there- from are strikingly bright red with dark legs. Control. — These bugs are attracted to cotton seed and may be killed by making use of small piles of seed and pouring hot water or kerosene upon the bugs when gathered together. The Orange Basket Worm. — The male insect is dark brown, the female whitish. Eggs are laid in a case hanging from a leaf or twig made by a larva when full grown. Before mating, the case is dragged about by the occupant, whose head and legs protrude. This case is evidently made up by bits of bark or leaves held together by a thread secreted by the caterpillar. The pupa is found hi the suspended case, the male pupal skin protruding from the case after the perfect insect has issued. Control. — These cases are so conspicuous that hand-picking is the most obvious method of control where the insects are discovered. The Angular Winged Katydid. — A night-loving insect is this katydid (Microcentrum retinervis Burm.). It is green in color and about two and one-half niches long. It is better known .by its rasping note heard in the evening than by any other feature. The eggs are laid in such a way that they overlap on both leaf and twig (Fig. 203). This insect is fortunately attacked in the egg stage by an abundance of parasites and as an adult it is preyed upon by birds. Control. — Winter pruning and destruction of cuttings are help- ful. Instead of destroying all cuttings, enterprising orchardists often collect eggs in winter and place them in boxes covered by fine wire gauze. If the young hatch, they are destroyed. But if the egg parasites issue hi the spring, they are allowed to escape. The Lubber Grasshopper (Romalea microptera Serv.). — This huge, slow-moving Orthopteran occasionally damages citrus fruits. It does not fly and consequently can be easily controlled. QUESTIONS 1. Name five, scales injuring oranges and lemons. 2. Give briefly the life history of scale insects. 3. Tell what class of insecticides is called for in their treatment. 4. Describe fumigation of orchard trees for scale insects. 5. Mention several other insects attacking citrus fruits. 6. Describe the injury of each of these; give methods of control for each. CHAPTER XII INSECTS AFFECTING FIELD CROPS AND PASTURAGE THE enormous amount of grain and other field crops raised in this country, and the importance of stock-raising and milk produc- tion, are such as to make consideration of insects affecting field crops and pasturage of special importance. The pests concerned are discussed in the following pages. WHEAT INSECTS Hessian Fly (Mayetiola destructor Say). — This fly, which causes an annual loss of many thousands of dollars in the United States, is hardly ever observed by the layman on account of its ex- tremely small size. It is a dark- colored gnat with two wings. As it is only one-tenth of an inch long (Fig. 204), probably not one in a thousand of our farmers has ever seen this insect in the adult stage. Life History. — The so-called "flaxseeds" (Fig. 205) which repre- sent the pupal stage are easily ob- served under the sheathing leaves, next to the stem, generally above the first joint, although they may be found higher up on the stem. The fly emerges from these flax- seeds either in the stubble or in the grass or weeds along the edges of the fields. It lays from one hundred to One hundred and fifty eggS in FIG. 204.— Hessian fly on wheat plant, much enlarged. early spring on young wheat plants. The maggots hatching from these eggs work against the stem beneath the sheath leaf as above indicated. The winter is passed in the pupal stage; called "flaxseed" because of its resem- blance to the seed of the flax plant. Injury. — Affected plants, when young, appear darker than 185 186 INSECTS AFFECTING FIELD CROPS normal plants. Later, when the head is formed and about the time the grain is in the milk, the weakened straw breaks just above the working place of the maggot, causing the grain to lodge or FIG. 205.— Puparia of Hessian' fly, so-called "flaxseeds, " in infested wheat stems. Also showing characteristic breaking down of stem. (Original.) the heads to lie on the ground and be missed by the binder. Ker- nels in affected plants are poorly filled and shrunken. Control. — Plowing the stubble and rotation of crops are good farm practices in connection with this insect. All volunteer ENGLISH GRAIN LOUSE 187 wheat or other small grain, as well as grass growing around the edges of the fields, should be destroyed. Varieties of wheat with coarse, strong stems are less liable to injury. Field wheat should be sown as late as possible. Burning the stubble where practicable will destroy the flaxseeds. A good system of plowing, crop rota- tion, and modern methods of agriculture, however, are the best methods of prevention. The Wheat Stem Maggot (Meromyza americana Fitch). — Un- like the Hessian fly, the larva of this two-winged insect feeds imide the stem, causing it to become discolored or to die. Sometimes the stem is cut off entirely. The adult fly is one-fifth of an inch long, of a general yellowish-white color, with three black stripes on the thorax and abdomen. The eyes are bright green. The larva or maggot is light green in color, one-fourth of an inch long, tapering toward either end. The adults lay eggs at intervals during the summer. The winter is passed by the larvae in young plants, where they transform into pupae. This insect also attacks rye (Fig. 206). Control Measures. — Since this bisect feeds and breeds also in wild grasses, it is difficult to control. Where possible and safe, it is suggested that the stubble be burned over. Fall-plowing, clean cultivating, and rotation of crops are the most desirable measures of prevention. The English Grain Louse. — Only in latitudes where the winters are comparatively mild will grain plant lice (Macrosiphum granaria Buckton) seriously injure crops. They are found on wheat, rye, and other winter grains. They feed on the leaves when young and later gather on the ripening kernels in the heads, injuring the yield and quality of the grain very seriously. The life history is approximately the same as for other plant lice. There are both winged and wingless forms. Each female gives birth during the summer to forty or fifty young, the same reaching maturity in about twelve days. When there is need of migration, winged forms appear. As many as fourteen generations have been observed in one summer hi the latitude of Minnesota. These lice are yellowish green. The two honey tubes projecting from the back of each insect are quite long and black hi color. Control. — Parasites and other natural enemies generally hold this pest in check. No practical remedy is known and none needed in most latitudes. Clean farming and rotation of crops are recommended. 188 INSECTS AFFECTING FIELD CROPS FIG. 206. — Wheat stem maggot; three infested stems, full-grown larvse, and parasite. Hair lines indicate natural size in each case. (Lugger.) FRIT-FLY 189 The " Green Bug." — The spring grain aphis (Toxoptera grami- num Rond.) has of late years caused much injury to grain in Kansas, Oklahoma, Texas, and a few other states where the winter weather is such as to check the growth of parasites which normally keep this pest within bounds, and yet allows the continuous breeding of the louse. Figure 207 gives a good idea of the appearance of this aphid. Winged forms (Fig. 208) are carried northward by the wind, but in northern states it does practically no damage. Control. — No measures of control are necessary in the northern states where cold winters are the rule. In the South no volunteer grain should be allowed to grow; all such growth should be de- stroyed in the early fall. FIG. 207. — The "green bug" FIG. 208. — The "green bug," winged migrant form. (Toxoptera graminum). The Frit-fly (Oscinis sp.).— This fly (Fig. 209) looks very much like a small house fly. The tiny white eggs are laid in the fall on fall-sown wheat or other grain. The larvae pass the winter within the plant. In regions where spring-sown grain is the rule, the insects hibernate in the larval stage in the straw and stubble. The adults emerge in spring and lay eggs] which produce the first brood of maggots. Another brood of flies emerge during midsummer in regions where fall-sown grain is grown, laying eggs on volunteer grain plants and various grasses, the next brood of flies— the fall brood — laying their eggs on the young plants of the fall-sown field. Injury. — Heads of wheat and other grains sometimes wither and die or are filled with shrunken kernels as a result of the work of this insect. Sometimes the stem is cut off by the young maggot within. The presence of the pest is indicated by a premature 190 INSECTS AFFECTING FIELD CROPS yellowing of the head and of the stalk above the infested point, generally three or four inches above the ground. This is followed by a breaking down of the plant. Just below the point of breaking the maggot can generally be found within the stem. Control. — If straw is stacked, many hibernating insects will not be able to reach the surface of the stack. Burning or feeding up the straw will, of course, destroy all wintering forms. In regions of spring-sown wheat, burning the stubble in the fall, where possible, is a good remedial measure, as is also the plowing under of stubble. The latter method is the most practical in the northern states. Y FIG. 209. — The frit-fly: a, imago; 6, larva or maggot; c, puparium containing the pupa. All much enlarged. (After Lugger.) The Wheat-head Army Worm (Meliana albilinea Hbn.). — This is one of the cut-worm moths. The female lays her eggs on leaves of different grains, timothy and other grasses. The worms are observed at work in June and July and have been found entering the pupal stage in the middle of the latter month. Injury. — Timothy sometimes suffers seriously. Four-fifths of the timothy seed crop has been known to be destroyed during one season, and the hay crop seriously injured. On wheat the worms eat the kernels of the grain, allowing the chaff to fall to the ground (Fig. 210). CHINCH BUG 191 Description. — The adult moth is brownish yellow, resembling in a general way other cut-worm moths. The caterpillars or larvse vary in color from green to very dark brown or blackish; they almost invariably show characteristic stripes on back and sides. When full grown, they are one and one-fourth inches long. The pupae are of mahog- any color; three-fourths of an inch long. They are found two or three inches in the ground. i Control Measures. — Some of the following methods are applicable to pastures when attacked, and some to grain : Early fall pasturing will starve the second brood. Wild grasses in the vicinity of cultivated crops should be destroyed. Plow stubble early in the fall. Land should not lie in pas- ture for more than three or four years. Since these worms sometimes march to a field in a vast army, furrows can be plowed across this line of march, throwing the furrow away from the crop to be protected. The worms may be killed in the furrows with kerosene or by covering them with straw and burning it. Where prac- ticable, a strip of grain or pasturage across the line of march should be sprayed with a strong solution of Paris green, or, better, with arsenate of lead. The Chinch Bug (Blissus leucopterus Say).— This vile-smelling bug is well knOWn tO mOSt Of OUr farmers and ..... . owes its names to its bedbug odor, its name being a corruption of a Spanish word meaning bed- bug. The adult is one-fifth of an inch long. It has a black body and white wings, each marked with a black triangle on the outer margin. The bases of feelers or antennae and bases FlG. 210._The wheat.head army ^ d> two views of eggs, enlarged; the male moth. (After Riley.) 192 INSECTS AFFECTING FIELD CROPS The young bugs are brownish black. They yellowish or grow darker of the legs are reddish, bright red, marked with with age. Life History. — This insect passes the winter hi the adult stage under shocks of corn or under leaves in the woods or under rubbish of any sort in the fields. It comes out as soon as warm weather arrives in the spring, generally early in May, and flies to wheat, rye, barley, or grass lands. Here the female deposits eggs upon the ground close to the roots of the plants or upon the bases and roots themselves. About 500 eggs are laid during a period of ten to fifteen days. These hatch in two weeks, the nymphs beginning at once to feed like the adults by sucking the juices from the young plants. There are generally two broods. Since, however, the eggs laid by one female are not all de- posited at once, in the latter part of the summer insects of all stages are observed. From fifty-seven to sixty days are required for the life cycle of one generation. Injury. — Although grains and grasses are weakened by attack, the worst injury occurs upon corn, for corn is sought aftes the grasses or grains ripen. Frequently one ob- serves in the field a vast army of chinch bugs of all ages migrating from grain field to corn field, appear- ing to know instinctively the direc- tion in which their chosen food lies. Control — We have not as yet learned to successfully control this pest in wheat fields, and all our efforts are directed against protecting the outer rows of corn. While the Hessian fly prefers the moist weather, rams destroy young chinch bugs and encourage the growth of parasitic fungi (Fig. 211). Unlike the Hessian fly, therefore, the chinch bug prefers and revels in the hot sun. It is a frequent practice to interpose some barrier between the advancing bugs and the corn fields. A deep furrow with the steep side toward the corn may be plowed if the bugs are observed in time. The insects which gather in the furrow may be destroyed with kerosene FIG. 211. — Diseased chinch bug. (Lugger.) GRASSHOPPERS 193 or burned with straw. A band of tar road oil three inches wide may take the place of the furrow. In irrigated regions a water barrier is effective. Some states have found burning the bugs in their winter quarters to be extremely helpful ; and this may protect the wheat fields. Spraying the outer rows of corn with nicotine sulfate has also been practiced. It has been observed that in chinch-bug years farmers who allow pigeon grass and other so-called weeds to grow among the corn have not suffered from the attacks of chinch bugs as much as the more careful farmers. Careless farming is not to be encouraged, but it may be suggested that in cultivating corn in chinch-bug FIG. 212. — A grasshopper ovipositing. (After Howard.) years the three or four outer rows be left uncultivated in order that the weeds may have a chance to grow and protect the balance of the corn crop. Grasshoppers. — It is hardly desirable to describe the various species of grasshoppers in a work of this kind. All of our related grasshoppers have approximately the same life history. They are really locusts belonging to the family Acrididae, not grass- hoppers. The winter is passed in the egg stage, the young hatch in spring. The wingless young are rather inactive and clumsy until after the second or third moult. If food is scarce at this time, they congregate in great numbers and march across country, devouring every green thing in their path. Often fields and forests are deprived of every bit of foliage. 13 194 INSECTS AFFECTING FIELD CROPS •OJT, FIG. 213. — Details of con- struction of hopperdozer. The back and sides are canvas. (Original.) These insects are essentially single- brooded. Figure 212 illustrates a female, with badly frayed wings, egg-laying. Natural Enemies. — They are at all times subject to the attacks of birds, skunks and many other animals, and the eggs are eaten by two or more species of blister beetles, as well as ground beetles, harvest mites, etc. Fungous and bacterial diseases also play a large part in reducing their numbers. Control Measures. — Deep plowing in the late fall or early spring helps to break up the egg masses. Alfalfa land should be thoroughly disked. When the young appear in the spring) it is sometimes possible to burn the stubble. Bunches of straw may be scattered about on cold days and the grasshoppers gathering thereon may be burned. Farmers some- times destroy the newly hatched "hop- pers" when occurring in grass land or a field in any crop by plowing, beginning at the outside and working into the center of the field. Many are buried hi the furrows. Ditches two feet wide and two feet deep may form impassable barriers in the line of their march. If there is water in the ditches, the surface should be oiled. Before grasshoppers become winged, hop- perdozers are used effectively. Figure 213 illustrates details of structure of a hop- perdozer. See also figures 70 and 71. Flocks of turkeys in the field do much to reduce the numbers of this pest. Coopera- tion among farmers when the grasshoppers first appear is not only desirable but very necessary. A poison spray, quite successfully used, is made as follows: Arsenite of soda, 3 pounds; molasses, 1J/2 gallons; water, 180 GRASSHOPPERS 195 gallons. Fifty gallons of this is sprayed over an acre. The material costs about thirty to fifty cents per acre. Insects partaking of this poison appear to be paralyzed and die in from twelve to thirty-six hours. No injurious effects are noticed among animals eating foliage thus sprayed (Fig. 214). Poisoned bran mash may also be scattered about where cattle and chickens have not access to it. It is found useful hi portions of the West and South. It is made as follows: two pounds Paris green, twenty-five pounds bran, two gallons cheap molasses. Mix FIG. 214. — Spraying for grasshoppers. the Paris green with the dry bran, moisten with water, and stir in the molasses. This mixture should be about the consistency of chicken feed and should be broadcasted over infested fields in the evening or early hi the morning, before sunrise. The United States De- partment of Agriculture recommends the following as an effective bait : Mix one pound Paris green with twenty-five pounds of wheat bran. To two quarts of cheap molasses or syrup add the juice of two oranges or lemons, as well as the finely chopped skin and pulp of the fruit; dilute this with two gallons of water and add it to the poisoned bran. Add enough more water to make a stiff dough. This is to be spread as above indicated. 196 INSECTS AFFECTING FIELD CROPS Joint Worms. — The different species of this group, Isosoma, are four-winged flies. They live through the winter as larvae or pupae in cells in the stem of wheat and some other grains. The adults emerge in spring after the young grain hag thrown up stems so that several joints have become exposed. The female places her eggs in these stems and the larvae feed within, becoming full grown by the time the straw is hardened. They pass the winter in the cells thus made. Injury. — This is a serious pest in the wheat regions west of the Mississippi River. The damage varies from being slight to a total loss of the entire crop. ' Swellings and other malformations arising from the presence of this insect often occur in infested straw. Such straw is brittle and woody. By cutting off the sap supply from the head, worms prevent the filling out of the kernels. The wind also breaks down these brittle straws. At threshing time its presence is shown by hard bits of straw containing larvae appearing in the threshed grain. Control. — The following suggestions are not always applicable; a farmer must select such as are practicable for the circumstances existing on his farm : Fields should be worked into the best possible condition before seeding. Sow as early as possible, and use early- maturing varieties. Fields should be well fertilized, thus inducing rapid and vigorous growth. Practice rotation of crops. Plow under or burn stubble in late fall. Burn all infested straw which has not been fed or used by the last of April. INSECTS ATTACKING CLOVER AND ALFALFA The Clover-seed Chalcid. — This tiny, four-winged fly (Bruco- phagus funebris How.) is sometimes erroneously referred to as a "weevil" by farmers. It deposits its eggs in the young seeds. This gives rise to a tiny grub, which devours the entire contents of the seed. It may also enter larger seeds. It transforms from the larval form to the pupal form within the seed (Fig. 215). Injury. — This insect has been so destructive in places that the raising of clover for seed has been abandoned. In clover-raising sections of Minnesota the depredations of this insect cause an annual loss of many thousands of dollars. The clover itself is not injured by its work. Affected seeds are more or less misshapen or undersized and can, for the most part, be detected in the mass of seed offered for sale. Control. — Cut the hay crop while heads are still green to pre- vent the maturing of the pest and the consequent attack on ths CLOVER ROOT-BORER 197 seed crop. As is very evident, cooperation among farmers in the neighborhood is very necessary. These recommendations apply to medium red clover, not to mammoth clover, since in this variety the first cutting is utilized for seed. One should also cut all volun- teer red clover along roadsides and fences, and all waste about the huller should be swept up and destroyed, since many of the in- fested seeds are separated out by the huller. FIG. 215. — Alfalfa-seed or clover-seed chalcis fly: a, adult; b, larva; c, pupa. Much enlarged. (Urbahns, U. S. Bu. Ent.) The Clover Root-borer. — The adult insect is a reddish-brown beetle (Hylastinus obscurus Marsh) about one-eighth of an inch long. These insects hibernate in the clover roots, beginning their work in the roots when warm weather begins. Eggs are deposited along the sides of the burrow in the spring. Frequently, however, they are laid on the crown of the plant and sometimes even at the sides of roots two or three inches below the ground. Fre- quently the larvae feed in the excavation made by the mother, but soon start burrows on their own account. By the middle of summer 198 INSECTS AFFECTING FIELD CROPS most of them have become full grown and pass into the pupal stage. The second brood of beetles appears in the fall, not leaving the plant, however, until the following spring. The dispersal of these insects takes place in spring; the beetles then fly about seeking uninfested plants. Injury. — The tap roots of Mammoth and Common Red Clover are sometimes seriously injured by this insect, while alsike is not so subject to attack. Since alfalfa in Europe has been injured, we may expect ultimately to have the same trouble here. The first- year clover is exempt from attack on account of the small size of the roots. Control. — Wherever possible, summer fallow the soil as soon as the first cutting of the crop is removed. This dries out the roots and starves the larvae. Fields of clover should not stand in clover more than three years. Scientific rotation of crops is also desirable. The Clover Hay Worm* (Hypospygia costalis Fab.). — This caterpillar attacks hay in the stack. It interweaves the hay with white silken webs mixed with black particles of excrement, giving the hay an appearance of being mouldy, and reducing much of it to chaff. Such hay is not attractive to stock. Description. — The caterpillar is three-fourths of an inch long when full grown. It is dull brown in color, and may be found in barns throughout the winter, pupating in the spring. The moth is rather striking in appearance, with whig expanse of one inch. The silky wings are tinged with purple above, margined with yel- low, and fringed with orange. There are two large, conspicuous, golden spots on each fore-wing. Control. — Old hay is more apt to be attacked than the new crop. Therefore, farmers are advised not to keep hay over a second year. Feeding the hay to stock will cause the young cater- pillars in infested hay to perish before the new crop comes in. Hay-mows should be cleaned out each spring, and one should never place new hay on top of the old. It is suggested, further, that new stacks of hay be built at some distance from the old. All refuse from old stacks or the bottom of the hay-mow should be burned. Stacks should be raised above the ground on a foundation of logs or rails so that the bottom may be kept fairly cool and dry. These caterpillars are more active where there is warmth and moisture. It is further suggested that hay be salted on the bottom of the stack or mow, using about two quarts of salt to every ton of hay. Blister Beetles (Macrobasis unicolor Kby. and Epicauta penn- BLISTER BEETLES 199 sylvanica DeG.)- — The first named of these beetles is grayish in color, and the second shining black. These beetles are striking in appearance, have rather long legs, with a somewhat elongated thorax or neck (Fig. 216). The bodies are long, straight-cut, and are said to cause blisters when crushed on the skin. A near rela- tive found in Europe is known as the " Spanish fly" and is used in medicine. The adult beetle emerges in the spring. Injury. — Occasionally these beetles are extremely injurious to leguminous plants, although they may be regarded as general feeders. They work also on sugar- beets, potatoes, various flowering plants, and trees and shrubs. Benefit. — These insects have the redeeming feature that when hatched the small, long-legged larvae imme- diately run about searching for grasshopper eggs in the field. Upon these they feed. A little later the skin of the larva is shed, together with the long legs of the first form of larva, and we find them in the second stage possessing very short rudimen- tary legs. This form is found in grass- hopper nests feeding upon the eggs. Control. — These beetles are quite resistant to arsenicals, but can be driven off of a crop by applying Paris green or arsenate of lead sprays. When occurring on trees, they may be jarred off on sheets and destroyed by being thrown into kerosene. This same method may perhaps apply in the case of some other plants if the attack is not too general. The usual arsenical sprays applied to potatoes will serve to keep them in check upon these plants. A mixture of arsenate of lead, three pounds hi fifty gallons of water, if sweetened with cheap molasses or syrup, makes a fairly effective spray. When alfalfa or other crop is seriously attacked, any remedial measure, to be effective, should be applied at once. Alfalfa may be sprayed with arsenicals as above indicated, in which case more than one application may be necessary, and the sprayed portions should not be used for hay. FIG. 216.— A blister beetle. 200 INSECTS AFFECTING FIELD CROPS Dean suggests, the field may be " beaten" with branches by a line of men or children, driving the beetles before them to the edge of the field where rows of dry hay or straw have been pre- viously placed. The insects will run beneath these rows for shelter and may then be destroyed by burning. The Alfalfa Caterpillar (Eurymus eurythene Boisd.). — The sulfur-yellow butterfly producing the alfalfa caterpillar is common practically over the entire United States and the southern part of Canada. It is an insect familiar to almost all young collectors. The wing expanse is about two inches. Description. — The black band on the wings of the female is more or less dotted with white, these dots being absent in the male. There is a prominent black dot in the center of the fore-wing, and a pale yellow spot in the center of each hind-wing in both male and female. Life History. — The small, spindle-shaped eggs are laid on green alfalfa. These hatch into dark-green worms, about one inch long when full grown, with a light stripe on each side, inter- rupted by black and red dots. The chrysalis is greenish yellow, and is attached, head up, by two threads to a stalk of alfalfa or to weeds and grasses. The winter is passed in this stage. It probably has two or three broods. Injury. — This insect is extremely abundant in the West where large fields of alfalfa occur, and it is a serious pest to this crop. This is particularly true in California, Arizona, and other parts of the Southwest. Enemies. — A contagious intestinal disease, resembling some- what in effect flacherie of the silkworm, may be in part responsible for keeping this butterfly in check in portions of California and Arizona (Circular 133, U. S. Bureau of Entomology). The caterpillar is preyed upon by Tachina flies and by hymenopterous parasites. The cotton boll worm is also said to attack it. Control. — Pasturing the affected fields is recommended. Also, keep the soil in the best cultural condition. Irrigate frequently, and immediately after the crop has been cut and the hay removed. Renovate by disking. Cut the alfalfa close to the ground, and cut earlier than the general rule. Always cut a few days before it is in blossom, Turkeys and chickens, if allowed to run in the fields, will reduce the number of caterpillars. Cooperation on the part of all farmers in an infected district is necessary. CORN LEAF APHIS 201 INSECTS ATTACKING BEETS The Beet Aphis. — This louse (Pemphigus betce Doane) is found in clusters on the small rootlets of the sugar beet, and is very destructive in some of the Pacific Coast states. Infested beet plants fail to make normal growth, and the beets become soft and spongy. Small rootlets are attacked, cutting off the plant food supply. A plant badly infested indicates its condition by wilting of the leaves, and if the plants are small they may die as a result of the attack. Life History. — Several generations occur in a season, and wdnged individuals appear from time to time. These winged forms are usually found in the fall, at which time they fly to cottonwood trees and give rise to true sexual forms. After mating, the female deposits a single winter egg in a crevice of the cottonwood bark. In the spring this egg gives rise to a louse, which forms a gall on the cottonwood. A single generation of lice are produced in the galls. These are all winged and migrate to beets, weeds, and grasses, there giving birth to young, which descend to the roots and start new colonies of winged viviparous females. Control. — But few measures of control are known. Scientific rotation of crops is advised, and it is suggested that root crops be not grown on the same land year after year. INSECTS AFFECTING CORN AND SUGAR CANE A number of insects affecting the corn crop are treated under other heads. The corn ear-worm eats into bolls of cotton and is called also the cotton boll worm. (See page 218.) It also bores into the fruit of tomato, and attacks corn in the silk. The chinch bug is a serious enemy of corn, wheat, and other crops. (See page 191.) The Corn Leaf Aphis. — This plant louse (Aphis maidis Fitch), like most others of the family, has both winged and wingless forms. The wingless lice are pale green in color, and the winged lice are black and green (Fig. 217). They appear in midsummer, at which time they may be found on young corn leaves, where they continue until cold weather. Injury. — This insect is rarely injurious, but heavily infested leaves turn yellow or red and may shrivel and die, especially in dry weather. Control. — Numbers of insect parasites help to control it under normal conditions, 202 INSECTS AFFECTING FIELD CROPS The Corn Root Aphis. — These are bluish-green lice (Aphis maidi radicis Forbes) found on the roots of corn, from which they suck the sap. Description and Life History. — The species is dependent upon colonies of small brown ants, Lasius niger americanus Em. The ants carry the eggs into their nests, bringing them into the sun- light on warm days and carrying them below the frost line in cold weather. The young are carried by the ants to suitable weeds until the corn gets up, when the ants transfer them to the corn. The lice multiply very rapidly, living young being produced by the females. There may be a dozen generations during the season. C Fio. 217. — The corn leaf-aphis, winged and wingless females and nymph. (After Forbes.) In some broods winged individals occur, and these migrate to new fields. Corn is not the only plant damaged, for squash, pumpkin, strawberries, cotton, etc., may be attacked and become stunted and lack color in consequence. Control. — Plow and harrow in the fall to break up nests of ants. Keep fields clear of weeds to deprive lice of food in the spring. Rotation of crops should be practiced. Thorough cultivation and proper fertilization are desirable to induce vigorous growth. The Sugar-cane Beetle. — This is a robust black beetle (Ligy- rus rugiceps Lee.) about one-half of an inch long, with stout, coarsely spined legs. Eggs are laid in the ground on weakened or decaying roots. The grub burrows in the stalks of corn and sugar cane (Fig. 218). The corn is usually killed. Injury occurs early in the growing season. The grub pupates in the fall, the [Y WOl 203 Rotation beetles hibernating in winter in the soil of the fields. One genera- tion is produced annually. Control. — Practice spring plowing and cultivation, of crops and clean cultivation are advised. The Western Corn Root Worm. — This worm or grub (Dia- brotica longicornis Say) is two- fifths of an inch long. It is slender, and is whitish or yellowish, with a black or brown head. It produces a small, greenish beetle one- fourth of an inch long (Fig. 2 19). Life History.— The beetle lays its eggs in the soil of corn fields in the fall and then dies. The winter is passed in the egg stage, the eggs hatching after corn is planted hi the spring. After that time until fall the grubs are found at the roots of the corn. The beetles, in late summer and until cold weather appears, are found on or about the silk of corn and on late summer flowers, such as thistles, golden-rod, and red clover. They disappear at once on the advent of cold weather. Injury. — By mining hi the main roots of the corn, the worm checks the plant's growth and may cause its death. Control. — Practice crop ro- tation. Corn planted the year following another kind of crop will not be injured. The Army Worm. — The full-grown caterpillar of this species (Heliophila unipunda Haw.) is nearly two inches long. It is either of a dark gray or dingy black color. It has three narrow, yellowish stripes above and a smaller, darker one at each side. FIG. 218.— The sugar-cane beetle. (U. S. Bu. Ent.) 204 INSECTS AFFECTING FIELD CROPS It closely resembles some of the cut-worms and is, in fact, a member of that family. The moths are among the most common of the so-called " millers." The front wings are clay or fawn colored, speckled with black scales. The hind-wings are somewhat lighter, with blackish veins and darker margins. Life History. — There are two or three broods a year. The winter is passed in the larval stage. The moths first appear in early spring. The female lays from ten to fifteen eggs at a time near the unfolded bases of the leaves of grass. One female may FIQ. 219. — The western corn-root worm, egg, larva, pupa, imago. (After Forbes.) lay seven hundred eggs. Ten days are required for hatching and from three to four weeks for the larvae to become full grown. When mature, the caterpillars enter the ground, transforming into pupae, and the adult moths emerge in two weeks and immediately lay eggs for the next generation. Injury. — As their name indicates, these caterpillars frequently travel in large numbers in search of food. They feed entirely at night, and whole fields of corn or other grain may be destroyed before their presence is realized. Grasses form their favorite food, and the heads of grasses are frequently cut off. Various garden crops are also injured. Clover, however, appears to be almost ARMY WORM 205 FlU. 220. — The erratic array worm, caterpillars, motha, and pupa. (Lugger.) 206 INSECTS AFFECTING FIELD CROPS immune; it is, however, eaten if found in the line of march. Figure 220 illustrates a closely allied form. Control. — Various parasitic two-winged and four-winged flies attack it. Barriers may be constructed to check its march. These are described in connection with another form of army worm, and also in connection with remedies advised for chinch bugs. Deep fall plowing and thorough harrowing will help to destroy hibernating larvse. Where safe and feasible, burn the grass along fence rows and hedges or waste places where larvse normally live. A strip four feet wide across their line of march, dusted or sprayed with Paris green or other arsenical poison, may be effective. When gathered in furrows plowed to check their march, they may FIG. 221. — Wire worm and "click beetle be destroyed by spraying with pure kerosene or crude petroleum, or straw may be placed over them and burned. Whatever remedy or remedies are chosen by the farmer, prompt action is necessary in order to save certain crops. Wire Worms. — The adults are known as click beetles (Fig. 221) or snapping beetles, from the fact that if they are placed upon their backs they recover their normal position by a quick contrac- tion of muscles, causing the forceful moving of the thorax upon the abdomen, which is accompanied by a clicking sound. They are from one-half to three-fourths of an inch long. They are brown, brownish gray, or black in color. Their larvse, called "wire worms," are slender, cylindrical, hard, shining brown or yellow grubs, about three-fourths of an inch long (Fig. 222). WIRE WORMS 207 Habits. — Native sod or old pasture land is the natural home of these insects, and for the first two years after sod, crops should be chosen, whenever possible, which are not attractive to wire worms. The worst damage occurs in the second year after planting grass land in grain, and it is believed that from three to five years are required for the life cycle of the various species. The last year of the larval stage is passed in a small cell, where it transforms to a pupa. Injury. — There are many species of these insects (Elateridce) . They attack a large variety of crops. The seed of corn suffers, as does also the seed of cot- j.— ^^^••r""' ^i ton and young cotton plants. Young wheat plants, pota- toes, turnips, young corn, and many garden and farm crops are attacked. The worst damage occurs in the case of corn. Control. — Suitable crop rotations, early fall plowing, and thorough cultivation are recommended. As a rule, legumes are not injured by these insects. It is therefore wise to include a legume with the rotation. Land should not be allowed to lie in a grass crop several years. On a small scale when occurring in kitchen gardens, these grubs can be trapped by pieces of potato put on short sticks and buried near plants that are threatened. Summer fallowing, where possible, is desirable, for it keeps all growth which might serve as food off the field. Any farm practice which is practical and which will stimulate early growth is recommended. This enables plants to better withstand attack. For example, the early planting of corn in the southern states, followed by frequent cultivation, is good. Corn should not be planted two years in succession on the same ground, par- ticularly if the field is infested. Corn or other grain crop following sod is likely to suffer from wire-worm attack. FIG. 222.— Wire worms. (Enlarged.) 208 INSECTS AFFECTING FIELD CROPS Southern Corn Root Worm, Bud Worm, or Drill Worm.*— The larva of this beetle (Diabrotica 12-punctata Oliv.) is particularly injurious to corn in the South. Plants are weakened and die from its attack. There are probably three or four generations in the southern states. Eggs are laid at the base of the plant and hatch in a few days. The grubs at once burrow into the stalks, at the surface of the ground or just below it. Even if an infected plant does not die, it will not, in all probability, produce marketable ears. Control. — Intelligent crop rotation and fall plowing are the only practical remedies. In rotating crops, cotton may follow or precede corn, as may most of the grasses and many vegetables. Since this insect attacks curcubits, such as melons, squash, pump- kins, and cucumbers, they should be kept out of such rotation. It also attacks beans, and hence these should be prohibited in any rotation plan. An excessive amount of seed in each hill would probably insure the proper maturing of some of the stalks. Late planting and the draining of bottom lands used for corn are recommended. The Angoumois Grain Moth. — This moth (Sitotroga cerealella Oliv.) is about one-quarter of an inch long. It is brownish or buff colored with fringed wings. Its grub is white and somewhat smaller. The original infestation occurs in the field, where there may be as many as three generations. These generations are continued in the corn crib, granary, or seed-house. The larvae in infested kernels are brought in with the harvested grain. Injury. — In different parts of the country, notably in the South, stored corn and other grains are infested with the larvae of this moth. Its work is first made apparent by the appearance of tiny holes in the kernels, and the entire contents of the kernel may be destroyed, thus rendering it useless for seed or market. Control. — -Corn with the husk on is not so liable to be attacked. Hence, corn husked late in the season, after the advent of cold weather, and stored in cribs will suffer but little. Corn and other grains, however, stored in seed-rooms or in bins early in the season may deteriorate during fall and winter, owing to the continued work of this pest. Such grain should be watched, and upon the first appearance of the pest or upon indications of its presence, the grain should be fumigated twice, or, if necessary, three times, at intervals of two weeks. Use six pounds of bisulfid of carbon * See page 218, under insects attacking truck crops; also page 217, rice insects. CORN BILL BUGS 209 to every one thousand cubic feet of space, because this insect requires intensive fumigation. (See fumigation methods, Chapter VI.) Corn Bill Bugs, or Curlew Bugs. — These are weevils or snout beetles, and are of wide distribution. One species is slate colored, about three-quarters of an inch long. Another is only one-quarter of an inch long and black in color (Fig. 223). In a general way the life history of the many species is the same. Life History. — After hibernating in rubbish they lay their egg usually on the roots of rushes or sedges. Grubs or larvae hatched from these eggs are white, with brownish or blackish heads. Fia. 223. — Two different species of corn bill bugs. Injury. — They often injure corn, particularly if it is planted on low, sedgy land, by eating into the tissues of the plant, thus caus- ing the elliptical holes seen when the corn leaves are unfolded (Fig. 224). A southern form of bill bug is restricted in its range to the more southern states. Control. — Early planted corn in the South (March and April) shows less injury than the same crop when planted later. Rota- tion of crops, generous fertilization, good drainage, late summer or early fall and winter plowing, are all advised as methods of control. Plowing, in the case of grass land or recently cleared 14 210 INSECTS AFFECTING FIELD CROPS lowland, is an important measure. It is well, however, not to follow sod or newly cleared swamp land with corn, but to plant flax, potatoes, or other truck crops the first year. Swamp or grass land infected with bill bugs may be burned over. The Corn Ear-worm. — The caterpillar of this moth, which belongs to the family of cut-worms, is also known as the tomato fruit-worm, tobacco-bud worm, cotton boll worm, etc. (Heliothis obsoleta Fab.). It gives rise to a dull olive-green or yellowish moth, about three-fourths of an inch long. The caterpillars them- selves are variable in color; they are generally striped, but the ground color may be light green or rose color or brown or almost black. When full grown they are nearly one and one-half inches long. Life History. — The moth lays eggs for the first brood on corn, peas, beans, or almost any avail- able food plant. In from three to five days these eggs hatch and the caterpillars of the early broods attack the corn when it is about knee-high. They feed in the axils of the leaves. It requires two and one-half weeks for them to reach full size, at which time they burrow from two to five inches in the soil, at the base of FIG. 224. — Details of injury to corn plant the plant. The pupa is four- by bill bugs. „ f, , . , , , . . fifths of an inch long, shining reddish brown in color, and it gives rise to the moth in about two weeks, making its complete cycle in warm weather in something over one month. It may have three broods in favorable lati- tudes. Winter is passed in the pupal stage. Injury. — The caterpillars of the second and third generations feed upon the silk of the corn ears, and eat out the kernels at the end of the cob, furnishing favorable conditions for moulds which may do further injury. It is estimated that the annual damage in the United States WHITE GRUBS 211 (See from this insect alone is something like fifty million dollars, page 223, under, cotton insects.) Control. — Land should be plowed in the late fall in order that the pupae may be turned up to be subjected to the variations in weather, and where it is practicable and hi line with good farming the land should be harrowed. The early plantings of corn gener- ally escape injury, since corn passes the silking stage before the moths of the second brood appear. Caterpillars of the first brood may be killed by applying a soray of arsenate of lead — two pounds FIG. 225. — May beetle or "June bug"; larva or white grub pupa and adult. (After Linville and Kelly.) to fifty gallons of water. This will not injure the plant tissue. Better still, powdered lead arsenate may be dusted into the funnel of the young plants. Spraying the silk with a mild poison is now being tried with some success in killing the young caterpillars of the second and third broods. Dusting the young silk with poison is sometimes tried successfully. White Grubs. — These destructive grubs sometimes feed on the roots of corn. For the life history and an account of injury, see page 135, under insect pests of berries and grapes. Sod land is the natural home of this insect. It should be plowed early in the fall to destroy the pupae and tender adults. 212 INSECTS AFFECTING FIELD CROPS Crop rotation is, of course, advisable, as is also pasturing with hogs. Figure 225 illustrates the different stages; and two eggs, much enlarged, are shown in Figure 226. These eggs are laid in sod. The Stalk-borer (Papaipema nitela Gn.). — This moth lays its eggs in the autumn upon ragweed, dock, and other plants which are normally the food of its larvae. The young larvae climb to the leaves and first mine small galleries in the leaves. When the leaves are riddled, they work down the bases and enter the stalks. After one plant is de- stroyed, the worm may migrate some dis- tance and attack another. Infested plants wilt above the point of injury. This pest is sometimes noticed in corn and is entered as a corn pest. FIG. 226. — Eggs of May Control. — Clean farming is the best method of control. Weeds in the vicinity of the garden should be destroyed by removal and burning in early spring. The insect has many parasitical enemies, and the injury is largely local in nature. Infested plants should be promptly destroyed where practicable, to prevent the migration of the worm to another plant and thereby increase the damage. Little trouble will be experienced in fields that are clean. TURNIP INSECTS Field and garden turnips are frequently infested with plant lice. No practical remedy is available, as kerosene emulsion can- not easily be sprayed on the under side of the leaves. Parasites help to keep them in check. The cabbage maggot is also a turnip pest. BARLEY, TIMOTHY, RYE, AND GRASSES These crops are all injured to a greater or less extent by in- sects described under other heads and in all cases the treatment is practically the same as that already given. See corn and small grains. On timothy one frequently finds the false chinch bug (Trapc- zonotus nebulosus Fab.), often mistaken for the true chinch bug, since it has the same bedbuggy odor. It also resembles it some- what in coloration and belongs to the same family. Timothy is rather seriously injured by this bug, which is, generally speaking, a feeder upon weeds. TWO ONION MAGGOTS 213 INSECT PESTS OF SUGAR BEETS Flea Beetle (Disonycha xanthomelcena Dalm.). — This is a small black flea beetle which, with its larva, eats holes in the leaves of beets. The adults hibernate, laying eggs on the crown of the plant in the spring. Plants so affected may be dusted or sprayed with arsenate of lead. INSECT PESTS OF THE ONION Onion Thrips. — A very small insect belonging to the order Thysanoptera (Thrips tabaci Lind.). Description. — Adults and larvae eat the epidermis of onion leaves, causing them to wilt, turn white, and die. FIG. 227. — The onion maggot. FIG. 228. — Tritoxa flexa. Control. — Tobacco extracts afford the best spray for this pest. Three-quarters of a pint of nicotine sulfate in one hundred gallons of water, with four or five pounds of soap added, is recommended by the Cornell Station. Three sprayings should be given at inter- vals of four or five days. Weeds should not be allowed to grow about the edges of the field. Two Onion Maggots. — One of these maggots (Pegomyia cepa- rum Bouche) (Fig. 227) is a common pest of the onion, causing the leaves to yellow. As a result of its attack, the plant generally dies. Tritoxa flexa (Fig. 228) gives rise to a maggot which may also work in onions. Control. — Old, infected fields should not be used for onions; rotate the crop and thus avoid this enemy. The poison spray 214 INSECTS AFFECTING FIELD CROPS recommended for cabbage maggot, page 232, can be well used against onion maggots, which closely resemble cabbage maggots in appearance and life history. INSECTS AFFECTING HOPS The Hop Plant Louse (Phorodon humuli Schr.). — The hop louse, which was introduced from Europe about the time of the Civil War, is light green in color. The summer is passed on the vine and both winged males and females migrate to plum trees in the fall, where wingless females are produced and fertilized by the males. Eggs are then deposited upon the twigs of plum and in axils of buds. The " stem-mothers " hatch from these eggs in the spring, giving rise to two or three broods of wingless viviparous females (Fig. 229) before winged migrants are produced. The mi- grant flies to the hops and continues to bring forth females asexually until the fall. In warm parts of the country it has been shown that this louse may remain the entire year on the hop, and some may stay on the plum during the summer. It will be noted that in a general way this aphis follows the same general rule, as regards reproduction, that is observed in connection with other plant lice. For further information on the reproduction of In- plant lice, see page 14. Injury. — This is probably the most seri- ous pest of hops. The hop plant louse not only draws the sap from the vines, but by exuding a "honey dew," which drops to the leaves below, coats the surface of the leaves with a glistening film, which affords an excellent medium for the growth of a fungus, giving to the vines a dark, blighted appearance. Control. — Where this pest is abundant, spraying with whale-oil soap, quassia chips, or with tobacco extract gives relief if done thoroughly and before the lice become too numerous. After the leaves are curled as a result of their attack, it is much more diffi- cult to hit them with a spray. A solution of quassia chips is made by soaking eight pounds of chips in sufficient water to cover them, for a few days; then boil for about one hour; add one hundred gallons of water and five pounds of whale-oil soap. If the latter FIG. 229. — Hop-plant louse, female. (From sect Life.") RICE WATER WEEVIL 215 cannot be obtained, soft soap may be used. Nicotine sulfate, one part to three thousand parts water and four pounds of whale-oil soap in every one hundred gallons of spray, is effective. Fish-oil soap may also be used in place of whale-oil soap, if the latter is not procurable. Red Spider (Tetranychus gloveri Bks.). — Brownish, shrivelled, and dropping leaves, or spotted, discolored, and imperfect cones, on hops indicate the presence of a small mite called red spider. The loss occasioned by this pest may run as high as fifty dollars per acre. The adult and eggs of this species are found on the under side of the leaves. The winter is passed on vegetation adjoining the fields. Reproduction is rapid and injury to plants severe. Control. — Fall plowing and doing away with weeds and other vegetation which offers winter food and shelter should be prac- ticed. Particular attention should be given to weeds at the edges of fields. The sprays recommended for the hop aphis are advised for the control of this pest, particularly the use of nicotine sulfate with soap. Several applications should be made. A soap solution alone, consisting of one pound of soap to two gallons of water, is also effective if used at the very first appearance of the insects. This is also a cotton insect. (See page 221.) RICE INSECTS Rice Water Weevil or Rice Root Maggot (Lissorhoptus simplex Say). — The adult weevil is gray in color and only about one-eighth of an inch long. It may be seen swimming either on the surface or below. The eggs, barely visible to the naked eye, are deposited upon the roots or in the mud. The larvae or maggots, according to Hood, are found in the rice fields in from one to three weeks after turning on the water. Two broods may appear in one season. The winter is passed in the adult stage (Fig. 230). Injury. — This is the principal insect enemy of rice plantations ; it also attacks wild rice, feeding as a larva on the roots, at which time the least injury is inflicted on the plant. The adult snout beetles feed on the leaves. The vitality of the plant is thus weak- ened and its bearing qualities impaired. After attack the leaves turn yellow and the plant wilts. In addition to rice, this weevil is known to feed upon water lilies and other aquatic plants, and possibly upon a few grasses. Rice growing in running water does not suffer. Control, — Draining the rice field completely will kill the larvae. Fio. 230. — The rice water- weevil: a, rice plant showing injuries; b, scars made by larva on section of root; c, section of rootlet showing feeding scars; d, water line; e, e, e, roots severed by larva; /, injured leaf; ;', enlarged section of injured leaf; g, adult beetle, dorsal view, much enlarged; h, antenna; i, larva side view, much enlarged; j and A;, details of struc- ture of larva. (Tucker, Circ. 152, U. S. Bu. Ent.) STORED PEANUTS 217 The ground so drained should be allowed to dry. This should be done before a large number of the plants have become weakened. Tucker (U. S. Bureau of Entomology, Circular 152) recommends alternate flooding and drying. Freeing ground, by cultivation, of all weeds and grasses, and doing away with depressions and dead furrows, is desirable. Rice Stalk Borer, or "White Blast."— The caterpillar of this insect (Chilo plejadellus Trinck) bores in the rice stem. This attack causes the head of the infected plant to die and become light colored, hence the term "white blast." Control. — It is recommended that one should burn over the fields in whiter, destroying all volunteer rice, weeds, etc., on the edges of the field. If this is not practical, cut all volunteer weeds and rice close to the ground, taking them away from fences, and burning them in a safe place. Rice Grub (Chalepus trachypgnus Burm.). — The adult insect is shiny black, two-thirds of an inch long. The larva is white. Overflowing is recommended as the best remedial measure. Corn Root Worm. — J. B. Garrett, of Louisiana, says he has seen whole fields of rice ruined by the southern corn root worm (Diabrotica 12-punctata). See page 240 for a discussion of this insect. Drowning out by flooding is recommended for this pest. Enemies of Stored Rice. — Attacks on stored rice are made by the rice weevil (see page 347) and other mill and warehouse insects. All of these are controlled to a greater or less extent by fumigation. Rice held in cold storage will escape attack. Termites or white ants (Termes flavipes) are said, by Garrett, to sometimes attack stored rice. PEANUT INJURIES DUE TO INSECTS Stored Peanuts. — Many of the tender shells of peanuts are broken by machine handling and by the workmen climbing over stored sacks. This invites the attack of the Indian meal moth, described under mill insects, page 349. One or more of the flour beetles, saw-tooth grain beetles, and others also attack stored peanuts. These insects all yield either to the "heating method" or fumi- gation. The heating method consists in tightly closing all openings in a storeroom or warehouse and keeping the temperature at from 120 to 125 degrees F., but not above the latter figure, for eight or ten hours. When this method is not available, fumigation with 218 INSECTS AFFECTING FIELD CROPS hydrocyanic acid gas or with bisulfid of carbon may be employed. (See page 61.) A species of aphis works on the roots of peanuts. This calls for crop rotation ; the same land should be used for peanuts only once in four or five years. (U. S. Farmers' Bulletin 356.) INSECTS ATTACKING TOBACCO Southern Tobacco Worm. — This sphinx moth (Phlegethontius sexta Johan.) is perhaps the most destructive insect with which tobacco growers have to contend. In the larval stage it is a green worm with seven oblique, whitish lines on each side. It is about two inches long when full grown. On the posterior end of the body is a prominent horn. It pupates slightly below the surface of the ground. It emerges as a brownish moth with a few white dots at the base of the front wings. There are two broods. The winter is passed in the pupal stage. The Northern Tobacco Worm. — This closely resembles the above species and has practically the same life history and yields to the same treatment. In the caterpillar stage it is a voracious feeder and destroys an enormous number of plants. The two insects cause an annual loss of nearly nine hundred thousand dollars in the southern states. Enemies. — Several insect parasites attack tobacco worms, and the common skunk eats both larval and pupal forms. The caterpillars are also attacked by fungous and bacteriological diseases. Control. — Three sprayings with arsenicals, preferably arsenate of lead, or dusting the plants with powdered arsenate of lead is recommended. When powdered arsenate of lead is used it should be applied in the early morning, when the leaves are wet with dew. It will be effective until washed off by frequent or copious rains. All traces of this insecticide on leaves at harvest time should be removed by spraying with water after sunset. Picking by hand may be practiced where help is abundant and cheap. Hand-picking among growers is perhaps more popular than treatment with arsenicals. Bud Worm, Cotton Boll-worm, or Corn Ear-worm. — In the South this moth sometimes lays its eggs in the buds of tobacco, the worm feeding upon the tender, unopened leaves. When treat- ment is necessary, dusting the buds with cornmeal poisoned with Paris green has been found most effective. About two teaspoon- THE " SUCK FLY " 219 fuls of Paris green should be mixed with a quart of cornmeal. (See also page 210.) The "Suck Fly." — In spite of its name, this insect (Dicyphus minimus Uhl.) (Fig. 231) is a true bug, and has in recent years become quite troublesome to tobacco growers. FIG. 231. — The so-called "suck fly": o, b, c, nymphs in different stages; d, adult female; «, head and beak from side; all figures much enlarged. (L. O. Howard, U. S. Bu. Ent.) Life History. — The insects are found on both sides of the leaves, affecting the under side of the nymph or imperfect stage. The eggs are said, by Quaintance, to be deposited singly within the tissue of the leaf and they require about four days for hatching. The entire cycle of one generation is completed in about fifteen days. 220 INSECTS AFFECTING FIELD CROPS Injury. — Leaves of the second crop of tobacco are injured by this pest sucking the sap from the leaf tissue, causing it to yellow and rendering it nearly worthless. Control. — Tobacco extracts applied by spraying both upper and lower surface of the leaves appear to give the best results. The strength to be used is given on the containers. Early application at the very first appearance of the insects is desirable. Tobacco Leaf-miner or "Split- worm." — The adult of this insect (Phthorimola operculella Boisd.) is a small moth whose wings measure about one-half an inch from tip to tip. The female lays its eggs upon the leaves, and the small caterpillars bore into the body of the same, causing discoloration and sometimes a mis- shapen leaf. The gray blotches due to the miner in leaf tissue have been thought by some growers to be a disease and have been referred to as " weather rot." The caterpillars do not remain con- stantly between the upper and lower surface of the leaf, but may emerge and, after crawling about the surface, enter at a new place. Control. — Destruction of all leaves made worthless by the pres- ence of the insect is advised. Destruction of all weeds in the spring, particularly horse nettle, upon which the insect feeds, will do much to reduce its numbers. Tobacco Flea Beetle. — This small brownish beetle (Epitrix parvula Fab.) is abundant in almost all tobacco-growing districts in the United States. When abundant its attacks cause the leaf to exhibit small dry spots, which grow larger, and eventually the leaf becomes full of small holes. These afford entrance to fungous diseases. Eggs are laid at the base of the plant, and the young grubs feed upon the roots. Plants of the nightshade family are attacked also. Control. — All weeds, especially those belonging to the night- shade group, should be kept off the ground. Particular attention should be given to the edges of the field, fence rows, etc. Clean cultivation is most important. Cut-worms. — Several species of cut-worms attack tobacco. These are generally well controlled by the use of a poisoned bran mash made by mixing Paris green and bran until the latter is decidedly green in color ; then add water and sweeten with molasses or syrup just before using. This bait may be placed in a ring around each plant and a short distance from the plant, or small amounts placed at frequent intervals among the plants. Care should be taken not to place this bait too close to a plant, for bring- RED SPIDER 221 ing the Paris green into contact with the roots through the agency of rains should be avoided. The bait is best placed in the field at sundown in order that it may not become dried by the sun before night, which is the chosen feeding time of cut-worms. Other insects which at times injure tobacco are: The cabbage plusia, grasshoppers, white flies, and crickets. Naked snails or "slugs" are at times injurious. The so-called cigarette beetle works on stored tobacco and is combated by fumigation with car- bon bisulfid. INSECTS AFFECTING THE COTTON PLANT The Cotton Boll-weevil. — Undoubtedly this dark-gray snout beetle (Anthoncmus grandis Boh.) is one of the most destructive insects in America. Introduced from Mexico about 1891, it has gradually spread over nearly the entire cotton belt in the southern states, causing annually a loss of several million dollars. As the name indicates, it works in the bolls of cotton, in which it lays its eggs. Several broods occur in a season (Fig. 232). Control. — Of all remedies and methods of control which entomol- ogists and growers have tried, the best, if not the only dependable means, consists in early planting, or in the use of early varieties, or in both factors. These are coupled with the use of fertilizers and thorough cultivation in an effort to hasten the maturing and ripening of the crop. Plants should be placed at least four feet apart. This allows the sunlight to reach infested squares which have fallen to the ground, and kills some of the young larvae therein. The burning or plowing under of infested plants before winter will destroy the quarters where the adults try to hide for winter. Intelligent crop rotations are also recommended. Red Spider (Tetranychus bimaculatus gloveri Bks. Harvey). — Although this is called "red spider," the females may vary in color from red to yellow or green or dark brown. In the South the whiter is passed on weeds or cultivated plants, notably the violet, the mites migrating thence to young cotton plants. Injury. — This mite, which goes under different specific names and attacks a large variety of plants, 'may cause an immense amount of damage to cotton (Figs. 233 and 234) (ree related spe- cies, page 215). In 1912 it occasioned the loss of about three hundred and ninety-four thousand dollars in South Carolina alone. Basing estimates upon these figures, it is probable that "during a severe red spider year the Southeast may suffer a loss of two FIG. 232. — The cotton boll-weevil: 1 and 2, adults; 3, egg; 4, grub at beginning of second stage, about three days old; 5, full-grown grub about ten days from the egg; 6 and 7, two views of the pupa; 8, adult with spread wings; figures 3 and 4, enlarged about 20 diam- eters; all other figures enlarged 10 diameters. (Hinds, Ala. Bull., 188.) COTTON BOLL-WORM 223 million dollars through the ravages of this pest" (U. S. Farmers' Bulletin 735). Control. — Destruction of weeds in the winter, and spraying or destroying beds of violets where the mites occur if such beds are near cotton, are recommended. Wide spacing of cotton plants and pulverizing the surface of the ground which renders migration difficult are advised. Spraying compounds which have been found efficient when applied to weeds and other plants are as follows : (a) One pound arsenite of soda in twenty gallons of water. This is very effective, but it is a deadly poison, and care should be taken that animals do not have access to poisoned plants. (6) One ounce of cyanide of potassium in two gallons of water. This is also a deadly poison. (c) One gallon of flour paste in twelve gallons of water. Whatever spray is employed, there should be two applications, with an interval of seven or eight days between them. Figure 235 illustrates a convenient spraying outfit for treating weeds. The Cotton Worm.— The moth producing this worm (Alabama ar- gillacea Hubn.) is migratory. Win- tering in the most southern districts it moves northward in the Spring. It Dearly all leaves, squares and bolls have \ been shed. (McGregor, U. S. Bu. Ent.) is an interesting fact that it has of recent years been found in states far north of the cotton belt. The caterpillar feeds upon the cotton leaves. The pupal stage is passed upon the leaf. The insect passes the winter in the adult condition. There are several broods. Control. — Dust the leaves of cotton in the early morning with powdered arsenate of lead. Cotton Boll-worm. — The caterpillar of this moth (Helioihis obsoleta Fab.) eats both leaves and boll. It has several broods. It also attacks tomatoes and corn. (See page 210 for full discussion.) Control. — Late fall plowing, early spring planting, and crop rotation are recommended. Dusting leaves with powdered arse- nate of lead when the young larvae first appear is also advised. (See page 210, under corn insects.) 224 INSECTS AFFECTING FIELD CROPS •if FIG. 234. — A severe example of red-spider work in a cotton Leld. (McGregor U S Farmer Bull., 735.) FIG. 235.— Portable barrel pump for application of arsenate or other herbicide to weedy borders. (U. S. Farmers' Bull., 735.) QUESTIONS 225 Other Insects Injurious to Cotton. — Other insects attacking cotton are the cotton wire-worm, the cotton root-louse, the cotton stainer, page 182, and the pink boll-worm. The last is a newly introduced pest, which bids fair to be very injurious. QUESTIONS 1 . Give the life history of the Hessian fly and methods of control. 2. Describe and give the life history and control measures for the chinch bug. 3. Discuss the wheat-head army worm and compare with the common army worm. 4. Give habits, life history, and remedial measures for grasshoppers. o. Name, in order of relative importance, the insects affecting alfalfa and give life history and remedies for the first three named. 6. What are wire worms and why are they especially destructive and hard to combat? 7. What are three of the most injurious enemies of corn in the South? 8. Give life history of the hop plant louse. 9. Name two leading pests of rice. Give life history and control measures for each. 10. Name three important insects affecting cotton and give remedial measures for the same. 11. Do the sarr.e with tobacco insects. 12. Describe and give the life history of theAngoumois grain moth. How is it injurious, and what means of control are recommended? 13. Which crop is the greatest sufferer from the chinch bug, wheat or corn? 14. What insects are most destructive to field crops in your section? 15 CHAPTER XIII INSECTS AFFECTING TRUCK CROPS AND THE VEGE- TABLE GARDEN IT is difficult to sharply separate truck crops from field crops. It will be noticed that corn insects are treated in the preceding chapter on insects affecting field crops. Insects attacking onions, tobacco, turnips, and beets are likewise considered there. Irish potato and sweet potato insects are treated in the present chapter. Potato Insects The Colorado Potato Beetle. — This well-known beetle (Lep- tinotarsa decemlineata Say) and its larvae are so familiar that they need no description. The adult beetles hibernate below the surface of the ground, appearing on the plants in the spring, soon after reaching the potato plants. They lay their eggs on the under sides of the leaves. These eggs hatch in something less than a week, the larvae passing through four stages and requiring about three weeks to complete their growth. They pupate below the surface of the soil and occasionally upon the leaves. The pupal stage requires from one to two weeks. The egg-laying period lasts about five weeks, and the broods consequently overlap each other. We therefore find all stages upon the plant at the same time (Fig. 236) . The female beetle lays from five hundred to one thou- sand eggs, these eggs being placed in masses of from nine to thirty- five eggs each. It may be mentioned here that the so-called "old-fashioned potato beetle" (Epicauta sp.) sometimes occurs on potatoes. Control. — The young larvae can be killed by a spray of one pound of arsenate of lead in twenty-five gallons of water. As they get older, however, it is more difficult to poison them, and the adults are particularly resistant. Therefore, in order to make the poison more effective, it is advised to use one pound of Paris green, two pounds of arsenate of lead, and fifty gallons of water for all forms. Arsenate of lead is preferable to Paris green alone, since potato foliage is susceptible to injury. Several applications of the spray during the season may be necessary ; it should be used 226 COLORADO POTATO BEETLE 227 whenever the beetles are observed to be destructive. The old-time remedy of knocking the beetles into a pan in which there is a little kerosene is practicable for a few hills. In treating potatoes for fungous diseases and potato beetles at the same time, it is recom- mended that arsenate of lead be combined with commercial lime- sulfur diluted in volume to one part lime-sulfur hi eighty parts of t*TWi-' f.-M,- FIG. 236. — The Colorado potato beetle, different stages ; also two blister beetles. (Lugger.) water, at the rate of two pounds of arsenate of lead to fifty gallons of the lime-sulfur solution. Or use one pound Paris green in twenty-five gallons of the Bordeaux mixture. Potato beetles are subject to Tachinid parasites, and one or more bugs feed upon the larvse. The quail and the rose- breasted grosbeak appear to be fond of this unpleasant insect, 228 INSECTS AFFECTING TRUCK CROPS The Garden Flea-beetle. — These small, shiny, black beetles (Epitrix sp.) are frequently seen upon potato vines and are hard to control. They attack not only potatoes but also tomatoes, egg-plants, beans, peas, clover, etc. Injury appears first as white spots on the upper sides of the leaves. Control. — Plants thoroughly sprayed with arsenicals are appar- ently not injured as much as untreated plants, although this beetle is quite resistant to poisons. Air-slaked lime dusted on FIG. 237. — External view of potato, FIG. 238. — Details of work of potato- showing work of potato-tuber moth. (After tuber moth: a, section of tuber, showing eye Chittenden, U. S. Bu. Ent.) and eggs deposited about it; 6, egg in out- line; c, side view of egg; d, f, vines of larvze in potato; a, natural size; b, c, greatly en- larged; d, somewhat reduced. (After Ililey and Howard.) infested plants we find to be quite effective. This flea-beetle hides on the under sides of the leaves, and one can knock many of them off into a pan in which there is a little kerosene by striking the plants with a brush or paddle. Bordeaux mixture is a good repellent. The plants should be sprayed with this when a few inches high. The Potato Tuber Moth (Phthorimcea opercuklla Zell). — The adult is a grayish moth with a spread of wing of about one-half IMPORTED CABBAGE WORM 229 inch. The female lays her eggs in leaves or stems, and the larvae feed within the tissues, also boring into the tuber, where the most serious harm is caused. It is to be noted that this injury occurs both in the field, while the tubers are yet in the ground, and while they are in storage (Figs. 237 and 238). Injury. — The quality and consequently the salability of the potato crop in some sections is at times seriously affected by this evidently introduced pest, particularly if the potato market in the early fall is slow, necessitating the holding of the tubers by growers. The insect occurs in California in abundance, in Washington, Texas and other southern and western states, and appears to be spreading northward. It is an enemy, but not a serious one, of tobacco also. (See tobacco insects.) Control. — Hogs turned into an infested field after removal of the crop will consume practically all tubers left therein, with the contained larvse. Infected potato plants, as well as weeds and all volunteer plants, should be burned. As in the case of many other insects, crop rotation is advised. Avoid having potatoes, tobacco, tomatoes, or egg-plants follow each other, since they are all host plants of this insect. Stored potatoes, if infected, should be fumigated with hydro- cyanic acid gas or bisulfid of carbon, using the latter at the rate of three pounds for every one thousand cubic feet of air space, and exposing to fumes in an air-tight house, or in bins, or in air- tight barrels for twenty to twenty-four hours. Use precautions against fire. This fumigation should be repeated two weeks later. In fumigating with hydrocyanic acid gas the cubical content of building, room, or receptacle must be determined and the dosage based upon that. (See page 61.) An expert should be consulted. CABBAGE INSECTS The Imported Cabbage Worm. — The adult of this insect (Pontia rapce Sch.) is the familiar white cabbage butterfly. The female has two black spots on each fore-wing — the male but one (Fig. 239, a and 6). Both sexes have a black spot on the anterior mar- gins of the hind-wings. The caterpillars are velvety green, about one or one and one-half inches long. They have a faint yellow stripe down the center of the back and a row of yellow spots on both sides. Life History. — The butterflies are seen early in the spring and summer, flying over the fields and depositing their yellowish eggs 230 INSECTS AFFECTING TRUCK CROPS * -KT l\ iv C sra ,?• , #' ' I ?^ FIG. 239. — Stages of the imported cabbage butterfly, a, b, c, d; zebra caterpillar and moth, e, f; the cabbage plutella, g, h, i, j, and its parasite, k. (After Lugger.) IMPORTED CABBAGE WORM 231 on the leaves of any food plant available. It requires about a week for the eggs to hatch, and the larvae grow rapidly. It requires about two weeks for them to attain their full growth. They then transform into chrysalids, which are suspended by threads of silk from the leaves of food plants. The chrysalid changes from being greenish at first to a light brown. In one or two weeks the butter- flies emerge. In the South there are from one to four or five broods each season. The last generation passes the winter in the chrysalid form among the old stalks and rubbish in the field. Injury. — This insect eats large, irregular holes in the leaves of cabbage, cauliflower, and related plants, and disfigures the heads of cabbage and cauliflower by deposits of excrement. FIG. 240.— Cabbage maggot: a, larva; 6, pupa; c, adult female; d, head of male; e, antennae. Hair lines show actual sizes. (After Riley.) Control. — Cabbages and cauliflower are not susceptible to injury by Paris green; hence, Paris green may be used upon cab- bages for this insect as strong as four or five pounds to fifty gallons of water without any injury whatever to the plant. A little soap, however, should be added to the water to enable it to spread over the leaf; otherwise the spray runs off the leaf like water off of a duck's back. There is absolutely no danger to human beings on account of spraying cabbages. In the first place, little or none of the poison gets inside the head, and it has been demonstrated satisfactorily that a person would have to eat several bushels of sprayed cabbages at one sitting in order to obtain enough poison 232 INSECTS AFFECTING TRUCK CROPS to cause serious results. This is self-evident. Cauliflower, when not headed out, may be sprayed with Paris green. These worms may also be reached by the use of poison bran mash, such as is prepared for cut-worms. White hellebore may be used as a poison, if timid gardeners fear Paris green. As additional measures children may be hired at a nominal sum to pick the caterpillars from the plants or to catch the white butterflies over a cabbage field. This pest is extensively parasitized. FlQ. 241. — Female cabbage maggot fly, much enlarged. (After Slingerland.) Figure 239 also illustrates the zebra caterpillar and its moth, and the cabbage plutella and parasite. The Cabbage Maggot. — The adult insect is a small fly (Pego- myia brassicce Bouche) resembling the house-fly, but it is smaller. Life History. — Eggs are laid abundantly during the spring, either upon the stalk or upon the ground close to the crown of the plant or upon the roots just below the surface of the ground — one egg being generally laid in a place. One fly deposits a large number of eggs, flying from one plant to another. The egg stage lasts from three to five days, and the life of the maggot is of about CABBAGE MAGGOT 233 three weeks' duration. The larval skin hardens at the end of that period, and the insect pupates either close to the stalk or two inches away. This stage lasts about two weeks. The fly has two or more broods (Figs. 240 and 241). It attacks the cabbage and cauliflower, also turnips and radishes, but cauliflower is its preferred food. The maggot tun- nels in the roots of the plants, causing those attacked (Fig. 242) to wilt and usually to die. Control. — Clean cultivation is helpful. Crop rotation is desir- able. Cabbages and cauliflower in a breezy location are not so FIG. 242. — A cabbage plant wilted down, as result of attacks of cabbage maggot. liable to suffer as those sheltered from the breeze. Plants hi sandy soil appear to suffer most. Seed beds in cold frames invite attacks of the fly, and young plants are often affected when transplanted; cold frames containing the cabbage or cauliflower plants should therefore be covered with screens in order to prevent the entrance of the fly. Old cabbage or cauliflower stalks should not be per- mitted to remain in the field over winter. Tarred paper disks are in some localities placed around the crown of the plant when it is set out, but these are not always practicable or effective (Fig. 243). Since the adult flies are, like the house-fly, attracted to sweet substances, recent experiments indicate that plants may be sprayed with a sweetened poisoned liquid, thus destroying them 234 INSECTS AFFECTING TRUCK CROPS before many of them have laid their eggs. Two different recipes for this poison spray are as follows: (a) 3 ounces arsenate of lead, 2^ pounds brown sugar, 4 gallons water. (6) 1/5 ounce arsenite of soda, ^ pint cheap molasses, 1 gallon water. It is not necessary to spray all the plants in a field. If an occa- sional row is treated, sufficient attraction is offered. Late planted cabbages are not so seriously affected as are early cabbages : Hol- land cabbage appears to be exempt. Applications to the roots are rarely very effective. The Cabbage Aphis or Cabbage Louse. — On the under side of the leaves of cabbage and other members of the mustard family : • FIG. 243. — Tarred paper disks applied to plants: a, correctly applied; 6, incorrectly. are frequently found, in summer, large colonies of these lice (Aphis brassicce Linn.). They are yellowish. Winged individuals appear from time to time and fly from one plant to another. The average length of life of each generation is about twelve days, and each wingless female gives birth to about forty young. In the fall winged males and females appear which mate and thus produce eggs for the next season's generations. Injury. — Plants are weakened by a constant drain upon the sap and are thus made unfit for use, even if they reach a market- able age. Control. — Practice clean cultivation and the destruction of all refuse of the year's crop in the fall. The curling of leaves protects the lice and prevents successful spraying, for any spray used must THE STRIPED FLEA-BEETLE 235 actually strike each aphid in order to destroy it. Wild mustard and shepherd's purse in the field should be destroyed. Young plants in the seed bed are often infested before transplanting; hence the necessity, as in the case of the cabbage maggot, for screening the cold frames with fine screens or cheesecloth. Young plants, if infested, may be dipped at their tips in a weak solution of soap in order to destroy the lice upon the leaves. If spraying is resorted to, nicotine sulfate may be used at the rate of one part of the extract to sixty-four parts of water. Or use whale-oil soap at the rate of one pound to six gallons of water. Or use any laundry soap at the rate of one pound to three gallons of water. These lice, like other species, are subject to extensive attacks by parasites. The Harlequin Cabbage Bug (Murgantia histrionica Hahn). —This is a shiny black or deep blue insect with brilliant red or orange markings. It is about one-half inch long and is more or less flattened. It is sometimes called " terrapin bug" on account of its shape and markings. The young bugs resemble the older ones closely, but have no wings (Fig. 244) . These bugs will prob- ably never be very injurious in the northern tier of states, since they are particularly a southern pest. Life History. — They feed on any of the mustard family of plants, but prefer cabbage. The adults live over winter in old cabbage stumps and in weeds and rubbish left on the field, and emerge in the spring. Eggs are laid on kale or wild mustard or other wild plants of the mustard family to which cabbage, radishes, and turnips belong. There are three or more broods. Control. — When once established, they are difficult to combat. Old stalks and leaves should be cleared up to remove from the field hibernating quarters. A few piles of brush may be left to attract the adults in the fall that they may be destroyed. A trap crop of kale or mustard may be planted early in rows through the field that is intended for cabbage. The bugs prefer kale to cabbage, and these trap rows can be sprayed when covered with bugs, using pure kerosene. The nymphs or young bugs may be killed with a whale-oil soap solution. Use one and one-half or two pounds of soap to a gallon of water; or use one part stock solution of kero- sene emulsion in six parts of water. Sprays, however, are not to be depended upon in this connection. The importance of killing the hibernating brood cannot be too strongly emphasized. The Striped Flea-beetle (Phyllotreta vittata Fab.).— This is a striking insect, one-tenth of an inch long or less. It is black, 236 INSECTS AFFECTING TRUCK CROPS with a broad, wavy, yellowish stripe on each wing-cover. Like other flea-beetles, it is very active and is hard to catch. The larval form is found in the roots of young cabbage plants. The female lays her eggs in openings in the root of the cabbage or other crucif- erous plants, near the crown. When the larva is mature it trans- forms into an earthen cocoon close to the plant, and in a few days the beetle emerges. Injury. — While the beetle eats the leaves of turnips, cabbages, etc., and is sometimes found on strawberries, its chief injury, perhaps, is inflicted through mining into cabbages, turnips, and radishes. It may occur in such numbers as to become a serious pest, causing considerable injury. FIG. 244. — The harlequin cabbage bug, different stages. (After Riley, U. S. Bu. Ent.) FIG. 245.— The striped flea-beetle. (U. Bu. Ent.) Control. — The adults may be controlled by dusting with helle- bore. It is also advisable to dust with air-slaked lime, soot, or ashes on foliage when beetles are present. The beetle and grub are shown in figure 245. The Zebra Caterpillar (Mamestra picta Harr.). — This cater- pillar is conspicuous on account of its striking colors. When full grown it is two inches or more in length. The body is yellow, with a black stripe down the back and another down each side. The head is red. The first generation feeds in early summer and the second in the fall. The species hibernates in the pupal stage. It attacks cabbage, spinach, celery, and peas. Control. — Hand-picking is the usual remedy, but it may be controlled by spraying with strong solutions of arsenate of lead or Paris green (Fig. 239, /). (See, also, colored plate.) THE STRIPED CUCUMBER BEETLE 237 The Diamond-back Moth (Plutella maculipennis Curtis). — This is the insect whose caterpillar riddles cabbage leaves with small holes. It is found upon the plants along with the green cab- bage worm. The moth which lays eggs producing these cater- pillars is yellowish above, and its wings, which are kept folded, are turned up slightly at the tips. The wings also bear a long fringe. The lower part of the folded wings is bronze brown. The caterpillar is one-third of an inch long and pale green hi color. It tapers toward each end, and is quite active. These caterpillars pupate in small cocoons of delicate silk lace-work, and the brown- ish pupa may be seen through the thin walls of the cocoon (Fig. 239). In winter-time the cocoons are to be seen on old cabbage stalks in the field or on stored cabbages. Control. — The remedies advised for the green cabbage worm also control this pest. INSECTS ATTACKING CUCUMBERS, MELONS AND RELATED PLANTS The Striped Cucumber Beetle. — This insect is destructive in both the larval and adult stages. The beetle (Diabrotica vittata Fab.) is slightly less than one-half of an inch hi length, and is FIG. 246.— The striped cucumber beetle. (U. S. Bu. Ent.) black with yellow stripes (Fig. 246). It lays its yellowish eggs in clusters upon the root of the plant, and the grub feeds on the root within the ground. The pupal period is passed in the soil, and the adults winter in rubbish and waste in the fields. Frequently one finds small mites upon these beetles, but evidently the mites use the beetles as a means of transportation, and it is doubtful whether they appreciably reduce their numbers. 238 INSECTS AFFECTING TRUCK CROPS Injury. — The adults feeding on plants opens the way for infection by fungous diseases. The presence of the larvae on the roots or in the stems is shown by the wilting of the plant. Both cucumbers and melons are attacked. Control. — Two tablespoonfuls of tobacco extract in one gallon of water, poured about each plant at the rate of a cupful to each hill, is excellent if done any time before the plant is seriously weakened by the larvae. This, as applied, costs from forty to sixty cents for each one hundred gallons. It should be done every four or five days, at the first appearance of the beetles. The appli- cation acts also as a stimulant for the plants. It is also advisable to protect young cucumbers and melons as soon as up with inex- pensive covers of cheesecloth placed over the plants in such a way as to prevent the attacks of the adult beetles. These net covers should be used as long as possible, that the plants may have a good start. Some planters sow the seed in rows rather thickly, and thin after the worst damage is over. The planting of an excess of seed, afterward thinning, is common practice. Air-slaked lime dusted on the young plants is excellent. This should be done while the leaves are moist with dew, and should be repeated as often as the dust is washed off. Arsenate of lead, four or five pounds to a barrel of water, affords a good spray. All old vines should be gathered and destroyed as soon as the crop is off the ground. This also applies to all refuse. The beetles are thus deprived of food and hibernating quarters, and this indirectly causes the death of many. The above remedies are applicable to melons and cucumbers as well as squashes and pumpkins. The Melon Louse (Aphis gossypii Glov.). — The wingless form of this louse is light yellowish or olive or even black in color. It is about one-fifteenth of an inch long. It is found on the under surface of leaves, which it causes to curl (Fig. 247). Tender- growing shoots are favorite points of attack. Winged individuals are developed whenever the lice are compelled, from lack of food or removal of crop, to seek new feeding grounds. Control. — Detect infested plants early and destroy them. Spray under the surface of leaves with tobacco extract. Fumigate with nicofume paper, using one sheet to a plant, in an enclosed space. Or fumigate with bisulfid of carbon, using one teaspoonful to each cubic foot of space, Plants may be enclosed within a THE CUCUMBER FLEA-BEETLE 239 light frame covered with oiled muslin. The under side of leaves may be dusted with pyrethrum powder. The Cucumber Flea-beetle (Epitrix cucumeris Harr.). — These tiny beetles occur throughout the United States and are found upon tomatoes and potatoes, as well as cucumbers, melons, and allied plants. When found in potatoes, the grubs mine in the Fid. 247. — Melon leaves curled by attacks of lice. (Chittenden, U. S, Bu. Ent.) tubers. The principal injury is done to the foliage by the young beetles, just after it is up in the spring. The leaves are riddled. A badly riddled leaf appears as if hit by a charge of bird shot, though sometimes the surface is eaten off at each feeding place. The beetles are black, one-sixteenth of an inch long (Fig. 248). They hibernate over winter in leaves and rubbish, and emerge 240 INSECTS AFFECTING TRUCK CROPS in the spring and lay eggs on the roots of common weeds of the nightshade family. The larvae of this brood live in the roots of these plants and later transform to beetles and attack foliage. Control. — Bordeaux mixture, combined with Paris green, or lime-sulfur combined with arsenate of lead, are perhaps the best sprays, acting as repellents, largely. Dusting with air-slaked lime is helpful. The Twelve-spotted Diabrotica or Southern Corn-root Worm. — These yellowish-green beetles (Diabrotica 12-punctata Oliv.), with twelve black spots on the back and a black head, are prac- tically omnivorous. They feed on a large variety of foliage and flowers, of forage and garden crops. Injury. — The larvae or grubs feed upon the roots of melons, cucumbers and allied plants. Plants frequently die as a result of attack upon their roots. In the South this is known as the "Southern Corn-root Worm," and it attacks the stalk of corn just above the roots. If it eats to the center of the stalk the "bud" will die; hence it is locally known as the "bud worm" (see page 208). Life History. — There are two generations. The beetles are among the first insects to ap- pear in the spring, and their life cycle, from egg to adult, occupies from six to nine weeks. Bu?i51t? They may be seei1 on clover or alfalfa in the late fall. Figure 249 illustrates the species. Control measures are the same as for the striped cucumber beetle. The Neat Cucumber Moth or Pickle Worm. — This worm, the larva of a yellowish-brown moth (Diaphania nitidalis Cramer), is three-fourths of an inch long. It is greenish or yellowish green in color, with a brown head. The larva bores into the stems and leaves of the cucumber. It takes about two weeks for a caterpillar to attain its full growth; it then spins a thin silken cocoon in a fold of the leaf. The pupal stage requires about a week, and the complete cycle lasts from three to four weeks in midsummer. The winter is passed in the pupal stage, either in the old vine left on the field or in other trash. Injury. — The larvae hatching from eggs laid on the blossoms usually feed in the blossoms, and six or more may be found in a single squash blossom at one time. Older caterpillars bore into THE SQUASH BUG 241 the fruit itself. This injury to the fruit causes decay. In some localities this insect is a serious pest to cucumbers, squashes, and melons. It destroys the blossoms, mines the stems, and bores into the ripening fruit. Control. — Since the injury is worse in late summer, it is ad- visable to plant early and also to grow early maturing varieties of the vegetables which this worm seeks. All litter on the field, including old vines, should be destroyed after harvest. Since these pests prefer to lay eggs on the squash, this plant may be used as FIG. 249. — The 12-spotted Diabrotica, different stages, details of structure and injury. Hair lines indicate actual size. (U. S. Bu. Ent.) a trap crop, if melons or cucumbers are to be protected. For example, one might plant rows of summer squash through cucum- ber or melon fields at an early date, planting every two weeks, so that some would be in flower during July. The flowers could be collected and destroyed with the contained larvae at frequent intervals. This method of control has been carefully tested and found to give almost complete protection to muskmelons. Arseni- cal sprays are of little value. When possible, change the location of plants each year. Collect and destroy badly infested fruit whenever it is observed. The Squash Bug (Anasa tristis DeG.). — The adult bug is a 16 242 INSECTS AFFECTING TRUCK CROPS rich brown or black insect, five-eighths of an inch long. It has a strong sucking beak and a small head. This insect attacks cucum- bers, melons and squashes, and is well known to most of our gar- deners (Fig. 250). The young, or nymphs, are grayish to black, and cluster in colonies. The orange or red eggs are laid in batches on the under side of the leaf. The adults hibernate over winter in the old vines. One brood is hatched in the northern states and two or three in the southern. The insect appears as soon as the vines are up. The eggs hatch in a few days after being laid. As a result of the attacks of the squash bug leaves curl, turn brown, and die. Control. — The egg masses may be destroyed. The young nymphs may be killed with kerosene emulsion. Use one part of the stock emulsion diluted with nine parts of water by volume. The adults may be trapped under bits of board where they hide. The vines should be destroyed as soon as the crop is off the ground, in order to kill the bugs not yet matured. Any contact spray is effective for adults. Growers should plant an excess of seed, and it is wise to protect young plants by coverings of some sort. Early in the morning, while still cool, the adults are more or less sluggish and may be hand-picked. The Horned Squash Bug (Anasa armigera Say) calls for the same measures of control. It is similar in general appearance and habits to the species above discussed. INSECTS AFFECTING BEANS AND PEAS Bean Aphids. — These small black plant lice (Aphis rumicis Linn.) may be observed crowded together in clusters on the tender tips of bean stalks and on the under side of the leaves. They also attack dahlias, dock, shepherd's purse, pigweed, snowball, etc. Winged forms appear during the season. Eggs are laid in the fall around buds of certain weeds and shrubs. In the spring the first generations multiply upon these plants and then separate to other FIG. 250. — The squash bug; a, mature female; b, side view of head and beak; c, abdominal segments of male; d, same of female; a, twice natural size. (After Chit- tenden, U. S. Bu. Ent.) BEAN APHIDS 243 common weeds, migrating in May or June to beans. Aphids mul- tiply during summer by giving birth to living young. Control. — The usual remedies applicable to other plant lice FIG. 251. — The bean maggot fly, different stages, and its work. (After Lugger.) may be used here if necessary. Whale-oil soap, one pound to five or six gallons, is probably safer than kerosene emulsion or laundry soap in the same proportion. One or two tablespoonfuls of nicotine sulfate in a gallon of water is an excellent and effective 244 INSECTS AFFECTING TRUCK CROPS spray for all lice. It should be used, if possible, in a way to hit the insects. The Bean Maggot or Bean Fly. — These maggots (Pegomya sp.) are about one-fourth of an inch long when full grown, yellow- ish in color, blunt at one end, tapering at the other. The change to the pupal stage takes place in the ground near the plant injured. In about a week the perfect fly, which closely resembles a house- fly, emerges from the puparium and works its way to the surface of the ground (Fig. 251). Injury. — This maggot bores in planted beans, and works not only in the seed but in the stem of the growing plant as well, thus causing it to wither and die. « 2 c FIG. 252. — Bean weevil and pea weevil. (After Brehm.) Control. — Rotation of crops and fall plowing appear to be the only available remedial measures. The Bean Weevil. — This is a small robust snout beetle (Bru- chus obtectus Say), brownish gray in color, with head bent at right angles to body. The wing-covers are shorter than the ab- domen.' Eggs are laid on the growing pods in the field, and the grubs enter the young beans, sometimes several in one bean. They continue their work in dry beans, rendering the same unfit for seed. This insect also attacks peas and occasionally other seeds. Control. — Infested seeds, for the most part, float on the water, while sound seeds sink. This affords a means of separating good from bad seed. A still better method is fumigation of the seed with bisulfid of carbon. Place the seed in a tight receptacle, THE ASPARAGUS BEETLE 245 pour the liquid upon it, and keep the receptacle closed for one or two days. No flame should be brought into the vicinity of bisul- fid of carbon. A tablespoonful of the liquid used in a two-quart jar full of seed is effective if the jar is closed tightly. Figure 252 illustrates both the bean weevil and the pea weevil. The Pea Weevil (Bruchus pisorwn L.). — This beetle is similar in general appearance and habits to the bean weevil. In color it is blackish, covered with soft brown hairs, and its back is marked with black and white. The adults appear in the field at blossom- ing time. The yellow eggs are laid on the pea pods, and the grub bores through info the seed. If undisturbed, the adult may re- main in the seed until spring. The same remedies as given for the bean weevil are applicable to this insect (Fig. 252). The Pea Aphis. — This is a large green louse (Macrosiphum pisi Kalt.) attacking peas. It has many natural enemies in the shape of parasites and predaceous insects. Since it passes the whiter on clover, it is suggested that peas, if possible, be not planted near clover. Otherwise control measures are practically the same as for the bean aphis. The blister beetles (page 198), so-called "old-fashioned potato bug," occasionally attack beans and may cause serious injury locally. INSECTS AFFECTING RADISHES Flea beetles of various species may justly be regarded as enemies of radishes. Their attacks may be controlled to some extent in the garden by the use of air-slaked lime or ashes. Cabbage Maggot. — The chief pest of the radish is the cabbage maggot, which tunnels in the roots. This insect has been de- scribed under Cabbage. The writer has secured immunity for his radishes by using a decoction of tobacco stems, and more recently by using nicotine sulfate solution, at the rate of two tablespoonfuls to a gallon of water. This solution is poured along the rows of plants when they are about an inch or two high, and is repeated once hi every five or six days until the radishes are nearly fit for table use. Early-sown radishes are not so liable to attack as later crops. Radishes, when young, may also be treated with the poisonous spray recommended for the cabbage maggot. The Asparagus Beetle. — This destructive insect (Crioceris asparagi Linn.) is one-fourth of an inch long. It is of a general bluish-black color, with yellowish wing-covers, marked on the 246 INSECTS AFFECTING TRUCK CROPS edges with dark blue. The thorax is red. The beetle is quite active and shifts its position around the stem when disturbed. The larva or grub is one- third of an inch long, grayish or olive hi color, with a shining black head. The winter is passed in the adult stage. The beetle emerges about the time that the asparagus shoots are ready for cutting. Later, eggs are laid on these shoots and on the older stems of the plant. Injury. — The young shoots and leafy tips of the asparagus are attacked by both larva and adult (Fig. 253). The shoots are rendered unfit for use, and the injury to the tips weakens the plants. Control. — Where this pest is injurious, one may obtain some relief by allowing a few stalks to grow up in the early spring and then poisoning them with Paris green or ar senate of lead. Air- slaked lime dusted on the larvae will kill them. Shoots should be frequently cut for table or market. INSECTS INJURING CELERY, PARSNIPS, CARROTS The tarnished plant bug attacks plants of this group (see page 84). The celery tree hopper attacks celery. Remedies for this insect are similar to those given for the grape-vine leaf-hopper (see page 164). Besides the three insects treated under this head, others affecting these crops are the parsnip web-worm and the parsnip leaf miner. FIG. 253. — The asparagus beetle and injury caused thereby. (U. S. Bu. Ent.) OTHER ENEMIES OF CELERY 247 The Carrot Beetle. — This is a brown scarabid beetle (Ligyrus gibbosus DeG.), a little more than one-half an inch long. It works upon carrots, celery, and parsnips, and also attacks corn, potatoes, and other crops. Adults are found attacking the crown or root of the plant below the surface. They are sometimes present in large numbers in a field of root crops. The work may be nearly destroyed without injuring the top of the plant. The larvae re- semble in miniature the familiar " white grub." Control. — Rotation of crops and fall plowing are the standard remedies. Hogs and chickens allowed to run in the infested field after the removal of the crop will lessen their numbers materially. Some success has been attained in combating other members of this family (Lachnosterna and allied genera) by the use of a lantern trap, to which they are attracted, early in the season before egg- laying begins. Manifestly such traps would be of little service after that period. The Celery Caterpillar. — The adult of this insect is the common black, swallow-tailed butterfly (Papilio polyxenes Fab.). The caterpillar itself is green or yellow, with black stripes, having re- tractile yellow horns placed a short distance back of the head. These horns are extended when the caterpillar is disturbed. In the northern states the winter is passed in the chrysalid (pupal) stage, the butterflies appearing in May. Eggs are laid on the foliage and hatch in from four to nine days. The young caterpillars are nearly black, with a white band around the middle of the body. The complete life cycle requires about eight weeks. The caterpillars feed on the foliage and undeveloped seed of almost all umbelliferous plants, including celery, parsnip, caraway, parsley, fennel, dill, and wild carrot, wild parsnip, as well as the garden carrot. Control. — Hand-picking is often all that is necessary. Spraying or dusting with arsenicals may be best for large areas if the insects are very numerous. The Carrot Rust Fly (Psila rosce Fab.). — Celery leaves some- times turn a reddish color, due to the attacks of this small insect, which belongs to the order Diplera, or two-winged flies. The roots are also discolored by the maggot which is often found in the roots of carrots. Clean cultivation after cropping is recommended, as well as rotation of crops. Celery should not follow carrots. Other Enemies of Celery. — Wire worms of several species sometimes injure celery, as does also the tarnished plant bug. 248 INSECTS AFFECTING TRUCK CROPS INSECTS -AFFECTING TOMATO Refer to tobacco insects in the chapter of field crop insects, as several of the tobacco insects also attack the tomato. See also treatment of the corn ear-worm, pages 210 and 218. The Stalk Borer. — More than one species of this genus of moth (Papaipema sp.) probably bores in the stalks of tomato, as well as in dahlias, lilies, and other garden plants. Its eggs are laid in the fall of the year on various weeds about the garden; the larvae hatch in the spring, and first feed as leaf miners and then burrow into the stalk of the plant upon which they were hatched. They may migrate to other cultivated plants. They pupate in the lower part of the stalk. Control. — Since the eggs of these insects are laid by the moths at the base of weeds, all weeds in the garden and in the vicinity should be destroyed late in the fall by burning. Further, the entire stock of weeds should be burned and not merely the tops. When a tomato plant is infested, it is shown by a drooping of the affected part of the plant. The affected shoot, if small, may be cut off, and the borer destroyed. If the worm is in a larger stem, a few teaspoonfuls of bisulfid of carbon may be injected into the opening with a medicine dropper and the hole plugged with cotton, wool, or soil to confine the gas. Too much bisulfid of carbon should not be used on account of danger of injury to the plant stem. See also Chapter XIV, page 256. INSECTS ATTACKING GINSENG Ginseng is attacked by white grubs, and the reader is advised to turn to the description of this pest, and study methods of pre- venting injuries. (See page 135.) RHUBARB INSECTS A plant of such rapid, vigorous growth as the rhubarb is natu- rally more or less exempt from injury on the part of insects. As a matter of fact, the rhubarb curculio is its most serious enemy. The Rhubarb Curculio. — This reddieh-brown snout beetle (Lixus concavus Say) is about three-quarters of an inch long. It injures the plant by making food punctures in the leaf stem and sometimes in the leaves. Eggs are deposited in the stems of rhubarb or in dock. The size and color of these insects make them fairly conspicuous, and they may be hand-picked from rhubarb and the weed above mentioned. TORTOISE BEETLES AND " GOLDEN BUGS " 249 The Rhubarb Flea Beetle. — This greenish flea beetle (Psyl- liodes punctulata Mels.) exhibits a preference for rhubarb, but it is also found on other vegetables. Its presence is recognized either by holes in the leaves or by brownish-yellow spots on the leaves. When necessary, one may resort to the usual remedies for flea beetles. (See page 228.) INSECTS AFFECTING SWEET POTATOES The sweet potato in most districts is quite free from insect attacks, as compared to many other truck crops. The sweet potato borer is perhaps the most injurious of the eight or ten pests which are found attacking these plants. The Sweet Potato Root-borer or Weevil.— This snout beetle (Cylas formicarius Oliv.) is known to occur in China, India, Australia, Madagascar, Jamaica, and Cuba. It was probably first imported into this country from Cuba hi shipments into Louisiana. It is a slender beetle, one-quarter of an inch long. It some- what resembles an ant. The general color is bluish black, with the pro-thorax brown. Injury. — The female eats cavities into the potatoes or into the vine at its base and deposits its eggs therein. The young larvae at first bore into the vine and later into the tubers. The pupal stage is passed within the tuber. Evidently this insect may con- tinue to increase and cause injury even after the potatoes are stored. Control. — No treatment is available while tubers are in the ground. Badly infested potatoes may be fed to hogs and the vines burned. Growers who receive potatoes from infested localities should fumigate them before planting. Use either bisulfid of carbon or hydrocyanic acid gas. (See page 61.) Tortoise Beetles and "Golden Bugs." — Several species of these insects, members of the family Cassidce, are fond of the foliage of the sweet potato. Of these, a very common form is the golden tortoise beetle (Coptocycla bicolor Fab.), the common name of which indicates its color. The black-legged tortoise beetle (Cassida nigripes Oliv.), however, is the largest of this group and the most injurious. The mottled tortoise beetle (Coptocycla signifer Feb.) is another member of this family affecting the sweet potato. Another is the two-striped sweet potato beetle (Cassida bivitata Say). 250 INSECTS AFFECTING TRUCK CROPS Description and Life History. — All tortoise beetles have ap- proximately identical life histories. The adults resemble some- what minute tortoises in shape. They originally fed upon weeds, particularly wild morning glories. The taste for cultivated plants is an acquired one. The leaves of the young sweet potato plants are attacked, and frequently the entire plants are ruined, requir- ing resetting. The eggs are laid on the stems and leaves. The larvse are less injurious than the adults. They are short, bristling creatures, with the disgusting habit of heaping their excrement on the top of their bodies by means of fork-like appendages on the posterior ends of the abdomen until they are nearly or quite covered and concealed from view. The pupal stage is passed upon the leaves, and the beetles hibernate in the adult stage. Control. — Dip young plants in a solution of one pound of arsenate of lead in ten gallons of water just before they are set out. This is perhaps the most efficacious means of control. A pint of molasses added to this makes it adhere better to the plants. This material may be sprayed upon the plants when they are first attacked. Cut worms. — These pests cut the young and tender plants shortly after they are set. They are controlled either by the use of poisoned bran mash, described on page 195, or by dipping the plants in arsenate of lead and water at the time of planting, as advised for the tortoise beetles. In case of severe attacks both measures might be advisable. Flea Beetles. — One or more species of this sort attack young sweet potato slips. One should use the same remedies as advised for tortoise beetles. (See page 249.) Saw Flies. — The larvae of these insects are the small slimy " slugs." They are not to be confounded with the true slugs or naked snails, which are mollusks. Two species are known to attack sweet potatoes and feed upon their leaves. Plants coated with arsenate of lead, as previously suggested, would be immune to attacks by this insect. Other insects which may attack sweet potatoes are sweet potato plume moth, the cucumber flea beetle, the sweet potato hawk moth, and, occasionally, crickets. PEPPER PLANT INSECTS The Pepper Weevil. — This insect (Anthonomus ceneotinidus) , quite injurious in Texas, was originally introduced into this coun- QUESTIONS 251 try from Mexico. It works in the pepper pod, causing distortion and rendering it unfit for food. It is in part controlled by gather- ing and destroying infected peppers which fall to the ground. EGG PLANT INSECTS Three enemies of egg plants have already been described under other heads. For the aphis, see melon aphis, page 238. For the potato tuber moth, see page 228; see also tobacco insects where it is referred to as " split worm." Potato beetles attack egg plants (see page 226). Flea beetles are often very serious enemies of egg plants. These are described among the potato insects. INSECTS ATTACKING OKRA Plant lice, leaf-eating caterpillars, leaf -hoppers, and a few other forms affect this plant, but not seriously. QUESTIONS 1. Give life history of the Colorado potato beetle. 2. What is the best insecticide for this beetle, and how applied? 3. What is the best treatment for flea beetles on potatoes? 4. Discuss the potato tuber moth and give remedial measures. 5. Give life history of the corn ear-worm. 6. Give description, life history, and remedies for the imported cabbage worm. 7. Why is soap used in the spray? 8. What injury is caused by the cabbage maggot? Describe its work. What crops are affected? 9. WThat are the best measures of control? 10. How should a cabbage grower treat a five- or ten-acre field badly affected with cabbage aphis? 11. Give life history of and control measures for the striped cucumber beetle in both larval and adult forms. 12. Give treatment for melon lice. 13. Give description and life history of the southern corn root-worm. 14. Enumerate the injuries caused by this insect and state treatment advised. 15. Give description, life history of, and control measures for the common squash bug. 16. How should we treat seed beans or seed peas if infested with weevils? 17. Give life history of the asparagus beetle. 18. Enumerate the insects attacking celery, parsnips and carrots. 19. Give remedial measures in each case. 20. How is the stalk borer combated when attacking tomatoes? 21. Enumerate the insects which attack sweet potatoes. 22. Give remedies in each case. 23. What insects attack the pepper plant and how combated? 24. What radical difference is to be noted between the treatment of the Colorado potato beetle and melon lice? Why? 25. Give accounts of damage from insects in gardens in your section. CHAPTER XIV INSECT ENEMIES OF THE GREENHOUSE AND HOUSE PLANTS, AND OF THE FLOWER GARDEN THE growers of flowers for home adornment, as well as the commercial florist, often make use of a greenhouse conservatory or of other indoor places for plants a part of the year. A number of insect enemies cause much trouble to these plants, either indoors or outside. In this chapter such enemies are divided into two groups: (1) those most troublesome inside, and (2) enemies of the flower garden. INSECTS OF THE GREENHOUSE AND ON HOUSE PLANTS Among the insects found in greenhouses occur one or more species of mealy bug, greedy scale, rose scale, white fly, green- house leaf roller, "red spider/' and various aphids or plant lice. Last, but by no means least, are sow bugs or wood lice. These are Crustaceans and not insects. The Destructive Mealy Bug. — These insects belong to the scale family, but, unlike most others in this group, can move about when adult. A mealy bug of this species (Dactylopius destructor Comst.) is one- eighth of an inch long and one-twelfth of an inch wide. It is brownish yellow below, and white with an indication of a median line above. A powdery secre- T tion covers the surface of the body. ^ The segments of the body are quite FlG' "^ distinct and a number of filaments are borne on the sides (Fig. 254). The male has two transparent wings, and has a wing expanse of less than an eighth of an inch. The body is dark brown and the eyes dark red. Life History. — The female begins to lay eggs before she is fully grown. The eggs are attached in a cottony mass at the pos- terior end of the abdomen. This egg mass increases with her growth. Since the end of the body is forced upward by the in- creased mass of eggs, the insect finally appears to be almost stand- 252 MEALY BUG WITH LONG THREADS 253 ing on her head. When the young hatch they spread in all direc- tions over the plant, generally settling along the midrib or on the under side of the leaves, or in the forks of the young twigs. They form closely packed colonies at first, and at this stage there is only a slight covering of the powdery secretion referred to above. Injury. — The mealy bug is a very troublesome pest in green- houses, for it attacks almost all plants. However, when the greenhouses are fumigated at regular intervals, these insects are rarely troublesome. Control. — Nicotine sulfate or whale-oil soap may be used. If only a small number of plants are to be treated, the pyrethrum decoction is to be recommended. FIG. 255.— The mealy bug with long threads, male. (After Comstock.) FIG. 256. — The mealy bug with long threads, female. (After Comstock.) The Mealy Bug with Long Threads (Dactylopius longifilis Comst.). — This bisect resembles the previous pest very closely except in technical details. The lateral filaments are seventeen in number and are quite long, and the last on each side is equal to or longer than the body. These filaments give the bisect its name. The female surrounds herself, when mature, with a cottony substance, amid which the young cluster for a time. The larval male forms a small cotton cocoon in which it pupates and from which the winged adult emerges. The transparent wings expand only one-tenth of an inch. Control. — The same remedies and methods of prevention are applicable to this bisect as to the preceding. Lady-bird beetles 254 INSECT ENEMIES OF THE FLOWER GARDEN are very efficient in holding both of these pests in check. Figures 255 and 256 illustrate the male and female of this species. The Greedy Scale (Aspidiotus rapax Comst.). — The female scale is one-sixteenth of an inch long, quite convex, and of a grayish color. The insect beneath the scale is bright yellow. Yellow eggs are found under the mature female, from which yel- lowish larvae soon hatch. These larvae are extremely small — at the time of hatching, one one-hundredth of an inch in length. FIG. 257.— The white scale. For a time they are able to crawl about, but soon settle and, after secreting a scale from their bodies, lose the power of locomo- tion. The females remain stationary; winged males emerge from the male scales, fertilizing the females, which deposit several hundred eggs or give birth to living young. This scale is nearly cosmopolitan in range, but is seldom very troublesome. The Common White Scale (Aspidiotus nerii Bouche). — This is a flat, whitish or grayish scale about one-tenth of an inch in diameter when mature. The male scale is smaller than the female and slightly elongated. It is white, tinged with yellow, one LICE ON PEAS, ROSES, AND GOLDEN GLOW 255 twenty-fifth of an inch in diameter. The winged males are minute, and are yellow, mottled with reddish brown (Fig. 257). In a general way the life history of this scale is identical with that of the other scales. The methods of control are practically the same as for the others. Palms, ferns, and other house plants affected with a few scales can be freed of these pests by the use of an old tooth-brush dipped in strong soapsuds to which tobacco extract has been added. The plants are afterward washed with pure water. The White Fly. — Scattering of powdered sulfur on hot water pipes or steam pipes of greenhouses, it is claimed, is more or less efficacious in exterminating the white fly and red spider. (See pages 46 and 67.) Plant Lice or Aphids. — These insects are generally controlled by fumigation with nicofume paper. Fumigation with cyanide of potassium or other approved agent is one of the best remedies for greenhouse pests, but it must be done understandingly and with proper precautions. (See page 64.) Sow Bugs or Wood Lice. — These small, grayish forms (Conis- cus) are not true insects. They are among the most troublesome of greenhouse pests. However, they may be easily controlled by a mixture of sugar and Paris green sprinkled along the edge of the boards forming the sides of the beds. This will attract and kill many. In fact, this seems to be the approved remedy. It is claimed that slices of young, juicy potatoes, sprinkled with Paris green and left in places frequented by the sow bugs, are also efficacious. (See page 44.) SOME INSECTS OF THE FLOWER GARDEN Lice on Peas, Roses, Golden Glow and other plants. — A small cake of ivory soap, or a similar quantity of good laundry soap, dissolved in five gallons of hot water and the solution sprayed forcibly against these insects, is effective in exterminating them. The spray will not injure delicate plants. Each louse should be hit with the liquid, and a repetition of the treatment may be necessary, for if even a few escape destruction the plant will very shortly become infested again. Tobacco extract, or nicotine sulfate, added to the solution, at the rate of two tablespoonfuls to the gallon, will increase its efficiency. A forcible spraying, frequently repeated with water from the garden hose, will wash lice off of sweet peas and other delicate plants. 256 INSECT ENEMIES OF THE FLOWER GARDEN Ants in the Lawn. — Colonies of black ants (Fig. 258), which build large nests sometimes a foot high, may be exterminated by the use of bisulfid of carbon. Make eight or ten holes at intervals over the nest, using a cane or any pointed stick of similar size, and push it in for eight or ten inches. Pour a tablespoonful of bisulfid of carbon into each hole, stop the opening with earth, and throw two or three burlap sacks or a piece of canvas over the nest to help confine the gas. Preferably the sacks should be wet. Leave them for twenty-four hours. Repeat if necessary. The small red ants which make tiny hills are sometimes trouble- some when abundant. Repeated hoeing and cultivation will discourage their work, as will also copious watering. If many small hills in a cluster impair the lawn, treat with bisulfid of carbon as recommended above for black ants. FIG. 258. — The common black ant, much enlarged. The Stalk Borers. — Golden glow, dahlias, hollyhocks, gaillardia, delphinium, asters, daisies, peonies, lilies, and sunflowers in the flower garden, as well as tomatoes and other plants in the vege- table garden, may suffer as a result of the attack of several species of borers belonging to the genus Papaipema. A drooping or wilt- ing tip or branch (Fig. 259) is generally an indication that just below the affected portion a hole in the stalk may be found from which protrude castings left by the caterpillar. This caterpillar excrement, wherever found, is proof positive of the presence of the pest, and a little searching will result in the burrow being discovered. Life History. — These moths (Fig. 260) emerge in late summer, WHITE GRUBS IN LAWN 257 deposit their eggs at that time on the stalks of weeds, such as giant bur elder (evidently the preferred food plant), ragweed, burdock, thistle, and others, close to the ground. The winter is passed in this condition, the eggs hatch in the spring and the larvae then leave their first food plant for garden plants in the vicinity. If a neglected lot or weedy field is close to a flower garden, the latter is quite sure to be affected, even if the garden itself is free from such weeds. Control. — Choice beds of lilies or other plants (or, if practi- cable, an entire flower garden) may be protected from attack by a six- or eight-inch board placed around the outside, the lower edge an inch or more below the surface of the ground ; this board to have on the outside a band of some sticky material like tree tanglefoot, which will remain sticky or can be kept so by repeated applications FIG. 259. — Tip of golden glow plant, wilting as result of attack of a stalk borer. during late spring and summer. This tanglefoot should be applied far enough above the ground to prevent its being spattered with earth during a rain. (See page 248 for other remedies.) Green Cabbage Worms. — These cabbage pests are sometimes found in destructive numbers on nasturtiums. If the white butter- flies which produce them are seen in flower gardens, one may expect nasturtium leaves to be eaten later. Hand-picking of the worms, which are found on the under side of the leaves, is perhaps the only practical remedy. White hellebore dusted generously over the affected leaves will lessen their numbers. White Grubs in Lawn. — Dead patches may appear in lawns 17 258 INSECT ENEMIES OF THE FLOWER GARDEN as the result of the work of these larvae, which eat the roots. Sod thus affected can be easily rolled up from the earth, as one would roll a piece of carpet, disclosing the grubs below. At least two years are required for these bisects to mature, and since their presence for the first year, on account of their small size, is not evident, a lawn rarely suffers for two years in succession. Robins are very fond of white grubs, and may frequently be seen pulling them from the sod. Copious watering where water is convenient serves to keep the grass growing in spite of their ravages. Fre- quent hoeing and cultivation about plants occasionally discloses grubs, which may be guilty of eating the roots and thus killing a plant. Lantern traps are sometimes employed (see page 49) to catch the adult beetles (June bugs) before their eggs are laid. Flo. 260. — Moth of one of the stalk borers, Papaipema nitela. Moles are also useful in this connection, as they destroy large numbers of grubs. Rose Chafers, "Woolly Bear" Caterpillars, and other Leaf- eating Insects. — All leaf-eating insects in the flower garden may be controlled with arsenate of lead, one-half pound to five gallons of water, but this insecticide will leave a white stain on the foliage. White hellebore dusted on the leaves when they are moist has not this objectionable feature. Lice on Roots of Asters. — Aster blight occurs on account of a disease and because of the presence of root lice. Frequent watering with weak tobacco extracts, poured close to the plant, holds lice in check. Use two tablespoonfuls of nicotine sulfate in one gallon of water. Asters call for a fairly rich soil, and it has been the writer's personal observation that where they get QUESTIONS 259 shade for half of the day they flourish better than when in full sun all of the time. If thrifty they may largely overcome the attacks of root lice. Leaf Bugs. — These destructive bisects (see page 148) kill buds both of asters and of dahlias. The best remedy known to the writer is frequent application of fine tobacco dust to the buds. Cut Worms. — Good tillage of the soil and the killing of worms when found are recommended. One should also encourage the presence of birds. Young plants, when set out, may be protected by "collars" of paper or cardboard or metal encircling the plant and inserted about three inches into the ground, care being taken not to enclose cut worms within the collar. Tablespoonfuls of poisoned bran mash (see page 195) may be placed at intervals among the plants in the flower beds. Slugs or Naked Snails in the Flower Garden. — While these are not insects, they nevertheless deserve attention here, since they sometimes eat the delicate leaves of flowering plants. Air- slaked lime dusted on the ground about plants is a good deterrent so long as it remains dry, and is very effective if applied directly upon the animals. Pieces of shingles or cabbage leaves or boards may be made use of as traps; the slugs will conceal themselves under them during the day. Slug Caterpillars on Roses. — These are true insects, the larvae of a saw-fly. Dust white hellebore on leaves, or add one ounce to a gallon of water and use as spray. Dusting with air-slaked lime is effective. QUESTIONS 1. Enumerate the insects which are most commonly found on house plants and in the greenhouse. 2. Which of these are you familiar with, in your experience? 3. Give remedies for mealy bugs, scales, and plant lice occurring on house plants. 4. Should Paris green or arsenate of lead be used against any of the above? State reasons for your answer. 5. Give remedial measures for each of the following insects of the flower garden: plant lice, stalk borers, ants, white grubs. 6. How are slugs or naked snails combated effectively? CHAPTER XV INSECTS AFFECTING SHADE TREES THE attractiveness of many of our towns and cities is due in large measure to the beauty of the shade trees in streets and parks. Occasionally insect depredations are such as to almost or quite denude these trees of their leaves or to cause their death. The object of this chapter is to discuss these pests and to offer either remedial or protective measures. The Box-elder Bug. — This is a bright-colored, black and red bug (Leptocorisa trivittata Say) familiar to many of our farmers. The red forms three broad lines over the black thorax, and the hard parts of the wings are edged with red. The adult bug, having passed the winter in this stage, lays eggs in the spring wherever it happens to be. Many of the young, hatched from the eggs, never reach their food. The insects are frequently found on the leaves and tender twigs of the box elder, which habit gives them their name. It may be seen, however, upon other trees and in various situations (Fig. 261). Control. — This being a sucking insect, it is difficult to control it by spraying. Villages and cities should own strong spraying outfits to protect their shade trees. In the fall, during cold days, the bugs collect in large numbers and become, for the time being, inactive. Such gatherings should be sought and the individ- uals killed with boiling water. However, the box elder bug is hardly ever sufficiently injurious to call for strenuous measures of control. Box Elder Plant Louse (Chaitophorus negundinis Thos.). — This is a green louse which may be a serious pest to box elders through sucking juices from the leaves and tender shoots, thereby causing them to wither and die. Eggs are laid in the fall and hatch before the leaves unfold. The lice gather about the opening buds and attack the leaves as soon as they open. Winged forms appear during the season to help dissemination. Parthenogenetic reproduc- tion is the rule during summer, males and females appearing in the fall. Eggs are then laid in the crevices in the bark and in the axils of the buds. 260 THE BOX ELDER GALL-FLY 261 The Box Elder Gall-fly. — This is a very minute, two-winged fly (Ceddomyia negundinis Gill) which lays eggs on the leaves FIG. 261. — Box-elder bug; male, female, and nymphs. (Lugger.) of the box elder. As a result the leaves form unsightly galls (Fig. 262) which interfere with the proper functioning of the foliage. Tiny maggots are found inside of the galls. Maple leaves (Fig. 262 INSECTS AFFECTING SHADE TREES 263) are subject to the attacks of these small flies (Fig. 264). Imperfect galls containing maggots are formed. The only remedy suggested is the picking off of affected leaves before the larvae become adult; destroy the galls containing the insects. The Bronze Birch Borer (Agrilus anxius Gory). — This borer is one of the most injurious and destructive of enemies to shade FIG. 262. — Insect-made galls on box elder. (Ruggles.) trees. The adult beetle is bronze-green or varies in color; it is about one-half of an inch long. Posteriorly there is a notch where the ends of the wing-covers come together. The larvse are small, flattened, footless grubs, creamy white in color, three-fourths of an inch long. The mouth parts are dark, and the small head may be partly drawn into the first segment of the body. Life History. — Hatching in June or July from eggs laid in crevices in the rougher parts of the bark, the grubs bore through the bark and at once begin to mine the sapwood (Fig. 265). The THE BIRCH LEAF SKELETONIZER 263 burrows are always packed with castings of the grub. It lives in the larval stage until the latter part of the following spring, trans- forming to a pupa within the burrow. A month later it changes to the adult form, and escapes from the tree in late June. Injury. — It then feeds on the leaves of trees. This insect infests all varieties of birch, and it is sometimes claimed that it attacks willows. Trees of large size are often killed by these borers within three or four years, and it is a common sight .to observe large birch trees dying from the top as the result of attacks from this insect. Control. — When this condition is observed, the only remedy practicable is to cut infested trees below the injured portion, FIQ. 263. — Imperfect galls on leaves of maple. Fia. 264. — Fly raised from galls on maple. taking pains to cut low enough to remove any portions infested by the grubs. These cut-off portions should be burned. This pruning should be done in winter or early spring. The Birch Leaf Skeletonizer. — This is a brown moth (Buccu- latrix canadensiella Cham.) less than one-half inch in length. The wings are crossed with delicate white bars. The green cater- pillar or larva has a brownish head; it is quite slender and tapers slightly toward the anterior and posterior ends. When disturbed, it may lower itself by means of a silken thread from the leaves. The cocoon is brownish or yellowish hi color and one-fourth' of an inch long. It is attached to the leaf or twig. This is a serious pest of the birch. It feeds on the soft parts of the leaf, leaving only the brownish skeleton. In late summer this injury is conspicuous. 264 INSECTS AFFECTING SHADE TREES Control. — Spray infested trees with arsenicals, preferably four or five pounds of arsenate of lead to one hundred gallons of water. FIG. 265. — Work of bronze birch borer. This is practicable if the trees are not too large. Even in the case of large trees, if valuable, bamboo extensions of spraying hose might be handled from raised platforms, THE ALDER "BLIGHT 265 The Fall Web Worm.— The adult insect is a white moth (Hyphantria cunea Dru.) with wing expanse of about one and one- fourth inches. The wings are slightly spotted with black. The pale yellow eggs, in clusters of a few hundred, are deposited on the under side of the leaves during the summer. About ten days are required for hatching. The young larvae are pale yellow with brown markings. These feed upon the leaves of various trees, and spin a pro- tective web as their feeding-ground enlarges, this nest enclosing the leaves (Fig. 266). The active larvae become full grown late in summer. At this time the cater- pillars are about one inch long and are covered with black and white hairs which project from numerous black tubercles. These caterpillars are somewhat vary- ing as to color; some are uni- formly yellow; others are almost white. They attain full growth in summer. After spinning light cocoons in the ground or under the bark or rubbish, they pupate and emerge as adults the following spring. The moth is a night flier. Control. — Cut away and burn branches containing colo- nies of caterpillars. Spray badly infested trees with arsenate of lead, using three pounds to fift}> gallons of water. Burn all rubbish on the ground beneath trees which were infested the previous year. Do this before the adults emerge in the spring and after their pupation in the fall. For- tunately many enemies tend to keep this pest in check. The Alder "Blight."— This is a woolly louse (Pemphigus tes- sellata Fitch) which receives the above name because of the fact that it secretes a honey dew which, falling on leaves beneath, creates a favorable condition for the growth of the blight fungus. The louse itself is dark in color, but is covered and hidden with a white, flocculent growth. It infests limbs and twigs of the alder, FIG. 266. — Nests of the fall web worm. 266 INSECTS AFFECTING SHADE TREES appearing in conspicuous and ^unsightly masses. It multiplies parthenogenetically, like other species of the plant louse family, during the summer, giving rise to winged migrants from time to time. The sexual forms occur in the fall upon the maple, at which time eggs are laid. The eggs are placed under loose bark "of the silver and soft maples. There is a hibernating form which descends to the ground and hibernates in rubbish, ascending the alders again in the spring. Control. — Kerosene emulsion is the best spray, since kerosene readily penetrates the waterproof waxy secretion which covers FIG. 267. — Cockscomb gall on white elm. the insects. Straw and leaves may be placed under the trees and later gathered and burned to trap the hibernating forms. Infested limbs should be cut off and destroyed as soon as noticed. The Cockscomb Gall. — This species of louse (Colopha ulmicola Fitch) causes a peculiar gall on elm leaves resembling a cock's comb. In a general way the life history of this insect resembles that of other aphids. The gall is about an inch long and one- quarter of an inch high. The sides are wrinkled perpendicularly and the summit irregularly gashed and toothed (Fig. 267). On the under side of the leaf the gall has a slit-like opening. Upon opening these galls, they are found to be crowded with lice and white flaky material. ANOTHER GALL OF THE ELM 267 The galls become dark with age. To a certain extent, these galls interfere with the 'proper functioning of the leaves and are unsightly. Nevertheless, the insects are not regarded as serious pests. Control. — The only practical remedy is to cut off galls when FIG. 268. — Gall on red elm made by a plant louse, Pemphigus ulmi fusus. FIG. 269. — Basswood leaf and fruit showing galls made by a two-winged fly. noticed on young trees and to burn them while still containing the lice. Another gall of the elm is that made by a plant-louse (Pem- phigus ulmi fusus Walsh) (Fig. 268). Basswoods also suffer from the attacks of gall-making insects (Fig. 269). 268 INSECTS AFFECTING SHADE TREES The Elm-leaf Beetle.— This beetle (Galerucella luteola Mull) is an importation from Europe. It is greenish yellow, with black stripes on the back. The eggs are yellow, bottle-shaped, and are laid on the under side of the elm leaves. The larvae are yellow, with black spots from which project small tufts of hair. Pupation takes place amid grass or litter on the ground under the trees affected. Injury. — The insect prefers European elms, and has been so FIG. 270. — The elm-leaf beetle, different stages, details of structure, and injured elm leaves. Hair lines indicate actual size. (U. S. Bu. Ent.) injurious to elms in the eastern part of the United States that municipal authorities have been obliged to hire gangs of men to save the trees by spraying (Fig. 270). Control. — The use of an arsenate of lead spray just as the grubs appear is recommended. The Elm Borer. — This handsome beetle (Saperda tridentata Oliv.) is grayish above. On each side of the thorax and on each wing-cover is a sub-marginal reddish or yellowish stripe. Fre- THE WHITE-MARKED TUSSOCK MOTH 269 quently there are two black spots on each side of the thorax and three on each side of the whig-cover. The larva is a footless grub a little over an inch long; whitish or yellowish (Fig. 271). Its life history extends probably over two or three years. Eggs are deposited in early summer. By burrowing under the bark the grub may girdle and kill the tree. A portion of an elm killed by this borer is shown in figure 272. Control. — To protect trees not infested, apply before May 1, and later repeat the application, a compound of thick whitewash containing crude carbolic acid. Use one quart of the acid to a pailful of whitewash. To fifty gallons of this wash add six pounds of arsenate of lead. This protective coat may be rendered inconspicuous by the addition of lamp-black, and should be applied FIG. 271. — The elm borer, larva, pupa, and imago, enlarged. with a brush to the trunk of the tree and to the lower portions of the branches. The White-marked Tussock Moth. — The caterpillar of this insect (Heterocampa leucostigma S. and A.) is strikingly beautiful. When full grown it is one and one-half inches long, hairy, with a pencil or brush of hairs like a horn on either side of its head and a smaller, median tuft near the tip of the abdomen ; it has four strik- ing white tussocks of hairs on the middle of the first four abdominal segments. The head is red; along each side of the black stripe down the middle of the back is a distinct yellow stripe (Fig. 273) . 270 INSECTS AFFECTING SHADE TREES The wingless female moth is somewhat spider-like in appearance and of a grayish color, while the male is dull gray, with several Flo. 272. — Tree in foreground killed by elm tree borer. 1\ A * I i | FIG. 273. — White-marked tussock cater- pillar. (After Riley.) FIG. 274.— White-marked tussock moth, male. (U. S. Bu. Ent.) dark gray lines crossing the fore-wings. It is about one inch in length (Fig. 274). Life History.— When full grown the caterpillar spins a yellow- THE VAGABOND GALL LOUSE 271 ish cocoon and attaches it to a tree or a fence or the side of a build- ing or a vine. A wingless female (Fig. 275) emerges therefrom in the spring and lays eggs in masses upon the silk of the cocoon. These egg-masses are covered with a white, frothy substance so that the individual eggs are obscured. They commence to hatch in a few weeks and continue until early summer, when some of the first hatched caterpillars begin to pupate. The moths from these pupse give rise, in some latitudes, to a second generation, which passes the winter as pupse. Injury. — This caterpillar is sometimes extremely destructive to the foliage of fruit and shade trees, and has been known to eat holes in the fruit of the apple. The destructive work of this insect is well shown in figure 276. FIG. 275. — Wingless female of the white-marked tussock moth. (Houser, Ohio Bull., 194.) Control. — Egg-masses should be destroyed when pruning the trees. If infestation is serious in any locality, trees may be banded with tanglefoot or any sticky substance to prevent the ascent of ohe larvae. Arsenical spraying when the larvae are hatching catches the first brood. Fortunately this pest is subject to the attacks of numerous parasites which have been at times a means of preventing serious injury. The Vagabond Gall Louse (Pemphigus vagabundus Walsh). —This insect forms unsightly galls on the cotton woods, but deserts these trees before the latter part of summer. The galls may be seen on the tips of twigs and become perfectly black when old. They do not seriously affect a tree's functions unless they occur in great numbers. 272 INSECTS AFFECTING SHADE TREES Clip off the galls, if possible, while green and burn them. No other remedial measures are suggested. The Cottonwood Scale. — These are small, papery, snow-white scales (Chionaspis salicis Linn.). The female scales are larger and more or less pear-shaped. They are found on the branches FIQ. 276. — Horse chestnut defoliated by first brood of larvae of white-marked tussock moth. (After Houser, Ohio Bull., 194.) of the cottonwood and some other trees. Eggs are laid under the female scale in the autumn. They hatch in early summer into small flattened, oval lice. These young lice are very active, spreading over all accessible branches. Like all lice, they weaken the tree by sucking the sap therefrom. Control. — Kerosene emulsion and whale-oil soap when the young are hatching form fairly effective sprays. The spray should be applied before the insects are protected by a scale. WILLOW SAW-FLY 273 The Willow Saw-fly. — This large saw-fly (Cimbex americana Leach) has a shining black head ; the body is steel blue, with three or four elongated, oval, yellowish spots on each side. The wings are smoky brown in color, and the legs bluish black with yellowish feet. The well-known larvae, when full grown, are three-fourths of an inch long, pale yellow or greenish hi color with a black stripe along the middle of the back. The head is large, rounded, and as wide as the body. When the saw-fly rests or is disturbed, it lies on its side and rolls its body (Fig. 277), a habit which distinguishes it from real caterpillars. Life History. — The female fly deposits her eggs below the sur- FIG. 277. — The willow saw-fly, caterpillar, adult, and open cocoon, d. Natural size. face of the leaf. The points where eggs are placed can be plainly seen on the under surface, being bluer than the rest of the leaf, and they become reddish with age. There may be from one to nine eggs on a leaf. The larvae, after hatching, remain within this blister-like structure for a time. In July and August they become full grown; they then leave the foliage and are found in tough, silken cocoons under the tree or shrub hi the ground just below the surface. They remain in this condition over whiter and emerge in spring. Injury and Control. — Although this saw-fly destroys the foliage of willows, poplars, and elms, and is recorded as attacking maples, lindens, and alders, it is not considered injurious and is 18 274 INSECTS AFFECTING SHADE TREES easily controlled by arsenical sprays. Of these, the safest is arsenate of lead. The Yellow-spotted Willow Slug. — This saw-fly larva is black or greenish black in color. It is a little more than one-half inch long, with heart-shaped, yellowish spots on each side of the body. The adult insect (Nematus ventralis Say) is brownish black marked with yellowish white. It is about one-third of an inch long. Injury. — -The first indication of the presence of these slugs is the blister-like swellings on the upper surface of the leaves. They have a wavy or crumpled appearance, due to the presence of eggs in the under surface. From four to eight days are required for hatching. These "worms" feed close together on the leaf, de- vouring it entirely, leaving only the midrib. Life History. — In ten days to three weeks the larvae become full grown, descend to the ground, where they form shining, dark brown cocoons composed of a glue-like secretion. In about a week the adult saw-fly emerges. Control. — Sometimes poplars and willows are defoliated by this pest, but it is easily controlled by any good arsenical poison. It is also attacked by Chalcid and Ichneumon parasites. The Mottled Willow Borer.— This is a snout beetle (Crypto- rhynchus lapathi Linn.) ,from one-third to three-eighths of an inch long, with a dull-black body. It is an imported species. Injury. — The white larva burrows around the buds and at bases of small stems, which latter it may partly girdle. The •injury is indicated on the willows by a purplish discoloration of the bark on either side of the burrow. The larva also bores into the center of small stems, making galleries one-eighth of an inch in diameter. It is reported as attacking willows, cotton woods, birches, and alders, and is perhaps as much a pest of the poplar as of the willow (Fig. 278). Control. — All seriously infested wood should be cut and burned in the early spring. Cottonwood Leaf Beetle (Melasoma scripta Fab.). — This beetle (Fig. 279) is found both on the willow and poplar, appear- ing hi the early spring, contemporaneously with the leaves. It shows a preference for tender snoots. Egg-laying begins imme- diately, the eggs being placed on the under surfaces of leaves. The young grubs, upon hatching, skeletonize the under" sides of the leaves and, as they get older, eat holes in the stem. When alarmed, they exude a milky substance along their sides for their THE TWO-LINED CHESTNUT BORER 275 protection; they appear to withdraw it at will. The pupal period is passed in the partly cast larval skin. Fifteen days are required for development of the larva and pupa. There are several genera- tions each season. The greatest damage is caused by the beetles on the young leaves and small tender shoots. Control. — Spraying with arsenicals has proved effective. The worst injury occurs in nurseries, and these remedial measures are for use there. The Locust Borer (Cyllene robinice Forst.). — This beautiful beetle, black, with gold markings, nearly three-fourths of an inch long, is a common pest of locust trees in some sections. Branches, and sometimes an entire tree, succumb to its attack (Fig. 280). In the fall it occurs on flowers of the goldenrod. i FIG. 278. — Mottled willow borer. FIG. 279. — Cottonwood leaf beetle, enlarged and natural size. (Ruggles.) The whitish eggs are laid in crevices in the bark in September. Control. — Some repellent wash, containing arsenate of lead and applied very early in the fall, is recommended. Fish -oil soap, with the addition of crude carbolic acid and arsenate of lead, at the rate of six pounds of the latter for every fifty gallons of the wash, is suggested. Badly infested trees should be cut down and burned during the winter or early spring. The Two-lined Chestnut Borer. — In some oak-growing regions, Minnesota for example, this is a very destructive insect (Agrilus bilineatus Oliv.). It kills more oaks than any other species of insect so far discovered. The grubs make burrows beneath the bark in the growing layer. The:r tunnels cut off the food supply 276 INSECTS AFFECTING SHADE TREES from the root to leaf, and a tree thus girdled dies. The burrows may occur anywhere from the base of the tree to the smaller limbs. The beetles (Fig. 281) are found flying in spring and early FIG. 280. — Young locust tree injured by locust borer and later broken by the wind. (After Houser, Ohio Bull., 194.) summer, at which time eggs are laid on the bark. One year is necessary for the life cycle. Control. — Chapman advises the cutting and burning of in- fested trees before the emergence of the adults in the spring. This WHITE PINE WEEVIL 277 is a hard thing for a tree owner to do, but quite necessary in order to protect other trees. He suggests the need of some other remedial measure, and reports successful results in spraying the trunks and large limbs of several trees with a mixture of iron sulfate and lime-sulfur, and others with Bordeaux mixture. This was done as a preventive measure during the egg-laying season. Turpentine Bark Beetle. — This is a bark-boring beetle (Den- droctonus terebrans Oliv.) nearly one-fourth of an inch long, brownish in color. It works in the bark of dying trees or stumps of pine trees. Healthy trees are attacked only when the insect is pressed for food. It prefers bark at the bases of the trees or on exposed roots rather than that which is higher on the tree. It is often attracted to recently painted buildings or freshly sawed pine lumber by the smell of turpentine. Hibernating as an adult, it begins to fly in April and May, eggs being laid in the late spring. There are a few natural enemies of this pest, and large numbers have been found in the stomachs of brook trout. (See Fig. 2.) White Pine Weevil. — This is a fairly large, reddish-brown beetle (Pissodes strobi Peck), one-fourth of an inch long, with a whitish spot on each side of the back near the posterior end. The sides •t 1 j I J 1 1 * 4 1 J- XVI. — < ' I . i W