^^i^^^t¥m^^^\^afM ^-^ f"F^ crA ^ 11 » m^!^5Sim\^ ■i. The Colorado Potato Beetle Insects Injurious to Vegetables By F. H. CHITTENDEN, SC. D. Untied States Dcpaiiment of AgiicuUiirc ILLUSTRATED NEW YORK ORANGE JUDD COMPANY LONDON KEGAN PAUL, TRENCH, TRUBNER & CO., Limited 1909 COrVRIGHT 1907 BY ORANGE JTTDD COMPAN^. AH Rights Reserved Entered at Stationers' Ilall l,ONDON, England Printed in U. S. A, PREFACE Among the hordes of insect foes with which the American farmer has to deal, those affecting vegetable crops are in many respects most troublesome. Vegetable plants are exceptionally perishable, and the control of their insect enemies entails a very considerable expenditure of money and time. The an- nual losses due to insect attack on vegetable crops is esti- mated at 20 per cent., or double that of the average farm crop. The injurious vegetable-feeding forms outnumber in species the insect enemies of any other single class of crops, excepting possibly deciduous fruits, and this nearly endless variety of pests necessitates information in regard to each. Many are intermittent in attack, hence the grower should be forewarned in order to guard against injury or to check it before irrep- arable damage has been accomplished. The progressive veg- etable grower should be as amply equipped with knowledge as the fruit grower, and if he would be entirely successful in avoiding losses from insect ravages he should be provided with a complete outfit for spraying operations and should keep on hand or know where to obtain at short notice a good supply of necessary insecticides. The more general observance of certain farming methods with a view to the prevention of in- sect injury will greatly lessen the losses from this source. Until within recent years few farmers in planning the manage- ment of the farm for the season considered the effect which any given method of tillage would have upon injurious insects. Too frequently they fail to look far ahead, and as a rule ro- tation of crops where practiced is more for the sake of soil improvement than for the avoidance of insect injury, and yet crop rotation is the best and sometimes the only remedy for V VI PREFACE certain species of insects. Among other general methods of farming strict cleanliness, including the destruction of weeds and burning over fields after harvest, fall plowing, crop ro- tation, the use of fertilizers, and the selection of the proper place and time for planting, must be considered. A knowledge of the classification of insects sufficient to enable the farmer to distinguish friends from foes is valuable, and finally comes a knowledge of what insecticides and repellents to use and the best means of preparing and applying them. Accounts of most of our noxious species of insects have been published. These accounts, however, are distributed through government and state publications, reports of agricultural so- cieties, magazines, and periodical publications of entomological societies, and even the daily press. As an example of the number of such publications on American economic ento- molog>', the Bureau of Entomology, United States Department of Agriculture, has cited no less than 12,645 titles that had appeared to January i, 1905, and the number of references to noxious insects is about 72,000. The average farmer has neither time nor opportunity to consult a tithe of these 12,- 000 odd works, and it is therefore the object of the follow- ing pages to collate concise accounts of the principal insects which affect one class of crops — vegetables. The order which will be followed is, as far as practicable, alphabetical, begin- ning with the insect enemies of asparagus, and ending with those which affect sweet potato, and finally miscellaneous or unclassified crops. The insect enemies of vegetables have not hitherto been con- sidered as a special topic in comprehensive form. Separate accounts, however, on the economic entomology of certain vegetables have been published, for example, of beets and of sweet potato. In presenting this work to the public its author does not claim originality for its contents. It is, however, largely com- PREFACE Vll piled from his own writings, although it has been found necessary to draw also from the works of others, and is based on an experience of about ten years with the subject with which it deals. The illustrations are in large part the same, or adaptations of, figures previously used in the Bureau of En- tomology, United States Department of Agriculture, and are so credited. F. H. Chittenden. United States Deportment of Agriculture, Sept en bcr, IQOJ. CONTENTS PAGE Preface » . . . v-vii Introduction , . . , x-xiv CHAPTER I Value of a Knowledge of Entomology .... 1-15 General considerations — Classification of insects — Orders of insects — Natural elements in the control of insects. CHAPTER II Prevention by Farming Methods 16-25 Selection of place and time for planting — The main- tenance of vigorous growth — Burning over fields and waste lands — Crop rotation — Diversified agri- culture— Fall plowing and cultivating — Clean farm- ing methods — Farm inspection — Cooperation in the control of insects. CHAPTER III Mechanical Methods of Destroying Insects or Prevent- ing Injury 26-29 CHAPTER IV Insecticides and Their Uses 30-48 Stomach poisons, arsenicals, etc. — Contact poisons — Insecticides which kill by suflfocation — Proprie- tary insecticides — Insecticide apparatus — Remarks on applying insecticides. CHAPTER V General Crop Pests 49-91 Cutworms and related insects — Miscellaneous cater- pillars— Leaf-beetles — Flea-beetles — Blister beetles — Grasshoppers and related insect.s — White grubs — Wireworms — Aphides, plant-bugs and related insects — The red spider. CHAPTER VI Insects Injurious to Asparagus . « « . . 93-98 viii CONTENTS IX CHAPTER VII fAGE Insects Injurious to Beans and Peas .0.0 99-ii9 CHAPTER VIII Insects Injurious to Beets and Spinach o . . 120-130 CHAPTER IX Insects Injurious to Cabbage and Other Cruciferous Crops i3i-iS4 CHAPTER X Insects Injurious to Cucumber, Melon and Related Plants I55-I75 CHAPTER XI Insects Injurious to Celery. Parsnips and Related Plants . i7<>-i88 CHAPTER XII Insects Injurious to Sweet Corn 189-212 CHAPTER XIII Insects Injurious to Potato and Similar Vegetables . 213-228 CHAPTER XIV Insects Injurious to the Tomato 229-234 CHAPTER XV Insects Infesting the Sweet Potato .... 235-243 CHAPTER XVI Insects Injurious to Miscellaneous Vegetable Crops . 244-251 The onion and other bulb crops — Rhubarb — Let- tuce— Okra or gumbo — Salsify — Pepper. CHAPTER XVII Bibliography 252-258 Index 259-262 INTRODUCTION Vegetables are subject to attack by insects from the time the seed is planted until the edible portion is ready for cooking. Insect injury manifests itself in different ways according to the plant attacked, the insect concerned, the stage of the insect, and the age and condition of the plant. Manifestations of Insect Injury. — If plants soon after the seed has been sown fail to appear in due time, such failure is apt to be attributed to unfavorable atmospheric conditions or to imperfect seed, but examination will frequently show that some insect is at work. Among insects destructive to planted seed are wireworms and root-maggots, and in some cases insects that have fed on the seed stock while in store are planted with the seed, and this they destroy by eating out the germ. Familiar ex- amples are the bean and pea weevils. Asparagus tips when ready for cutting are ruined for market by the asparagus beetles (see Fig 1 -Aspara- ^&- ^ ) ■ ^^ plants like tomato that are reset are g:us tip, showing cut off abruptly near the ground, cutworms are eggs and injury , , i t r i • ,, i r by asparagus "^^I'ly always at work. If the nnnute leaves of beetles. (Au- plants like cucumber, soon after beginning to thor's illustra- ^ , • i i ^ tion, u.s.Dept. sprout, are found eaten away, causnig the plants Agr) to die, cucumber beetles are present. Corn is similarly aft'ected by flea-beetles, as are also potato and other vegetables. When stems or stalks of various plants are found with one or more holes of varying size, from that of a straw to con- siderably larger, this is evidence of a borer within, particularly INTRODUCTION XI if excrement is exuding. Common species which do this in- jury are the common and corn stalk-borers and the grass-worm. When plants like corn make unequal starts, a hill here and there showing greater thrift than elsewhere, injury is apt to be due to root-aphides. As a rule, these insects are ac- companied by ants, which in most cases foster the "lice," and sometimes feed on the seeds. When the leaves of plants are seen to be withering, and aphides or other sucking insects cannot be de- tected above ground, search will usually reveal the presence of white grubs, wireworms or other insects working below the surface, and the same is true of corn plants that fall after windstorms, root-worms also being present at such times. Another manifestation of the presence of root- worms is in the plants requiring too long a time for maturing, and producing sterile stalks, and, in the case of corn, yielding nubbins instead of complete ears. When young leaves are found with small round holes of about the size of a pea or a little smaller, leaf- beetles are usually present, while much smaller holes occurring in great profusion over leaves usually betoken the presence of flea-beetles. Extremely large and irregular holes in leaves of older growth are made by grasshoppers, crickets, and the larger caterpillars such as "woolly bears." Fruits such as melons are attacked by the melon worm and pickle worm; tomato, beans and corn by the bollworm, tomato Fig. 2.— Bollworm entering bean pod. Somewliat enlarged (Author's illustration, U. S. Dept. Agr.) Xll INTRODUCTION fruit worm or ear worm (fig. 2), and the edible roots of such plants as beet and carrot, are subject to injury by the carrot beetle, while potato tubers are damaged by the potato tuber worm. Seed pods and similar coverings of seeds are attacked by numerous insects, such as the corn ear worm, cu- cumber beetles, and others. Growing seeds are liable to be injured by some of the last mentioned insects as well as by some others which begin development when the seed approaches ma- turity. Familiar forms are the bean and pea weevils, and the Angoumois grain moth. Many other forms of injury might be cited, but it may suffice to briefly mention the curling and dying down of leaves like melon, due to the presence of the melon aphis; the wilting and dying of squash caused by the severance of the stalks by the vine borer feeding within; the discoloration of leaves such as radish and their subsequent drying, owing to leaf-miner attack; and the destruction of whole plants of various kinds by army worms and migratory cutworms. Every year that passes brings with it some new entomolog- ical problem to be solved, and this is especially true of insect injury to vegetables. The cause is usually a general or local outbreak of one or more serious pests, and the species concerned may be an old and well-known injurious form ; it may be a com- paratively unknown species or one that has not hitherto been identified with injury to useful plants; again the habits of the species may never have been studied owing to previous scar- city. It has perhaps lived in obscurity since time immemorial before any considerable outbreak attracts attention. It may be new to our country or even new to science. Determination of the Injurious Insect. — The first problem that confronts the grower whose crops suffer from insect in- jury is the identification of the insect. Most insects have popular names, more or less local, which may be apt or may be rank misnomers, conveying no definite meaning. INTRODUCTION XUl Thus if a southern farmer complain of "the budworm," failing to state what plant is being injured, it is an impossi- bility to identify the insect concerned. The budworm of corn is the twelve-spotted cucumber beetle of the northern states, while the budworm of tobacco is the same as the tomato fruit worm and the corn ear worm or bollworm or a related species. The first pest is Diabrotica 12-punctata; the second is Fig. 3.— Diabrotica 12- punctata. (Riley, U. S. Dept. Agr.) Vv<-X- Fig. 4.— Bollworm moth in natural position. About twice natural size. (Quaintance, U.S. Dept. Agr) Hdiotliis ohsoleta} The parent of the first is a beetle (fig. 3) and of the latter a moth (fig. 4). It should be added that the first named species is also known as drill worm, while the latter is also called the shatter worm, this last name being shared also by the larger corn stalk-borer and perhaps by other species hav- ing the same habits, such as the fall army worm. The last is the grass-worm of the South and the fall army w^orm of the * It is to be regretted that the scientific names are not more stable, but the bollworm was generally recognized under the name of Heliothis. until it was recently changed to H. obsoleta. XIV INTRODLICTION North. It is the "alfalfa worm" of Kansas and Nebraska and elsewhere it is simply called the army worm. Its technical name is Laphygma frugipcrda. It will thus be seen from the examples cited that the poptdar name of an insect has frequently little bearing on its identity. The scientific name must be determined. A frequent source of injury to plants is due to contiguous growers who raise the same, or similar crops, for different pur- poses, c. g., some may raise cucumbers for pickling, and in the immediate vicinity others grow melons for fruit, so that pickle-growers pick their crops while quite young, and the fruit-growers when older. This means that after the pickle- grower has stopped pickling, numerous vines remain, and the insects scatter from them to melon fields. ID W c 6 Qu a 5« O, Insects Injurious to Vegetables CHAPTER I VALUE OF A KNOWLEDGE OF ENTOMOLOGY GENERAL CONSIDERATIONS For an intelligent understanding of the subject of insect control by agricultural practice one must know not alone that certain conditions produce an increase or decrease of certain forms of insects, but how this is accomplished, why the alter- nation of one crop with another is apt to result in insect injury, and why a system of crop rotation that would be of value in the control of one class of insects might be ineffective against another; how fall plowing, though destructive to one species, would not affect a different insect, and so on. In short, a knowledge of economic entomology beyond the fact that arsenicals are the proper remedies for mandibulate or chewing insects, and that kerosene will kill aphides or plant- lice, scale insects, and other soft-bodied insects, is a prereq- uisite to intelligent effort in the control of noxious insects. Before we can hope to avert losses we must know what our insect enemies are, what species are destroying each crop, which ones are responsible for primary injury, which are sec- ondary or merely auxiliary, how injury is accomplished, when injury begins each year, when it ends, as well as other facts. Similarly desirable is it to be able to recognize useful in- sects, such as ladybirds, syrphus flies, tachina and ichneumon flies and other parasites, that these may not be unnecessarily destroyed, but, if possible, encouraged in their useful work. z 2 INSECTS INJURIOUS TO VEGETABLES The different stages of some insects are so diverse that they can be identified only Ijy specialists, and many entomologists are unable to recognize them without reference to technical descriptions and illustrations. Some knowledge of the distri- bution and origin of a species is of value, as well as some acquaintance with its history and literature. A knowledge of the life history of an insect consists in knowing : when, where and how its eggs are deposited ; how the larva feeds, and how many stages there are in this period ; the habits of the larva, whether diurnal _ or nocturnal, whether omnivorous or a dainty feeder; how and where it transforms to pupa; how and where and in what stage it passes the winter; the number of generations produced each year; the first appearance of the insect and its disappearance, and the same of each generation ; its food plants, natural and culti- vated, and above all, its favorite foods, both as larva and adult. If to this we add a knowledge of the effect of farm practice and of insecticidal and mechanical methods on the insect we have, in a general manner, the main facts desired. We must determine in what stage and at what time the insect is most vulnerable, and by practice and experiment learn the best remedy. A knowledge of the appearance and place of deposition of the eggs will, in the case of some species, furnish means for their control, for many insects can be combatted successfully merely by destroying the eggs. Others may be killed in their cocoons. The most valuable weapon that can be used in combatting an insect consists in an intimate knowledge of the insect itself and its life economy, its natural enemies, its susceptibility to natural influences, heat and cold, dryness and moisture, and their effect upon its increase or decrease directly, or indirectly by destroying or favoring the growth of its enemies. A knowledge of the weeds and wild plants that furnish food for these insects, in addition to cultivated plants, and the soils in VALUE OF A KNOWLEDGE OF ENTOMOLOGY 3 which they attain their greatest development is also desirable. To this we must add a knowledge of the ehects of different farm practices upon the insects, as well as of insecticides. There are many insects with which we cannot cope by the use of poisons, and it is only by a thorough knowledge of their life economy from the time the eggs are deposited until the perfect insect emerges, that we are able to mitigate losses from their ravages. The knowledge of some one or more facts appar- ently trivial in themselves may frequently enable us to pre- vent by farming methods injury which we cannot cure by means of poisons, mechanical or other direct methods After seed has been selected with reference to its adapta- bility to the soil and climatic and other conditions one of the next problems that confront the grower is how to protect the crop from noxious insects and diseases. Fortunately we know approximately the life history and habits of a large proportion of the injurious insect inhabitants of this country, with the exception of some few species which have only been recently associated with injury, or which have lately been introduced from abroad. As a necessary preliminary to the discussion of the insect enemies of the various vegetable crops, some idea of the struc- ture and classification of insects must be given. It is perti- nent to follow as a matter of course with general methods of control, which include (i) mechanical methods, (2) farm prac- tice as preventives and (3) the preparation and means of applying poisons for the destruction of insects. Following this the different groups of insects which affect various crops and are not attached to single crops will be considered. CLASSIFICATION OF INSECTS If we would have an intelligent understanding of the causes that have led to the destruction of our crops, we must know something of the classification of insects and their nearest rel- INSECTS INJURIOUS TO VEGETABLES atives in order that we may be able to distinguish friends from foes and true insects from related forms. It is, of course, not essential that all of the Latin names which insects bear should be memorized, nor that anything approaching a complete classification be studied. The object of what is here presented on this topic is to assist in the ready identification by orders of such creatures as may come under observation as enemies or suspected enemies to plants under cultivation. It is first desirable to eliminate animals which are not true insects but are related to them. These are all included (with true insects) under the , branch Arthropoda of the Animal King- dom and are distinguished by having their bodies composed of rings or segments more or less similar, joined together, most of them bearing jointed legs, the last character separating them from earthworms, eel-worms, or hair- worms, which have many segments but no legs. This branch is di- vided into four classes : Crustacea {Crabs, lobsters, shrimps, craivfish, and sozv-biigs [Oniscidcc]). — Of this class only the sow-bugs or pill-bugs are apt to be confused with insects, and are of some economic importance, though not so injurious as many suppose. A common injurious species is shown in figure 5. Arachnida (Scorpions, daddy long-legs, spiders, mites, etc.). — The scorpions are well known in the South and need no de- scription. The same is true of the daddy long-legs or harvest- men, and spiders are everywhere. Among the mites, however, we have one species, the so-called red spider, which is quite in- jurious at times and which as it is commonly supposed to be an insect we will treat in one of the following chapters. Fig. 5.— Water-cress sowbug iMan- casellus brachyurus). Enlarged. (After Richardson.) VALUE OF A KNOWLEDGE OF ENTOMOLOGY 5 Myriopoda (Tlwiisand-lcggcd zvorms). — These creatures are known to most persons, and are divided into two orders: The Centipedes constitute a group in which each segment bears only a single pair of legs, while the body is generally flattened, and the antennae are long with many joints. They live mostly by preying upon other insects. The Millipedes (fig. 6) have two Fig. 6.— Myriopod. Enlarged pairs of legs to each segment except the first three ; the body is more or less cylindrical, and the antennae are shorter with few joints. Most species feed upon decomposing vegetable matter, but some attack growing plants, more particularly those of the garden and greenhouse. Injury by these creatures, how- ever, is frequently exaggerated, as in the case of the sow- bugs, previously mentioned. Hexapoda (Insects). — This brings us to the true insects which are distinguished from the other three classes that have been mentioned by having the body divided into three distinct portions, — head, thorax (chest), and abdomen (belly) (fig. 7). They have a single pair of an- tennae or feelers, normally three pairs of legs, and in the mature stage, one or two pairs of wings (save in exceptional cases). In our present advanced state of knowledge of the classification of true insects they have been divided into no less than nine- teen^ orders, but for present purposes what is known as the 1 For a list of these orders the reader is referred to pp. 77-81 of Comstock's Manual for the Study of Insects, Comstock Publishing Co., Ithaca, N. Y. Fig. y.—Polfstes bellicosus. Somewhat enlarged. (Marx del, U. S. Dept. Agr.) 6 INSECTS INJURIOUS TO VEGETABLES old Linnsean classification will suffice. This embraces seven orders, — Coleoptera, Orthoptera, Lepidoptera, Hymenoptera, Neuroptera, Diptera, and Hemiptera. The first six of these orders are mandibulate or chcz\.'iiig insects, at least in the most active stage of the insect, while the last are haustellate or sucking insects. This is important to know as on this classifica- tion depends the question as to whether stomach poisons, such as the arsenicals, or contact poisons, such as kerosene and its dififerent preparations, are best suited for their destruction. ORDERS OF INSECTS Coleoptera or Beetles. — Beetles are distinguished by having a pair of more or less horny elytra or wing-covers which nor- Fig. 8.— Convergent ladybird (Hippodamia conue gens), a Adult; b, pupa; c, larva. All much enlarged. (Author s illustration, U. S Dept Agr ) mally meet in a straight line down the back. Beneath them are the true membranous wings, usually folded. The mouth - parts of beetles and their larvae (the latter usually called grubs) are formed for biting. A common beetle, a beneficial ladybird, is shown in figure 8, in different stages. Many species of beetles are injurious both in the adult and larval stages Among the best known forms of this order that injuriously VALUE OF A KNOWLEDGE OF ENTOMOLOGY 7 affect vegetables are wireworms, white grubs and their parents the May and June beetles, leaf-beetles, flea-beetles, pea and bean weevils, blister beetles, bill-bugs and other snout-beetles. Lepidoptera {Butterflies and moths). — This order consists of insects having four membranous wings covered with more or less minute overlapping scales. The mouth-parts of the adults are formed for sucking, but the larvae (called cater- Flg. 9.— Cabbage looper (Autographa brassies), a, Male moth; b, egg; c, caterpillar; d, pupa in cocoon, a, c, d. One-third larger than natural: b, mors enlarged, (a, c, d, after Howard; b, Chittenden, U. S. Dept. Agr.) pillars, "worms," etc.) have well-developed chewing mouths. The Lepidoptera are of about equal importance with the Coleoptera or beetles as pests. Examples of noxious forms that are destructive to vegetable crops are found in the cutworms, army worms, webworms, cabbage and tomato worms and various caterpillars. The cab- bage looper is shown in figure 9 in its four principal stages. 8 INSECTS INJURIOUS TO VEGETABLES Hymenoptera (Sazi' flics, ants, -a'asps, bees, etc.). — In this order there are two pairs of membranous wings with comparatively few veins, the hind-wings being the smaller pair. The mouth- parts of the adults are formed for both biting and sucking, and those of the larvae, which are injurious, for biting. The females are furnished with stings, piercers or saws. In this order there are comparatively few noxious forms, and most of these are confined to the sawflies whose larvae, known as slugs and false-worms, consume vegetation, doing injury similar Fig. 10. — Screw-worm (Compsomyia macellaria), a. Maggot; b. head of same; c, anal segment from rear; d, puparium; e, adult IXy, f, head from side. All enlarged. to that accomplished by caterpillars. Some species of ants are troublesome, both directly and indirectly, in the latter case by acting as carriers of aphides or plant-lice, scales, and some other insects. This order, however, contains many bene- ficial forms, such as ichneumon and chalcis flies — parasites of noxious insects, and wasps which also destroy insect pests. One of these is shown in figure 7. Diptera, or Flies. — Insects of this order have a single pair of wings which are borne on the mesothorax or middle por- tion of the thorax. The metathorax or hind portion bears a pair of knobbed thread-like processes called halteres, poisers, or balancers. The mouth-parts are formed for sucking in the adult condition, but in the larvae (called maggots) the mouth- VALUE OF A KNOWLEDGE OF ENTOMOLOGY parts are for biting. To the Diptera belong such pernicious insects as mosquitoes, house and horse flies, and root-maggots. For illustrations of the Diptera, see figures lo and 20. Orthoptera (Grasshoppers, crickets, roaches, katydids, etc.). — In this order the insects have two pairs of wings, — the first somewhat horny and overlapping when at rest, the second pair thin and folded when at rest in plaits like a fan. The metamorphosis is incomplete, and all forms of the insect (ex- cept the Qgg) are active, with biting mouth-parts. The Rocky Mountain locust is an example of this order (figs. 11 and 12). Hemiptera. — This order divides into three suborders, — the Heteroptera or true bugs, the Homoptera containing aphides, leafhoppers, etc., and the Physopoda or thrips. These groups have in common four wings, the mouth-parts in all stages formed for sucking, with in- complete metamorphoses. Fig. H . — Rocky Mountain locust (Melanoplus spretus). a. a. Newly- hatched nymph; ii, full-grown nymph; c, pupa, natural size. (After Riley.) Fig. 1 2.— Rocky Mountain locust (.Melan- oplus spretus). Adult. Natural size. (After Riley.) Suborder Heteroptera. — In the true bugs the anterior wings are thickened at the base and thinner at the extremities and overlap on the back, and the beak arises from the anterior portion of the head. It includes various forms of noxious insects, such as the chinch bug, numerous plant-bugs, (fig. 13), squash bug, and certain beneficial species, such as soldier-bugs. Suborder Homoptera.— In this group the wings are of uni- form thickness and usually slope at the sides of the body, the beak arising from the hinder portion of the lower side of the head. In this suborder most injurious pests are found in the aphides (fig. 14), leaf-hoppers and the like. lO INSECTS INJURIOUS TO VEGETABLES Suborder Physopoda. — The thrips have two pairs of wings of similar form — long, narrow, membranous, not folded, and Fig. 13.— Brown p\a.nt-hu^ {Euschisfus variolarius). Adult at right; last nymph stage at left. Enlarged. (Howard. U. S. Dept. Agr.) with few or no veins. These are fringed with long hairs and do not fold, but are laid horizontally along the back when at rest' (fig. 15). Neuroptera. — This order has l)cen subdivided by re- cent writers into numerous other orders, but as they are of comparatively little if any economic importance, these Fig. 14. — An apliis. Much enlarged Fig. \5.—Enthrips tritici. a, Adult thrips; b. antenna; c, leg All highly magnified. (After Hubbard, U. S. Dept. Agr ) subdivisions need not be discussed here. The Neuroptera, in fact, have served as a "catch-all" for the groups that could not 1 .\cc.irding to recent classification the Physopoda constitute a distinct order, bnt tin- Parasitica, which includes the parasites of man and other mammals, is a siibindLr of C(|ual rank with the Ileteroplera and Homoptera. VALUE OF A KNOWLEDGE OF ENTOMOLOGY II be classified with other orders. Among neuropteroid insects of interest to the farmer are the aphis Hons or young of the lace- winged flies (fig. i6) which are beneficial by feeding on noxious insects and the dragon flies, which also do some good in destroying injurious forms. The Coleoptera, Lepidop- tera, Hymenoptera, Neurop- tera and Diptera have what is termed a complete metamor- phosis, which means that they undergo four totally different stages, of egg, larva, pupa and adult or imago. In the remaining Fig. 1 6-— A lace-wing with eggs at right Fig. 1 7. —Tarnished plant-bug; four stages of nyinphs. Enlarged (After Forbes) two orders, Orthoptera and Hemiptera, the metamorphosis is incomplete, which means that in the stages between the egg and the imago the insect undergoes only a gradual change, each successive substage (nymph) after the first being very like the one that precedes or follows it (fig. 17). NATURAL ELEMENTS IN THE CONTROL OF INSECTS The benefits which the agriculturist reaps from the friendly assistance of various forms of insects which prey upon nox- ious forms is very considerable. Every tiller of the soil 12 INSECTS INJURIOUS TO VEGETABLES should recognize their usefuhicss, but some are prone to ex- pect too much from them in the subjugation of farm pests, biid opinions are so diverse that the grower is sometimes in doubt as to whether the insects which are indicated as his allies are not, in reality, pests. A little study is necessary in many cases to discriminate between noxious and innoxious species and those which are truly and exclusively beneficial. Organisms beneficial to agriculture may be variously classi- fied, but fall naturally into four groups. The most important ! 8- — Fiery ground-beetle, a, Larva; b, beetle. (From Riley) a- Fig. 19. — A soldier-bug (MUyascinctus). (Riley, U. S. Dept. Agr.) forms are: (i) predaceous insects, consisting of those which feed externally upon their prey; (2) predatory animals other than insects, such as birds and mammals; (3) parasitic insects which live in the bodies of their hosts; (4) fungi and diseases of bacterial origin. The weather has quite as great effect in the control of in- sects as in the yield of the crops themselves. Extremes of heat or cold, excess of moisture or dryness have the same effect on insect as on plant life. The results of severe rainstorms, sudden cold snaps and prolonged drought on many insect pests are well known. Of predaceous insects the most useful are undoubtedly the VALINE OF A KNOWLEDGE OF ENTOMOLOGY 13 ladybirds^ (fig. 9), from their destruction of aphides alone, although some forms also do as good if not even better work in limiting the numbers of scale insects. Ladybirds also devour the eggs and larva; of various other insects, and especially of soft-bodied forms. Several ground-beetles (fig. 18) live at the expense of cutworms and other vegetable-feeding caterpillars and the larvse of beetles. Of this number the great Lebia ^ follows the Colorado beetle wherever it goes, and appears to Fig. 20.— Syrphus-fly (Syrphus n'besih. a. Fly; h, lateral view of head; C. larva or active immature form- All much enlarged. (Author's illustra- tion, U. S. Dept. Agr.) have a very considerable efifect in limiting its overproduction. Soldier-bugs* (fig. 19) of several species attack and kill soft larvje of beetles and of moths. Other important predatory enemies of noxious insects are syrphus and robber flies, spiders, and daddy long-legs or harvestmen. The syrphus flies* (fig. 20) are particularly useful in destroying aphides. Wasps of many forms provision their nests with the larvae of beetles and of moths, and certain species of mites help in reducing insects of pestiferous habits. >■ Coccinellidae. * Lebia grandis. s Podtsus spp. ' Syrphidae. 14 INSECTS INJURIOUS TO VEGETABLES Several kinds of birds, as also mammals, amphibians, and reptiles, are well-known enemies of noxious insects, and domes- tic fowls are of considerable value as destroyers of larvae, especially such as are not hairy, like the "slugs" of asparagus and potato beetles. Among beneficial birds, quail are important enemies of such pests as the potato beetle and boll weevil. Mamipals include skunks, which kill great numbers of May beetles. Toads of the amphibians are particularly useful as insect destroyers. Chickens, ducks and turkeys are all used in a practical way by farmers for disposing of a variety of insects. Turkeys ap- pear to be naturally adapted as substitutes for "hand-picking" tomato or tobacco worms and are actually employed and loaned for such purposes, and swine Fig. 2\.-Pieyomalus puparum. Male, are equally fitted for the destruc- Higlily magnified. (Author's illustra- . ... , , , tion. U. s. Dept. Agr.) ^lon of white grubs and other subterranean pests. The parasitic enemies of noxious insects are legion, but their activity as useful allies to the farmer is to a large extent dependent on atmospheric conditions. As a general rule also they seldom appear in their greatest numbers until their injurious hosts have done more or less damage. Their principal useful- ness, then, is in so decimitating the numbers of noxious species in one season that few are left to prey upon crops the following year. The principal useful parasites belong to the family Hymenop- tera, four-winged creatures of wasp-like appearance and variable size. Of these are the ichneumon flies,^ chalcis flies," bra- conids,* the &gg parasites* and some others. 1 Ichneumonidse. •"* Chalcidoidea. * Braconids. * Proctotrypidse. VALUE OF A KNOWLEIK'.l-: OF 1:NT()M0L0GY 15 An excellent example of the value of parasites as insect destroyers is afforded by the imported cabbage worm. One of its parasites, Pteromalus pupariim (fig. 21), destroys in some seasons from 80 to 90 per cent, of these "worms." Another parasite, Apantdes glomcratus was purposely introduced by the United States government about 1883. During the autumn of 1Q04 this species held its host under complete control in the District of Columbia, killing every "worm" which came under the writer's observation. This species is shown in figure 2ix. Fig. 2lx.—Apanteles ghmeratus. a. Adult fly: b, cocoon: c, flies escaping from cocoons 0, b, Highly magnified, c, natural size. (Author's illustration, U. S. Dept. Agr.) CHAPTER II PREVENTION BY FARMING METHODS Having shown in a general manner what is desirable for the best understanding of the subject under consideration, it is next in order to point out how this knowledge may be utilized in the prevention or mitigation of injury. A knowledge of the origin and distribution of insects enables us to judge of the probable and ultimate spread of introductions from abroad and from one portion of our country to another. Thus we can predict, with a considerable degree of certainty, that certain species will not be injurious beyond certain bound- aries, and that others will widen their range beyond known limits. Knowing the effects of atmospheric conditions, of heat and cold, dryness and humidity upon insect reproduction, we can be forewarned of injury and can plan accordingly. Experience having taught that the clearing of uncultivated or neglected land is almost certain to be followed by depredations of insects which had inhabited the wild plants and weeds, we are enabled to plant such crops as will be least affected by these insects. Knowing what insects are controlled by predaceous, parasitic and other enemies, such as beneficial insects, contagious diseases, wild and domestic animals, we can in many cases, untilize these natural agencies in our warfare against them. Most of the different farming methods which Aill be con- sidered are of use in combatting insect enemies of cereals; in short, without their employment it is impossible to avoid losses from these insects, as it is seldom practicable to use insecticides on growing grain. The usefulness of many of these methods is due to the slow spread of many species except at more or l6 PREVENTION BY FARINIING METHODS I7 less regular periods of migration and the strong tendency which many have of depositing their eggs in the same field where they have bred or hibernated. The value of these methods in the treatment of the Hessian fly is summed up by Prof. F. M. Webster in the statement that "four-fifths of its injuries may be prevented by a better system of agriculture." SELECTION OF PLACE AND TIME FOR PLANTING With a knowledge of the insects which attain their highest development in sandy locations, in marsh land or in the neighbor- hood of woodland, we can prepare for attack from them after the ground has been cleared for planting. Much depends upon a judicious selection of the crop to replace weeds or to be grown in forest clearings or in land that has long laid waste. Unfortu- nately the crops frequently selected for planting in new land are the very ones most subject to attack, and if farmers generally are to preserve their crops from insect injury they must employ new tactics. Corn and other cereals, potatoes and strawberries are crops especially attractive to insects which have developed in unused land. They should therefore not be planted in new land until after some less susceptible plant be used as a first crop. Buckwheat and clover are less likely to be injured. Corn should not as a rule be planted in marshy tracts or in reclaimed river beds owing to the danger of injury from bill-bugs, root-worms, wireworms and the like. Nor should corn follow wild grasses, which are liable to be affected by the same classes of insects as well as cutworms and white grubs. Next in order is the choice of the proper time to plant to avoid insects which are liable to attack the crops which we in- tend to grow. With early and late planting must be combined occasional planting between two generations of an insect, and the timely disposal of the crop, particularly if this is damageable. l8 INSECTS INJURIOUS TO VEGETABLES Late planting is practiced against numerous insects with ex- cellent success, the object being to have the crop appear after the disappearance or dispersion of the insect whose ravages are feared. It is, in fact, a standard remedy against some insects. THE MAINTENANCE OF VIGOROUS GROWTH If plants be weakened through atmospheric or other cause or through a combination of unfavorable conditions they are as a general rule more subject to injury by insects, but there are many crop plants, as for example certain varieties of wheat, that the ranker the growth the more they are subject to infestation by such insects as the Hessian fly. Some have claimed that weak plants only are subject to injury, and that plants might be grown by artificial methods for the production of such great vigor that insects would not seriously damage them. Although this might be possible with a limited number of plants, we can not now procure all of the most favor- able conditions. As an instance, we have only to cite the re- ported successful use of kainit and nitrate of soda as a remedy for wireworms and some other insects in New Jersey, and their failure when applied in other states. Possibly soil and atmos- pheric conditions have in some instances had some bearing upon these failures. Most failures, however, are due to wrong methods. BURNING OVER FIELDS AND WASTE LANDS A farm practice in favor in many regions against cereal- feed- ing insects consists in burning over fields after harvest or be- fore plowing. It affects particularly such insects as hibernate on or just below the ground. Among well-known pests that can be reached by this method are cutworms, many of which live all winter long above the earth's surface partially grown, also webworms. grasshoppers, aphides and plant-bugs, and some forms of beetles and other insects which hibernate in the adult stage at or near the surface. PREVENTION BY FARMING METHODS I9 CROP ROTATION One of the best of farming methods is crop rotation, as it serves several purposes. If pursued on scientific principles it is not only a benefit to the land, but is one of the easiest means of preventing attack from insects, fungous and other diseases, and weeds. In a general way it may be said that crops of like kind, that is, belonging to the same botanical groups, and much sub- ject to insect attack, should not be planted in successive years in the same fields. Thus it is inadvisable to plant corn in old wheat fields, and it is equally unwise to grow small grains after corn. Where insects occur like the bollworm, which attacks several plants, injuring tomato fruit, corn ears, bean pods, etc., in similar manner, still greater care is necessary in selecting the land for planting. It follows that it is bad practice to plant corn after tomatoes or tomatoes after corn, or to plant either of these crops in or near cotton fields. Here is where a knowledge of botany sufficient to enable the grower to know the botanical families to which his crops, as well as the weeds, belong becomes of value ; since with the ex- ception of insects known as general feeders, most species feed by preference on one or more plants of the same botanical group. Thus an insect destructive to cabbage will attack any cole crop, such as turnip or radish, and weeds such as wild mustard and pepper-grass ; hence care should be used not to plant cabbage in fields in which the other plants have grown. The same rule holds with plants of the cucumber kind. Melons should not follow squashes, nor pumpkins cucumbers. Rotation of crops is prac- tically the only means of dealing with some of the most im- portant insects, among which arc the western corn root-worm. Where diversified farming is practiced, such leguminous plants as crimson clover and cowpea are most useful as alternates, be- cause valuable as soil restorers, and not as a rule subject to serious insect injury. 20 INSECTS INJURIOUS TO VEGETABLES DIVERSIFIED AGRICULTURE Entire plantings are frequently failures because growers rely on single, or, at best, two or three crops for a livelihood. The practice of growing large areas to cotton in the South is an ex- ample. Occasionally this is varied by corn or tobacco, and all three crops are likely to be injured by the same insects, c. g., by the bolhvorm. corn-ear worm or tobacco budworm, as this one species is variously termed. In Texas there was at one time the threatened danger of an abandonment of cotton culture owing to the rapacity of the boll weevil. The large appropria- tions that have been made available by Congress for the con- trol of this pest should result in materially reducing the losses occasioned by it, which now bids fair to seriously hamper the production of this staple which nets our country $500,000,000 or more annually. The melon or cotton aphis has done great damage in Texas since the beginning of the new century and various crops in the South are threatened with new pests. It is quite a problem, therefore, to decide what may be grown most advantageously. Other striking illustrations of the danger of cultivating a single crop can be pointed out. In some years in the past it was simply impossible for truckers in parts of Maryland and Virginia to make a living from cabbage, or other cruciferous crops or from melons and other cucurbits, but by growing several crops of widely different kinds they make a profit. In the Northeast the farmer does not have such problems with which to contend and yet raises many crops, keeping his hands busy nearly the year round, and there is no excuse for growers in the South and elsewhere cultivating only a few crops when by diversified or general farming losses from insects, from plant diseases, and from adverse climatic conditions could be avoided. PREVENTION BY FARMING METHODS 21 FALL PLOWING AND CULTIVATING One of the best methods of deterring insects from injurious attack, comparable with clean culture, burning over, submersion and the like, is fall plowing and other ways of cultivating. The process may be varied by harrowing, disking, and raking, and sometimes in cases of serious infestation a cross-plowing is advisable. The object of fall plowing is to bring the insects that are feared to the surface where they will be exposed to cold and other elements and to natural enemies such as domestic and wild birds and mammals. This method is particularly valuable to prevent the recurrence of severe attacks and is beneficial for most forms of insects which hibernate under or near the surface of open fields, meadows and like places. It is particularly indi- cated for many insects affecting cereals, cucurbits and some other vegetables, and where corn and other crops subject to injury by white grubs, root- worms and wireworms and other subterranean insects, as well as cutworms, grasshoppers and others, are to be planted in sod or weedy land. Where the forms of insects mentioned are extremely troublesome, the land should be very thoroughly broken, and the insects, whether larvae, pupae, or adults, should be as much exposed as possible. This remedy is very efifective in cold climates since the exposed insects are unable to obtain secure shelter before severe frosts. Fall plowing should be practiced for most crops where it does not interfere with other methods of cultivation. The numbers of the squash-vine borer can be greatly reduced by lightly harrowing the surface of infested fields after harvest so as to bring the cocoons to the surface, and then plowing in the spring to a uniform depth of six inches or more, so that the adults will not be able to issue. Disking, or cultivation with a disk harrow, is particularly recommended against the fall army worm, which hibernates as pupa near the soil surface. A somewhat similar method of 22 INSECTS INJURIOUS TO VEGETABLES treating lawns infested by army worms, and root webworms, consists in going over them thoroughly with a long-toothed steel rake. CLEAN FARMING METHODS The most valuable of all methods of controlling destructive insects, if we except the employment of insecticides, consists in the observance of clean cultural practice, and when with this we combine the judicious use of other methods, including me- chanical ones, only moderate use of poisons, employed at the proper time, is necessary. It is a more or less complete safe- guard against the bulk of insects that ravage our crops. Clean farming should always be practiced in the growing of crops that are liable to severe insect injury. Where the char- acter of a crop will permit, still more can be accomplished by using portions of the same or a similar crop as baits. In ad- dition, it is also desirable to employ as trap crops such weeds as the insects normally affect and w^hich already grow in the fields, while in many cases it has been found of value to plant weeds or other crop plants to lure the insects from the main crop. Clean methods of management, though indicated as protective against most insects, is a practical necessity where there are many species that injure fall crops, such as cabbage, turnip and other crucifers, and for such insects as pass the winter in rub- bish in the fields that they have ravaged. FARM INSPECTION An old proverb, "An ounce of prevention is worth a pound of cure," is as applicable to man in relation to insects which injure his crops as to other matters which affect his well-being. Eter- nal vigilance is also the price of a good crop. The fact that the greatest injury due to such insects as army worms, cut- worms, blister beetles and the like is accomplished before their presence is known, indicates the value of prompt action in the treatment of the crops affected. Too frequently attack is un- PREVENTION BY FARMING METHODS 23 noticed until damage is beyond repair, and this might be averted if the grower would only employ some simple farm practice like fall plowing. Promptness cannot be too strongly urged, for the application of remedies if too long deferred may be useless. As soon as a crop is planted it should be inspected every few days for signs of injury. If plants growing under the same conditions make unequal growth, over a considerable area, the backward plants should be examined for evidence of insect work. Insect injury is manifested in different ways, as has already been described in the Introductory Chapter (page x). After crops have made some growth, a weekly inspection will in ordinary cases suffice until the danger point has passed; and as attack usually begins on the borders of a field, by walking around it most forms of insect injury may be detected. Pre- ventive work, such as clean culture, rotation and fall plowing, should be instituted as a part of the routine of farming; and if systematically pursued losses through insect ravages will be reduced to a minimum; while prompt action at the very outset of attack, in the application of insecticides or mechanical methods will, in exceptional cases, save the crop. COOPERATION IN THE CONTROL OF INSECTS The grower who institutes practical methods for the control of insects which menace his crops has a distinct advantage over one who does not. The enterprising farmer is enabled to ob- tain a good yield while the careless grower stands a chance of a money loss on his crop. It has long been recognized that insects of many forms are a direct benefit to the progressive man, who farms on scientific principles, enabling him to pre- serve his crops while the damage that may be done to his more careless neighbors enhances the market value of what the scientific farmer raises. This is a decidedly narrow-minded and selfish way of looking at the subject. 24 INSECTS INJURIOUS TO VEGETABLES Large corporations like seedsmen, canners, and picklers, plant very extensive areas and employ others in growing the same crops. Such firms provide seed and machinery, and keep posted on what will benefit not only their own interests, but those who labor for them. This applies to the means of controlling in- sects, including the purchase of insecticides and spraying ap- paratus, and by purchasing at wholesale they greatly reduce the cost for themselves and their co-laborers. The scope of this work might be extended (and perhaps is in use in some measure) to those who grow on a smaller scale, the farmers of a given locality having a community of interests pooling their interests for the purpose. Growers having small areas are often so little troubled with insects that it does not pay to buy expensive outfits ; and insecticides cost at retail frequently two or three times as much as when purchased in quantity. For example, bisulphid of carbon, a standard remedy for the melon aphis, bean and pea weevils and root-maggots, costs only lo cents a pound in fifty-pound lots, and from 20 to 30 cents when bought in smaller quantity. This difference could be saved by the co- operation of several neighbors, and it could be extended to the purchase of expensive spraying outfits. Co-operation is of especial value in the control of insects such as the squash bug, cucumber beetle, harlequin cabbage bug, and cabbage looper, that cannot be held in subjection by ordinary poisons. If growers who suffer most could induce neighboring farmers to employ clean farming methods and crop rotation, the ravages of these pests would be greatly reduced. The harlequin cabbage bug is quite resistant to poisons, and since about the year 1900 it has been so nearly exterminated in its northern range, that if farmers would work together when it again makes its appearance northward and use trap crops over large areas, for example over townships, the insect might be prevented for several more years from regaining its lost foothold. This, with clean methods of cultivation, would leave little else neces- PREVENTION 1!Y FARMINC. METHODS 25 sary to keep the insect down, unless by carelessness it were permitted to return unmolested to its old haunts. Immeasurable benefits would undoubtedly accrue by the subordination of self- interest for the common weal. Indeed this subordination is only apparent and it has been pointed out that one of the best, as it is the noblest, methods of self-help consists in helping our fellow men. Fig. 21)'.— A simple coal-tar pan to be drawn by hand 1 After Riley) CHAPTER III MECHANICAL METHODS OF DESTROYING INSECTS OR PREVENTING INJURY Many valuable mechanical methods of controlling insects are employed, such as hand-picking, "bugging" or beating, collecting in nets or in hopper-dozers, ditching, disking, driving and others. Hand-picking is useful for large conspicuous inactive insects, such as the squash bug, potato beetle, cutworms and similar caterpillars. It is one of the simplest measures that can be em- ployed, and is valuable where other means cannot be used and where labor is cheap. Bugging. — This term is often used for jarring and beating in- sects from low plants into pans containing water and a thin scum of kerosene. The water prevents the insect from es- caping, and the floating kerosene kills every insect which comes in contact with it. Collecting in nets. — Hand nets of muslin or cheese-cloth such as school children employ for the capture of butterflies, are use- ful against some insects which affect truck crops. Among such are the tarnished plant-bug, which affects about equally vege- tables and small fruits. By sweeping over the plants to be protected and the weeds and grasses of the vicinity, thousands can be captured in a short time, and they can then be killed by throwing them into a fire or into hot water. Collecting in hopper-dozers. — Many forms of these death-deal- ing devices are in use for grasshoppers (see figs. 2iy and 21^) and for leaf-hoppers, which will be described in the discussion of those insects. 26 MECHANICAL METHODS OF DESTROYING INSECTS 27 Brushing methods. — Different methods of brushing more or less sluggish insects from their cultivated food plants have been in vogue for many years. Potato beetles and their larvae may be brushed from potato plants by means of a short-handled broom, a second person to follow dragging by horse power a bundle of brush or a harrow to crush the insects and bury them. This process is simplified in the treatment of the asparagus Fig. 21^.— A canvas hopper-dozer to be drawn by horse, (After Riley) beetles. It consists in beating or brushing the insects from the plants with a stick so that they will drop to the bare ground on a hot dry day. The larvae are delicate creatures, crawl very slowly, and few are able to regain the shelter of the plants and die from exposure to the heated earth. A somewhat more com- plicated system came into rather extensive use in 1900 against the pea aphis. It is known as the brush and cultivator method, and at the time of writing is the best remedy that has been de- vised for this pernicious species. It will be described in dis- cussing pea aphis remedies. Cloth covering. — To prevent injury from some forms of in- sects to young plants before they are fairly above ground early in the season cloth coverings are used. A cheap frame may be 28 INSECTS INJURIOUS TO VEGETABLES made by cutting a barrel hoop in two so as to form two semi- circles, which are then placed at right angles to each other, and the lower ends inserted into the ground with the curve upper- most. This is then covered with gauze or similar material, held in place with earth packed about the edges, to prevent the beetles working under it. It is necessary to keep the plants covered only while they are young, and the same covering may be used year after year. Such covers are much used against the striped cucumber beetle, and radishes have been successfully protected from root-maggots. Trapping. — Several methods of trapping insects are practiced with success. Trapping under boards, shingles, chips, etc., is useful for squash-bugs and cutworms and if employed properly will serve as a means of destroying many pests. In the case of cutworms poisoned baits are placed under such traps. Pruning and the destruction of affected parts, practiced with benefit against many tree-borers, are useful methods for killing some vegetable feeders, c. g., aphides or "lice" when congre- gated on seedstalks of crucifers, etc. Miscellaneous mechanical remedies. — Such remedies as ditch- ing, disking and driving are applicable to only a few forms of insects and will be mentioned in the body of the present work as remedies for those insects where described. Ditching is prac- ticed against the army worm, as is also di.sking, and such insects as blister beetles and cucumber beetles may be driven by various means from cultivated fields. Repellents. — Various substances have been advised in the past and are claimed by "knowing ones" to be valuable as preventives of insect attack, but comparatively few deterrents will stand a thorough test The best for use on vegetable crops will pres- ently receive mention because of their value as insecticides or fungicides. These are: Tobacco; carbolic acid, used in emul- sified form ; Bordeaux mixture ; kerosene emulsion ; sulphur, when freshly applied ; and fish-oil soaps. Certain substances like MECHANICAL METHODS OF DESTROYING INSECTS 29 ashes and road dust, finely pulverized and sifted on young leaves serve to drive insects to other clean leaves which should be poisoned. Substances which are of little or no practical use as repellents, for vegetable insects at least, are legion. Among those for use as topdressings, or about the soil of the plants, which do not commend themselves or which produce indifferent results are : Bone dust, soot, coal dust, liver of sulphur, lye, ben- zine, naphtha, naphthaline, alum water, salt, saltpetre, etc. Bordeaux mixture is one of the most valuable insect deter- rents and is particularly useful for flea-beetles, leaf-beetles and other foliage-feeders. Its value as a fungicide is too well known for further comment. The formula follows : Into a 50-gallon barrel pour 30 gallons of water, and sus- pend in it 6 pounds of bluestone in coarse sacking. Slake 4 pounds of fresh lime in another vessel, adding water slowly to obtain a creamy liquid, free from grit. When the bluestone is dissolved' add the lime milk slowly with water enough to fill the barrel, stirring constantly. With insufficient lime the mixture sometimes injures the foliage, and it should be tested with a solution obtained by dis- solving an ounce of yellow prussiate of potash (potassium fer- rocyanide) in one-half pint of water. If there be insufficient lime in the Bordeaux mixture the addition of a drop or two of this solution will cause a brownish-red color, and more lime should be added until no change takes place when the solution is dropped in. Use the Bordeaux mixture promptly, as it de- teriorates on standing. Stock solutions of both the bluestone and lime may be kept for any length of time. Make the stock bluestone by dissolving in water at the rate of 2 pounds to the gallon. The stock lime is slaked and kept as a thick paste. Cover both mixtures, to prevent evaporation and keep the lime moist. For the 50-gallon formula add 3 gallons of the bluestone solution to 50 gallons of water, and introduce the stock lime slowly until there is no reaction with the testing solution. — Galloway. CHAPTER IV INSECTICIDES AND THEIR USES The most approved means of controlling insects consists in the use of poisonous mixtures administered in the form of a spray, wash, or dry powder in conjunction with such methods of farming, as fall plowing and rotation of crops, which tend to decrease the chances of injury from insect attack. Insecticides, or the substances used for the destruction of in- sects, may be classified as internal or stomach poisons, and ex- ternal or contact poisons. The former kill by being eaten with the insects' food, the latter by direct contact causing corrosion of the bodies of the insects, or the closing of their breathing pores. STOMACH POISONS, ARSENICALS, ETC. Paris green. — Of the various internal poisons in use against insects none are so valuable or so much used as Paris green,' the standard remedy against biting or chewing species, which include the bulk of injurious forms, such as cutworms and other caterpillars, beetles, grubs, slugs, etc. Paris green is applied in two ways,— dry and as a spray, the latter being the method most extensively used, as it is cheaper and more effective, answering all the purposes to which dry powders are put. A spray is prepared by combining one pound each of the poison and fresh slaked or quick lime with from 75 to 150 gallons of water. A slight excess of lime is advisable. A somewhat 1 Palis green is now chemically known as co/'/'er aceto-arsenitc; in other words, it is a chemical compound of oxid of copper, acetic acid and arsenious acid, and when properly combined the proportions of the different chemicals are as follows: copper oxid, 31.29 per cent.; acetic acid, 10.06 per cent.; arsenious acid, 58.65 per cent. 3^ INSECTICIDES AND THEIR USES 3I Stronger mixture can he used on resistant plants like potato, and a weaker solution (i to 200) must be made for young and delicate foliage. For the proper preparation and application of this and other sprays a sprayer or spray pump is necessary. The Paris green should first be mixed with a small quantity of water into a thin paste before the bulk of the water is added, and should then be thoroughly mixed by churning in the force-pump. As the mix- ture is only a mechanical one the Paris green tends to sink to the bottom, and to avoid this it must be constantly stirred while being applied, otherwise the mixture near the bottom of the tank or reservoir will become so strong as to scorch the foliage. Care should be exercised in the purchase of a spray pump that it be equipped with a proper agitator. When applied dry, it is generally mixed with from 10 to 20 parts of flour, plaster, or lime. This remedy affords best results early in the season on young plants. It should be dusted on preferably when the dew is on, or after a shower, and by means of powder guns or bellows, or the so-called "dust-spray" ma- chines, so as to cover the plants and leave as little surface as possible for food for the first-appearing insects. It is often advisable "to use Bordeaux mixture in combination with an arsenical, especially if a disease is present. This is a valuable insect repellent as well as a standard fungicide, and it operates also against different forms of blight and other diseases which may threaten the crop. It is used as a diluent instead of water and in the same proportions, and prevents scorching. Its preparation is discussed on page 28. Paris green is more usually recommended for general pur- poses because it is known to most farmers, can be obtained in drug stores anywhere, and because of its supposed cheapness. Its use, however, is being superseded in some degree by arsenate of lead and other arsenicals. Paris green is very frequently adulterated by unscrupulous 32 INSECTS INJURIOUS TO VEGETABLES dealers, c. g., with white arsenic, which makes the liquid luixturc (containing an excess of free arsenic) still more scorching ni its effects on vegetation. The New York (Geneva) Experiment Station has ascertained that this insecticide possesses about one- third the fungicide value of Bordeaux mixture. Arsenate of lead, lead arsenate or "disparene" has the ad- vantage of being less harmful to growing plants and adheres better to the leaves than other arsenicals. It is less apt to burn delicate foliage, hence does not require the same care in its application as is necessary for Paris green, and can, moreover, be obtained ready made on the market. Numerous brands are for sale, and care should be exercised to obtain a good quality as some alleged arsenate of lead preparations contain free arsenic. The commercial preparations are mostly like paste or putty and must be worked in a little water in a bucket before being added to the spray tank. It is prepared by combining acetate of lead (6 or 7 parts) with arsenate of soda (3 parts). In spraying it can be employed at any strength from 3 to as high as 12 pounds to 100 gallons of water without injury to most vegetable crops. Its cost at present writing is 12 to i^ cents a pound when purchased in bulk. Quite a number of other arsenicals have been more or less used as insecticides and some of these are of considerable value while others have no especial advantages over Paris green or arsenate of lead, or are decidedly inferior. London purple was formerly used in spraying. As sold in the market its composition is unstable owing to its being apt to be adulterated, and it is very caustic, hence liable to scorch tender foliage. For these reasons it is rapidly going out of use. As a spray it is applied in the same proportions as Paris green, as is also arsenite of copper. Arsenite of copper (Scheele's green or "green arsenoid") is of similar composition to Paris green, and is even superior owing to its more rapid effects and less liability to produce scorching. It is, however, not as yet so readily obtainable. INSECTICIDES AND THEIR USES 33 White arsenic (pure arscnious acid) is the active principle of all the arsenicals. It is particularly dangerous when used alone in solution, but as it is the cheapest of the arsenicals it is employed in the preparation of poisoned baits for cutworms and grasshoppers. Combined with lime it forms arseiiitc of lime. Arscnitc of lime has been highly recommended by those who have tried it. It is prepared by such methods as follow: The Kedzie formula: Boil 2 pounds of white arsenic and 8 pounds of sal-soda 15 minutes in 2 gallons of water. Put into a jug, label "poison" and lock it up. When ready to spray, slake 2 pounds lime and stir into it 40 gallons water, adding a pint to a quart of the mixture from the jug. Formula No. 2 : Boil together i pound white arsenic, 2 pounds lump or stone lime and 3 gallons water. Dilute with about 200 gallons of water before spraying. Still other arsenicals possess insecticidal properties. Of these "pink arsenoid" has given good results experimentally, "White arsenoid" has been practically withdrawn from the market. "Paragrene" is reported as having equal insecticide value with Paris green, is about as likely to burn foliage, but remains longer in suspension.* The arsenicals are also useful in the preparation of poisoned baits, which will be discussed in the consideration of cutworms and locusts or grasshoppers. Hannlessness of arsenicals zvhen properly applied. — Chemical analysis has shown that cabbage which has been dusted or sprayed with an arsenical in the way prescribed, and then prepared for cooking in the usual manner a week later has not even a trace of arsenic remaining. The use of arsenicals against cabbage worms is almost universal, although growers are some- times loath to acknowledge the fact for fear of the loss of customers who are not fully acquainted with the harmlessness More detailed directions for the preparation of the arsenicals here dis- cussed are given in Farmers' Bulletin 127, U. S. Department of Agriculture. 34 INSECTS INJURIOUS TO VEGETABLES of this remedy. There are no authentic recorded instances known to the writer of poisoning from the consumption of cabbage or other vegetables treated with an arsenical. Ac- cording to Gillette, 28 cabbages dusted in the ordinary way would have to be eaten by a human being at one meal in order to produce poisonous effects ! It is preferable, however, in order to avoid all danger, to use other insecticides in the case of vegetables soon to be eaten. Caution. — It is advisable in using all arsenicals to sec that they are correctly labeled and kept under lock and key, as they are dangerous to human as well as other animal life. The utensils employed in preparing arsenical mixtures should be thoroughly cleansed after use. Lime (oxid of calcium) possesses considerable value as an insecticide and repellent, its efficiency being in proportion to its dryness and caustic quality. It is more effective against delicate and moist insects, such as the larvae of asparagus and potato beetles and root-maggots. For leaf-feeding species it is sifted on the plants and kills by contact, literally burning holes into the soft bodies of the larvae which it touches. Certain root- maggots and white grubs are without doubt largely attracted to gardens by the presence of manures and decomposing veg- etable matter, and if this be powdered with lime, finely sifted, it soaks into the material with rains and, moreover, acts as a deterrent, especially against the flies which produce the root- maggots. It is useful also for slugs or snails. Fresh air-slaked or quick lime should be used, as when stale it loses its caustic properties. Gas lime is of value in clearing infested land of white grubs before planting some crops. It is a refuse product of gas plants and may be obtained frequently merely for the cost of hauling. It contains much gas in a crude form, and to be of greatest value should be fresh so as to give out a strong gassy odor for several days after application. When applied to lawns it is INSECTICIDES AND THEIR USES 35 Sprinkled over the surface as a top dressing. In fields of potato it should be applied between rows and covered by earth, by drilling or other process, as there is a possibility of injury to plants, and this method should be used experimentally at first. The amount to use will vary according to the degree of infesta- tion by white grubs and other conditions. It has been employed at about the rate of 4 barrels to 100 square feet of ground on a lawn with the result that the spring after application all forms of vegetation, including weeds, came up, and only five or six white grubs could be found. In Europe gas lime has been used with some success in connection with other remedies for wireworms at the rate of i>^ tons to the acre. The best time to apply the lime is in September, after the crop is made. Caution.— There is always danger to plant life in the use of gas lime, hence before employing it on growing crops on a large scale it should first be used experimentally. Hellebore, or white hellebore (Verafrum album) is less dan- gerous than the arsenicals, hence has some votaries for its use on cabbage and other plants soon to be eaten. Its use is open to the same objection as pyrethrum that it loses its insecticidal properties by exposure to the air. It is also poisonous to man and domestic animals. It is a specific against the slugs or false-worms (none of which commonly affect vegetables), which attack raspberry, currants and other bush fruits. As many truck- growers raise bush fruits it might be added that it is used in both dry and liquid form, but can be applied more thoroughly as a spray, >4 ounce of powder to 2 gallons of water. Dr. James Fletcher recommends its employment as a remedy for certain kinds of cabbage pests, including "worms" and root- maggots. On the latter it is applied at the rate of 2 ounces of powder to the gallon of water, and applied with a force-pump about the infested roots. 36 INSECTS INJURIOUS TO VEGETABLES CONTACT POISONS Kerosene emulsion is the standard remedy for sucking insects such as aphides or plant-lice, plant-bugs and the like, and is of value against other soft-bodied insects, which cannot for different reasons be safely poisoned by Paris green and su".iilar insecticides. The best form for ordinary use is the kerosene-soap emulsion, made by combining 2 gallons of kero- sene, 3'-' pound of whale-oil soap, or I quart of soft soap with I gallon of water. The soap should be dissolved in boiling water and then poured while boiling (away from the fire) into the kerosene. The mixture is then churned violently for about five minutes by means of a force-pump and direct-discharge nozzle throwing a strong stream by pimiping the liquid back upon itself. At the end of this time the mixture will have become of the con- sistency of thick cream. Properly prepared an emulsion will keep almost indefinitely, and should be diluted only as needed for use. For most insects, except scales, the staple emulsion should be diluted with from 15 to 20 parts of water. A 10 per cent, solution, or even stronger, is sometimes necessary. In the preparation of kerosene emulsion a force-pump is a necessity, since, if not made according to directions, a perfect emulsion is nut formed. There is then danger of injury to the plants by the kerosene, as also useless waste. There is also danger and waste if the insecticide is not applied by means of a fine nozzle in the form of a spray, which should be fine and mist-like. It should be sprayed only long enough to cover the plants and not so that the liquid forms into globules and runs off. In the practical application of this insecticide certain setbacks are frequently encountered. One of these is due to the fact that aphides and many other sucking insects feed more or less exclusively on the under surface of leaves, which necessitates INSECTICIUKS AND TIIF.IR USES 37 ail under-spraying of the leaves in order to reach the pests. This is frequently of difficult accomplishment owing to the thick growth of the plants after they have got well started, and the fact that many leaves overlap others. An example of the dif- ficulty experienced in spraying for aphides is afforded in the pea aphis, particularly where peas are grown broadcast, which does not permit the driving of a machine through the fields. The leaves interlace and intertwine in such a manner that the insects cannot be reached. The same is the case with melons after they have attained any growth. There is also danger of injury to the vines by the wagon wheels and the horse in going through the fields. For success with this remedy it is in many cases absolutely necessary that the emulsion should be applied so that it will actually come in contact with or strike the insects against which it is directed. Kcroscnc-inilk ciuulsion is sometimes used, but it is hardly as satisfactory as kerosene-soap emulsion, since the soap in the latter has also considerable killing and repelling power. Corbolic-acid emulsion. — For some purposes it is desirable to add to kerosene emulsion a quantity of carbolic acid, e.g., for the treatment of various root-infesting insects, such as root- maggots affecting seed-corn, onion, and cabbage. This emulsion is prepared at the rate of i pound of soap, i gallon of water, and Yi gallon of crude carbolic acid, and is diluted with from 35 to 50 parts of water. It has been found quite effective against root-maggots, the plants showing no injury due to the insecticide. It should be applied a day or two after the plants are up, or, in case of crops that are transplanted, the da^r after they are set in the field, and should be repeated every week or ten days until about the latter half of May. Carbolic acid is at once a repellent and a contact and stomach poison. It should be handled with care as it is corrosive ! Corrosive sublimate (Bichlorid of mercury) is prepared by 38 INSECTS INJURIOUS TO VEGETABLES mixing 2 to 2^ ounces of the poison with 15 gallons of water. The poison is first dissolved in 2 gallons of water, and more is added to make 15 gallons. This is allowed to stand 5 or 6 hours, and the solution agitated several times. This is a fun- gicide as well as insecticide, and is useful both for potato scab and the potato scab gnat. Seed potatoes are soaked from an hour and a half to three hours in this solution before planting. As corrosive sublimate is a violent poison, unusual care should be exercised in handling it. It should not be mixed in metallic vessels, nor exposed where it might be eaten by stock. Formalin is prepared by mixing 8 ounces of 40 per cent, solution with 15 gallons of water, and is used for the same purposes as corrosive sublimate, but is less poisonous. Seed potatoes are immersed two hours. Soap preparations. — Soap solutions are valuable as washes in the control of noxious insects. Both hard and soft soaps are used, but "whale-oil" soaps, usually manufactured of fish-oil, are of greatest value. A solution of fish-oil soap is prepared by dissolving I pound of the soap in from 4 to 10 gallons of water. On some hardy plants a strength of i pound of soap to 2 gallons of water can be used, but this is harmful to delicate plants and must be employed with caution. A wash of i pound soap to 6 or 8 gallons is of most value for aphides, minute leaf- bugs, leaf hoppers, and thrips, and some forms of small larvae. These soaps possess no particular advantage, however, over kerosene-soap emulsion and are, in fact, less effective against vegetable-feeders. Castile or "neutral" soaps, among which are ivory soap, are much used on plants grown under glass and as a means of arresting the ravages of "red spider" and the same insects that have been mentioned. Cold and hot -i^atcr are properly speaking contact insecticides of value in the destruction of mimitc insects such as aphides. A strong sjjray of ice cold water applied to louse-infested plants is a very useful remedy, but hot water is still more effectual INSKCTICIDES AND THEIR USES 39 as a means of riddance of these pests. The latter is most ap- plicable to such plants as cabbage, which withstands a high degree of temperature, which would be hurtful to less hardy plants. A water thermometer is employed, and care is observed that the temperature does not reach far above 150°, the scalding point for most plants. From 125 to 135° is sufficient for the destruction of most insects, but applied still hotter where possible is still more effective. Cabbage will withstand a tem- perature of 180° without special harm. When setting out cab- bage and some other plants they can be freed from "lice" by dipping them into water heated to between 125 and 150°. Hot water cannot be thrown in a spray owing to its cooling too rapidly, and it is necessary if it is to be thoroughly effectual for it to actually strike the insects which it is desired to destroy. Where only a few plants are to be protected and it is possible to reach the "lice" with water applied with a garden hose, syringe or spraying machine their work can be checked. Such as come in direct contact with a stiif spray at an ordinary temperature are unable to survive, while many that are dis- lodged cannot return to the plants as most of them are wingless and unable to crawl any distance, particularly if the ground be dry and hot. INSECTICIDES WHICH KILL BY SUFFOCATION Under this caption will be included insecticides which do not properly fall under the heading of either stomach or contact poisons. Of these are pyrethrum ; tobacco, which acts both as a repellent and, when vaporized, as a destroyer of aphides and thrips; bisulphid of carbon and hydrocyanic-acid gas, two deadly gases, and some others. Pyrethrum. — Several forms of insect powder, the pulverized dry flowers of different forms of daisies, are on the market under such names as Persian and Dalmatian insect powder. One of these is buhach, made exclusively from Pyrcfhnnii 40 INSECTS INJURIOUS TO VEGETABLES ciucniriccjoUum. It was carefully tested years ago by the De- partment of Agriculture at Washington, and although not use- ful against all forms of insects, is very valuable for household pests, aphides, and small plant-bugs and caterpillars. It is best used dry by dusting the plants affected with an insufflator or bellows while wet with dew. It acts by closing the breathing pores of the insects, and has the advantage of being harmless to man and the higher animals. It is also used in liquid form, as a spray, the buhach being first mixed with enough water to make a thin paste and allowed to stand about two hours, after which more water is added to bring it to the desired strength, the usual proportions being: 2 ounces to 5 gallons of water. An alcoholic decoction is also sometimes used. Under different trade names, pyrethrum is placed on the market in hermetically sealed tin cans, so that it retains its full strength until used. Powders that are not packed in tightly sealed cans lose their strength, and are therefore less effective. In small lots pyrethrum costs 10 cents an ounce; if six pounds are purchased it can be had for about 50 cents a pound. Tobacco is an old-time remedy for many insects, and still in vogue among a certain class of farmers and florists, but in recent years it has been largely replaced by other and more approved insecticides, such as Paris green and kerosene emul- sion, and in greenhouses by the hydrocyanic-acid gas process. The method of its application varies according to the crop af- fected and the insect. Where tobacco stems and other refuse can be easily obtained from the factories it is advisable to use it as a protection against certain species of insects. For the striped cucumber beetle and melon aphis, it is used by sprinkling the hills, particularly when the soil is moist, with refuse dust. Thus used it has the advantage of acting as a fertilizer and mulch for the plant, as well as being a repellent to the beetle and other insects. Applications must be repeated after rainfall. INSECTICIDES AND THEIR USES 4I Nicotine extracts and pozcders are extensively used by florists as general funiigants for aphides, thrips, white fiy, and other small and soft-bodied insects in greenhouses. These extracts are manufactured by a number of firms who advertise chiefly in florists' journals. They contain a much larger proportion of nicotine than decoctions, and are proportionately more ef- fective. They are used in various ways : Dry fumigants are placed in shallow pans and a few drops of kerosene poured on to facilitate ignition. These burn slowly, producing a smudge which is fatal to aphides and similar insects. The liquid prep- arations are evaporated over an alcohol lamp, or are "painted" on steam pipes, or hot irons are put into the receptacles. The amount of nicotine solution to use depends upon its strength (varying from about 35 to 85 per cent, nicotine), the plants to be treated, the size of the frames or greenhouse and the construction of the latter, whether tight or loose. A pre- liminary test, on a small scale, is therefore a prerequisite to the use of a nicotine fumigant. Follow the directions accom- panying the preparation used and increase or decrease the strength as necessary. If cucumbers are being fumigated, a smaller amount may be desirable. • One of the most widely known of these nicotine solutions has been used with great suc- cess at the rate of 5 or 6 teaspoonfuls of the liquid to 8 quarts of water vaporized in 5,000 cubic feet of greenhouse sp^ce. Used thus on cucumbers at night it did not injure the plants, while thrips which infested the plants were killed. Aphides are more easily killed than thrips, while white flies require still longer exposure and repeated applications. After treatment plants are carefully syringed with whale-oil or similar soap and the house ventilated. A second fumigation is sometimes given, allowing the tobacco smudge to remain over night. A surplus of moisture is to be avoided, as it induces spot, mildew, and similar fungous diseases. Sulphur, applied dry in the form of "flowers of sulphur," is 42 INSECTS INJURIOUS TO VEGETABLES a veritable specific for "red spider" on certain plants grown under glass. It is also applied dry mixed with an equal bulk of air-slaked lime, and by means of a powder bellows. It is also used in conjunction with kerosene emulsion or soap washes, added in the proportion of i to 2 pounds to 50 gallons of the spraying solution. It is first mixed into a paste. As a vapor it is exceedingly harmful to plant life, hence should not be used as a fumigant in forcing houses or in a confined structure. Bisulpliid of carbon (CS-), a specific against insects affecting stored grain and other products, has a special value in the treat- ment of some forms of insects affecting vegetable crops, more particularly aphides, and root-feeding insects, such as root-mag- gots of cabbage and onion. This reagent, when pure, is a color- less liquid and has a powerful and disagreeable odor; it vapor- izes rapidly when exposed to the air, is highly inflammable but not explosive, and is deadly to all forms of animals, including human beings. Its field of usefulness is among such insects as we cannot reach with poisons by direct contact or through their foods. The method of applying bisulphid of carbon varies according to the nature of the plants affected and the insects to be de- stroyed. The method of treating the melon aphis and root- maggots will be described in the consideration of those insects. PROPRIETARY INSECTICIDES Numerous proprietary insect destroyers are on the market, and their number is increasing. Analyses of these are being made, with the result that although a few are not without value they are as a whole decidedly inferior to approved combinations advised by entomologists, of the character that are mentioned in preceding pages; in fact, they occupy the same relation to standard insecticides that quack nostrums do to the prescrip- tions of reliable physicians, or preparation of recognized value INSECTICIDES AND THEIR USES 43 and known composition.' Among proprietary insecticides that have been reported to be found by analysis of little or no value or too costly are those bearing names suggestive of "sure pop," "bug shot," "certain death," "kill-em-quick," and certain lice and "vermin" exterminators, roach destroyers, etc. On this head it is advised that in view of the fact that so many proprietary insecticides are either fraudulent or extremely expeiisiz'e, considering the value of their ingredients, it would be well to make sure of the composition and value of each before purchasing. Among the most useful proprietary remedies are nicotine solu- tions or tobacco extracts and powders which are not mixtures or nostrums, but just what their manufacturers claim for them. INSECTICIDE APPARATUS In the application of insecticides different types of apparatus are necessary, according to whether the material used is to be applied dry in powder or as a spray. The types necessary for the former are simple, the spraying devices are numerous and many efficient sprayers and like mechanisms are on the market. For dry application, such as pyrethrum, sulphur, and Paris green mixed with flour, powder bellows or atomizers costing about $2 are much used, particularly for gardens or where small areas in larger fields are infested. For spraying. — No stronger evidence of the progress in economic entomology could be cited than tfie number of firms engaged in the manufacture and sale of spraying apparatus. Such crude mechanisms as are for sale at from 75 cents to $2 or $3, both imder the title of syringes and sprayers, can scarcely be reconmiended for up-to-date work. They do not, as a rule, produce a true sjiray ; they are too apt to gel out of '■ Such as paregoric, Rochelle salts, Seidlitz powders, and various extracts, elixirs, tinctures, mixtures, solutions, anodynes, etc. 44 INSECTS INJURIOUS TO VEGETABLES order and therefore do not last longer than a season or two. The want of an instrument to fulfill modern requirements for a Hue spray is met by various manufacturers in the form of knapsack sprayers, bucket pumps and barrel spray pumps. The spray is obtained by a hose attachment and different forms of nozzles, of which the vermorel type is the best. The knapsack sprayer is a copper tank made to be strapped Fig. 22.— Knapsack sprayer on the back of the operator (fig. 22). Within there is a small pump which is operated with one hand while the nozzle is held in the other. The handle may be removed, if desired, and the tank carried by hand instead of on the l)ack. The cost is from $9 to $18. It is good for gardens and for moderate-sized plats on truck farms. Of its usefulness Mr. M. R. Waite, a patlu)logist of the United States l)r])arlment of Agriculture, says in substance : The barrel pump has nearly driven out the knapsack outfit INSECTICIDES AND THEIR USES 45 in commercial operations. In spraying several acres of can- taloupes once the writer was surprised to find that a man with a knapsack outfit could do the work at the same price as an outfit consisting of a i)arrel mounted on a sled drawn by a horse and operated by three men, one to pump and drive and two to carry the nozzles. The latter outfit, however, got over the ground so much more rapidly and saved so much time that it was mainly used. The objec- tions to the knapsack pumps are numerous. It is hard to get the rc- (juired pressure in the pump on account of its small size and instability. It is rather heavy to carry on the back and is very liable to leak, and the oper- ator who can handle one all day with- out getting his back wet and some of the liquid down his neck is fortunate. As a rule, the low pressure obtained by the knapsack pump results in an inferior job of spraying, though with a strictly first-class vermorel nozzle this is not necessarily so. Bucket pumps. — Good hand bucket spray pumps of about the type shown in figure 23 may be had at from $6 to $7.50. They are of great value in the preparation of kerosene emulsion, which, as has already been stated (p. 36), should be applied as a fine mist-like spray. They may be used with ordinary or special buckets and a longer hose than figured (fig. 23) and may be necessary. Barrel spray pumps. — These are the largest force pumps and useful both for the field and orchard. They are mounted on barrels or tanks and drawn for field and garden use on wheels, so geared as to straddle rows of vegetables, or a narrow sled may be made to serve the same purpose. A serviceable sled may Fig. 23-— Hand bucket pump 46 INSECTS INJURIOUS TO VEGETABLES Fig 23x. -Hand barrel spray with cart in operation in a cucumber field (After Orton, U S. Dept. Agr.) be made by fastening- planks across two pieces 2 or 3 x 4 inches and with rounded ends for runners. Two-wheeled carts may also be used for such an outfit. Such a one designed for spray- ing four rows of plants and from two sides at once is used by Prof. F. L. Washburn of the Minnesota Experiment Station (fig- 24). Fig. 24— A tour-row sprayer. (After Washburn) INSECTICIDES AND THEIR USES Noc::lcs. — One of the main causes of failure on the part of farmers to obtain good results from spraying is the use of inferior nozzles which are too often supplied by dealers. The ver- morel type (fig. 24X) , for sale (single) at about $1.25, is the best, having stood the test of 25 years and more of use. Fig. 24x.-Ver- morel nozzle REMARKS ON APPLYING INSECTICIDES In the application of remedies 12 points are selected as im- portant to be observed : 1. Be sure of the insect which is the primary cause of the damage. 2. Make certain that the best remedy or remedies are used. 3. When an insecticide is employed, ascertain if it is of standard quality, because if it is lacking in strength it will fail of its purpose. If not diluted according to directions, and if therefore too strong, there is danger of scalding or otherwise injuring the plants. 4. The preparation used should be properly prepared. Thus if kerosene emulsion is the remedy, it should be a true emulsion and not a mere mixture of water, soap and kerosene. 5. The best insecticide apparatus for the purpose for which it is designed should be obtained, and for vegetables it is nec- essary in most cases that a sprayer be used, and as often as not the spray must be applied so as to reach the under surface of the leaves, and remain on them and not roll off. 6. The smallest amount of poison should be used to produce the desired result ; much poison is wasted by persons who do not understand its proper application. 7. Remedies should be applied at the right time, usually i^hen the insect first appears; as, for example, when a cater- pillar has just hatched from the tgg, or when a beetle begins to come out from winter retreats in search of food. Inex- 48 INSECTS INJURIOUS TO VEGETABLES pericnced persons apply for information after the principal damage is done, and before an answer in regard to remedial treatment can be received it is too late to apply remedies. In the treatment of insects which may always be expected, foi example the striped cucumber beetle, preparation should be made before the appearance of the pest. 8. In the case of many insects it is usually necessary to apply remedies more than once, sometimes three or four times, according to the number of generations of the insects, and whether severe rains have intervened to wash away applications before the insects have fed upon them. 9. If injury is severe it is often desirable to apply remedies for other insects and diseases which may be present, as other- wise the crop may be ruined, though the primary cause be re- moved. Fertilizers are often advisable to stimulate plants and enable the production of a crop in spite of insect injury. 10. Clean methods of farming are of more value in preventing injury than any other method that can be named, and if it were more generally observed insect injury would soon be very mate- rially reduced. 11. The cooperation of one's immediate neighbors is very desirable in the treatment of many insects, particularly those which arc not free-flying. 12. The timely application of a remedy acts as a preventive. CHAPTER V GENERAL CROP PESTS Injurious insects may be classified, as regards the nature of their food plants, into several more or less distinct groups. The most important of these are choice or special feeders, and include many of our worst pests. They attack only single crops or crops of a single class, save in the direst necessity when they sometimes resort to other crops and weeds. Examples of this group are the two asparagus beetles which live exclu- sively on asparagus, the cotton worm and boll weevil, which are injurious only to cotton, and the tobacco worms which affect only tobacco, tomato and plants of the same botanical family. Many insects are more or less nearly omnivorous. Although some have favorite host plants, they are likely to attack many other plants, and when extremely numerous or when the favored food becomes scarce they devour nearly every form of vegeta- tion that grows in the garden, field, orchard or forest. This group is not so numerous as the first and not so destructive, as a rule, because of attack being distributed, but certain cutworms and other caterpillars, leaf-beetles, flea-beetles, aphides and others may do very serious damage, while still others, like locusts and army worms, sweep over large areas and in a short time ruin entire crops. CUTWORMS AND RELATED INSECTS Cutworms are among the most troublesome insects with which the market gardener has to deal. They are familiar to most persons, and sooner or later everyone engaged in plant growing has to contend with these pests, for they are what are termed 49 50 INSECTS INJURIOUS TO VEGETABLES "general feeders," and al)le to eke out a living wherever they may be. Thus it happens tliat they are to be found in most gardens and nearly everywhere else, in pasture land, vineyards, fields and orchards, and even in greenhouses. The species are very numerous, and many of them, like white grubs and wireworms, were the original inhabitants of the soil of this country, but some have been supplanted in injuriousness by species introduced from abroad. Taken as a class, cutworms rank with such insects as the San Jose scale, Hessian fly, the chinch-bug, and others of our worst pests. When conditions favor the multiplication of cutworms they will feed upon anything green and succulent, whether foliage, flowers, buds, fruit, stalks, tubers, or roots. Although nearly ubi(juitous, they are more especially destructive in truck gar- dens, and young, tender plants when first set out, such as tomatoes, cabbage, and plants just appearing above the soil, such as potatoes and corn, suffer most seriously. Several are destructive to foliage of fruit trees, and from their habit of climbing, are known as climbing cutworms; while in years of unusual abundance, some assume the army worm habit. Cutworms are the progeny of owdet moths (fig. 27, c), and are nocturnal, remaining hidden during the day to come forth at night, the moths to mate and deposit their eggs, the cutworms to feast upon whatever happens to be most available and palatable. There are so luany species of injurious cutworms — between two or three score — that it is impossible to give a description that would fit all, but most common species are robust, soft- bodied, smooth or nearly smooth, cylindrical caterpillars, varying in color from pale whitish or dirty gray (like fig. 28, a), to near- ly black, many being more or less plainly striped or spotted, as is the case with the w-markcd cutworm shown in figure 25. They seldom attract attention except in early spring, and then experienced persons can only too readily detect their GENERAL CROP TESTS 5 1 presence by fiiKling young plants with tender stL-nis that have just been set out, cut off near the surface of the ground. The culprit rests in a curved position during the day concealed in the earth around the plants which it has destroyed during the previous night. Some species leave open holes where they have buried themselves in the earth, others seek shelter under any debris, such as old boards, stones or dead leaves, and a few species have pig. 25. -w-marked cutworm a habit of dragging portions of plants (Noctua cianaestma) which they have cut off to their sub- ^"^ ' ^^ terranean retreats where they can feed at leisure. ]\Iost species are single-brooded northward, but many produce two or more generations southward. The greatest injury, as previously stated, is done in early spring for the following reasons: The last-appearing genera- tion of moths issue from the ground in midsummer or autumn, and deposit eggs from which larvae hatch and feed until cold weather drives them to their winter quarters. A considerable proportion of such larv.-e are from half to three-quarters grown, and in this condition many hibernate, although a few species pass the winter in the pupal condition and less exceptionally as moths. The eggs are deposited, often in large masses, on such growth, grasses and weeds as spring up after a crop has been harvested, and when this is plowed under to m.^ke room for the new crop that is planted in spring, comparatively few plants come up, and as a result, the immature cutworms are forced to feed upon whatever is available. This explains their great destructiveness, as it is a matter of yearly occurrence in many neighborhoods for cutworms to destroy large portions of a planting and even entire crops, necessitating replanting sometimes a third or fourth time before a good stand can be obtained. The life histories of cutworms vary according to the species 52 INSECTS INJURIOUS TO VEGETABLES and tlic locality which each inhabits; hence little that is really typical of the group can be spoken of in general terms. After cutworms have accomplished their customary injuries in the spring and have attained full growth, they enter the earth, and many species remain in little, rather compact earthen cells (fig. 26) for several weeks or even months before assuming the pupal stage, which is of variable duration in thf^ summer, from three to six or more weeks before the moths is- sue to perform the functions of their nature. The Greasy Cutworm (Agrotis y/^silon Rott.) is typical as regards its general ap])earance and is abundant in most localities suitable to it. It is one of our larger species, measuring when Fig- 26.— Pupa of cutworm in earthen cell. (After Riley) Fig. 27. — Greasy cutworm, a. Larva; b. head of same; c, moth. Natural size. (After Riley & Howard, U. S. Dept. Agr.) mature about one inch and three-fourths. It is of the dull, dirty brown color, characteristic of so many cutworms, with the lower surface ])aler and greenish. The moth (fig. 27, c) has brown fore-wings marked with darker brown, more or less like GKNKRAl. CROP I'KSTS 53 the specimen figured, aiul wilh an average expanse of an inch and three-fourths. It is a cosmopolite. This cutworm has a most pernicious cutting habit. It will sever large tomato plants over six inches in height generally at an inch above ground, and after destroying one plant it travels to others and thus in a night a single worm ruins three or four plants. It shows Fig. 28- -Granulated cutworm- a. Larva; /, moth Natural size. (After Riley) some partiality for cabbage which it frequently devours as fast as transplanted. Potato, corn, lettuce and tobacco are favored, while ornamental flowering plants are not exempt. Of many plants it eats leaves and roots. It is probable that this species is double-brooded or has a dual method of hibernation. The Granulated Cutworm {Feltia anncxa Treitsk.) (fig. 28) is brownish gray and similar to the greasy cutworm, but lacks the greasy appearance, and may be recognized by the character which has suggested its English name. The entire surface of the body, as viewed with a magnifier, is seen to be closely covered with very small, round, blackish granules, each bearing a minute sharp point. The length, when full grown, is about an inch and one-half. The Variegated Cutworm (Peridroma saucia Hub.). — This is with little doubt the most destructive and widely known of all cutworms. It occurs nearly everywhere and although, like others of its kind, it appears to favor garden plants, it will 54 INSECTS INJURIOUS TO VEGETABLES attack nearly any form of vcgx-tation, feeding- on all parts ot plants when it occurs in numbers. It is a climbing cutworm, and when exceptionally abundant, assumes the army worm habit. Its progenitor is a large moth (fig. 29. a) with pale, grayish-brown fore-wings tinged with reddish and shaded with Fig. 29. — Variegated cutworm {Peridroma saucia). a, Moth; b, larva, lateral view; c, same coiled up; d, dark form, dorsal view. (After Howard, U. S. Dept. Agr.) darker brown. There is considerable variability in markings, which are often suffused. The same holds of the cutworm itself (fig. 29, c, d). At maturity this cutworm measures about one and three-fourths inches. The variegated cutworm is cosmo- politan in the broadest sense of the word, and is injurious throughout practically all arable regions. METHODS OF CONTROL Poisoned baits are the standard remedies against cutworms. To be effective they should be applied as soon as attack is noticed and are particularly valuable in cases where the direct application of poisons is impossible owing to the danger of poisoning persons or stock when it is used for food. There are two kinds of bait— fresh vegetable and bran mash. Vegetable bait. — Vegetable bait may be prepared by spraying GENERAL CROP PESTS 55 a patch of clover, or useless succulent plant with Paris green, I pound to 150 gallons of water; mowing it close to the ground, and placing it while fresh in small heaps about infested plants at intervals of a few feet. Owing to the wilting of this bait, in dry, sunny weather, it is advisable to cover each heap with a chip, shingle, or something similar. Bran mash or bran-arsenic mash is, according to some, still more efficacious. Paris green, white arsenic, or other arsenical can be used for poisoning, and in its preparation, on account of the weight of the poison and the fact that it soon sinks when stirred, it is best first to mix the bran with water and sugar and then add the poison. The proportions are 2 or 3 ounces of sugar or a similar quantity of glucose or molasses to a gallon of water and sufficient bran (about a pound per gallon) to make, when stirred, a mixture that will readily run through the fin- gers. Before planting a crop it is advisable to use bait, and for perfect success the ground should be bare, which will have the effect of practically compelling the cutworms to feed on it. Protection of plants that are set out, such as tomato and cab- bage, started under glass, may be secured by placing about the base of each a tablespoonful of poisoned bran or a small bunch of the poisoned vegetable. Sometimes it is feasible to dip plants like tomato and sweet potato in poison before setting out. Arsenate of lead is best for this purpose prepared as for spray- ing I pound to 25 — 50 gallons of water. Where it is possible, however, to spray grass or weeds which have grown up in fields about to be cultivated, this should be done, as it is an easy means for riddance of cutworms and less troublesome than the preparation and distribution of baits. Plants may also be pro- tected by paper wrappings and tin collars. Bordeaux mixture has been tested against the variegated cut- worm upon potato vines and asparagus. It was sprayed on as a remedy for blight, and it was discovered that plants thus treated were free from attack. The use of this fungicide as a 56 INSECTS INJURIOUS TO VEGETABLES cutworm deterrent is certainly advisable. In any case, it should be employed as a diluent for whatever arsenical is used. Hand methods. — On some plants it is next to impossible to apply any but hand methods with good results. Experiments in Washington State during 1900 demonstrated conclusively that in some cases it required less time to shake or brush the variegated cutworm from affected plants than to destroy them by spraying or otherwise. In ordinary cases of cutworms in greenhouses they can be held in check by hand-picking. It is the custom of some florists to hunt for them at night with a lantern, when they are feeding and can readily be discovered and destroyed. Treatment os an army ivorm. — When cutworms assume tlic habit of traveling in armies they should be treated in the same manner as advised against the fall army worm in pages which will follow. The Fall Army Worm (LapJiygma fnigipcrda S. & A.).— The fall army worm or grass-worm feeds normally on grasses and grains and weeds belonging to the grass family, but will attack in its seasons of abundance almost any form of vegetation that is encountered in its line of march. At such times it becomes a pest in garden and orchard, on lawns and in greenhouses, as well as in pastures and in fields of grain. The moth is quite unlike that of the common army worm and very variable, there usually being two distinct forms, a dull gray and an ornamented form (fig. 30, a and b) . The hind-wings are glistening white with rosy reflections. The wing expanse is from an inch to an inch and three-eighths. The eggs are deposited in clusters of from fifty or more, often in two or three layers. The mass is covered with down from the body of the moth. The differences between this and the true army worm are shown by figures 30, a, 2,ox and 31. This insect is undoubtedly native to North as well as South America. Its greater abundance in semitropical regions in- dicates that it was originallv. althousjh not in very recent times. GENERAL CROP I'ESTS 57 tropical. At present it is more at home in the South where opportunity is afforded for its increase in swamp land, among wild rice and rank grasses, but it is also acclimatized in the southern portions of the North and appears to be gradually working its way still farther northward. Injury has been noted as far north as Chicago and westward to Colorado and Montana. A feature of this insect's attack, from which it derives its name of fall army worm, is that it seldom does appreciable in- Fig. 30— Fall army worm, a. Moth, plain gray form; b, fore-wing of Prodenia-like form; c, larva; d, abdominal segment of larva; e, pupa. d. Twice natural size: others enlarged one-fourth. (Author's illustration, U. S- Dept. Agr.) Fig. 30x.-a, Head ot fall army worm; b. of army worm. Both enlarged. jury except in the fall. It is not often noticed, therefore, except in the extreme South, earlier than the first of August, while the outbreaks of the common army worm usually occur prior to that time. There is no doubt that there are two or three generations produced each year, and each succeeding generation usually becomes more destructive. It attacks practically all vegetables. The larvre, in years of ordinary abundance, live like cutworms 58 INSECTS INJURIOUS TO VEGETABLES and are -so dark and evidently secretive in their nature as to usually escape recognition. When, however, an undue increase in numbers takes place and the habit of moving in armies is assumed, their presence becomes manifest, too late, however, in most instances, for remedial treatment. Transformation to pupa takes place in little earthen cells, but occasionally pupae are not so protected. Methods of Control. — In the case of large armies in ex- tensive fields, poisons are of little value when outbreaks are at their height. When the armies are first noticed the "worms" are as a rule approaching maturity, they have effected much damage, and it is difficult at this stage to prevent them from passing from one field or other tract to another. It follows that, although arsenical poisons are valuable in many cases, we must place more reliance in preventives such as cultural and mechanical methods. In fields of young grain and on lawns many "worms" may be killed by crushing with a heavy roller, when the insects are at work early in the morning or toward dusk. In fields that are injured beyond recovery, sheep or other cattle may be turned in in numbers with benefit, as they will kill the larvae by trampling upon them. Other useful methods of this nature include trenching or ditching, or plowing deep furrows in advance of the traveling hosts to entrap the larvcX which will fall into them, and here they may be crushed by dragging logs or pieces of brush through the furrows. If possible to fill the trenches with water, or if they become partially filled by rains, the addition of a small quantity of kerosene, so as to form a thin scum over the surface of the water, will prove fatal to the "worms." Rotation of crops should always be practiced, as well as burning over fields when they are too badly infested to recover. Above all other precautions necessary to secure immunity from attack is that of keeping the fields free from volunteer grain GENERAL CROP PESTS 59 and wild grasses, since experience shows that these are the favorite hreeding grounds of the insect ; wlicn tlie larv.e hatch- ing from these eggs have devoured the grain and grasses they are driven to cukivated fields for food. Fall plowing and disking should always be practiced where circumstances will permit. The Army Worm (Hcliophila [Lciicania] unipiDicfa Haw.). — The true army worm is so well known as a grain and grass pest that a short account only need be given, more particularly since it seldom injures vegetables other than corn. Its general economy closely resembles that of the fall army worm, previously treated. The army worm proper (fig. 31) is larger, a little stouter, more distinctly striped and much smoother than the fall army worm, measuring about an inch and a fourth in length. The parent army worm is a pale yellow- ish brown moth with a white spot near the center of each fore-wing. This insect appears much earlier in the year than the fall species. From May to July it accomplishes it's greatest injury; and although nocturnal by nature, when conditions favor its increase it soon exhausts its food supply, crowds then gather and march in armies — the habit from which it has received its name — in the . , ,,r- • F'ig. 31.— Army heat of the day as well as at night. Winter is ^orm. About passed usually in the partially grown caterpillar one-third en- . , . larged. state in the same manner as with cutworms, injury may be accomplished by any generation, but is most often due to the second brood. Remedies are practically the same as advised for the fall army worm. 6o INSECTS INJURIOUS TO VEGETABLES MISCELLANEOUS CATERPILLARS Caterpillars of omnivorous habits other than cutworms and webworms may be divided into two groups — naked and hairy caterpillars. Both forms are in the main diurnal, at least during their early stages, but some naked species as they approach maturity crawl into shelter where they are more or less pro- tected from the sun's rays as well as from natural enemies. The Fig- 32.— Yellow bear, a. Female moth; b, full-grown larva; c, light form of larva, not quite mature; d, cocoon; e, pupa. All slightly enlarged. (Author's illustration, U. S. Dept. Agr.) naked caterpillars are more abundant and injurious, and include such species as the zebra and clover caterpillars and corn-ear worm. Among the hairy caterpillars are such well-known forms as the yellow bear (Diacrisia virginica, figure 32), salt-marsh and hedgehog caterpillars and smeared dagger. Most hairy caterpillars are rather more abundant on useless plants than on crops, a fortunate thing for the grower. gen]':ral crop picsts 6i Garden Webworm (Loxosfcgc sii)iilalis Gn.). — This species affords an excellent example of an insect that feeds normally on weeds and only in times of abundance becomes a pest and general feeder. In such times it will attack most vegetables. In 1885 a serious outbreak occurred over a large area in Kansas, Nebraska, ]\Iissouri. Arkansas, Texas, and in what was then known as Indian Territory. Corn suffered most and a replanting Fig. 33.— Garden webworm. a, Male moth; b, larva, lateral view; c, larva, dorsal view; d, anal segment; e, abdominal segment, lateral view; /, pupa; g, cremaster. (After Riley, except c, Chittenden, U. S. Dept. Agr.) was necessary in several instances, and the yield per acre was much reduced, owing .largely to the ravages of this webworm. The moth (fig. 33, a) is variable, yellow, buff, or reddish- brown. It has an expanse of wing of about three-quarters of an inch. The larva (b, c) varies also, the ground colors run- ning through pale and greenish yellow to dark yellow. It is strongly marked with black, piliferous spots (d, c). The garden webworm occurs generally throughout the United States and is most injurious in the South. Its favored natural food plant is "careless" weed ( Amaranthus). The caterpillar, soon after hatching, draws together the edges of a leaf by means of its web, or fastens together two contiguous leaves, forming a shelter, from which it crawls forth to feed. Remedies. — A spray of Paris green has been used with per- fect satisfaction against this webworm, the fact that it is more 62 INSECTS INJURIOUS Tl) VEGETABLES or less surrounded hy webs and leaf tissues offering little or no barrier to tbe etTects of tbe poison. In addition, elean cultural methods, including late plowing in the fall followed by deep plowing in spring, and the burning of all waste material and weeds, are of service in controlling this pest. Early planting is useful as a safeguard for some crops. LEAF-BEETLES Leaf-beetles (Chrysoiuclidcv) are among the most important groups of insects, economically speaking. Many of them select in the larval stage single species or plants of the same or similar botanical families, but the beetles arc more inclined to be omnivorous, and some devour nearly all forms of vegetation. Their larval habits are variable, but a considerable proportion subsist on plant tissue on the external su'rface of leaves. A smaller number develop in mines which they construct in the leaves or in the roots, in fruits and seeds, and even in flower heads and in stems. A familiar example of a leaf-beetle larva that lives externally on leaves is the Colorado potato beetle, and of the root-feeders are the corn root-worms. An example of those which live in seeds is the twelve-spotted asparagus beetle. Such as feed on the outer surfaces of leaves are more or less grub-like, with six true legs and a proleg at the posterior ex- tremity. Their colors are often well marked, red or yellow, with rows of black spots as in the case of the Colorado potato beetle. The root-feeders, however, arc pale, frequently white and elongate, even threadlike in form. The greatest amount of injury is generally due to the hiber- nated beetles on young and tender plants before they have made good growth. Some species, indeed, cause little trouble after this period, while others, like the Colorado beetle, occasion losses of greater or loss extent throughout the growing season of the plants which they affect. Our most common omnivorous leaf-beetle is the twelve- GENERAL CROP TICSTS 63 spotted cucumber beetle (fig. 3), the parent of the southern corn root-worm It will be considered more at length in the chapter on corn insects. FLEA-BEETLES Flea-bcetlcs (Halficiiii) constitute a sub-family of the leaf- beetles. They are of elongate oval form and similar color, frequently striped like the cucumber beetle, and may be dis- tinguished by their enormously developed hind thighs, which furnish them with powerful leaping ability. The most injurious forms are minute and dark-colored. Their habit of suddenly hopping from the vegetable on which they are feeding has given them the common name of flea-beetles or fleas, some species being known as "potato flea," "cabbage flea," etc., according to the plant infested. Many flea-beetles are general feeders, and nearly all are subject to a periodicity, dependent on factors with which we are little acquainted, but doubtless in large part traceable to atmospheric conditions, moist weather furnishing the best conditions for the development of the young or larva?, and dry weather being inimical to their increase, this hypothesis being based upon the knowledge that the larva; of many species are subterranean. Injury is frequently very severe on young plants and is due in the greatest measure to the ravages of the adult flea-beetles which frequently appear in prodigious numbers in cultivated fields and like a pestilence sweep everything before them, their depredations often necessitating the replanting of entire crops. The larvje of most flea-beetles develop in weeds, a compara- tively small proportion living on cultivated crops. Knowledge of this fact is of value in indicating methods of control. The Pale-striped Flea-beetle (Systcna hlanda Mels.) is a de- structive vegetable-feeding species. It measures about an eighth of an inch, is cream-colored, with nearly ])lu-k abdomen and eyes, and the wing-covers are ornamented with a bright sutural and two narrower marginal strii)es of dull light brown (fig- 34. &)• The larva is white and slender, with light brownish- 64 INSECTS INJURIOUS TO VEGETABLES yellow head. The legs end in blunt padlike processes. It is an American species and of rather wide distribution, from New Jersey southward to Georgia and westward to California. The beetle is nearly omnivorous and injurious to beans, beets, po- tatoes, tomatoes, eggplant, corn, carrot, melon and other cucur- I)its, turnip and other crucifers. It also attacks strawberry, cotton, oats, peanuts and the leaves of pear. The beetles some- times do severe damage in three or four days. The species hibernates as a beetle, and appears in the vicinity of the District Fig 34 —Pale-striped flea-beetle, a. Larva; b. beetle; c, eggs; d, sculpture of egg; e. anal segment, from side; /. same from above, a-d-, six times natural size; e. f, much enlarged. (Author's Illustration, U. S- Dept. Agr.) of Columbia early in June ; Qgg laying continues to the middle of July, if not later; injury is usually due to the beetles upon their first appearance and almost any valuable crop may be injured. The larvae live below the ground, and have been ob- served by the writer and others feeding on roots of corn, lamb's- quarters and Jamestown weed. The Banded Flea-beetle (Sysfcna tceniata Say). — The banded flea-beetle has similar habits to the preceding and similar struc- ture ; it was in fact, until quite recently very generally confused with the pale-striped form, and many references to injuries by it are really due to the latter. Like the latter it varies con- GENERAL CK(.)P TESTS 6^ siderably. It is polislied black with white stripes. A coninion dark form is shown in figure 35. METHODS OF CONTROL Arscnicals and Bordeaux mixture. — The best remedies for loaf-beetles and flea-beetles are Paris green or other arsenical and Bordeaux mixture, either in combination or separately. Bordeaux mixture alone acts as a deterrent, and the writer sug- gests that instead of using either one separately, or both in combination, that the greater portion of an infested field or garden be sprayed with the Bordeaux mix- ture freely and as often as may be nec- essary, particularly after heavy rains, while strips here and there be sprayed ex- clusively with Paris green. This will have the effect of driving the beetles from the Bordeaux-sprayed plants to the poi- soned ones. Paris green alone, dusted dry on infested plants, is thoroughly effective against many species. Arsenate of lead r 1 , r . , , Fig. 35.— Banded flea-beetle. IS preferable for spraymg tender dark variety. (Author's ii- plants like beans, whose foliage is lustration, u.s.Dept.Agr.) liable to scorching. Plants like to- mato, eggplant, and cabbage that are started under glass and that are liable to flea-beetle attack, should be dipped in a solution of Bordeaux mixture and Paris green or lead arsenate before transplanting. For direction see page 55. Kerosene emulsion and soap zcashes, even strong soap-suds, have been used with profit in combating some flea-beetles. Pyrethrum, dry, mixed with flour or road dust, may be em- ployed for small gardens. Cultural methods. — In the ])rotection of young plants knowl- edge of the fact that the Iarv 68 INSECTS INJURIOUS TO VEGETABLES the two are frequently confounded, and injuries inflicted by one attributed to the other. The form under consideration (fig. 37) is a little more slender, has three stripes on each wing-cover instead of two, and is a little longer. It is very abundant south- ward, and is partial to potato, cabbage, squash, and to beet tops. The Spotted Blister Beetle {Epicauta maculata Say). — The southwestern portion of the United States is the home of many species of blister beetles not found in the north and east. Among the most abundant is the species illustrated in figure 38. Its body is covered with fine gray hairs, with small areas on the elytra, through which the natural black of the body shows, giving it the appearance of a gray insect finely dotted with black. It abounds from Texas and New Mexico northward to South Dakota, thence westward to California and Oregon. It is found upon potato, beet, clover and other plants. Remedies. — Paris green is one of the best remedies for blister beetles when they occur on potatoes and most other crops. It may be applied dry, or as a spray, according to directions al- ready given in the discussion of insecticides. Arsenate of lead is also excellent for these pests. Repeated ap- plications are sometimes necessary, since the poisoned beetles are replaced by others. A remedy employed with success in the West consists in sending a line of men and boys through infested fields to drive the beetles, by short flights and running, before them until they alight in windrows of hay, straw, or other dry vegetable material which have previously been pre- pared along the leeward side of the field. When the beetles have taken refuge in such a windrow, it is fired and the beetles Fig-. 38-— Spotted blister beetle. (Author's illustra- tion, U. S. Dept- Agr.) GENERAL CROP PESTS 69 are burned. Whatever remedy is employed should be applied at the outset of attack in order to be of substantial value. GRASSHOPPERS AND RELATED INSECTS Of great importance in the West, and in some seasons in other regions, are numerous species of locusts, or short-horned grass- hoppers. Several related insects, such as katydids and crickets, are also injurious. All of these are general feeders, and as a rule destructive to vegetable crops only in seasons which have been particularly favorable to their multiplication. The num- bers of species of these insects mount into the hundreds, but the most important forms might be reduced to a double score. For present purposes it will be necessary to mention only a few of the most abundant forms. Grasshoppers are mostly large insects, with mouth-parts formed for biting, with young more or less closely resembling the adults, save for the lack of wings. Their name is sufficient indication of their habits : they live normally in grasses, and their hind thighs are enlarged for leaping. Everyone knows them so well that further descrip- tion is unnecessary. . Some species are capable of extended flight for hundreds of miles with intermissions of daily stops for food. At such times they occur in swarms, and sometimes darken the face of the sun, or at night of the moon. Grasshoppers may be classified in regard to their habits as non-migratory and migratory. In the latter group are our com- monest species which breed and pass their entire lives in or near the place where the eggs were laid from which they de- velop. The migratory species develop in enormous numbers, and when they become too abundant for the food supply of the region where they originated .they migrate. They are most troublesome in arid and semi-desert regions, and their numbers are subject to variation according to climatic conditions and locality. Dry regions are liable to the visitation of a locust 70 INSECTS INJURIOl'S TO VEGETABLES swarm at any time of the year, and they are the most dreaded of pests, because of the rapidity of their attack, when they lay waste lari^e (hstricts, and even considerable portions of states. The Red-legged Locust {Mclanoplus fcrmir-rubrum DeG.).— This is our commonest North American grasshopper, being found practically everywhere. Tt is one of the smaller species (fig- 39)' ^iid where it is not held in subjection by natural enemies it may become a de- cided nuisance in cultivated lands. It seldom exhibits the migratory tendency, but some- times gathers in swarms and moves in concert, not. however, rising to great heights, but drifting with the wind as do the true migratory species. The Rocky Mountain Locust (Mclanoplus sprctiis Thomas). — This is the most destructive of all native grasshoppers, and has been the cause of greater losses to agriculture in the past than perhaps all of the other known species of grasshoppers Fig 39-— Me/anoplus femur-rubnim Natural size. (After Riley) Fig. 40-— Rocky Mountain locust, a. a, a. Female ovipositing; b, egg-pod extracted from ground, with end broken open: c. a few eggs lying loose on ground; d, e, earth removed, to illustrate egg-mass in place and one being placed;/, wliere a mass has been covered up. (After Riley). GENKRAL CROP PESTS Jl combined. Its range of injuriotisness is not limited to the Rocky Mountain region, but it is more abundant there than elsewhere. It is illustrated in figure 40. Those who were interested in farming in the 70's in Kansas, Nebraska, and some neighboring states have cause to remember the depredations of the Rocky Mountain locust. During 1874-1877 it was directly responsible for the loss of $100,000,000, in addition to an indirect loss by the stoppage of business and other enterprises which might have aggregated as much more. It was for an investigation of this species that the United States Entomological Commission was formed, which published from 1877 to 1879 two voluminous reports on it alone. The Differential Locust {Mclanoplns diifcrentialis Thomas) . — In the Middle West the farmer is much bothered at times by Fig. A\-—Melanoplus differentialis- Natural size (After Riley) the large yellow locust, shown in figure 41. It is found along roadsides and on the edges of groves, preferring rank vegeta- tion where such abounds. When it becomes unusually numer- ous it is quite destructive to vegetable crops and to cereals. METHODS OF CONTROL Locusts or grasshoppers are largely kept within normal num- bers by numerous enemies, among which are many large forms of insectivorous birds and mammals, batrachians and reptiles. They also have large numbers of predaceous and parasitic insect enemies, which kill them off in ordinary seasons. With changes of the weather, however, the insect enemies are frequently de- stroyed, and then the locusts become abundant. In such cases ^^2 INSECTS INJURIOUS TO VEGETABLES the grasshoppers can be controlled by several artificial methods. The remedies that have proved most efficient are plowing under the eggs before these have had time to hatch, and the capture by means of hopper-dozers of the unfledged locusts, as well as many of those which have become winged. These are shallow sheet-iron pans in which are placed tar or coal-oil tar or kero- sene oil, and which may be drawn or pushed by hand over the ground or by horses, in such a manner that the hoppers will leap into the pans and be killed by coming into contact with the tar or oil. Hopper-dozers are shown in figures 213; and 2\z. Other remedies of great value in the prevention of injury to our cultivated crops are the bran-arsenic mixture and poisoned horse droppings. Directions for preparing the former have been given on page 54. Poisoned horse droppings consist of i part of Paris green mixed thoroughly in 60 parts of fresh horse droppings, 2 pounds of salt to half a barrel of mixture being added after being dis- solved in water. This is placed in half barrels and drawn on carts to the edge of the infested field or one likely to be invaded. The mixture is then scattered broadcast along the edge of the crop, or wherever needed, by means of a trowel or wooden paddle. The locusts are attracted to it and are killed in large numbers by eating the poison. Although this mixture is "sure death," it sometimes requires from two to five days for it to kill the locusts. Turkeys are of great value in freeing orchards and vine- yards of locusts, and they may be employed in other fields for the same purpose. In one case a flock of 766 turkeys were kept at work in the destruction of grasshoppers. The turkeys have to be watched, as they sometimes vary their diet with vegetables. In some cases it has been possible to ascertain the particular breeding places of grasshoppers, some species depositing their eggs in pasture lands and among foothills at the bases of mountains in the Far West, in regions in which the tar weed GENERAL CROP PESTS 73 grows. Here the eggs can be destroyed by burning over the ground late in the fall after all of the eggs are deposited, or by plowing them in to a depth of six or eight inches before they hatch in the spring. In case it is for any reason not feasible to employ any of these last mentioned remedies, and the place of egg deposit is ascertained, a watch should be kept for the young grasshoppers, and they should be destroyed as soon as possible after hatching by means of bran-arsenic mash. Cooperation is greatly desirable in the treatment of grass- hoppers, particularly in regions where they reach their greatest development ; and the thoroughness with which work is done in one year will show the next season in the greatly reduced numbers with which the farmers will have to deal. Remedies for grasshoppers in general are applicable to the migratory species, but the latter sometimes occur in such im- mense swarms that it is difficult to treat them. It is of the highest importance that whatever remedies are employed must be used at the very first onset and generally over considerable territory, as the insects fly from one field to another. WHITE GRUBS White grubs occupy a prominent position among the many insect foes to agriculture. There are several hundred distinct forms of these creatures, each representing a different species of the family Scarabaeidse. A considerable number are of prime importance economically, the remainder are less injurious or do not attack useful plants. The noxious forms subsist on roots and are very abundant under sod, and in similar locations. Of these a considerable majority of the typical white grubs belong to the genus Lachnosterna, of which nearly a hundred species are known. The parents of white grubs are known as May beetles or "May bugs" in the South and Middle states, and as June beetles 74 INSECTS INJURIOUS TO VEGETABLES or "June bugs" in the North, from their occurrence in numbers in these months in these different regions. Injury is by no means confined to the white grubs, but can often be laid to the account of the beetles, but the latter are most destructive to shade and fruit trees. White grubs or "grub-worms," with wireworms and cutworms were the original inhabitants of the soil before the advent of civilized man. They lived in our open prairies when America was still a wilderness, and they continue to dwell in our grass lands, meadows, fields and gardens and repel all attempts toward their permanent removal. The farmer who imprudently plants corn or potatoes in fields that have long laid waste and become grown up with weeds and grasses, or where strawberries have been the previous season, does so at the risk of losing his crop. The problem of how to destroy them and to protect the crops from their ravages is a subject requiring constant and scientific treatment. Injury appears to be most noticeable to corn, grasses, small grains, beets, potatoes and other root crops, and strawberries, but the roots of young shade, fruit and forest trees are also attacked. As with insects of similar habits, white grubs and May beetles are liable to considerable fluctuation of numbers in dif- ferent localities and years. This is most noticeable after crop rotation, particularly, as might be inferred from what has al- ready been said, where susceptible crops are planted in grass lands. Attack may commence from the time the plant sends out roots, and continue for a much longer time, as these insects pass two or three years from the egg until they reach the adult condition. When the larvae are present in great numbers at the roots, the plants soon die and whole crops are ruined. In a general way white grubs may be described as large, soft white or yellowish grubs, with wrinkled bodies, sparsely covered with fine hairs, having yellowish or brownish heads with strong nian(lil)les, three pairs of distinct legs on the fore part of the GENERAL CROP PESTS 75 body (the three thoracic segments) and the hinder portion of the body considerably thickened toward the end. Tlie normal position of typical white grubs is curved, as shown in figure 42, c. They crawl on their sides, not on their backs as is the case with the non-injurious white grub of the June beetle. The parents of the injurious or typical white grubs (Lach- Fig. 42.— Arcuate May beetle, a. Beetle; b, pupa; c, egg; d. newly- hatched larva; e, mature larva; /, anal segment of same. (Author's illustration, U. S. Dept. Agr.) nostcrna spp.) are for the most part large, shining brown beetles, known to every one from their habit of flying into lighted rooms through open windows, in late spring and early summer, buzzing and bumping upon the ceilings and walls and finally falling to the floor. A comparatively small number are yel- lowish, or plum color, and some few are nearly blad'C. From April to July, according to climate, these beetles appear, often in great numbers, about our electric lights and upon our fruit and shade trees, their appearance each day beginning al- most uniformly at sundown. They feed voraciously upon the leaves of trees, and bushes such as blackberry, but are especially fond of the foliage of nursery stock and other young trees, particularly oak, chestnut, hickory, maple, and fruit trees, often doing such damage to newly transplanted shade and orchard trees as to result in their complete defoliation and destruction. The beetles fly and feed only at night, and during the day remain perfectly quiet in the vicinity of their feeding places. It has lately been shown conclusively (what was previously in- 7^ INSECTS INJURIOUS TO VEGETABLES ferrecl by deduction) that one species, Lachnostcnia orcnata! requires only a little over two years for larval development, but about three years are consumed from the time the egg is laid until the appearance of the beetle above the ground, and this is probably true of most of the species which occur in this country. Thirteen days was ascertained as the tgg period, twenty-three for the pupa, and the total period from egg to adult required two years and fifty-one days. The sexes pair soon after their first appearance and the females enter the earth for oviposition. The eggs, which are rather large and whitish or gray, are deposited singly in the ground. The grubs, hatching among the roots of grass and similar plants, feed at first upon the tender rootlets and after- ward on the larger roots, and slowly increase in size until mature. The species which have been observed usually transform to pupae from the middle of June to September of the second or third year after hatching, and become fully-developed beetles in August or September of the same year. They remain in the earthen cells in which transformation has taken place, some- times at a depth of from twelve to eighteen inches, where they are protected from cold and frost, and appear abroad the fol- lowing spring to repeat the life cycle. Hibernation may occur in two stages of the larva, and occasionally in a third, and as beetles. The Arcuate May Beetle (Lachnostcrna arcnata Sm.) is the common May beetle of the Middle Atlantic region. The North- ern June Beetle (Lachnostcra fiisca Frohl.) is abundant in the Middle Atlantic region, and is quite as destructive and over a wider extent of territory. It is the common species from New England to Illinois, and occurs, but comparatively rarely, farther west. A large proportion of the injury caused by white grubs and June beetles in the region specified are due to this insect. » See article by the writer, Bui. No. 19, Div. Ent., U. S. Dept. Agr., pp. 74-80. GENERAL CROP TESTS ^^J The winged Northern forms of May beetles are replaced in Texas and some other portions of the South by three common species, two wingless (Lachnostcnia crihrosa Lee. [fig. 43] and L. lanccolata Say) and one with similar habits (L. farcta Lee.) which do great damage in their beetle stage to trucking industries. They subsist largely upon weeds, hence in addition to treating af- fected plants with arsenicals, the weeds should be similarly treated. Late fall or winter plowing and avoidance of weedy fields for planting are advisable as pre- ventives. Swine should be used for de- stroying them and on small areas hand- picking can be employed, when the beetles p^^ '^2,.- Lachnosiema cHb- make their appearance an hour or more '"o^a- Female. (Sander- ^^ son, U. S. Dept. Agr.) before sundown. Among white grubs that are likely to be mistaken for the more injurious forms (Lachnostcnia spp.) are the carrot beetle, which will be considered in a later chapter; the "muck worm," which occurs in manure and in the droppings of cattle, and which appears to be normally a purely dung-feeding species; the sugar-cane beetle; the rice grub; the green June beetle, and the brown fruit-chafer, which last will be described in the consideration of insects affecting sweet corn. PKEDACEOUS AND PARASITIC ENEMIES Although white grubs are apparently protected by their sub- terranean mode of existence and their life, as beetles, is com- paratively brief, many predatory animals as well as parasitic and predaceous insects attack and destroy them. Birds of sev- eral species and most wild mammals which still linger in cul- tivated regions are among this number. Domestic fowls are very fond of white grubs and. when given the opportunity, fol- 78 INSECTS INJURIOUS TO VEGETABLES low the plow for them. Swine also search out and eat many which they obtain by uprooting the turf. Of the insect enemies of white grubs are Tachina flies, wasps Fig. '^A.— Tiphia inomata- Parasite of white grub, a. Female wasp; b, head of larva; c, larva from below; d, cocoon cut open. (After Riley) and parasitic Hymenoptera, mites, and predaceous ants. Among these insects is the wasp, Tiphia inomata (fig. 44). Under certain conditions white grubs are also much subject to infec- tion by fungous parasites. REMEDIES FOR WHITE GRUBS Insecticides. — Good results have followed the use of bisulphid of carbon and kerosene emulsion against some species. The emulsion is diluted about ten times and poured on the ground about the infested plants. Application is made just before rain- fall, to insure the emulsion being washed deep into the soil so as to come into direct contact with the larvse. If rain does not fall within a day or two a copious watering should follow the application. Gas lime is also valuable. (See page 34.) Fall ploK ing is a most effective remedy. The land should be thoroughly broken, and loosened to expose the grubs and beetles to the elements during winter. This is particularly valuable in cold climates, as white grubs are unable to with- stand exposure to severe frost. Cross-plowing is sometimes advisable where there is severe infestation. This will insure the ground being often disturbed, and, if kept clean of weeds and other vegetation, the grubs can be "wiped out." Preventive measures are still more valuable. The best of GENERAL CROP PESTS 79 these consists in avoiding for the planting of vegetable crops land which is already known to contain white grubs and espe- cially grasslands, whether meadow or prairie. Corn fields should not be planted to root crops and the like without rotation with clover or other immune crops. Summer fallowing of infested land is said to be useful. Rotation of crops is valuable in connection with fall plowing. In case infested land is desired for the planting of corn, beets, potatoes, or other crop subject to severe injuries by white grubs, an application of fertilizer, such as nitrate of soda or kainit, put on as a heavy top dressing after the ground is prepared and before planting, has proved of benefit in some cases. Domestic animals.— Much good may be accomplished by en- couraging domestic fowls to follow in the furrows to pick up the grubs as they are turned up by the plow. Hogs are also exceedingly fond of white grubs, and if allowed the run of localities where these are abundant, after the crop is made, they will root up the ground and devour great numbers of them. WIREWORMS Of similar importance to white grubs as general farm pests are the wireworms. Though not related to the white grubs, they have very similar habits, the injurious vegetable-feeding forms being strictly subterranean and subsisting at the expense of various crops, especially corn, cereals, and grasses, but at- tacking, in the absence of these, various vegetables and other plants. The subject of soil and environment as regards attack by wireworms has not been thoroughly studied, but certain species are more numerous in sandy lands, and others are almost always found in unbroken prairies and in wild grasses. Thus it happens that, as in the case of white grubs, injury is most apt to occur when corn and other vegetables are planted in old sod, along the borders of marshes, in pastures and meadows. Nearly every tiller of the soil is familiar with wireworms, 8o INSECTS INJURIOUS TO VEGETABLES and there are many species, but, fortunately, a small percentage only of nearly 600 described forms have been identified in con- nection with losses. From an agricultural viewpoint they fall into two classes, such as feed upon living vegetation, and those which subsist upon rotten wood and similar material. Most of the noxious forms that have been recognized are wire-like, hence the common name, and are nearly cylindrical, hard, smooth and shining, and of a yellowish or reddish color. They have three pairs of legs placed far forward on the anterior extremity, and the last segment (the thir- teenth counting the head) ends in a proleg on the un- Fig. 45. — Wheat wireworm. a. Beetle: b, larva: c, anal segment of larva in profile. (Author's illustration, U. S. Dept. Agr.) Fig. 46. — Common click- beetle. Three times natural size. (After Forbes.) der surface. They are surprisingly hard in texture and among the most vigorous insects known, being difficult to poison by means of anything that has been tried. A common and destruc- tive species known as the wheat wireworm (Agriotes mancus Say) is illustrated by figure 45. GENERAL CROP PESTS 8l Wirewornis arc the offspring of snapping or click Ijcctlcs or "snap-bugs," which arc rather liard, pubescent creatures of elongate, oval form, and readily distinguishable from any other insects by the habit from which their common name has been derived, of vaulting into the air with a sudden click when they happen to fall upon their backs. The common click-beetle (Mclanotus communis Gyll.) is shown in figure 46. Of the various vegetable crops attacked potatoes, according to record, are most injured, by having the surface of the tubers gnawed into and eroded by the worms." Turnips suffer similar injury, as do also to a less extent carrots, beets, cabbage, onions, lettuce, and others. In attacking growing plants wirewornis usually devour the smaller roots or tender tubers, according to the plant affected, and in the case of attack on corn they fre- quently kill the plant by boring cylindrical channels through the under-ground portions of the stalk. The life histories and habits of wireworms vary according to species and climate, but in many respects they resemble the white grubs so closely that details may be omitted. The Cornell University experiment station carried on, through Messrs. Comstock and Slingerland, a valuable series of experi- ments against these pests extending over three years, with the result that none of the alleged standard remedies produced satisfactory effects. In short, the results were negative rather than positive, and no single method has yet been devised by which we can destroy these insects as we can most other pests. This is due to natural causes — viz., to the hardness and con- sequent hardiness of wireworms, two qualities which go hand in hand as regards insects and which render these creatures almost impervious to poisons that would destroy other insects, and to the fact that they live during nearly their entire active stage as wireworms usually rather deeply in the soil. They require two or three years, like the white grubs, for full matur- ity from egg to adult. 82 INSECTS INJURIOUS TO VEGETABLES METHODS OF CONTROL No application that can be made to the soil will kill the wire- worms without, at the same time, rendering the land unfit for cultivation for some time afterward. Most remedies, preventives, repellents and poisons that have been tried are hardly more than palliative. From among these the ones that give most promise are early fall plowing, the use of poisoned baits early in the season, with the selection of un- infested land for planting, and rotation of crops. We are in fact confronted with much the same problems as in the treat- ment of white grubs, only wireworms are even more difficult of suppression. Selection of land for planting —The most important of de- fensive methods is the selection of the land for planting. It is inadvi-sable to plant crops peculiarly subject to wirevvorm attack, such as corn, potatoes, and other vegetables, as well as cereals in sod land or in unbroken prairie, and it is equally unwise to'^cultivate such crops in fields in which wireworms are known to be present. Fall plowing. — Infested or "suspicious" soil should first be prepared for the crop by plowing early in the fall. By this process the cells in which the pupae and hibernating adults are resting are broken up and the insects destroyed in great num- bers, so that fewer individuals survive to deposit eggs for an- other generation of wireworms the following year. Such as are not destroyed outright by this method will be more exposed to the elements and to predatory enemies. Crop rotation should also be practiced in the same manner as prescribed for white grubs. In addition to clover, buckwheat is said to be a valuable alternate because of the roots being too tough and hard to be injured, and possibly this is true of some forms of wireworms, but not of all, so we cannot place much reliance on this crop. If clover or other alternate be allowed to remain for one or two years after grass has been cut, veg- GENERAL CROP PESTS 83 ctablcs subject to attack can then be planted with much less danger of serious infestation. It is difficult with our present knowledge to name an absolutely immune crop. Poisoned baits. — An efficacious remedy is found in poisoned baits. One of these consists in sowing corn, soaked in water, containing arsenic or strychnine, over the field about ten days before the crop is planted and then harrowing it in. The larvae that attack the poisoned kernels will be destroyed. For luring beetles, as well as larv?e, baits of sliced potatoes or other veg- etables, or wads of succulent vegetation, such as clover, or pig- weed, or sweetened corn-meal dough, are useful. These are poisoned in the same manner as the corn and placed about the fields under boards early in the season. These traps should be renewed as often as possible. Experiments have shown the futility of starvation of wireworms by clean fallowing. Although these remedies are not infallible against wire- worms, they are of value in certain sorts of soils against some species, and they serve in a manner to destroy white grubs and cutworms which are also apt to be present. APHIDES, PLANT-BUGS AND RELATED INSECTS Nearly all forms of plants are attacked by sucking insects, the aphides, plant-bugs, leafhoppers and numerous related forms. The best known are the aphides or plant-lice, many of which do injury to vegetable crops. Among other insects which obtain nourishment by suction are several species of true bugs of the family Capsidae, generally termed plant-bugs, although some forms are also known as leaf-bugs, chinch bugs, and other names indicative of their habits or appearance. The commonest and most injurious of these insects to vegetables are two forms of false chinch bugs, the tarnished plant-bug and garden flea-hopper. The thrips also obtain their food by suc- tion, and for convenience may be included in the same category, although they are not closely related to them structurally. 84 INSECTS INJURIOUS TO VEGETABLES Aphides or Plant-lice. — Nearly every one knows the plant- lice or aphides, since there are few succulent plants that are exempt from their attack. Many staple cri)ps of the field, garden, and orchard are very severely damaged when these insects multiply in unusual numbers, as so frequently happens. Aphides are also known as "lice," "aphis'" and "green fly." There are many species, as varied in appearance as Tn habits, and although they have attracted attention for years on account of the injuries which they cause and their interesting habits, they are perhaps less understood than any large group of insects which could be named. In fact, we are not as yet able to estab- lish beyond a certain degree of doubt the identity of some of our most injurious forms and we know less of their life economy. Gardens are seldom free from their attacks, and cabbage and like crops, melons, cucumbers and similar plants, peas and young budding fruit trees suffer severely in some seasons. The best-known aphides are soft-bodied and green, very minute in size, with long legs and antennae. Immense masses of them frequently congregate on single plants, sometimes over- running entire fields. If a mass l)e closely examined it will be seen that many are wingless during the greater part of the season ; later, however, there are many which develop wings and are capable of flight. There are many stages of these in- sects, but the body is usually formed more or less like a pear, and the winged forms have two pairs of very delicate trans- parent wings with a few simple veins. The first and second pairs of wings are usually connected as in wasps and bees, by a booklet. The haustellum or beak by which aphides obtain their food is three-jointed and of variable length. The eyes are compound and project prominently at the sides of the head. The aphides exude "honey-dew," a transparent fluid with a sweetish taste. iM-eciuently it is excreted in such (juantity that it forms a shining cover to the leaves of plants. The honey-dew of most species is very attractive to a number of GENERAL CROP TESTS 85 Other insects — ants, wasps, bees and flies — and in the fond- ness of ants for this substance there is developed a curious inter-relationship. The various phases of development, the varieties of forms produced by some genera, in fact, the life economies of these Fig. 47.— Melon aphis, a. Winged female; aa. enlarged antenna of same; ab. dark female, sida view: b, young nymph or larva c. last stage of nymph; d, wingless female — all greatly enlarged. (Author s Illustration, U. S. Dept. Agr.) Fig. 48.— Flavescent leaf- hopper (Empoasca flaves- cens). Highly magnified. (Author's Illustration, U. S. Dept. Agr.) insects would fill several volumes, and there is such great diversity of habit that it is difficult to generalize. The species which feed upon vegetable crops live for the most part on the under surface of leaves; but some are root-feeders, and the destructive grape phylloxera is an example of one of these subterranean forms which produce galls. The melon aphis (fig. 47) is one of our commonest and best known vegetable-feeding forms of this class. The best remedies for aphides are kerosene emulsion, fumiga- tion with bisulphid of carbon and with tobacco extracts, clean cultural methods of farming and the encouragement of natural enemies. These remedies are considered on pages 165 to 168. The Leafhoppers. — Leafhoppers are familiar to nearly everyone, although not everybody knows them by this name. 86 INSECTS INJURIOUS TO VEGETAELES As we walk over lawns and through meadows and pastures generally, particularly in niidsuninier and later, myriads of these minute creatures fly up and are sometimes annoying by getting into our faces and even our eyes. Recently their true economic value has been ascertained, and this was brought about mainly through the studies of Prof. Herbert Osborn, in Iowa. They are most numerous in grasses from which they drain the vitality by sucking the sap from the blades. It has been estimated that between one-fourth and one-half of all the grass growing annually is destroyed by leafhoppers, a startling statement but borne out by actual observation. Although most of these insects feed on grasses, there are some which, partic- ularly in their later stages as nymphs and as adults, attack various vegetables and other plants. Leafhoppers are mostly small, some very minute and slender, with short heads more or less crescent-shaped, and with long hind-legs which fit them for jumping. They also have long wings and are strong flyers. The species illustrated (fig. 48) attacks a variety of vegetables. In their attacks on plants the usual method is to puncture the cells from the under side of the leaves, causing yellowish, brownish or other discolored spots to appear later. When punctures are numerous entire leaves wilt and die. A few forms attack culinary vegetables by preference, but most others occur on different plants. No less than thirty distinct species have been found on beets. Methods of Control. — Several methods have been devised for keeping leafhoppers in subjection. The standard remedies are kerosene-soap emulsion and sprays of soap. An underspray- ing is always necessary. The spray should be as fine as possible, and applied upon the first appearance of the insects, not only to produce the best effect, but because by using it early in the spring the insects may be prevented from developing in large numbers later in the season, for with many forms there are two and sometimes three generations produced annually. GENERAL CROP PESTS 87 Leafhoppers may also be captured on sticky surfaces, and one good way of destroying them in small gardens is by causing them to fly up and capturing them on large frames coated with sticky substances such as coal tar. If this method is persisted in for several days few of the insects will be left, as they are readily caught. A good time for this work is just before sun- down. Special hopper-dozers are used for leafhoppers, similar to those described as grasshopper destroyers (page 71). Some of these are termed "hopperettes." The Tarnished Plant-bug (Lygus pratensis Linn.). — This bug Fig. 49 —Tarnished plant-bug. Adult at left: last stage of nymph at right (Author's illustration, U. S. Dept. Agr.) is one of the most troublesome of its kind. It is found prac- tically everywhere in North America, and attacks many plants, cultivated and wild. It occurs throughout the warm season, and frequently does damage to vegetables and to trees grown in nurseries. The mature plant-bug (fig. 49) is of nearly elliptical form, and considerably flattened. The head is nearly triangular, with the eyes showing prominently at the sides. It is pale, obscure, grayish brown, marked with black and yellow, the thorax also with red. The length is about one-fifth of an inch. With little doubt this plant-bug has five stages of the nymphs to agree with related species which have been traced through their metamorphoses. The first stage measures only about one- 88 INSECTS INJURIOUS TO VEGETABLES twentieth of an inch, and is yellowish green. This species is quite injurious to cahbage, turnip, potato and cucumber, and attacks also salsify and celery. The principal injury is ac- complished in the spring, by the adults piercing and sucking the juices from flowers and leaf-buds, and later by attacking tender fruits and shoots. The tarnished plant-bug is credited with being the author of "buttoning" of strawberries, and forms of "blight," the insect in the latter case acting as a transmitter of germs from dis- eased to healthy plants. Were it not that this plant-bug dis- tributed its attack by feeding on a variety of crops and weeds, it would be more injurious than it is. The bugs are extremely active, quick of flight as well as of foot, and when disturbed have the habit, in common with kindred species, of hiding by dodging to the opposite side of a plant. Hibernation is usually in the adult stage. In early spring, the females deposit their eggs singly on plants, continuing for two weeks or longer. According to Prof. J. M. Stedman. three generations develop in southern Missouri, and two in the northern portion of that state. The duration of the life cycle may be placed approx- imately at about four weeks, or a little longer, the length of time depending on season and climate. Remedies. — The standard bug remedy, kerosene emulsion, is the best, sprayed on as thoroughly as possible to all crop plants as well as weeds attacked. Pyrethrum is of value, but must be applied repeatedly and is rather expensive. Hand methods are also valuable, and a hand net is useful for sweeping the plants and surrounding grass and other vegetation. Frequently more individuals can be captured in this way than in any other. When a considerable number have been taken, they can be killed by throwing them into large pans of water with a few drops of kero.sene. After the crop is off "back firing" should be practiced in the same manner as described as a remedy for army worms on page 58. GENERAL CROP PESTS 89 The Onion Thrips (Thrips tabaci Lincl.)- — Few gardeners are unacquainted with "thrips," of which there are several species injurious to plants grown under glass. The commonest and most destructive vegetable-feeding species in America are the onion thrips and the wheat thrips. All thrips are exceedingly minute, the common species not exceeding one-twentieth of an inch in length. They have y=^^=^f^^^^::::^ '"AW;;;, "•'"^ S^'ig. 50.— Onion thrips. a, Adult: b, antenna of same; c, young larva; d, full-crown larva— greatly enlarged. (Howard, U. S. Dept. Agr.) elongate bodies, and the winged lorms have four very slender wings fringed with long, delicate hairs. These insects are somewhat anomalous in the manner of their feeding: their mouth-parts are fitted, chieily for sucking, but they also have bristle-like mandibles. The general appearance of the onion thrips is shown in figure 50. a, highly magnified. It is pale yellow, with the thorax somewhat darker. The wings are paler yellow, with dusky fringes and bristles. The parent insects are usually found on the lower sides of leaves or imbedded in flowers of various kinds. In their attacks they induce the withering of the parts affected, and they some- times destroy entire plantings. The onion thrips injures a great variety of field and garden crops, to which it is quite as de- structive as to plants grown artificially. Besides onion it in- juriously affects garden leek, parsley, cabbage, celery, melon, 90 INSECTS INJURIOUS TO VEGETABLES cucumber, squash, turnip, cauliflower and strawberry, and does more or less damage to nasturtium, mignonette, carnations, candytuft, four-o'clock and rudbeckia. The female thrips cuts a slit, in a leaf or stem usually, to deposit her eggs. In a few days the young thrips work their way out and begin to feed. They suck the juices of plants and, as they feed continuously, their growth is rapid. The entire life cycle from the time of the deposition of the eggs until the maturing" of the adult is passed under favorable conditions, in a warm atmosphere, in three weeks. Out-of-doors in a cooler atmosphere a longer period would be required for the life cycle. The minute size of thrips, with their habits of feeding by suction, in concealment in their host plants, renders it difficult to treat them successfully. The best contact poisons are dilute kerosene-soap emulsion, applied as for aphides (p. 361). It is practicable in some cases to dip whole plants, when being transferred from the hothouse to the field, in kerosene emulsion. For fumigation, hydrocyanic-acid gas, carbon bisulphid and different preparations of tobacco are useful. Tobacco prepara- tions, containing about 40 per cent, nicotine, have been found effective at the rate of 5 or 6 teaspoonfuls to Ij4 pints of water when vaporized in a space of 5,000 cubic feet. This method does not injure cucumbers while nearly all the thrips on plants thus treated are killed. In the field drenching affected plants with a hose will kill many of the pests. Clean methods of farming is a necessity, as thrips develop largely in grasses, weeds and other vege- tation in and near onion fields. All other infested plants should also be treated with kerosene-soap emulsion, and the weeds Inirned where possible. The Wheat Thrips (Thrips tritici Fitch). — This native spe- cies, also called the strawberry midget, has been reported as GENERAr, CROP PESTS 91 doing injury to parsley, pea, endive, cotton, orchard and small fruits and roses. Its color is yellow, with the thorax tinged with orange, and the antenn?e or feelers are ringed with a dusky color (fig- 15)- It is distributed from Canada to Florida, and westward. Remedies. — The same as for the onion thrips. The Red Spider {Tctranychns bimacidatus Haw.). — Few vegetables are free from the attacks of red spider (fig. 50^;). These creatures are extremely minute, and are frequently not noticed until they become excessively numerous, as hap- pens during summer droughts. They do considerable damage in vegetable gardens and to plants grown under glass. Remedies. — Flowers of sul- phur, mixed with water at the ration of one ounce to the gallon, and sprayed over the plants, is of great value in eradicating this pest. Fish-oil and other soap solutions are F'g- 50x -Red spider, o, Adult; b. palpus- . r ^' c'aws. (After Banks, U- S- Dept. Agr .) valuable, and the addition of sulphur increases their effectiveness, but are too strong for some delicate plants. Greenhouse plants are sprayed with water two or three times a week during the growing season, and care is exercised to wash off the spiders and not drench the beds. Fig. 5 1 .—Spray of asparagus, with common asparagus beetle in different stages Natural size. (Author's illustration, U. S. Dept. Agr.) Q2 CHAPTER VI INSECTS INJURIOUS TO ASPARAGUS Asparagus was introduced into America with the early settlers from Europe, and was cultivated here for two hundred years before being troubled with insects. Few edible plants down to the time of the Civil War have enjoyed such immunity from the ravages of insects. The principal insect enemies of asparagus are two leaf-beetles, both imported from the Old World, and limited for food supply to this plant. The Common Asparagus Beetle {Crioceris asparagi Linn.), as its English name indicates, is the more abundant asparagus Fig. 52. — Common asparagus beetle, full-grown larva; e, pupa— a. Beetle: b, egg; c, newly-liatched larva; d, 11 enlarged. (Author's illustration) beetle and by far the most important foe of this plant. Its first appearance was noted in this country at Astoria, near New York City, in i860, where it was introduced about 1856. The injury inflicted by this insect is due to the work of both adults and larvae upon the tender shoots, which they render unfit for market early in the season. Later they destroy by defoliation growing plants, and are particularly injurious to 93 94 INSECTS INJURIOUS TO VEGETABLES seedlings, the roots of which are weakened by having their tops devoured. Larvse, as well as beetles, attack the tendcrest por- tions of the plants, but the latter gnaw with seemingly equal relish the epidermis, or rind, of the stems. The beetle, illustrated by figure 52, is a most beautiful creature, slender and graceful in form, blue-black in color, with red thorax, and lemon-yellow and dark-blue elytra or wing-covers, with reddish border. Its length is a trifle less than one-fourth of an inch. From the scene of its first colonization. Queens County, N. Y., the insect migrated to other truck-growing regions, and has now extended its range northward through Connecticut and Massachusetts to the State line of New Hampshire. Southward it has traveled to southern Virginia. At the present time it is well established in the principal asparagus-growing sections of the northern Atlantic region, and occurs westward to Illinois and Michigan. In a very few years we may expect its spread to other portions of states in which it is now local, and later it will naturally move westward. The insect passes the winter in the beetle state under con- venient shelter, and in April or May, according to locality, or at the season for cutting asparagus, issues from its hibernating (|uarters and lays its eggs for the first brood. The eggs are deposited endwise upon the stem or foliage and in early spring on the developing stalks, in rows of from two to six or more. In from three to eight days the eggs hatch, the young larvae, "grubs" or "worms," presenting the appearance indicated in figure 52, c. They at once begin to feed, and are from ten days to a fortnight in attaining full growth. When full grown the larva appears as in figure 52, d. It is soft and fleshy, and in color is dark-gray or olive, which becomes lighter and yellowish with age. The mature larva enters the earth, and here, within a little rounded, dirt-covered cocoon which it forms, the pupa state is assumed. In from five to eight or more days the beetle INSECTS INJURIOUS TO ASPARAGUS 95 is produced, which issues from the ground in search of food and of a suitable place for the continuance of the species. The duration of the life cycle, according to Fitch, is about thirty- days from the time the egg is laid until the insect attains matur- ity. In the District of Columbia the eggs, in the warmest part of midsummer, develop in three and the pupae in five days. In the present range of the species two and perhaps three broods are usually produced. The beetles enter into hibernation in September. The asparagus beetle has efficient checks in predaceous in- sects, which prey upon its larvae and assist in preventing its undue increase. Among these are the spotted ladybird {Mcgilla maculata DeG.), the spined soldier-bug {Podisns macnli- vintris Say) and the bordered soldier-bug (Stirctnts anchor- ago Fab., fig. 53). Wasps and small dragon flies also prey upon the larv:e. Im- mense numbers of beetles are sometimes killed in winter dur- ing severe cold spells follow- ing "open" weather. Remedies.- — The common asparagus beetle, under ordinary circumstances, may be held in restraint by the simplest means. Chickens and ducks are efficient destroyers of them, and their services are often brought into requisition for this purpose. A practice in high favor is to cut down all plants, including volunteer growth, in early spring to force the beetles to deposit their eggs upon new shoots, which are then cut every few days before the eggs hatch. Another measure of value consists in permitting a portion of the shoots to grow and serve as lures for the beetles. Here they are killed with insecticides, or the plants after they become covered with eggs are cut down and burned, and other shoots are allowed to grow up as decoys. Fig. 53.— Bordered soldier-bug. Enlarged (Author's illustration, U. S. Dept. Agr.) g6 INSI'XTS INJURIOUS TO VEGETABLES One of the best remedies against the larv;c is fresh, air-slaked lime dusted on the plants in the early morning while the dew is on. It quickly destroys all the grubs with which it comes in contact. The arsenicals, applied dry in powder mixed with lime, an- swer well, and possess the advantage of destroying beetles as well as grubs, and are of value upon plants that are not being cut for food. To produce satisfactory results the lime or arsenite must be applied at frequent intervals, or as often as the larvae reappear on the beds. Arsenate of lead is an excellent remedy. A simple method of killing the larvae in hot weather is to brush them from the plants so that they will drop to the heated earth, where they die before being able to return. The Twelve-spotted Asparagus Beetle {Crioccris 12-punctata Linn.). — The chief source of damage from this species is from the work of the hibernated beetles in early spring on young and edible asparagus shoots. Later the beetles as well as larvae ap- pear to feed exclusively on the berries. The eggs are deposited singly, and apparently by preference, on old plants toward the ends of shoots, which, lower down, bear ripening berries, and they are attached along their sides instead of at one end, as with the common species. Soon after the larva hatches from the egg it finds its way to an asparagus berry, enters it, and feeds upon the pulp. In due time it leaves this berry for an- other one, and when full growth is attained it deserts its last habitation and enters the earth, where it transforms to pupa and afterwards to the beetle. The life cycle does not differ materially from that of the common species, and there are probably as many generations developed. This species is at present distributed throughout nearly the same territory of the North as the preceding. The beetle rivals the common asparagus species in beauty, but may be distin- guished by its much broader wing-covers and color. It is orange red, and each wing-cover is marked with six black dots, and the knees and a portion of the under surface of the thorax are also INSECTS INJURIOUS TO ASPARAGUS 97 marked witli black (fig. 54, a). The beetle as it occurs on plants when in fruit very closely resembles, at a little distance, a ripe asparagus berry. The full-grown larva is shown at figure 54. b. It measures. Fig 54 —Twelve-spotted asparagus beetle, a. Beetle; b, larva: c. second abdominal segment of larva; d same of common asparagus beetle, a, b. Enlarged; c, (i more enlarged (Chittenden. U S Dept. Agr.) when extended, three-tenths of an inch, being of about the same proportions as the larva of the common species, but is readily separable by its ochraceous orange color. Remedies are those indicated for the common asparagus beetle, with the exception of caustic lime and other measures that are directed solely against that species, but the habit of the larva of living within the berry places it for that period beyond the reach of insecticides. The Asparagus Miner {Agromyza simplex Loew.). — Aspara- gus stalks are sometimes considerably injured by a maggot (fig. 55jir, a) which mines undei the skin near or just beneath the base. The appearance of the affected stalk (/) is charac- teristic. The parent insect is a small black fly. Remedial Suggestions. — Permit a few volunteer asparagus 98 INSECTS INJURIOUS TO VEGETABLES plants to grow as traps to lure the female fly to deposit her eggs. Afterward, in late June or early July, pull the trap Fig. S?i.—Criocens 12- punctafa. Egg. natur- al size, on asparagus, right: enlarged at left. (Chittenden, U. S. Dept. Agr.) Fig. 55x- — Asparagus miner, a. Larva; b. c, spiracles; (3'. e. puparium / section of asparagus stalk, showing injury and puparia. ae. Much enlarged; /, slightly reduced. (Author's illus- tration. U. S. Dept. Agr.) plants and promptly burn them with their contained insects (in the flaxseed stage, fig. 55^-, d, c). If this is carefully done over a considerable area, there will be little necessity for other methods, as few insects will be left for another season; unless, indeed, this insect has an alternate food plant. Cooperation and thoroughness are essen- tials for success. This method will operate also against the rust which is often present in fields infested by the miner. CHArXER VII INSECTS INJURIOUS TO BEANS AND PEAS Edible legumes are subject to injury by certain weevils, which deposit their eggs upon or within the pods on the grow- ing plants and develop within the seed. The specific enemy of the pea is the pea weevil, and of the bean, the common bean weevil, both of sufficiently wide distribution and abundance to hold high rank among injurious insects. The inroads of these weevils in seeds cause great waste, and particularly is this true of seed kept in store for any considerable time. In former times popular opinion held that the germination of leguminous food seed was not impaired by the action of the larval beetle in its interior, but this belief is erroneous, as will be shown in the discussion of the nature of the damage by the pea weevil. Although it is not probable that any serious trouble follows the consumption by human beings of the immature weevils in green peas or beans, the use for food of badly infested dry seed filled with the dead bodies and excrement of the beetles would naturally be attended with unpleasant consequences. Growing pods in the fields are invaded by the bollworm and pea moth, and the foliage is preyed upon by numerous insects. Of foliage feeders are the bean leaf-beetle, bean ladybird, blister beetles, cutworms, and other caterpillars. Several forms of plant-bugs, leafhoppers, and aphides also exhaust the plants by sapping their juices. The Pea Weevil (Bruchus pisonim Linn.). — Seed peas are often found with a single round hole in them, due to the attack of the pea weevil or "pea bug," the largest of the pea and bean- 99 ICXD INSECTS INJURIOUS TO VEGETABLES feeding weevils found in this country, measuring about a fifth of an inch in length. Its ground color is black, but it is thickly covered with brown pubescence, variegated with black and white markings arranged as illustrated in figure 57, a. In 1748 the celebrated Swedish naturalist Pehr Kalm gave an account of this weevil, stating that the culture of the pea had been abandoned in Pennsylvania, New Jersey, and southern New York on account of it. There are reasons for believing that this species came orig- inally, with so many other injurious insects which live upon cultivated seeds, from the Orient, and it has now become dis- tributed over nearly the entire globe, wherever peas are culti- vated. It does comparatively little damage in the colder parts of Canada; hence, seed peas for planting in the United States are largely imported from Canada or are bought from seed dealers who obtain them from our more northern states. Fig. 56. -A buggy pea Fig. 57.— Pea weevil, a. Adult beetle; b. larva; c. pupa. All greatly enlarged (Author's illustration, U. S. Dept. Agr.) Nature of injury. — Every pea in a pod is sometimes infested with this weevil ; and although nearly every one is familiar with "buggy" peas, it is not generally known that in eating green peas we often eat also a "worm" with nearly every pea. The only external evidence of infestation in a green pea is a minute INSECTS INJURIOUS TO BEANS AND PEAS Id dot on its surface, but in dry seed the cell inhabited by the insect is visible under the skin. The belief was once more or less prevalent that the larva working within the seed, by some wonderful instinct, avoided the germ or embryo, and that weevil-infested peas were there- fore of equal value for seed to uninfested ones, but this is in- correct. Many "weeviled" seed will germinate, but as they are deficient in plant food the resulting plant is apt to be weakly and nonproductive. This species develops only a single generation annually. As it does not breed in dry peas, the new generation for another year is dependent on such beetles as are contained in planted seed or which escape from the storeroom. REMEDIES Holding over seed. — A simple and effective remedy consists merely in keeping seed peas in a close receptacle, a tight bag or box, over one season before planting. The beetles which issue die without being able to lay their eggs in the field. Primary injury to the seed has been effected by the larva the first summer and after the weevil develops, always during the first autumn in the writer's experience, further damage prac- tically ceases. Late planting. — Comparative immunity from pea weevil at- tack is claimed in some localities, e. g., in the southern states, by planting late, and is all that is necessary to secure sound seed stock. Bisulphid of carbon. — When it is desired to plant the first season after gathering the seed, bags in which peas have been kept tightly closed should be placed in a tight box or vessel and disinfected with bisulphid of carbon, at the rate of an ounce or two to 100 pounds of seed. This method will kill the weevils I02 INSECTS INJURIOUS TO VEGETABLES Fig. 58.— Common bean weevil. Greatly enlarged. (Author's illustration, U. S. Dept. Agr.) without injury to the germinative property of the seed. A similar remedy consists in soaking infested seed for one minute in boiling water. A longer time is apt to injure it for planting. No efficient preventive of in- jury is known, but cooperation in the treatment of infested seed would .render further action un- necessary. The Common Bean Weevil (Bruchus obtcctiis Say). — The most formidable enemy to the culture of beans is the common bean weevil. In the nature of its attack it differs from the pea weevil in that it not only develops in the pods in the field but continues to breed for suc- cessive generations in seed, after harvest and storage, until the seed is useless for planting or as food for man or stock. As with peas, the market gardens of the North provide the dry seed for consumption and for planting in the Southern States. In and about Washington, D. C, it is next to impos- sible to procure a crop of beans uninfested by this weevil; hence, the stores of the city are supplied mainly from the North, New York State furnishing the greatest quantities. This bean weevil is smaller than the preceding, averaging about an eighth of an inch in length. It is coated with fine brown-gray and olive pubescence which gives the body that col- or. The wir'^-covers are mottled, as shown in figures 58 and 60. From the pea weevil this species may be known by the different shaped thorax and the two small teeth in addition to the large tooth with which the thighs are armed. In figure 6c, a, the beetle is represented in profile with its head bent under in natural INSECTS INJURIOUS TO BEANS AND PEAS 103 resting position. Until recently this species, like the preceding, was generally believed to be indigenous. It is certainly not native to the United States, and if introduced from the Eastern Hemisphere probably became acclimated in tropical America before establishing itself in the North. Its distribution is now Fig. 59.— Bean showing injury by common bean weevil. (From Riley.) Fig. 60.— Bean weevil, a, In profile; b, section of bean-pod showing slit for egg deposit; c, portion of interior of pod showing egg mass inserted through slit, a, c, Much enlarged. (Reengraved from Riley, U. S. Dept. Agr.) world-wide. It occurs in nearly every State and Territory of the Union, and is generally diffused through Central and South America. Oviposition takes place primarily in the field, the eggs being deposited, as with the pea weevil, upon or inserted in the pod through a hole made by the female and through openings, such as are caused by its drying and splitting. In shelled beans the eggs are dropped loosely in the receptacle in which they are stored, or are placed in holes made by the weevils in their exit from the seed. Less seldom they are attached to the outer surface of the seed. There are probably produced annually an average of six generations in latitudes such as the District of Columbia and a less number in more northern localities. Unlike the pea weevil, a large number of individuals will develop in a bean, as many as twenty-eight having been found in a single seed. I04 INSECTS INjL'RIOUS TO XKGETABLES Any single indoor generation is capable of exhausting seed and completely ruining it for food or planting or any other practical purpose. The beetles begin to issue in the field in a climate like that of the District of Columbia as early as October, when in the natural course of events the eggs for a new brood would be deposited in such pods as had cracked open so as to expose the seeds within. This beetle prefers the bean as a host plant, but it will also breed in cowpeas in the field as well as in store, and in confinement develops in dried peas, lentils, and chick- peas. It is no more true of seed infested by this species than of that attacked by the pea weevil that germination is not im- paired by the work of the weevil in the bean. Weeviled beans should not be planted. In a test only 50 per cent, of the infested seed used germinated, and only 30 per cent, could have passed the germinating stage, and these, owing to injury to the seed leaves, would probably have produced plants of low vigor and correspondingly low productiveness. Remedies. — From the fact that this species breeds continuously in dried seed, neither the expedient of holding over seed for a year before planting nor that of planting late for seed stock would be productive of good, as in the case of the pea weevil. Recourse must therefore be had to fumigation or to heat, and the earlier the seed is treated after it has been gathered the better the result. Just before it is planted seed infested with this bean weevil should be lightly thrown into water. Badly injured seed will float, and may be picked out or poured ofT and destroyed. Sound seed only should be reserved for planting. The Cowpea Weevil {Bniclnis chincnsis Linn.). — Cowpeas are quite liable to ])e infested by the cowpea weevil and the four-spotted bean weevil, which injure its seed in the same manner as the common bean weevil. Like that species they begin work in the field and continue to breed in the stored seed, INSECTS IXTl'RIOUS TO IlEAXS AND PEAS lO^ Fig. 61.— Cowpea weevil. (Author's illustration. U. S. Dept. Agr.) until Ihoy entirely spoil it. or seriously impair its .germinating power. Both species are generally distributed and injurious in the South, and arc widening their range with the increasing use of their food plant as a soil renovator and as forage. They resemble each other after a manner superficially, in appearance as in habit, but they dilTer to some ex- tent in various details of their life econ- omy as well as in structure. The cowpea weevil may be readily dis- tinguished from the kindred four-spotted species by the two large, elevated ivory- like lobes at the base of the thorax and by the strongly pectinate antennae of the male (fig. 6i). This is undoubtedly an Old World species and an ancient enemy of edible pulse. Cowpea is the favorite food seed, but the insect is also injurious to common and pigeon peas, lentils, chick-pea and "mungo." Table beans also serve as food. Mate- rial infested by this weevil undergoes a marked elevation in temperature. In one instance the temperature of a small sack of seed infested by the cowpea weevil was found to be 25° F. higher than the surrounding atmosphere. Remedies. — The similarity of the habits of this and the com- mon bean weevil renders it amenable to the same remedies. The Four-spotted Bean Weevil (Bntchiis qiiadriinaculatus Fab.) is the more slender species and differs from the cowpea weevil by many characters. What appears to be the commonest form of coloration is illustrated in figure 62. a, which is suffi- cient to separate it from the-preceding which it much resembles, especially in its manner of life. The Remedies are practically the same as for the common bean weevil. io6 INSECTS INJURIOUS TO VEGETABLES The Seed-corn Maggot (Pcgoiitya fusciccps Zett.)-— When the seeds of beans, peas, corn and other plants fail to develop, damage is frequently due to a maggot which works by scraping the seeds, sprouts, roots, stalks, and stems of plants underground/ Where this insect works decay soon sets in and the plants die. Entire plantings are sometimes destroyed, but when only a few seeds or sprouting plants are attacked, Fig. 62.- Four-spotted bean weevil, a. Beetle; b. larva: c, pupa All enlarged. (Author's illustration, U S. Dept. Agr.) injury may escape notice. Early crops suffer most and if they can be preserved until larger growth they will as a rule sustain considerable attack without material damage. The insect in question is called the seed-corn maggot and bean fly, and its parent looks like a small house fly. It can be identified by the male (fig. 63,0)." The female can scarcely be distinguished from related species, such as the adults of the cabbage root-maggot and onion maggot. The length is about one-fifth inch and the wing expanse about two-fifths. The larva is footless and of cylindrical form {d) , narrowed at the anterior extremity and enlarged posteriorly. It is considerably smaller 1 Injury of this cliaracter is also committed by wireworms, wliite grubs and some otiier insect.s, e. g., weevils in the seeds. - His principal characteristics consist of a row of short, rigid, bristly hairs of nearly equal length on the inner side of the posterior tibiae or shanks. INSECTS INJURIOUS TO BEANS AND PEAS IO7 than the onion maggot, measuring about one- fourth of an inch. This fly is evidently of European origin, and was first rec- ognized in New York State in 1856. Like so many other flies, it ranges through several life areas, and we know of its occur- rence in New England, Canada and Minnesota, southward to the Gulf, and westward to the Pacific. Injury is most severe to young plants, and particularly to beans, peas, and Indian corn. Cabbage, turnip, radish, beets, 9> . full-winged female All much enlarged. (Author's illustration U. S Dept. Agr.) and in its saltatory power. Other food plants include potato, pumpkin, cabbage, ornamental plants, clover and many weeds. Remedies are the same as for leafhoppers. Beans, peas and other plants subject to injury should not be planted in or near old clover fields. Nuttall's Blister Beetle (Caiitharis nuttalli Say). — Blister beetles do much injury to leguminous food crops and are par- ticularly harmful to beans and peas. Nuttall's blister beetle is a large and beautiful insect, variable both in color and size (fig. 73). It is bright metallic green, the head and thorax have usually a coppery luster, and the wing-covers are often purple. It varies from a little over half to nearly an inch. Its habitat extends from the northern Mississippi valley region to the Rocky Mountains, and it is abundant from South Dakota to the northwest territories of Canada. It is related to the Spanish fly, the Cantharis vcsicatoria or cantharides of commerce, has INSECTS INJURIOUS TO BEANS AND PEAS 1 19 the same blistering- properties, and might he pnt to the same use. The beetles make their first appearance about the first of July, ravenously devour the blossoms and tender leaves of beans and other vegetables, and, if report speaks truly, they are capable of destroying a crop in a day- From the rapidity with which this insect works, poisons are of little value. We must, therefore, resort to mechanical meas- ures, and in their employment promptness and thoroughness are Fig. 74.— Ash-gray blister beetle. Fig. 73.— Nuttalls blister beetle. Female at right, twice natural size; One-third larger than natural nriale antenna at left. Greatly en- size. (Author s illustration, larged. (Author's illustration, U. S. U. S Dept. Agr.) Dept. Agr.) essential. The beetles may be destroyed by driving them into windrows of dry straw or similar material and burning them; by sweeping them into a net, such as is used by insect collectors, and throwing the captured insects into a fire; or by beating them into specially prepared pans of water on which there is a thin scum of coal oil. The Ash-gray Blister Beetle (Macrobasis unicolor Kby.). — This is one of our commonest Eastern species (fig. 74). and although very destructive to beans and peas, is also a serious enemy of beets, potato, and tomato, and attacks besides sweet potato and some flowering plants. Blister beetle remedies are discussed on page 68. CHAPTER VIII INSECTS INJURIOUS TO BEETS AND SPINACH The recent extension of the sugar-beet industry in this country has been the means of bringing to notice a large number of insects not previously identified with that plant. Owing to its lesser prominence as a merchantable product, spinach is not grown to the same extent, and it follows that its known insect enemies are fewer still. With the exception of some insects which will be mentioned, the majority of those which live more or less habitually on beets and spinach feed normally on related wild plants, including the goosefoot, amaranth, saltbush and the like. During the last quarter century several insects have been so prominent as pests in fields of sugar-beet, that they have received names indicative of their beet-feeding habit, while some few take their common names from spinach. Of these are the beet army worm, beet webworm, spinach leaf-miner, spinach flea-beetle, beet carrion-beetle and the beet aphis. Up to 1907 nearly 200 species of insects have been observed to use beets as food. The greatest losses from insect attack are ])robably due to flea-beetles, but they, as well as cutworms and similar groups, are so irregular in their depredations that an exact estimate cannot be made. Different species of leaf-beetles and cater- pillars, other than cutworms, do more or less injury, and several blister beetles devour the foliage of sugar and table beets freely ; most forms of the last, however, usually make their appearance so late in the season that, although defoliation may be excessive, comparatively little damage is accomplished. The same is true of some species of grasshoppers. Two common forms of farm :20 INSECTS INJURIOUS TO T.EETS AND SPINACH 121 insects, white grubs and wireworins, are at times injurious to the roots, and root-aphides injure the roots so as to render them comparatively useless. FLEA-BEETLES AND LEAF-BEETLES As flea-beetles are among the most troublesome sugar-beet pests from their early occurrence and the rapid'ty with which Fig. 75.— Spinach flea-beetle. a. Beetle; b, egg mass, showing mode of escape of larva at right; bb, sculpture of egg; c, full-grown larva; d, pupa; e, newly-hatched larva; /, abdominal segment of same, a, c, d, Five times natural size; b, e, more enlarged; bb, f, still more enlarged. (Author's illustration, U.S. Dept. Agr.) they work, they may receive first mention, especially as no less than twenty forms have been observed attacking this plant. Some of these are widely distributed ; others are local. Most farmers are familiar with flea-beetles, better known perhaps as "fleas," and it will be unnecessary to enter into detail in regard to more than one species. The Spinach Flea-beetle (Disonycha xanthomel(cna Dalm.). — This flea-beetle (fig. 75) is black with a reddish-yellow thorax. It appears early and. like other species of its kind, works 122 INSECTS INJURIOUS TO VEGETABLES rapidly. It can be controlled in the same manner as other flea- beetles and leaf-beetles, and there is no doubt that if growers took pains not to allow chickweed and lambsquarters to spring up in the fields that the insect could be still more easily de- stroyed, as the first generation is produced on this and some similar weeds, and it is the second generation which attacks the beets. Its young, or larva, has the same habit as the adult, and the species frequently "cleans out" entire rows of beets before its appearance is suspected. Remedies for flea-beetles are discussed on page 65. The Larger Beet Leaf -beetle (Mouoxia puncticollis Say). — Two species of native leaf-beetles are important enemies of the sugar-beet in the West, where they are sometimes known as "French bugs" and "alkali bugs." The larger beet leaf-beetle (fig. 76) lays her eggs on the under side of leaves, where they hatch in about six days, the young larva; commence feeding at once, continuing for nine or Fig. 76 —Larger beet leaf-beetle a, Female beetle; b eggs; c. larva. <■> . male daw; $ , female claw- All much enlarged; claws more enlarged. (Author s illustration. U.S. Dept. Agr.) ten days, when they dig their way into the ground, and, a few days later, come forth as beetles. Damage is due to both the larvse and beetles, hundreds occurring on a single plant, which INSECTS INlL'KIOrS TO BEETS AND SPINACH 123 13 either consumed or so injured that it shrivels and dies. Since 1897 this species has done more or less i-njury to sugar-beet in Colorado, Idaho, Utah and neighboring States, the beetles often occurring in swarms like blister beetles. This species resembles the elm leaf-beetle, but is larger and differently marked. It is oblong, narrow in front and dull brown while the wing-covers are more or less distinctly striped. The Western Beet Beetle (Monoxia consputa Lee). — Beets are much injured by this species along the Pacific Coas^;. It Fig- 77.— Western beet beetle. Eight times natural size; antenna at left highly magnified. (Author's illustration, U. S- Dept. Agr.) Fig. 78.— Margined blister beetle. Enlarged. (Author's illustration, U. S. Dept. Agr.) eats holes through the leaves, in some instances leaving only a network of the original leaf, and this seriously interferes with the growth of young plants, which are s >metinies killed. This beetle (fig. jy) is closely related to the preceding, but is smaller, measuring only about one-sixth of an inch in length. Remedies. — These beet leaf-beetles are important enemies of sugar-beet culture. The general methods for the control of leaf and flea-beetles (see page 65) are applicable, but a few remarks should be added in regard to particular remedies. Paris green, London purple, and paragrene have all been employed against the larger snecies with apparently good results when applied 124 INSECTS INJURIOUS TO VEGETABLES dry, mixed with flour, in the same manner as for the Colorado potato beetle. The beetles accumulate quite largely upon "mother" beets early in spring, which suggests that if a few beets be left in the ground over winter they will serve as trap crops for the protection of the younger plants in spring. The larger species practically confines its injuries to plants growing in or in close proximity to alkali soil. Hence such ground is to be avoided for the cultivation of beets. BLISTER BEETLES Blister beetles are among the most conspicuous of all beet enemies, and no less than ii species have been observed as doing injury to sugar-beet alone. One of the commonest is the margined blister beetle (Epicouta marginata, fig. 78). The writer has seen entire plantings of beet almost completely de- foliated ])y it ; but as a rule this and several of the other beet- feeding blister beetles occur too late in the season to do material harm, as the roots have by this time made nearly complete growth. This species also attacks beans, potatoes and tomatoes, as well as other vegetables, and is destructive to some flowering plants. It is most abundant in July and August. Remedies are the same as for other blister beetles (page 68). CUTWORMS AND OTHER CATERPILLARS When sugar-beets are cultivated over a large territory, there is comparatively little danger of injury from common cutworms which are such serious pests in the vegetable garden. Certain species, however, occur occasionally in great numbers, spreading from field to field, like the army worms, and sometimes sweep everything before them, as they feed upon every portion of the plant — foliage, flowers, stalks, and even roots. At such times they should be promptly destroyed. Methods of control employed against cutworms are considered on page 54. When traveling in armies cutworms should be treated as army worms (see p. 58). INSECTS INJURIOUS TO BEETS AND SL'INACII I25 The Beet Army Worm (Lapliygma cxigua Hbn.)-— This species has come into prominence since the extensive cultivation of the sugar-beet in the West. It is rapidly widening in distribu- tion, chiefly by the flight of the mature insect, a moth resembling the parents of the cutworms. This insect might be a still more injurious sugar-beet pest than is yet known, save for the fact that it attacks many other crops and weeds. The moth (fig. 79, «) is of a gray color, resembling the plain form of the fall army worm, to which species it is related. The Fig. 79.— Beet army worm, a. Moth; b, larva, lateral view: c. larva, dorsal view: a. head of larva; e. egg, viewed from above; f, egg, from side. All enlarged. (Authors illus- tration, U. S. Dept. Agr.) fore-wings are broader and paler, and the reniform and other spots as well as mottlings are more distinct. The wing expanse is less than an inch and one-half. The larva is striped, as shown at b and c. Remedies. — When occurring in numbers this insect can be controlled by means of an arsenical, but when unduly abundant, army worm remedies are necessary. The Beet Webworm (Loxostcgc sticficalis Linn.). — This in- sect is, like the preceding, of foreign origin, and is also rapidly 126 INSECTS INJURIOUS TO VEGETABLES increasing its range, and as it has developed an unnsnal fond- ness for sugar-beet it will in time become a beet pest of great importance. It has evidently been introduced on the Pacific Coast and has been found destructive as far eastward as Michigan and Nebraska, and has done considerable injury in other localities, including Canada where it was recently very destructive. It is cousin to the native garden webworm, which it resembles in general form. It is, however, darker and about Fig. 80.— Beet webworm. a, Moth, twice natural size; b, larva, less enlarged; c. urpei" surface of first proleg segment of larva; d, side view of same; c, d. more enlarged. (After Insect Life.) one-fourth larger. Fully expanded the wings measure nearly an inch, and are purplish brown in color, with darker and paler bands, as shown (fig. 80,0). The hibernating caterpillars make a burrow beneath the surface of the ground and construct a cocoon about three times as long as themselves. A similar but shorter cocoon is made by the midsummer brood. A favorite wild food plant of this species has been observed — the pigweed or careless weed (Amaranthus) — and injury to sugar-beet has been observed in many cases where the ground was allowed to run to the wild plant. Remedies. — The destruction of this and other weeds might in time lead to c()ni])arative immunitv from the attack of the webworm. Paris green or other arsenical sprayed several times over the infested plants will also compass its destruction. INSICCTS INIURIOUS TO IM^ETS AND Sl'IXACII I_7 Otlicr kinds of catcri)illars, incliulins;' such well-known forms as the zchra and sah-niarsh catcrpiUars, arc often found in hcct fields, hut seldom iri sufficient numhers to do serious injury. As a rule they readily yield to sprays of Paris green. GRASSHOPPERS Grasshoppers, or locusts, as well as crickets and some related insects, are of great importance in the West, and frequently do injury to sugar-beets. Many species attack this plant. Remedies. — The hopper-dozer is a necessary implement in our warfare against this class of pests. It is discussed with other grasshopper remedies on paj^T ']^ . d ^ ^^ J Fig. 81 —Beet leaf-miner, a. Fly; b, head of male fly; c, head of female; d. surface of egg, highly magnified; e, egg.' /, maggot; g. head of same; /, anal segment; k- ana! spiracles. All enlarged. (After Howard, U S. Dept. Agr.) LEAF-MINERS Hitherto insects which affect chiefly the foliage by chewing have been treated. We now come to a consideration of insects 128 INSECTS INJURIOUS TO VEGETABLES of different habits, and among these are the leaf-miners — small, white maggots prodncing two-winged flies resembling the house fly. These burrow between the two surfaces of the leaves and form blotches termed mines. The principal species, the beet or spinach leaf-miner (Pcgomya vidua Lint.), is illustrated (fig. 8i). We have not as yet ascertained any perfectly satis- factory remedy for the leaf-miners. PLANT-BUGS, LEAFHOPPERS AND APHIDES Hordes of sucking insects, many plant-bugs, leafhoppers and numerous related forms are present in fields of sugar-beet at all times, and sometimes accomplish very considerable in- jury. Among the most prominent of these are the false chinch- bugs. The most satisfactory manner of keeping false chinch-bugs in check is by clean farming methods, destroying purslane and other weeds, and the cleaning up of crop remnants before winter, so as to leave no place for the insects to pass the winter. Some growers have observed that the flooding of fields infested by these insects forces them to leave, and the growing of mustard as a trap crop gives good results, provided the precaution is always taken to destroy the mustard before it runs to seed. The sugar-beet leafhopper (Eutcttix tenclla Baker) came into prominence as a beet pest in Utah, Idaho and Colorado in 1905, doing damage that year estimated at $500,000. This insect has become locally known as "white fly" and its injury as "blight." It has been noticed that late-planted beets are principally damaged and that early plants are less injured, and it may be that on this or a similar point in its life economy may hinge the remedy. It is worthy of remark that the species was un- known to science until 1900. For the aphides which attack sugar-beet, it is sometimes un- INSECTS INJURIOUS TO BEliTS AND SPINACH I29 accessary to employ rcincdies, as these creatures are peculiarly susceptible to atmospheric conditions, doing their greatest in- jury in cool, damp weather, and being held in nearly complete abeyance at times by numerous natural enemies which flourish in dry and even hot weather, as is very well known. In gardens of table beets, kerosene emulsion, pyrethrum and fu- migation, according to directions given on page 165, are of value. Practically none of these remedies can be employed on large fields, but are useful in small ones. Clean farming and fall plowing are always advisable, and crop rotation should be prac- ticed where possible with potatoes or similar crop. Two species of root-aphides do great damage. They are the beet aphis and beet root-aphis. The Beet Aphis {Pemphigus hctcc Doane) ruined in one year in a single valley upwards of i.ooo tons of beets. This was in Oregon. The species also inhabits Washington, and probably California, and it is probable that it may be reckoned among the important beet pests of the future. Owing to the large acreage in sugar-beet growing regions of the United States we cannot successfully control the root-aphides by means of insecticides. It would be supposed naturally that heavy flooding and plowing in fall so as to expose the insects to the frost might control it, but this is sometimes a failure. Our knowledge of alternate food plants is somewhat limited, but we can recommend the avoidance of beet cultivation in land where other plants subject to the attack of this insect have grown; also crop rotation. If the aphides are found at work only in parts of a field, they could be destroyed here with kerosene emulsion applied preferably just before rainfall, or by following the application with a flooding of water. Root-aphides are almost invariably associated with ants, which foster them and act as distributers of infestation by car- rying wingless forms from plant to plant. It is therefore ad- visable to break up the nests of ants as fast as they are found. I30 INSECTS INJURIOUS TO VEGETABLES The Beet Root-aphis (Tychca brcvicornis Hart, fig. 82) is most destructive in Colorado. It has a variety of alternate food plants, and we can only learn by experiment what are the best for rotation. We should avoid corn, sorghum, and other cereals, grasses, and particularly should we avoid weeds, including wild grasses. Oth- erwise the remedies advised for the beet-aphis are suggested. WHITE GRUBS AND WIREWORMS t> 0 Fig. 82— a. Bean root-aphis; b, antenna; c, tarsus. Enlarged. (After ^ ^^^^^^^^^^ ^^ ^^^^^^^ ^^ ^j^j _ Carman. ) grubs and of wireworms attack beet roots, but none appear to favor this form of food. We have yet to learn of severe and extensive damage by them. Remedies. — Among the best remedies are fall plowing, rota- tion of crops, clean cultivation, in particular the suppression of grasses, the use of potash fertilizers as stinuilants to the plants found affected, all of these remedies acting to a certain extent on both forms of insects. In this chapter there have been considered quite briefly the principal forms of insects which trouble the beet-grower or which he may expect to meet in his fields. Several of the in- sects mentioned in the last four pages require additional in- vestigation before definite and detailed instructions can be furnished for their suppression. For further information appli- cation should be made to the Bureau of Entomology of the Department of Agriculture. CHAPTER IX INSECTS INJURIOUS TO CABBAGE AND OTHER CRUCIFEROUS CROPS Cabbage is peculiarly susceptible to insect attack, and there are probably more species of insects that injure it than any other truck crop. Other edible cole plants are attacked by the same species of insects, but as a rule suffer rather less injury. At- tack begins from the. time the seeds commence to sprout and continues in the case of cabbage until the edible product is ready for cooking. Fig- 83.— Cdbbags root-maggot, a. Larva; b, puparium, dorsal view; c. female fly; d, head of male; e, antefina- All enlarged. lAfter Riley, U- S. Dept. Agr.) ROOT-MAGGOTS The Cabbage Maggot (Pcgo)iiya brassiccc Bouche). — The roots of cabbage and related cruciferous crop plants frequently suffer severe injury from the attack of the cabbage maggot (fig. 83). Young plants are most seriously affected, the mag- 131 132 INSECTS INJURIOUS TO VEGETABLES gots eroding the outer surface and boring into tlie interior of the roots, devouring the tender rootlets and frequently pene- trating into the lower portion of the stalk. This insect, known also as radish maggot, is an imported pest. It does serious injury throughout the northern tier of States and Canada, at- tacking all forms of crucifers. It is the cause of more or less loss to these crops each year. Since 1902 it has not only been exceedingly destructive, but has increased in injuriousness from year to year. Frequently entire crops over considerable areas are completely destroyed. Two or three generations of this maggot are indicated where it has been observed. REMEDIES The remedies prescribed for the seed-corn maggot are ap- plicable. In addition there are certain preventive and other measures for its destruction that have been found successful, their use being justified by the great value of cabbage plants. Carbolic-acid emulsion, prepared as prescribed on page 37, and diluted about 35 times, is applicable when this maggot oc- curs on radish. Hand-picking, although laborious, has the merit of effective- ness, and is useful on cabbage, although not practicable on radish and similar crops. It consists in pulling up the young plants, examining the roots for eggs and maggots, and either destroying the eggs and maggots by crushing with the hand or by washing the roots in a strong solution of soap and then replanting. In most cases the plants show no ill effects from this treatment after two or three weeks have elapsed. Methods of cnltiz'ation.— Comparatively little can be expected from various farming methods which are safeguards against other insects. Keeping the soil well hilled around the cabbage plants develops more roots, thus affording more food for the maggots and leaving enough roots to strengthen the plant itself. Crop rotation should be followed with any plants other than INSECTS INJURIOUS TO CABBAGE AND OTHER CROPS I33 crucifers or onions. With these hitter it is inadvisable, as the same atmospheric or other conditions which induce injury by the cabbage maggot seem to operate in increasing the numbers of the onion pest, which has a similar distribution. Fall plowing is advisable and cabbage stumps should be removed and de- stroyed, especially early in the season. Bisiilphid of carbon treatment. — In case tarred paper cards, which will next be described, or other preventive methods are not employed, bisulphid of carbon may be used. It should be >< Fig 84.— Bisulphid of carbon injector in use Fig- 85.— Tarred paper card in outline. One- half size. 'After Coff-) applied below the root system with a special injector or syringe,'- taking care that the application is not made directly to the plants, as it is likely to kill them. A hole is made a little distance (3 or 4 inches) from the plant, and the injector in- serted at an angle, as shown in figure 84. After injecting the liquid the instrument should be withdrawn and the hole closed by packing with the foot. From a teaspoon ful to a tablespoon- ful to each young plant, and a single application, is generally sufficient. Tarred paper cards. — The use of disks or pads of tarred paper 1 The IVIcGowcn injector, no longer for sale, has proved very successful. 134 INSECTS INJURIOUS TO VEGETABLES for the protection of cabbage against the oviposition of the fly was perfected in 1889 by Mr. W. H. Goff. The cards are cut in hexagonal form (fig. 85), in order to economize material, and a thin grade of tarred paper is used, as the cards made from it are more readily placed about the plant without being torn. The blade of the tool, which can be made by a blacksmith, is formed from a band of steel, bent in the form of a half hexagon, and then taking an acute angle, reaches nearly to the center, as shown in figure 86. The part making the star-shaped cut is formed from a separate piece of steel, so attached to the handle as to make a close joint with the blade. The latter is beveled from the outside all around, so that by removing the part making the star-shaped cut the edge may be ground on a grindstone. It is important that the angles in the blade be perfect, and that its out- line represent an exact half hexagon. To use the tool, place the tarred paper on the Fig. se'-Tool for e"d of a section of wood and first cut the lower cutting cards. | jj^^.^ iiotches, as indicated in figure 87, using About one-fourth ^ ' o / o size.(AfterGoff.) only One angle of the tool. Commence at the left side, and place the blade as indicated by the dotted lines, and strike at the end of the handle with a light mallet, and a complete card is made. Continue in this manner across the Fig. 87.— Showing how tool is used, dotted line indicating position of edge of tool. (After Goff) INSECTS INJURIOUS TO CABBAGE AND OTHER CROPS 1 35 paper. The first cut of every alternate course will make an imperfect card, and the last cut in any course may be imperfect, but the other cuts will make perfect cards if the tool is correctly made and properly used. The cards should be placed about the plants at the time of transplanting. To place the card, bend it slightly, to open the slit, then slip it on the center, the stem entering the slit, after which spread the card out flat, and press the points formed by the star-shaped cut snugly around the stem. A Wisconsin grower protected 7,000 plants and secured a splendid crop, while unprotected plants nearby would have been a complete failure if the maggots had not been picked off by hand. Others have reported similar success. One lost only 25 plants out of 10,000 to 15,000 that he protected with the cards, where ordinarily he would have lost from 75 to 90 per cent, of the crop. The tarred cards are applicable to cabbage and cauliflower only, but it is claimed by those who have employed them that they are cheaper, more practicable, and more efficient than any- thing as yet devised for preventing the ravages of the cabbage maggot. Success in using them is dependent upon their being properly applied, to fit tightly, so that the fly is unable to obtain access to the stem for the deposition of her eggs. Cards must be renewed and their use continued for each maggot year to be effective. Coverings and hellebore. — Some success has also been attained by covering young plants in seed-beds with netting and by ap- plying hellebore about the roots. The Seed-corn Maggot (Pegomya fusciceps Zett.). — This species, previously considered on page 106 on bean and pea insects has been identified with attack to cabbage, turnip and radish on numerous occasions and in many localities. When occurring on such plants it should be treated in about the same method as the cabbage maggot. 136 INSECTS INJURIOUS TO VEGETABLES CABBAGE WORMS The Imported Cabbage Worm (Pontia rapce Linn.). — This is the worst of all cabbage pests and one of the most important of all truck insects. It is altogether too well known through- Fig. ZZ.—Pontia raps, a, Female butterfly; b. egg: c, larva on cabbage leaf; d, sus- pended chrysalis, a, c, d. Slightly enlarged; b, more enlarged. (Author's illustration, U.S. Dept. Agr.) out North America and Europe, and the white butter- fly is quite generally recognized as its parent. The cater- pillar is velvety green and measures, when full grown, about an inch and a quarter, presenting the appearance shown in figure 88, c. The butterfly has a wing expanse of nearly two inches, and is white, marked with black near the tips of the fore- wings. The female {a) has two conspicuous black spots on each fore-wing, the male has only one. This cabbage worm is the bane of every cabbage-grower, and the dread of every INSECTS INJURIOUS TO CABBAGE AND OTHER CROPS I37 careful cook and housewife. It begins work early in the season, when the principal damage is usually accomplished, and after riddling the outer leaves, attacks the more tender inner leaves as they form, frequently secreting itself in the heads, which are made most unsightly by its excrement. This species was first observed in the United States in 1865 and in about a score of years it had invaded nearly every state and territory in our domains. All cruciferous crops, but particularly cabbage and cauli- flower, are attacked, as are also nasturtium, mignonette and some allied plants. The butterflies are on the wing from early morn till dusk. As early as March they can be seen flying about cabbage fields and they continue until after severe frosts. The observed egg period is from 4 to 8 days. The larva eats voraciously and grows with rapidity, attaining full growth in from 10 to 14 days after hatching. The summer-time chrysalis period is from 7 to 14 days, but the last chrysalides remain undeveloped until the following spring. The life cycle has been traced from between 22 days to five weeks. Even in New England this species is credited with being triple brooded, but in the District of Columbia and vicinity there must be one or more additional generations, and there is a possibility of still more in the extreme South. A natural enemy of this species, Pteromalns puparum, is shown in figure 89, and a "worm" parasitized by Apanteles glomeratus is illustrated by figure 90. REMEDIES In treating this species it should be borne in mind that other "worms" and pests are more often present than otherwise. Arsenicals. — The best remedy is Paris green applied, prefer- ably as a spray, at the rate of about one pound of poison to 150 gallons or less of water, and it should be used when plants are first set out, to insure its reaching the young "worms" be- 138 INSECTS INJURIOUS TO VEGETABLES fore they have burrowed far into the heads. Other applications should follow frequently, as required, and can be made with safety until the heads are about half formed, and even later, as the poison, under ordinary circumstances, disappears from the plants two or three weeks after being applied. Bran mash is, according to the testimony of some, successful against cabbage worms. It is prepared in the same manner as for cutworms and grasshoppers. See page 55. Kerosene emulsion is not as efficient as arsenicals, because Fig. 89.—Pteroma!uspupani;s or cbickens. Croj) rotation and other white-grub remedies should be practiced. The Parsnip Webworm {Dcpressaria hcracUana DeG.)- — The parsnip webworm is injurious to the seed of parsnip, but for some reason, at least in the experience of the writer, prefers the wild carrot as a breeding plant. The moth is grayish buff, or pale ochraceous, with the fore-wings marked with fuscous (fig. 120, c) . The larva is pale yellow, greenish or bluish gray, marked with black, piliferous spots, and with bluish black head Fig. 120-— Parsnip webworm. a, Molh, b. r. caierpillars' i^. chrysalis: e anal segmen* of same: /. umbel of parsnip, webbed together by caterpillar, a e. Enlarged; /, some- what reduced. (After Riley ) and thoracic plate, as figured {a, b) . The species is of general occurrence through the northern portions of Europe and our Atlantic States and Canada westward to Michigan. Wild carrot and parsnip, which are altogether too abundant in fields throughout that section, yield it a sufficiency of food and in some years it is difficult to find these weeds that are not affected by the webworm. The larvae weave the flower heads (/) together until these are contracted into masses, with abundant excrement as a covering. Within the domicile thus formed the larvje dwell. After they have consumed the flowers and unripe 186 INSECTS INJURIOUS TO VEGETABLES seeds and are nearly mature, they enter the stems, feed on the soft lining, and transform to iDUpx. They sometimes destroy newly-sown parsnip, eating the tender leaves, but in attack on older plants they eat the umbels or flower heads and the inte- rior of the stems. Remedies. — A thorough spraying with arsenicals will destroy this webworm. To prevent injury by it avoid planting parsnips in or near waste places which have become overrun with wild carrot. Miscellaneous Insects. — Among other insects injurious to celery the tarnished plant-bug is an important species. It is figured and described on pages 87 and 88. The cotton leaf-bug (Calocoris rapidus Say), a species of somewhat similar habits and appearance (fig. I20.r), also attacks celery and is amenable to the same remedial treatment. CHAPTER XII INSECTS INJURIOUS TO SWEET CORN A GREATER number of species of insects have been recognized as attacking Indian corn than any other plant grown as a vegetable. Although, properly speaking, corn is a field crop, it is also grown for the sake of the unripe ears which are classi- fied as vegetables. What insects will attack field corn will also attack the garden variety, but for present purposes it will not be necessary to treat of any except tlie more important habitually garden-inhabiting species, and only a few of these need be considered at all in detail. Many of them are general feeders and have been considered in preceding paragraphs. The corn-feeding species of insects recognized in 1896 were 214 in number, and of these 18 attacked the seed, 27 the root and lower portions of the stalk. 76 the stalk above ground, 118 the leaf, 19 the tassel and silk, and 42 the ear. The remainder attacked the stored product. It is safe to say that at the present writing (1907) at least 350 species are on record as concerned in attack on corn. The Corn Root-aphis {Aphis maidiradicis Forbes). — Con- cerning this species. Dr. S. A. Forbes wrote in 1S96: "No in- sect affecting corn is more deserving of the attention of farmers and entomologists at the present time than the corn root-aphis. It ranks as a corn pest with the chinch bug and the army worm, less injurious at any one time than these are locally and occa- sionally. 1)ut overtaking them, on the other hand, by its general distribution and the constancy of its attack." This root-aphis does its principal injury while corn is small. The dwarfing of a plant in patches with a yellowing or reddening of the leaves, and i8q 190 INSECTS INIUKIOUS TO VEGETABLES a lack of thrift and vigor, arc the outward manifestations of injury. Another indication is the presence of numerous small brown ants which attend this species and without which it probably could not exist. The corn root-aphis is bluish green, slightly whitened by a waxy bloom. The body is oval, and the nectaries are erect or Fig. 12 1. ^Winged viviparous female of corn rooi-aphis; wingless egg-laying female. Enlarged. (After Forbes) project slightly backwards. Two of the different forms arc shown in figure 121. It is found from Massachusetts to Minne- sota and Nebraska and as far south at least as Virginia. The winged forms migrate to various weeds, among which are smartweed, pigeon grass, mustard, pigweed and plantain. Economic Treatment. — Our present knowledge of this insect suggests several methods of attacking it. Crop rotation and care not to plant in or near fields of weeds which serve as alternate hosts ; the free use of manures and other fertilizers to stimulate the growth of the plants; the disturbing and destruc- tion of the nests of the protecting ants; the destruction of all of the weeds which serve the aphides as food early in the season by plowing, and, in connection with this, late planting of corn.^ Such measures of procedure may not entirely pro- tect the crops in all localities in all seasons. ' These and other remedies are considered in detail by F. M. Webster in Circ. 86, Bu. Entom., U. S. Dept. Agr. INSECTS INJURIOUS TO SWEET CORN IQI The Southern Corn Root-worm (Diabrotica 12-pnnclala Ol.). ■ — The larvic of two species of leaf-beetles arc among the promi- nent enemies to the culture of corn by destroying the roots. One of these, the Southern corn root-worm is common nearly throughout the United States, but as its name implies is most destructive in the South. In the case of its attack not alone roots, but underground stalks are injured. The other, known as the Western corn root-worm, is somewhat confined to the middle West, where it would be a very serious pest were it not that farmers. generally in that region have adopted a sys- tem of rotation which greatly reduces injury. The principal form of its attack is in the interior of the fibrous roots, in which minute, more or less longitudinal, burrows are formed. The larva of the Southern species is also called in the South the "bud-worm" and "drill-worm." The beetle is commonly known northward as the twelve-spotted cucumber beetle be- cause of its frequenting the flowers of cucumber, as well as squash, and other cucurbits in the interior of which one can usually see one or more dusted with pollen, and the places where they have gnawed the petals, for they are most omnivorous in- sects and able to subsist on nearly any form of vegetation on which they happen to alight. They are, in fact, to be found in practically all fields of corn and in gardens everywhere. The beetle is yellowish green, and the wing-covers are marked with twelve black spots (fig. 122, a). The length is one-quarter of an inch or a little longer. The larva; (c) are slender, thread-like, delicate and soft bodied, and white or yel- lowish in color. The twelve-spotted cucumber beetle inhabits that portion of America lying between the Atlantic seacoast to the base of the Rocky Mountains, and from Canada to Mexico. It is a very common species and most destructive in the South, where in- jury is accomplished by its root-worm form as far northward as Maryland and Virginia. 192 INSECTS INJURIOUS TO VEGETABLES The adult is practically omnivorous, its known food ma- terials are legion, and include besides the pollen and flowers and partly matured kernels of corn, wheat and oats, the foliage of alfalfa, crimson clover, cotton, rye and tobacco. Of vege- tables it attacks all forms. It frequently injures the fruit of melon and other cucurbits. Larv?e or pupae have been ob- served at the roots of corn, wheat, rye, millet, beans, rudbeckia Fig. 122.— Southern corn root-worm, a, Beetle; b. egg; c, larva; d, last segment of same; e, section of cornstalk showing holes made by larvae; /, pupa, a, c. f, Consider- ably enlarged; i, to 83. A species of wireworm common in the corn fields of the South is illustrated in its several stages in figure 135.^1^. Fig. 135x.— Southern corn wireworm ( Momcrepidius vespetiinus). a b, Larva; c, beetle; d, pupa— about three and one-half times natural size. (Author's illustration, U. S. Dept. Agr.) CHAPTER XIII INSECTS INJURIOUS TO POTATO AND SIMILAR VEGETABLES SoLANACEOus vegetables include potato, tomato, eggplant, pepper and cultivated species of Physalis, one of which is known as husk tomato. A moderate number of insects are attached to these plants and most of them affect tobacco, be- sides weeds of the same family. The most important potato insect in the economic sense, is the Colorado potato beetle, followed by half a dozen or more destructive blister beetles, and less important species of the same group. Numerous species of cutworms select the tomato and potato as their particular prey and the latter plant is favored by several forms of flea-beetles. Among other insects which take their name from the potato are the potato stalk-weevil and potato stalk-borer, potato tuber moth and potato scab gnat. The two species last mentioned injure particularly the stored product, and several other insects attack the tubers in the ground. Of such are wireworms and certain cutworms, e. g., the variegated cutworm, when they become unusually numerous, and white grubs. All of the general feeders which have been mentioned are treated in introductory chapters. Some of the blister beetles, more particularly the striped blister beetle, are known as old- fashioned potato beetles. In the Southwest there are numerous species of these insects which affect the potato crop in that section. One of the potato stalk-borers is treated under the name of "the common stalk-borer'' in the chapter on corn insects (page 199). 8X3 214 INSECTS INJURIOUS TO VEGETABLES Three species of aphides commonly occur on potato and arc- apt also to attack tomato, eggplant, and other Solanaceae. Thf same is true of mealy-bugs. The aphides include the common "green fly," ^ "black dolphin," " and "melon louse." ' Some forms of tree-hoppers and related species, and thrips also, attack these plants. The Colorado Potato Beetle {Lcptinotarsa dccemUneata Say.). • — Soon after the Civil War the Colorado potato beetle created quite as great consternation as the San Jose scale at the present time. There is perhaps no more familiar insect to those who live a rural life, and every country boy or girl knows its two active stages. It is still one of our worst pests owing to the fact that we must wage more or less perpetual warfare to suppress it. In its early days there seemed to be no check to its increase, but in the course of years many natural enemies have learned to prey upon it, until in many localities it is largely kept in abeyance by such agencies. It is of peculiar interest as being the direct cause of the use of Paris green upon edible plants. Fortunately, with a little knowledge of the habits of this insect, the use of arsenicals and the friendly assistance of natural enemies, the insect can now be held in practical subjection, otherwise it would be one of the greatest scourges of this country. This insect is so well known that a description is hardly necessary, but that there may be no danger of confusing it with blister beetles and others of similar habits, with which it is occasionally associated, a few words of description may be given. The beetle is of the robust form shown in figure 136. d, d, ochre yellow in color, with the wing-covers ornamented with ten black lines. The eggs are oval and orange colored, and are deposited in masses of a dozen {a, a) or more on the lower surface of the leaves. The larvae or "slugs" {h, h) are 1 Rhupatosiphum dianthi Schrk. " Aphis ritmicis L. " Aphis gossypii Glov. INSECTS INJLIRIOUS TO POTATO, ETC. 215 as well known as the beetles. They are soft, slimy, red-colored, evil-looking creatures. The Colorado potato beetle was first associated with injury to potato in 1865, prior to which time it had fed on the sand bur.^ With the advance of civilization westward and the culti- vation of potato in the vicinity of its native home, the insect Fig. 136.— Colorado potato beetle, aa, Eggs; bb, larvas; c, pupa; dd, beetles— all enlarged about one-fourth; e, wing-cover— much enlarged. (After Riley) acquired the habit of feeding on this more succulent plant. By 1869 it had found its way to Ohio and the year following was very destructive throughout the Northwest, continuing its eastward march at an increasing rate. Since that time its migration eastward, northward and south- ward has continued. Its progress eastward was accomplished largely by flight, as the writer had occasion to observe when a resident of Cleveland in the early days of its invasion of the Buckeye State. With outspread wings numerous individuals could be seen on bright days in spring and early summer, being carried with the winds directly eastward. By the cen- * S. olanum rostratum. 2l6 INSECTS INJURIOUS TO VEGETABLES tennial year the Colorado potato beetle occupied an area com- posing more than a third of the United States. Beetles and larvae are destructive in nearly equal proportion. In its early occurrence as a pest it not only caused entire losses of crops, but sometimes destroyed the potato yield of whole counties, and large portions of some States. Indeed, at one time it materially affected the market price of potatoes by direct depredations and in discouraging farmers in the cultivation of this crop. At the present time growers recognize the fact that the control of the potato beetle is a part of the routine of the culture of this tuber, and that its natural enemies assist in a remarkable degree in reducing its numbers. The insect is nearly always found on its wild plants wherever they occur and it practically feeds on all solanaceous crops and weeds, including tomato, tobacco, ground cherry, thorn apple, and Jamestown weed, henbane (hyoscyamus), belladonna, petunia, and Cayenne pepper. The tender leaved varieties of potato are most affected, while those with less tender foliage, of the "Peach Blow" and "Early Rose" type, are comparatively immune. The beetle hibernates under ground and is credited with being double-brooded with sometimes a third partial generation, which hibernates in the pupal condition. The beetles appear early in spring, issuing soon after the first thawing of the ground, at this season flying during the more heated portions of warm days, making aerial journeys of considerable extent. Larvre hatch in from less than a week to a little later, accord- ing to the prevailing temperature, and in two or three weeks usually acquire maturity, when they undergo transformation to pupje and subsequently to beetles in cells which the larva? form in the earth. The insect is to be found in practically all stages during the summer months, and as long as there are suitable plants for food. A single female is capable of pro- ducing from five hundred to a thousand eggs. The entire life INSECTS INJURIOUS TO POTATO, ETC. 21/ cycle from egg to adult may be passed in a single month, and the last generation of beetles issues early in autumn and re-enters the earth for hibernation. Fluctuation in numbers of the Colorado beetle is noticeable at least locally every sea- son, and is largely attributable to the activity of its insect ene- mies and to atmospheric conditions. Up- wards of 30 species of insects prey upon this beetle. One of the most important of these is a predaceous ground-beetle, Lcbia grandis Hentz (fig. 137). Remedies. — No other methods are nec- essary than the free use of Paris green or arsenate of lead and mechanical means for its destruction. Hand-picking, if employed early in the season, is of great value, but where large F'g- i37. — Lfiw ^mncis. , , , , , Enemy of the potato areas are planted other methods are nee- beetle, ma^xxdel) essary. Gathering the beetles and their larvae in pans containing a little water on which a little kerosene is floating, is an effective remedy. Methods of preparing and applying the arsenicals are given in the chapter on insecticides. If the grower can secure the cooperation of his neighbors in the destruction of this pest, and will also kill the insects on wild plants, much can be done toward limiting its numbers in small areas. It seldom, if ever, migrates as formerly, and there is not so much likelihood of reinfestation from a distance. It is always wisdom to keep down weeds, and in the treatment of the present insect, if they were cut before seeding, it would serve a dual purpose in preventing the increase of weed as well as insect. The susceptibility of the "slugs" to extreme heat, indicates that the remedy for the asparagus beetle of brushing them from the plants on hot dry days will be effective. The Potato Flea-beetle (Epitrix cucumeris Harr.). — Much injury to potato is inflicted by flea-beetles which attack most 2l8 INSECTS INJURIOUS TO VEGETABLES solanaceous plants, of which they are specific enemies, riddling the leaves with punctures and causing them to die, thus weak- ening the vitality of the plants, while the larvie of some of them feed at the roots and do injury in this manner. The most im- portant of these insects are three species known respectively as the potato, the eggplant and the tobacco flea-beetles, their names indicating the plants which they most often injure. This potato flea-beetle (fig. 138) is the most destructive of this group. The name "cucumber flea-beetle" was given it by Fig- 138.— Potato flea-beetle. Much enlarged. (Author's il- lustration, U. S. Dept. Agr.) Fig. 1 39. — Egg-plant flea-beetle. Greatly enlarged. (Author's il- lustration, U. S. Dept. Agr.) Harris, who found it very destructive to cucumber, eating the seed leaves and destroying the plant. It is very minute, meas- uring only 1/16 inch in length, perfectly black, with clay- yellow antennae and legs, and there is a deep transver.se furrow at the base of the thorax. This species is generally known from Massachusetts to Georgia, and westward to California. Injuries are most apparent, however, in the North. The larva is confined to solanaceous plants for food, and is the cause of "pimply" potatoes. When this trouble attracted attention in New York in 1894, potato buyers were on the lookout for potatoes so affected, offering a reduced price for them. Fre- quently such sold for five cents a bushel below the regular market price. The so-called "pimples" were accompanied by INSECTS INJURIOUS TO POTATO, ETC. 2ig "slivers," and it was sonic lime before it was ascertained that they were due to the slender white grubs of this flea-beetle. Eggplant, tobacco and tomato are affected less as a rule than potato, but the beetles also attack plants of other orders, inclu- ding beets, cabbage, turnip, cucumber, celery and sweet potato. Sometimes they do injury to potatoes by gnawing the sprouts. Eggs are deposited in May or June, and the life cycle is very like that of the tobacco flea-beetle about to be described. Larvae feed entirely under ground and transform to pupae there. Treatment. — The usual flea-beetle remedies are applicable. See page 65. The Eggplant Flea-beetle (Epifrix fuscula Cr.). — The egg- plant flea-beetle so nearly resembles the preceding that unless the two occur on the same plant they are apt to be confounded. It is of the same color, but considerably larger than the potato flea-beetle, and when closely examined it is at once seen that the impression at the base of the thorax is very feeble and that the wing-covers are more pubescent. This species is most abundant on eggplant, but it is common on potato, horse nettle and similar wild plants. In Maryland, Virginia and the District of Columbia it is often difficult to find the foliage of eggplant that has not been very profusely punctured by the minute holes where the beetle has been feed- ing. Some little time after attack these holes become browner on the edges, and this portion at last dries, making the holes much larger and giving the plants a decidedly sickly appearance. It even attacks eggplant in frames. This species is obviously southern, not extending in the East, so far as known, north of New Jersey. It occurs in the Gulf region and in southern Ohio and Illinois, and in intermediate States southward. Remedies. — The same as those employed against other flea- beetles. The Tobacco Flea-heetle {Epitrix parvula Fab.). — This species is most important as an enemy of tobacco, and like 220 INSECTS INJURIOUS TO VEGETABLES the preceding is commonest southward. Where occurring nor- mally it is often found in about the same abundance on potato, eggplant, tomato, horse-nettle, night-shade and Jamestown weed. The plants mentioned are sometimes damaged and its work is evident on these crops from Maryland and Virginia southward. The beetle is scarcely more than one-twentieth of an inch long, pale brown in color, the elytra being normally marked near the middle with a dark, transverse band of greater or less extent (fig. 140, a). The larva (b) is delicate, thread- like and white, except the head, which is yel- low. The beetle riddles leaves in the same man- ner as do other flea- beetles, and in its attack on tobacco frequently renders plants unfit for Fig. 140.— Tobacco flja-beetle, a, Beetle; t, larva; use. It is doubtleSS a c, head of larva; d, posterier leg; e, anal segment; . . . /, pupa, a, b, f. Enlarged about fifteen times; transmitter of Certam c, a, e, more enlarged. (Author's illustration, U. S. diseases which forni a- Dept. Agr.) bout the punctures made by the beetle in obtaining its food supply. From experiments by the writer it has been learned that the full life cycle may be passed, in extremely hot weather, in 28 days. The egg period in such weather is about six days, the pupa is the same, which affords, by deduction, a larval period of 16 days. Remedies are discussed on page 65, on the flea-beetles. The Black Blister Beetle (Epicauta pennsylvanica DeG.). — The farmer is quite too well acquainted with this and other blister beetles as unwelcome visitors to his potato patch, and florists know it as the "aster bug," from the severe injuries INSECTS INJLTKJOnS TO POTATO, ETC. 2J1 whicli il (Iocs to asters aiul related plants. It . is iiniforiuly black, witluiut polish, and its length varies from a little more than a quarter to half an inch. It is well distributed east of the Rocky Mountains, and docs most injury be- tween the Atlantic States and Texas. Its time of appearance is more or less coincident with the blossoming of the goldenrod, on which it is a familiar object, from June until October. As a rule it appears later than other species. It is one of the worst insect enemies of potato and beet, and is also destructive to carrots, beans, cab- bage, corn, mustard, aster, clematis Fig- 1 4 1.— Black blister beetle. Enlarged. (Author's illustration, and other plants. For remedies see y, 3. Dept. Agr.) page 68. The Potato Stalk Weevil (Tnchobaris trinotata Say.). — This is an important insect enemy of the potato, and a common species almost everywhere east of the Rocky Mountains and south of New England. Its larva works normally in the stems of horse nettle, ground cherry, and jimson weed, in most fields where these plants are allowed to grow. The habit of this insect of attacking potato has been known since 1849. Since then injuries inflicted by it have attracted considerable attention, periodically and locally, and there is reason to believe that it is often present and doing damage, though undetected, in potato fields, where the insect itself has never been seen. Its habit of living in the stem in its larval condition, and the small size of the beetles, together with their trick of dropping from the plants when disturbed, is accoimtable for injury so often escaping notice. The potato stalk weevil (fig. 142) is a small snout-beetle, about 1/6 inch in length. Its real color is black throughout. 222 INSECTS INJURIOUS JO VEGETABLES l)ut its surface is covered with minute gray scales, which give it a nearly uniform gray appearance. The head, however, is black, and there are three black impressed spots at the base of the wing-covers. The snout is robust and rather strongly curved. The northern limit of injurious occurrence of the potato stalk weevil is reached in Pennsylvania and New Jersey in the East, and in Il- linois and Iowa in the West ; recently, however, the species has been reported a pest in Canada. Southward the insect is found to Florida and Texas. More often perhaps than not, injury by this pest is at- tributed to drought or blight. Fig. 142.— Potato stalk weevil, a, Beetle; It is more conspicuous in sea- b, larva; c, pupa: d-, section of potato stalk r i 11 1 . 1 opened to show larva and pupa in situ. ^O^S of prolonged drought and (7, i, c, Five times natural size; d, natural most severe on early varieties size. (Author's illustration, U. S. Dept. r , , rr^, , . . ^ ) 01 potato. 1 he undermmmg ot the stalks by the larvae causes them to wilt, and the wilting and the dying of the leaves is the first outward manifestation of attack. When the insects are present in the field it is often stated that the plants are "blighted." The diseases of potato are apt also to be mistaken for the work of the weevil, as in both cases the leaves look as if sunburned, especially after the vines have been afTected for some time. Not infrequently a field suffers from the combined effects of dry weather, disease, and stalk weevil. This insect attacks nearly all Solanace?e growing within its natural range. The list includes, besides potato, eggplant, horse nettle, bull nettle, jimson weed, purple thorn apple, ground cherry and, it is said, cocklebur. INSECTS INJLIRIOUS TO POTATO, ETC. 222, A single larva in a potato stalk is not sufficient to injure it to any extent, although it must have a weakening effect, but when many larvae occur destruction is complete. As many as 5 or 6 individuals may sometimes be found in a potato stalk. The beetles appear, in the vicinity of the District of Colum- bia, in the latter portion of May, and the female deposits her eggs singly in small slits about one-twelfth of an inch in length made in the stalks of the insect's food plants, and occasionally in the branches. In a week or ten days the larva hatches, and feeds bv making small channels which increase in size with Fig. 143-—Sigalphus curculionis. Parasiteof potato stalk weevil. (After Riley) the growth of the insect downward toward the bases of the stalks. The undermining of a stalk by the tunneling of several larvae has the effect of impairing the vitality of the plant and causing the leaves to wilt and die. Upon attaining full growth the larva makes a cell of castings and woody fibers in which to transform. The beetles of the new generation appear as early as July 24. In northern localities development is slower, the beetles seldom appearing before August and maturing as late as September, and hibernation is always as a beetle. The knowledge of this fact is of value in the control of the specie^-' as will be explained. 224 IXSliCTS INJURIOUS TO VECIETAISLES This weevil is subject to the attack of a small four-vvingcd parasitic ichneumon fly, Sigalphus curcitlionis Fitch (fig. 143), a well-known enemy of the plum curculio, and sometimes it falls a prey to wireworms. Remedies. — The best remedy is to pull infested vines as soon as they wilt and show evidence of attack, and spread them out so that they will be exposed to the sun and will dry and thus prevent the escape of the insects which they contain. All stalks in infested fields should be burned as soon as the crop is off. This will greatly lessen the number of weevils for the ensuing years. It is also advisable to keep down all solanaceous weeds. The time for their destruction is in July, after they have at- tracted the beetles for egg laying, or any time before the seeds are ripe. The use of fertilizers will often aid injured plants to recuperate from attack. Unfortunately, injury is not apt to be detected until the plants begin to die. As soon, therefore, as a plant shows weakness its stalk should be split open to ascertain the cause. Early potatoes are most subject to injury, and the latest varieties are practically exempt. The Potato Tuber Worm (Phfhoriincra opcrculclla Zell.). — The tuber worm is probably the niost injurious insect to the truck industry of California, where losses to the potato crop have been estimated as aggregating some years 25 per cent. In Salinas Valley, dealers claim that at times the loss has gone as high as 40,000 sacks a year. Potatoes from, other sections have to be watched carefully to avoid "wormy" ones, as a very few such may infest a whole storeroom. As the potato is a product that is expected to retain its value for months, the possibility of destruction by insects while in store becomes a question of great seriousness, more particularly because rots follow the "worm," starting in its burrow and ultimately in- volving the entire tuber. Although the species is introduced and rather commonly distributed in temperate portions of the IXSKCTS IXJl KIOIS TO I'O lAI (), ETC. 22- United States, injury to potato is nearly confined to California, although tobacco is attacked in the South where the insect is known as the tobacco leaf-miner or split-worm. It is probable that this insect may in time become a pest in other regions, though not in the colder temperature States. The moth (fig. 144) resembles a clothes-moth, but is darker. The wing expanse varies from Y% to about % of an inch. The fore-wings are mottled with dark brown and black, and the hind- wings are narrow, with long fringes. Eggs are deposited on the leaves, and the minute worms ih, c) hatching from them bur- row into the stems and afterward into the potato tubers. Fre- quently early injury is done to plants in the field, but as the larvae grow they work, later in the season, farther into the stems. a!a^SIS2IS2» and when these harden make Fig. 144— Potato tuber worm, a, Moth; b, c, larva or " worm " ; «/, pupa; e, /, abdominal segments of larva, a-d. Three times natural size; e, /, more enlarged. (Insect Lifci U. S- Dept. Agr.) their way to the tubers and finish their growth there. The potato is subject to infestation through- out the year, provided the tubers are stored in places that are not too cold for the insect's devel- opment. The life cycle, according to the studies of Mr. W. T. Clarke, may be accomplished in nine weeks, and in the winter, in the mild climate of California, this period is sometimes run in twelve weeks. W'hen the larva is about six weeks of age it comes to the surface and transforms to pupa at the 'mouth of its burrow, or seeks a crack or depression in the potato when the tubers are stored. The usual course of the tuber worm is to mine beneath the outer skin of the plant, and molds and rots (bacterial and fungous growths) follow in its wake, the stalk 226 INSECTS INJURIOUS TO VEGETABLES finally succumbing to the combined injuries of insects and dis- ease. Injury is three-fold to the plants above ground, and to the tubers in the field, and again in store. The moths oviposit on any part of a plant, on leaves, stems, on tubers in the hill and when exposed in the field and after they are stored. Methods of Control. — It is impossible to reach the tuber worms in their mines, in stalks or tubers growing in the field, therefore we must proceed against this pest in other ways. Several nuist be employed to insure success. First come clean methods of cultivation, which implies that all infested plants of potato and weeds of the vicinity must be destroyed, as such material affords a breeding place for the insect and its successful hibernation. Sheep and hogs can be utilized in the destruction of the remnants merely by turning them into the field. Crop rotation is desirable, and cooperation is practically a necessity. Where potatoes are extensively grown in a given region their cultivation might be discontinued for a year. Other plants than tomato, eggplant and tobacco would answer as alternates, and leguminous crops are particularly indicated, owing to their value as soil restorers. Careful compact hill- ing is an effective method in preventing infestation, especially to the tubers. Carelessness in digging, which consists in leav- ing potatoes in the field over night instead of promptly remov- ing them to uninfested shelter, should be avoided. The remedy that has been used with best results consists in placing infested potatoes in tight receptacles and treating them with bisulphid of carbon. Several treatments are sometimes necessary. The Potato-scab Gnat {Epidapus scabici Hopk.). — Some forms of potato-scab are due to the attacks of minute whitish maggots with blackheads which feed in decayed spots in tubers as well as upon healthy portions. The detection of these as the cause of scab is due to the investigations of Dr. A. D. Hopkins,' 1 Special Bui. 2, West \iiginia Agr. E.xp. Station, 1895, pp. 97-111. INSECTS INJURIOUS TO POTATO, KTC. 227 from whose publications the accompanying account has been compiled. The most destructive of these is known as the potato- scab gnat which, in its larval or maggot form, measures about one-sixth of an inch in length. It is the young of a wingless female and winged male gnat or midge, somewhat like the fickle midge treated in preceding pages as an enemy to cu- cumber. The female deposits eggs on tubers in the cellar from autunui to spring. The maggots enter old scab spots or slightly injured places, and under favorable conditions a generation is developed every 20 to 25 days. Later in spring the gnats deposit their eggs in manure or decomposing material, on seed Fig. 145-— Potato scab-gnat, o. Fly; ;, larva, g, egg: h, egg mass, etc- Much enlarged. (After Hopkins) potatoes and growing tubers in the hill, to which they may be transferred on seed tubers or in decaying matter. Once within the tuber and the conditions remaining favorable, the potato is destroyed; but if the maggots are driven out by natural enemies or the soil l^ecomes dry they disappear. The infested places show nearly the same characters as ordinary scab, for which malady it may be easily mistaken. The conditions most favor- able to the increase of this pest are moist, damp cellars, and wet weather during the warmer season. They cannot thrive in dry soil or in perfectly dry storerooms. Immense loss to potatoes was caused in West Virginia during 189 1 and 1892, in Phila- delphia and probably in other sections of the country. Under favoring conditions for their increase, the gnats may be even 228 IXSF.CTS INJURIOUS TO VEGETABLES more destructive than the fungus, on account of their pcnc trating while in the larval stages deep into the substance of the tubers, thus rendering them worthless for market. Methods of Control. — Preventive measures that will at the same time be effective against the scab fungus apply quite as well to the gnats and their maggots. Dr. Hopkins recom- mends the following measures for protection against injury: "Select sandy or other soils of a dry character in which a crop of surface growing vegetables or grain has been grown the previous year, and from which the refuse has been ihor- oughly removed in order that the soil may be as free from vegetable matter as possible. Do not use as fertilizers animal manures, lime, ashes, and like substances. If a fertilizer is necessary, use only a ground bone, phosphate, kainit and other commercial fertilizers of a like character. Select smooth and healthy tubers for seed. .... When the potatoes are dug, and before they are stored, carefully sort out all tuber:, sliowing the least indication of decay, as well as those which are seri- ously affected with scab. Do not plant the same land in pota- toes for at least three years after a potato crop is taken from it." Soak seed potatoes in a solution of corrosive sublimate oi formalin according to directions furnished in the chapter on insecticides. In case a piece of land is especially favorable for the production of potatoes of excellent quality, if the pre- caution is taken to remove and burn all rubbish, such as potato tops, weeds, refuse tubers, etc., the same land may be, by judicious fertilizing, planted in potatoes every alternate year. CHAPTER XIV INSECTS INJURIOUS TO THE TOMATO In the introduction to the chapter on insects affecting potato, eggplant, and similar crops, it was stated that nearly all of these insects affect to a less extent the tomato. The species which will be here mentioned affect more particularly the tomato, and exceptionally potato and similar crops. The most im- portant are the tomato or tobacco worms, the common stalk- borer, often so abundant on tomato as to be known as the tomato stalk-borer, which has previously been treated (page 199), and the tomato fruit worm, or the corn-ear worm. The aphides which infest potato, eggplant, etc., are likely to attack tomato and there are two additional species which have been observed on the latter.^ Mealy-bugs, thrips, plant-bugs and other sucking insects also feed on it. The Tomato Worms. — The large green "worms" that eat tomato leaves are well known. There are two distinct species of them, closely allied, much alike in all their stages, and practically indentical in habits. They are called indiscriminately tomato or tobacco worms and "hornblowers." In the District of Columbia and vicinity, the two species are of nearly equal occurrence as regards numbers on both tomato and tobacco. They are the larvre of large sphinx moths. The tomato worm {Phlcgcthontius quinquemaculata Haw.). — The tomato or northern tobacco worm is nearly as thick as one's little finger, and a])ont three and a half inches long when extended. The horn is larger and less curved, and usually dark in color, whereas the Southern species has a shorter and ^ Rliopalosiphum solani Thos. and Nectarophora ertgeronensis Thos. 229 230 INSECTS INJURIOUS TO VEGETABLES more curved red horn. On the sides of the body are eight longitudinal stripes which are met by a similar number of horizontal stripes, each segment forming an angle (fig. 146, b). The moth (a) which produces this tomato worm has a wing expanse of four inches or less. It is the paler form, and the liright orange spots on the sides of the abdomen are not so Fig, 1 46-— Tomato worm. a. Moth: b, full-grown caterpillar; c, pupa. Half natural size. (After Howard, U. S- Dept- Agr.) v'ivid as in the Southern species and only four in number, whereas the Southern form has five. The hind-wings are marked with zigzag lines more pronounced than in the Southern species. The dark mahogany brown pupje of both are fre- quently turned out of the ground by the spade in early spring and later. They are the possessors of a handle-shaped process projecting from the head, that in the present species (fig. 146, c) being longer than in the Southern (fig. 148, c), indicative of the INSECTS INJURIOUS TO THE TOMATO 231 longer or shorter proboscis of the moth of each. The pupa; measure about two inches in length. The Northern species occurs throughout the United States and into Canada. It is also found on Jamestown weed, matri- mony vine and ground cherry. The moths appear from May to June, according to locality and season, and as far north as New York City two generations are annually produced. The writer and others have noted two generations in Maryland and Virginia, while as far south as Florida, according to Quain- tance, a third generation occurs. The moths deposit their eggs, usually singly, on the under surface of leaves. The eggs, according to Alwood's observations in Virginia, hatch in from four to eight days, and the caterpillars in the course of their growth cast their skins four times in less than a month. When full grown they burrow into the soil and transform to pups. Both "worms" are sometimes quite dark in color, but when they turn nearly black they are usually infected by a bacterial dis- ease, which invariably kills them (fig. 147). Fig. 147.— Southern tobacco worm dead and shriveled from bacterial disease. Natural size. (After Howard, U. S- Dept. Agr.) Few observing persons have failed to see at sometime in their lives the caterpillars of these or other sphinx moths en- tirely covered with little white oval cocoons. These produce small four-winged parasites, and it is owing to the abundance of these and the bacterial disease that the insects are not more numerous than they are. Remedies. — The amount of damage done by tomato worms will vary according to the vigilance of the grower. On small patches the "worms" are readily seen after a little experience. 22,2. INSECTS INJURIOUS TO VEGETABLES and can be picked off by hand and destroyed, and if this is carefully done little apprehension may be experienced of dam- age. Clean culture and crop rotation are always to be prac- ticed a id the leaving of tobacco suckers, or abandoned rem- nants should be avoided, as the "worms" frequently remain in the field until the plants are killed by frost. It should be unnecessary to add that the worms may be killed by spraying with arsenicals. Turkeys are utilized in destroying these in- sects in the South. The Southern tobacco worm (Plilcgcfhoiitiiis sc.vta Job.). — The differences of this sj^ecies and tlie preceding have been pointed out. In brief, the moth (fig. 148, a) is darker, and the five orange spots on the body are larger and brighter. The "worm" has only seven oblique while lines on the sides, and Fig. 148.— Southern tobacco worm. a. Moth; b, full-grown caterpillar; c, pupa. Half natural size. CAfter Howard, U. S- Dept. Agr.) the tail is more curved and red. The pupa has a shorter I)roboscis. The Southern tobacco worm is distributed through the United States from the Atlantic to the Pacific, and from INSECTS INJURIOUS TO THE TOMATO 233 Canada to the West Indies. No Important differences between these two species have been noted as regards habits, time of appearance, susceptibility to diseases and to parasitic attack. In the writer's experience, the two species undergo their trans- formations throughout in about the same time. Remedies are the same as for the tomato worm proper previ- ously treated. The Tomato Fruit Worm (HcliotJiis ohsoleta Haw.). — This insect, as most modern farmers are aware, is the same species as the bollworm or corn-ear worm. It has been treated from Fig. 149.— Tomato fruit worm boring in tomato (After Riley) the standpoint of a cotton pest in innumerable publications, and is considered among corn insects on page 207, but as yet we have discovered no direct remedy for it in its occurrence on tomato. It is frequently the cause of serious trouble to tomato growers over large areas, due to the "worms" eating into and destroying the green and ripening fruit. Remedies. — For the protection of tomatoes, it is advisable not to plant in proximity to corn or cotton fields or on ground that has been grown the previous year to these crops or to beans or cowpeas, all of which are favorite host plants of this pest; nor should land be planted with tomatoes in infested 234 INSECTS INJURIOUS TO VEGETABLES regions until it has been fall or winter plowed. Although no reports are available of satisfactory experiments having been performed in spraying for this species in its occurrence on to- mato, it is possible that a spray of Paris green and Bordeaux mixture, or of either alone, might be satisfactory. It is there- fore suggested that three out of four plats of equal size be treat- ed experimentally in each of the manners described, the fourth plat to be left untreated, so that the effects can be noted. Spray- ing may be practiced up to about a week from the time of the fruit ripening without danger of poisoning human beings. Miscellaneous Insects. — Of insects most to be feared when the plants are first set out are cutworms of various species. The tomato grower is well acquainted with these pests, and no description of their methods is necessary here, beyond the state- ment that they cut off and destroy more than they eat and re- setting is frequently necessary. Cutworms are discussed more fully on pages 49 to 56. Flea-beetles also attack the plants soon after they are set out. Their injuries can be prevented by dipping the young plants before setting in a solution of arsenate of lead, about i pound to 50 gallons of water, or Paris green, i pound to 100 gallons. See page 65 on flea-beetle remedies. CHAPTER XV INSECTS INFESTING THE SWEET POTATO The sweet potato is a staple from New Jersey and Maryland southward. It is seldom that plants are not more or less in- fested by insects, and of these the tortoise beetles are con- spicuous because of the holes which they eat in the leaves. As the crop is started under glass and transplanted, it is subject to attack by cutworms and similar insects. There are several other defoliators, blister beetles, the larvx of sawflies, a hawk- moth and others; flea-beetles sometimes do considerable injury, while in the extreme South the sweet-potato root-borer is be- coming an important pest from its destruction of the tubers. In spite, however, of a considerable number of insects which attack this plant, it does not, on the whole, suffer very material injury save in restricted areas and in years when certain pests are abnormally abundant. The root-borer, however, threatens to be a permanent pest in the Gulf region. The Sweet-potato Root-borer {Cylas fonnicarhis Ol.). — In- jury by this insect in North America was first noticed about 1877 near New Orleans, La., when it was claimed to threaten the destruction of the sweet potato crop of the country, a pre- diction which was, happily, not verified until about 1903. The adult is a weevil of ant-like form except for the long snout which it possesses (fig. 150. a). It is small, about one- fourth of an inch in length, including the snout, the elytra are shining dark blue, the head and snout darker blue, and the thorax and long legs shining red. The larva {h, c) when grown is about one-fourth of an inch long, white, with brown head and darker mouth-parts. 235 236 INSECTS INJURIOUS TO VEGETABLES This sweet-potato borer is of Oriental origin, and its native liabitat is credited to Cochin China. It was probably in- troduced from the West Indies into Louisiana and Florida, and from the former States into Texas. The female deposits her eggs in the vines near the ground, and the larvae after hatch- ing tunnel through the tubers, and the vines die. Frequently tubers are so badly riddled and have such a bitter taste that neither fowls nor swine will eat them. The species is capable Fig. 150.— Sweet-potato root-borer, a. Male beetle; .?, antenna of male, enlarged; ?, antenna of female, enlarged; b, pupa: c, larva, dorsal view; d, larva, side view. All enlarged. lAfter Howard except d, original.) of undergoing trhnsformation from egg to adult in about 31 days and hence as many as four generations might be produced in a year. Considerable injury has been inflicted for a num- ber of years in Louisiana and in Texas. Remedies. — Care should be exercised not to transport tubers from infested localities to uninfested ones. If not too badly damaged the tubers may be disinfected with carbon bisulphid,^ small tubers should be fed to hogs, and badly infested ones should be l)urned with the vines. The Sweet-potato Tortoise Beetles (Cassi(Uni).—'[n many sections, particularly where sweet potato is grown largely for market, this crop is attacked by tortoise beetles of which ' See Farmers' Bui. No. 14.'i, IT. S. Department Agriculture. INSECTS INFESTING THE SWEET POTATO -'37 half a dozen species are common. They also affect morning- glory; it is seldom, in fact, that the latter plants are free from their attacks. The most common form of injury is manifested by numerous more or less rounded holes eaten in the leaves, and this, if traced to its source, will usually be found to be due to the presence of the tortoise beetles. Some of these insects are truly wonderful. The golden tortoise beetle, known as "the gold bug," is one of the most beautiful creatures imaginable when it is resting at ease or feeding in daylight. At this time it has the appearance of a globule of burnished gold. If the beetle is disturbed this golden color disappears, and it fades also toward sundown and does not remain after death in dried specimens. The larv?e which produce these beetles are also remarkable because of their singular habits. They are the Fig. 151.— Golden tortoise beetle. a. Larvag working on leaf; b. larva divested of "pack "; c, pupa; d, beetle, a, Na;ural size; b, c, d, enlarged. (After Riley) possessors of peculiar forked appendages which serve as recep- tacles for their cast-off skins and for their excrement as it is voided. When divested of the cast larval skins and excrement, the larvre are seen to be flat below, like the beetles, and convex above, the margins projecting into peculiar-shaped spines. These larvae are sometimes termed "pedlars," the fork with its load being designated as the pack. Beetles, as well as larvcX, feed chiefly on the under surfaces when not exposed to direct sunlight. Injury is mainly to young plants, the beetles making their first appearance at about the time plants are reset. Soon after appearing the females begin laying eggs, and in about 238 INSECTS INJURIOUS TO VEGETABLES a week or a few days longer the larvae hatch and assist the beetles in their work of destruction. Indications are that all of these tortoise beetles are single-brooded, hibernation taking place in the adult stage. The Golden Tortoise Beetle (Coptocycla bicolor Fab.) is the most striking of the tortoise beetles, and well known and destruc- tive. In this form (fig. 151) the entire body is golden with exception of the borders ; that is, when the insect is resting on leaves exposed to the sun. If a specimen be captured the colors fade to a dull, deep orange, sometimes with a few golden spots remaining, and two black spots are noticed near the middle of the insect. The size varies from two-twelfths to three-twelfths of an inch. The Fig. 152.-Golden , ,,. . • << tortoise beetle larva (o) cames Its pack directly over the egg. Much en- back, and the excrement is arranged in a more larged. (After * Riley.) or less regular three-lobed pattern. The Mottled Tortoise Beetle (Coptocycla guttata 01.). — This species is about equally as common and of the same size as the golden tortoise beetle. It is shown in its various stages in figure 153. It differs in having the elytral ground color Fig. 153.— Mottled tortoise beetle, a, larva; b. pupa; c, beetle. (After Riley) black, extending at the shoulders on each side. Sometimes it is flecked with gold and at other times with yellow. The larva (a) is green, with a bluish shade down the back. It carries its excrement and cast skins in irregular broad masses, fre- INSECTS INFESTING TllIC SWEET POTATO o injures sweet potato and some other cutworms and other caterpillars of less importance occasionally cause losses to this plant. Remedies for these insects are duly treated on page 54. Mealy-bugs {Dactylopius spp.). — A species of unidentified mealy-bug has been mentioned by Dr. J. B. Smith as destructive in Salem County, N. J., in 1901, to sweet-potato in forcing beds.' They were found clustered at the bases of the sprouts and of the small leaves. It is not probable that these insects would survive normal outdoor conditions wdien plants are set out in spring in New Jersey, but in the Gulf region they doubtless would develop out-of-doors quite as well as under glass. For protection against mealy-bugs cellars and storerooms should be thoroughly whitewashed and cleaned before the seed tubers are stored and the temperature should be kept low while in the beds where the roots are forced in spring. Cleanliness should be observed and the roots should be inspected before putting them in, and such as show the mealy-bugs should be rejected and destroyed. 1 Rept. Dept. Ent. N. J. Agr. CoU. Exper. Sta. for 1901 (1902), n. 489. CHAPTER XVI INSECTS INJURIOUS TO MISCELLANEOUS VEGETABLE CROPS THE ONION AND OTHER BULB CROPS Bulb crops arc so similar that what will attack one is apt to feed on the others. Six crop plants (genus Allium) are in- cluded in this grou]) : the common onion, Welsh onion, shallot, cive, leek and garlic. Of these only the first is grown to any extent in North America. "The onion," some one has remarked, "'is one of those strenuous vegetables about which one can- not be indifferent. One either yearns for it with a passionate longing or else utterly repudiates it." The same is true as re- gards insects, since few species are overfond of it. The leading species arc the onion maggot and onion thrips. A few insects of omnivorous tendencies, however, not infrequently do much injury to this ])lant. Of such are some forms of cutworms, and especially the dark-sided cutworm, wireworm, and the imbri- cated snout-beetle. The pungent odor of the onion and its kind renders it unpalatable to many insects, but some resort to these plants in the absence of other vegetation. Insect injury to onion and related plants is peculiarly local or intermittent, and in spite of the injurious species which will be treated, and the immense amount of damage that they have done, it is no uncommon sight, but in fact the rule, to see fields grown to these crops year after year for long periods without their sustaining any material harm. Such is the case about the District of Columbia, where no insects what- 244 INSECTS INJL'RIOUS TO M ISCEI.LAXEOLS CKOl'S 245 ever have been noticed in recent years injuriously affecting tlie onion crop. The Imported Onion Maggot (Pegomya cepetontm Meade) . — This maggot injures the onion l)y eating into the bulbs, the subsequent decay of the affected jjortions frequently destroying them. It is a most important drawback to the culture of onions here and in Europe, from which continent it was introduced years ago. It is nearly related to the seed-corn, and cabbage, maggots treated in former pages. In the adult state it re- sembles, as do the others, the common house fly. The average size is a little larger than the flies of the two root-maggots that have been mentioned, the body being about 3/16-inch long and the wing expanse nearly 3/8-inch. The maggot itself and the puparium can be distinguished from those of other root-mag- gots only by careful comparison. The life history is very like that of the cabbage maggot, the differences being due to the different character of the vegetables attacked. It follows that the natural enemies which prey on one are liable to attack the others, and the remedial measures to be adopted are also much the same. Remedies. — For a discussion of remedies the reader is re- ferred to the account of the seed-corn maggot. The Black Onion Fly (Tritoxa flcxa Wied.).— This is an old enemy of onion and a native species, recorded from the Atlantic coast to Illinois. The fly is about one-third of an inch long, black, with three oblique white stripes on each wing. The maggot itself is white and larger than the root- feeding species previously treated. Fig- 1 59.— Black onion fly. Three T, r 1 • 1 • 1 . • times natural size. (After Walsh) it feeds on onions and cives both m the field and in store. General remedies are the same as for the 246 INSECTS INJURIOUS TO VEGETABLES seed-corn maggot (page 108). In addition bisulphid of car- bon is desirable for tlie treatment of stored onions. Cutworms (Eiixua incssoria, etc.) — Onions, as has been stated, are not particularly favored by many insects of om- nivorous tendencies, but the variegated cutworm is quite de- structive to it and there is one other species, the dark-sided cutworm, which might well be called the onion cutworm, from the great injuries which it causes to this crop. In 1885, near Goshen, New York, this cutworm (shown in figure 160) threatened the extinction of the onion in- dustry, the annual value of which was estimated at half a million dollars. Although the people worked day and night to keep down the pest, the yield was reduced during that and the following year about one-half, or a total cash loss of about $500,000. Remedies. — This species can be treated in the usual manner for cutworms. The Onion Thrips. — For an account of the onion thrips see page 89. RHUBARB Rhubarb or pie-plant is rather uimsually exempt from in- jurious attack by insects, a fact which is largely to be accounted for by the rapid and early growth of this plant, its vigor, and large stalks and leaves. No natural enemies appear to have been introduced with it, and it generally attains full market growth before the appearance of most insects which might F\t- 1 60-— Dark-sided cnXv^orm (Euxoa mes- soria). o, Cutworm", i, moth. (After Riley) INSliCTS IXJURIOL'S TO MiSCELLANEorS CROPS 247 injure it. Several species attack rhubarb, Ijut only two or three appear to prefer it to other plants cultivated in this country. Two insects that are specially identified with rhubarb are the rhubarb curculio and the rhubarb flea-beetle. It is also quite subject to the attack of aphides. The other insects which infest this plant are general feeders, such as cutworms and some other caterpillars and a few leaf- feeding beetles. The Rhubarb Curculio (Lixiis concavus Say.). — Injury by the above-mentioned species is accomplished by the beetles punc- turing the stalks for food, although occasionally they attack the leaves and seed stalks. This causes the plant to exude juice copiously which, drying, forms clear, tear- like drops (fig. 161). Eggs are often deposited in the stems, but the leaves do not develop, doubtless owing to the moisture caused by the beetles' punctures. The larvae breed exclusively in weeds, such as dock (Rumex), and occasionally in sun- flower (Helianthus). The insect under discussion is a large, rusty-coated curculio or snout-beetle, measuring from the tip of its long proboscis about three- fourths of an inch, and being of the form shown in figure 162,0. Fig. 1 61. -Section of rhubarb stalk ^ rr^, J. • showing injury by rhubarb curculic Remedies.— The use of poisons ,A^thor, u. s. Dept. Agr.) on rhubarb during its growing season is out of the question, but the beetles arc so conspicu- ous that they can readily be seen on the leaves, and as they are sluggish there is no difliculty in capturing them. They should 248 INSECTS INJLKIDIS TO VEGETABLES be gathered also upon nearby plants of dock, and after the eggs have been deposited on the dock stems these plants should be pulled up and burned before the development of the adults. The Rhubarb Flea-beetle (Psylliodcs punctulata Mels.).— This species shows a great preference for rhubarb where ob- tainable over other vegetables, among which are cucumber, radish, and beet. It is dark, brassy green, and finely punctulated, with its femora, tarsi, and the basal joints of antenn;e pale, Fig. 162.— Rhubarb curculio. a. Beetle; *, egg: c, newly-hatched larva: (Z, full-grown larva: e. pupa: /.dorsal view of last abdominal segments of pupa. All about twice natural size. (Author's illustration. U. S. Dept. Agr.) obscure yellowish. Both the upper and lower surface of leaves are affected by the beetle gnawing through and devouring the pulp, leaving the skin on the opposite side entire, which be- comes discolored, forming yellowish brown freckles as the leaf grows and expands, the skin at these points becoming in time torn and showing holes. When the beetles occur in num- bers leaves are sometimes riddled by these punctures. Remedies. — Ordinary flea-beetle remedies are recommended. (See page 65.) INSECTS INJURIOUS TO MISCELLANEOUS CROPS 249 LETTUCE Of minor truck plants, which will be considered in this chap- ter, lettuce appears, on account of its tender leaves and lack of decided flavor, the most favored by insects. It does not seem to have any insects specially attached to it, but there is one species, the lettuce earth-louse, which may fall in this category. At least a score of species are known to affect it occasionally. Among the most troublesome of these are the common cabbage looper and celery worm, treated in the consideration of insects which affect cabbage and celery respectively. Cutworms are not partial to lettuce, but some species, particularly the va- riegated cutworm, attack it ; a species of thousand-legged worm has been recorded as being very destructive by attacking the outside leaves near the main stalk and four species of aphides or plant-lice are recorded as feeding on lettuce. The Lettuce Earth-louse (Rhicobiiis lactucce Fitch). — This common eastern species occurs sometimes in destructive num- bers at the roots of lettuce. It is oval, dull whitish, with dusky legs and antennae, and measures less than one-tenth of an inch. The entire body is coated as though dusted with a whitish powder. It should be treated in the same manner as the root- aphides to which group it belongs. OKRA OR GUMBO The insect enemies of okra are practically the same as of cotton, which belongs to the same botanical family. Okra, however, is little damaged, and the writer has for several years seen plantings that were not seemingly at all injured by the few insects which were present. One of the principal enemies of okra is the melon aphis, which sometimes occurs upon it in great numbers. The bollworm enters the pods, but evinces no special fondness for them. Several leafhoppers are foimd on okra, and of these is the waved sharpshooter (Oiiconictopia 2qo :XSECTS INJl'RIOUS TO VEGETABLES [Proconia] iinJata Fab.). The foliage at times shows holes where such general feeders as the twelve-spotted cucumber beetle have attacked it, apparently in wantonness, while the plants were still young. SALSIFY The insect enemies of salsify, or vegetable oyster, were un- der observation by Mr. F. M. Webster some years ago.^ He records the occurrence of two common species of leaf-rollers and three aphides on the plant, the yellow bear, or caterpillar of the ermine moth, and the tarnished plant-bug. There are other species which attack it. all general feeders, but there ap- pear to be few, if any, records of injurious occurrences, PEPPER Peppers were grown in the United States until 1904 without serious attack by insects being re- corded. That year a little pest known as the pepper weevil (Antlionomus eugenii Cano) attracted attention by its injuries to peppers of all vari- eties at Boerne, Texas. This species (fig. 163) is a relative of the notorious Mexican cotton-boll weevil and has the same origin and a similar life his- tory. It is a native of Mexico from which country it has been introduced into Texas. Remedies. — Gathering and destroying the fallen pepper pods in which the larva feeds and the beetle develops or burying the infested pods by bedding high and lowering the soil are suggested as methods of control. Where pepper is grown in irrigated land this practice serves to check the insects, as the Fig. 163. — Pepper weevil. Greatly magnified. (Hun- ter & Hinds, U. S. Dept. Agr.) 1 See list, Insect Life, Vol. II., page 259. INSECTS IXJI'KIOUS lO M ISCICLLANIiOUS CROl'S 25I decay of the pods is hastened and the larvae are thus deprived of a food supply.^ Some of the potato and tomato pests considered in earlier pages occasionally infest peppers, but do not as a rule do notice- able injury. Among these are the tomato worms, bollworm, white fly. and Colorado potato beetle. 1 This species is treated under the name of Anthonomus (sneotvictus Champ, in Bui. 54, Bur. Ent., U. S. Dept. Agr., pp. 43-48, and Bui. 63, pp. 5 5-58, by C. M. Walker and F. C. Pratt respectively. CHAPTER XVII BIBLIOGRAPHY A short list of some of the more important and readily available publications on economic entomology in which the insects injurious to vegetable crops are treated follows. In compiling such a list some precedence is given to the publica- tions of the Federal Department of Agriculture because as a rule they have a wider scope than State Agricultural Experiment Station publications, are printed in larger editions and are ac- cessible to all, being for the most part free on application. Many of these contain bibliographical references. The list begins with works on general and economic entomology. WORKS ON GENERAL AND ECONOMIC ENTOMOLOGY 1841. Harris, T. W. — ^Insects Injurious to Vegetation. Flint ed., 1851. Orange Judd Co., New York. First ed., Cambridge, 1841. 1855. FiTcii, Asa — Reports of the State Entomologist of New York. I.-XIV., Albany, 1855-1870. (See Lintner's First Annual Report, State Ent. New York, pp. 294-297.) 1865. The Practical Entomologist. Vols. I. and II. Published by the Entomological Society of Philadelphia, 1865-1867. 1868. The American Entomologist, edited by B. D. Walsh and C. V. Riley. Vols. I.-III., 1S68-1880. 1869. Riley, C. V. — Reports of the State Entomologist of Missouri. I.-IX. Jefferson City, 1869-1877. 1879, Reports of the Entomologists of the U. S. Department of Agriculture. J. H. Comstock (1879-1880) ; C. V. Riley (1878-1879, 1880-1894). L. O. Howard (1894 to date). 1882. Lintner, J. A. — Reports of the State Entomologist of New York, I.-XIV. Albany, 1882-97. 1882. Treat, Mary — Injurious Insects of the Farm and Garden. Orange Judd Co., 1882. (A small work compiled from Riley's reports.) 1883. Forbes, S. A. — Reports of the State Entomologist of Illinois, I.-XXIII. 1883-1905- 1891. Weed, C. M. — Insects and Insecticides. 281 pp., 143 figs. Han- over, N. H., 1891. 1895. Comstock, J. H. and Anna B. — A Manual for the Study of Insects. 701 pp., 797 figs. Ithaca, N. Y. 252 r.iiu.iocRAruY 253 1896. Smith, J. B.— Kcononiic Entomology. 481 pp., 483 lig^- Pli'l- adelphia, 1896. I90J. Johnson, W. G. — Fumigation Methods. Orange Judd Co., New York. 313 pp., 83 tig.s. 190J. Sanderson, E. D. — Insects Injurious to Staple Crops. New York. 295 pp., 162 figs. Bulletins of the Division and Bureau of Entomology of the U. S. Department of Agriculture, I-XXXTIL, o. s., 1883-1895, 1-71, n. s., 1896-1907. (Buls. 19, 23, 29, S3 and 43 treat of insects injurious to vegetables.) Insect Life, vols. I.-VIL, 1888-1897. Circulars, Division and Bureau Ent. U. S. Dept. Agr., 1891-1907. (Circ's. 10, 16, 31, 38, 39, 43, 57, 59, 60, 62, 63, 65, 80 and 87 treat of insects which affect vegetable crops.) The publications of the various state agricultural experiment stations may be obtained by residents of the States where these documents are issued. GENERAL CROP PESTS Cutworms. Smith— Bui. 109, New Jersey Agr. Exp. Sta., pp. 3-13, figs. 1-3, 1895; Slingerland — Bui. 104, Cornell Univ. Agr. Exp. Sta., pp. 553-600, figs., 1895. Spotted Cutworm {Noctiia c-nignim Linn). Chittenden— Bui. 27. n. s., Div. Ent. U. S. Dept. Agr., pp. 54-58, 1901. Variegated Cutworm (Pcridroina saucia Hbn. [Agrotis saiicia]). Chittenden— Bui. 29, n. s., Div. Ent. U. S. Dept. Agr., pp. 46-64, 1901 (includes bibliography). Black Cutworm (Agrotis ypsilun Rott.). Riley— Rept. U. S. Dept. Agr. f. 1884,^ pp. 294, 295, 1885. Army Worm {Hcliophila imipuncta Haw. [Leucama unipuncta]). Howard— Circ. 4, Div. Ent. U. S. Dept. Agr., 1894; Slin- gerland—Bui. 133, Cornell Univ. Agr. Exp. Sta., pp. 233- 258, 1897. Fall Army Worm or Grass Worm (Laphygma frugipcrda S. & y\.). Chittenden— Bui. 29, n. s., Div. Ent. U. S. Dept. Agr., pp. 13-45, 1901 (Bibliography). ,, tt • Wireworms. Comstock and Slingerland— Bui. 33, Cornell Univ. Agr. Exp. Sta., pp. 193-272, figs., 1891 ; Slingerland— Bui. 107, Cornell Univ. Agr. Exp. Sta., pp. 37-56, 1896; Forbes— i8th Rept. St. Ent. Ills., pp. 27-51, 1894. White Grubs. Forbes, S. A.— i8th Rept. St. Ent. Ills., pp. 109-145, 1894; Bui. 44, Univ. Ills. Agr. Exp. Sta., pp. 257-281, 1896; Chittenden— Bui. 19, n. s., Div. Ent. U. S. Dept. Agr., pp. 67-80, 1899. Grasshoppers or Locusts. Riley— Bui. 25. o. s., Div. Ent. U. S. Dept. Agr., pp. 1-62, figs, and pis., 1891. (Compiled from 1st and 2n(l Repts. U. S. Ent. Comm., etc.) Pale-striped Flea-beetle (S\stcna hlanda Mels. [S. tccniata Say]). Chittenden— Bui. 23, Div. Ent. U. S. Dept. Agr., pp. 23-30, 1900. 254 INSECTS INJ UKIOUS TO VEGETM'.LES Red Spider (Tctraiiyclms biiuaculalus [law. [7'. tclarius Authors]). Chittenden — Bui. jJ, n. s., Div. Ent., U. S. Dept. Agr., pp. 35-42, 190 1. ASPARAGUS General. Chittenden — Bui. 10, n. s., Div. Ent. U. S. Dept. Agr., pp. 54-t'-2. 1898. Common Asparagus Beetle (Crioccris asparagi L.). Chittenden — Ybk. U. S. Dept. Agr. f. 1896 (1897), PP- 341-349; Bui. 66, Bu. Ent., pp. 6-9, 1907 Twelve-spotted Asparagus Beetle {Crioccris n-punctata 01.). Chittenden— Ybk. U. S. Dept. Agr. f. 1896 (1897), pp. 349-352; Bui. 66, Bu. Ent., pp. 9, 10, 1907. Asparagus Miner {Agromyza simplex Loew.). L. c, pp. 1-5, figs. 1 and 2, 1907. BEANS AND PEAS General. Chittenden— Ybk. U. S. Dept. Agr. 1898 (1899), pp. 22,3- 280, figs. Bean Leaf-beetle {Cerotonia trifurcata Eorst. [C. caminca Fab.]). Chittenden — Bui. 23, n. s., Div. Ent. U. S. Dept. Agr., pp. 30, 31, 1900. Pea Aphis (Ncctarophora destructor Johns. [Ncctarophora pisi]). Chittenden — Bui. 23, n. s., Div. Ent, U. S. Dept. Agr., pp. ZZ-37, fig- 9. 1900. Bean Leaf-roller (Eudamus protcus Linn.). Chittenden — Bui. :i2, n. s., Div. Ent. U. S. Dept. Agr., pp. 92-96, fig. 20, 1902. Lima-bean Stem-borer (Monoptilota nuhilclla Hulst.). Chitten- den— Bui. 23, n. s., Div. Ent. U. S. Dept. Agr., pp. 9-17, 1900. Smaller Corn Stalk-borer (Elasmopalpus lignoscllus Zell.). Chit- tenden— Bui. 23, n. s., Div. Ent. U. S. Dept. Agr., pp. 17- 22; 1900. BEETS AND SPINACH General. Forbes and Hart — Bui 60, Ills. Agr. Exp. Sta., pp. 397- 532, figs. 97, pis. I.-IX., 1900. (A monographic account with bibliography) ; Chittenden — Bui. 43, Div. Ent. U. S. Dept. Agr., pp. 1-71, figs., 1903. (Short accounts of princi- pal insect enemies.) Leaf-miner (Pcgomya vicina Lint.). Sirrine — 14th Annual Rept. Board of Control, N. Y. Agr. Exp. Sta., pp. 625-633, PI. IV.; 1896. BlBLIor.UAl'IlY 255 Larger Beet Leaf-beetle {Monoxia ptiitcticullis Say. [Cjalci'uca inaritinia]). Chittenden — Bui. 18, n. s., Div. Ent. U. S. Dept. Agr., p. 95, 1898. Beet Aphis (Pciiifhi.mis bctcr Doane). Doane — Bui. 42, Wash. State xA-gr. Exp. Sta., 14 pp., 4 figs., igoo. Beet Army Worm {Laphygina cxigua Hbn.). Chittenden — Bui. 33, n. s., Div. Ent. U. S. Dcpt. Agr., pp. 37-46, fig., 1902. Beet Webworm {Loxostcgc sticticalis Guen.). Gillette — 13th Ann. Rept. Colo. Agr. Exp. Sta., pp. 128-130, 1900 (1901) ; Bui. 98, Agr. Exp. Sta. Colo., pp. 3-12. pis. I. and II., 1905. CABBAGE AND OTHER COLE CROPS Cabbage Maggot (Pcgomya [Phorbia] brassiccr Bouche). Chit- tenden— Circ. 63, Bu. Ent., U. S. Dept. Agr., pp. 3-6, figs., 1906; Slingerland — Bui. 78, Cornell Univ. Agr. Exp. Sta., pp. 481-577, 1894: Smith — Bui. 200, N. J. Agr. Exp. Sta., pp. 1-27, 13 figs., 1907. Imported Cabbage Worm {Po)itia rapcc Linn.). Chittenden — Circ. 60, Bu. Ent., U. S. Dept. Agr., 8 pp., 6 figs., April, 1905. Cross-striped Cabbage Worm {Ercrgcstis [Pioiica] riiiiosalis Guen.). Chittenden — Bui. s;^, n. s., Div. Ent., U. S. Dept. Agr., pp. 54-59, 1902. Cabbage Looper {Autographa brassiccc Riley [Plusta brassiccc]). Chittenden — Bui. 33, n. s., Div. Ent., U. S. Dept. Agr., pp. 60-69, 1902. Imported Cabbage Webworm (Hcllula undalis Fab.). Chitten- den— Bui. 19, n. s., Div. Ent., U. S. Dept. Agr., pp. 51-57, 1899. CUCUMBER, MELON AND RELATED PLANTS General. Quaintance — Bui. 45, Ga. Agr. Exp. Sta., pp. 25-50, figs., 1899; Smith — Bui. 94, N. J. Agr. Coll. Exp. Sta., pp. 3-40, 1893.. Striped Cucumber Beetle (Diabrotica znttata Fab.). Chitten- den—Bui. 19, n. s., Div. Ent. U. S. Dept. Agr., pp. 48-51. 1899; Circ. 31, Div. Ent. U. S. Dept. Agr., 1898. Twelve-spotted Cucumber Beetle (Diabrotica duodecimpunctata Oliv. ). See Corn root-worms. Squash Ladybird (Epilaclma borcalis Fab.). Chittenden— Bui. 19, n. s., Div. Ent. U. S. Dept. Agr.. pp. 11-20, 1899. (In- cludes bibliography). Melon Aphis (Aphis gossypii Glov. [.Ipliis cucnmcris Forbes]). Chittenden— Circ. 80, Bu. Ent. U. S. Dept. Agr., 16 pp., 6 figs., 1906. Squash Bug (A)iasa trisfis DeG.). Chittenden— Circ. 39, Div. Ent. U. S. Dept. Agr., 1899; Bui. 19, n. s., Div. Ent., pp. 20- 28, 189 256 INSECTS INJURIOUS TO VEGETABLES Squash-vine Borer {Mclittia satyrinifurmis Hbn. [/ISgcria cucur- bits and Mclittia ccto]). Chittendkn — Bui. 19, n. s., Div Ent. U. S. Dept. Agr., pp. 34-40, 1899; Circ. 38, Div. Ent U. S. Dcpt. Agr., 1899. Pickle Worm (Diaplntnia iiitidalis Cram. [Eudioptis and Margaro- nia Iiitidalis]). Chittenden — Bui. 19, n. s., Div. Ent. U. S Dept Agr., pp. 40-42, 1899; Lintner — nth Rept. N. Y. St Ent, pp. 126-133, 1896; Quaintance — Bui. 54, Ga. Agr Exp. Sta., pp. 73-91, tigs., 1901 (including bibliography) Melon Caterpillar {Diaphaiiia hyalinata Linn.). Chittenden— Bui. 19, n. s., Div. Ent. U. S. Dept. Agr., pp. 42-44, i8< Quaintance — Bui. 45, Ga. Agr. Exp. Sta., pp. 42-45, 1899. CELERY, CARROT, PARSLEY AND PARSNIP Celery Looper (Autographa simplex Gucn. [Plusia simplex]}. Chittenden — Bui. ;ii, n. s., Div. Ent. U. S. Dcpt. Agr., pp. 7?>, 74' 1902. Greenhouse Leaf-tyer {Phlyctccitia fcrrugalis Hubn. [P. rubigalis Gu(.n.|). Chittenden — Bui. 27, n. s., Div. Ent. U. S. Dept. Agr., pp. 7-26, 1901 (including bibliography). Celery Caterpillar (Papilio polyxcncs Fab. [/-". astcrias]). Davis — Bui. 102, Mich. Agr. Exp. Sta., pp. 21-24, 1893. (For mono- graphic treatment see works of Scudder and Edwards on Butterflies.) Carrot Rust-fly {Psila roscc Fab.). Chittenden — Bui. 2>i^ n. s., Div. Ent. U. S. Dept, Agr., pp. 26-32, 1902. Carrot Beetle {Li gyrus gibbosus DeG.). L. c, U. S. Dept. Agr., 1>P- 5-^-37 • 1902. Parsnip Webworm (Dcprcssana hcrachana DeG.). Riley — Insect Life, V. I., pp. 94-98, 1888. Parsnip Leaf-miner {Acidia fratria Loew. [Trypeta fratria]). Coouillktt — Insect Life, v. VII., pp. 383, 384. Little Negro Bug (Corimclcrna pulicaria Germ.). Davis — Bui. 102, Mich. Agr. Exp. Sta., pp. 13-18, 1893. SWEET CORN General. Forbes — 23rd Rept. St. Ent. Ills., pp. 1-273, figs., pis.. 1905 (includes bibliography). Seed-corn Maggot {Pcgomya fusciceps Zett. [Phorbia fusciccps, Anthomyia zccc, etc.]). Chittenden — Bui. :^z, n- s., Div. Ent. U. S. Dept. Agr., pp. 84-92, 1902; Circ. 63, Bu. Ent. U. S. Dept. Agr., pp. 1-3. fig., 1906. Corn Root-worms {Diabrotica longiconiis Say. [D. 12-punctata 01.1 ). Chittenden — Circ. 59, Bu. Ent. U. S. Dept. Agr., 8 pp., 3 figs.. 1905. Corn Bill-bugs. General. Forbes— i6th Rept. St. Ent., Ills., pp. 58- 74, 1890; Bui. 79. Ills., Agr. Exp. Sta.. 27 pp., 1902. BIBLIOGRAPHY 257 Southern Corn Bill-bug {Sphciiophonis maidis Chttn. [Spli. robus- tiis Authors]). Forbes— L. c. ; Riley— Rept. Comm. Agr. 1881-2. pp. 138-142, 1883. Clay-colored Bill-bug {Sphcnophorus ccqualis Linn.). — Treated as Spli. ochrcus Lee, by Forbes, 1. c. Northern Corn Bill-bug {Sphcnophorus zcce Walsh).— Generally called by authors S. sculptilis Uhl., 1. c. Larger Corn Stalk-borer (Diatnra sacchamlis Zell.). Howard— Circ. 16, Div. Ent. U. S. Dept. Agr., pp. 1-3, 3 %»., 1896. Smaller Corn Stalk-borer (Elasmopalpus ligiioscllns Zell.). Chit- TKNDEN- Bui. 23, n. s., Div. Ent., U. S. Dept. Agr., pp. 17- 22, 1900. Corn-ear Worm; Cotton Bollworm (Hcllothis ohsolcta Fab. [ann- iger Hbn.]). Quaintance — Farmers' Bui. 191, 1904; QuAiNTANCE and Brues— Bui. 50, Bu. Ent. U. S. Dept. Agr., pp. 1-155, figs, and pis., 1905 (includes bibliography). POTATO, EGGPLANT AND RELATED PLANTS General. Riley— Potato Pests, Orange Judd Co., N. Y., pp. 1-108, figs. 48, 1876. Colorado Potato Beetle {Lcptinotarsa dcccmlincata Say. [Doryph- ora io-lincata\). Chittenden— Circ. 87, Bu. Ent. U. S. Dept. Agr., 15 pp.. 6 figs., 1907.^ _ Potato-tuber Worm or Tobacco Split-worm (Phthonmcca opcr- culclla Zell. [Lita and Gelcchia solanclla]). Riley and Howard— Insect Life, v. IV., pp. 239-242, 1892; Howard— Farmers' Bui. 120, U. S. Dept. Agr., pp. 19-22, 1900; Clarke— Bui. I35, Cal. Agr. Exp. Sta., 29 pp., 7 %s., 1901. Potato-stalk Weevil (Trichobaris trinotata Say.). Chittenden— Bui 33, n. s., Div. Ent, U. S. Dept. Agr., pp. 9-19, 1902. Tobacco Flea-beetle (Epitrix parvnla Fab.) Chittenden— Bui. 19, n. s., Div. Ent., U. S. Dept. Agr., pp. 85-87, 1899- Potato or Cucumber Flea-beetle {Epitrix cucumens Harr.). Chittenden— Bui. 19, n. s., Div. Ent., U. S. Dept. Agr., pp. 89, 90, 1899. TOMATO Northern Tobacco Worm or Tomato Worm (Phlcgcthontius QuinqKcmaculata Haw. [Protoparce cclcus]). Howard— Farmers' Bui. 120, U. S. Dept. Agr., pp. 10-14. 1900. Southern Tobacco Worm or Hornblower (Phlcgcthontius sexta Job [Protoparce Carolina]). Howard— L. c, ; Alwood, Bui 17, n .s., Div. Ent. U. S. Dept. Agr., pp. 72-74, 1898. Common Stalk-borer (Papaipenia nitcla Guen. [Gortyna mtcla]). Smith— Rept. Ent. Dept. N. J. Agr. Coll. Exp. Sta. f. 190S (1906), pp. 584-587- , . „r , N ^r Greenhouse White Fly (Alevrodes vaporariorum Westw.). Mor- rill—Circ. 57, Bu. Ent. U. S. Dept. Agr., pp. 1-9, hg-, IQOS. 258 INSECTS INJURIOUS TO VEGETABLES SWEET POTATO General. Sanderson— Sweet Potato Insects, Bui. 59, Md. Agr. Exp. Sta., 1900. Sweet-potato Root-borer (Cylas fonnicarius Fab.). Conradi — Bui. 93, Texas Agr. Exp. Sta., pp. 3-16, figs., 1907. Larger Sweet-potato Sawfly {Sclucoccrus privatus Nort.). M.\r- LATT— Insect Life v. V., pp. 24-27, fig. 6, 1892. Sweet-potato Flea-beetle {Chcctocncma coniinis Cr.). SiMiTH — 13th Rept. N. J. Agr. Exp. Sta., pp. 472-475, 1892. Mottled Tortoise Beetle {Copfocycla signifcra Hbst. [C. guttata]). Sanderson — L. c. Golden Tortoise Beetle {Coptocxda bicolor Fab. [C. aurichalcca]). — L. c. ONION Imported Onion Maggot (Pcgo/itya ccptorum Meade [Antlioiiiyia and Pliorbia ccpanim Bouche]). Chittenden — Circ. 63. Bu. Ent. U. S. Dept. Agr., pp. 6, 7, 1906; Smith and Dick erson — Bui. 200, N. J. Agr. Exp. Sta., 27 pp., 13 figs., 1907 Onion Thrips {Thrips tabaci Lind.). Fergande — Insect Life, v, VII., pp. 39^-395- RHUBARB Rhubarb Curculio (Lixiis concavus Say.). Chittenden — Bui. 23, n. s., Div. Ent. U. S. Dept. Agr., pp. 61-69, 1900. INSECTICIDES 1902. Hinds, W. E. — Carbon Bisulphid as an Insecticide. Farmers' Bui. 14s, 28 pp. 1902-04. Haywood, J. K. — Reports on Analyses of Insecticides. Buls. 68, 76 and 82, Bu. Chcin., U. S. Dept. of Agr. and Farmers' Bui. 146. 16 pp. 1903. Marlatt, C. L. — Important Insecticides. Farmers' Bui. 127, U, S. Dept. Agr., 46 pp., 6 figs. INDEX Acidia fratria 184, 185 Agriotcs mancits 80 Agrotis ypsiion 52, 53 Alcyrodcs laporariorum 175 Alfalfa worm xiv Anasa tristis _ 161 — 164 Antlionomus arneotinctus 251 eugcnii 250 Apanteles glomcratus ..15, 137, 138 Aphides 10, 83—85, 127—130 Aphis brassictc 151 — 153 gossypii 165—168, 214 lions 11 maidiradicis 189, 190 rumicis 214 Anachnida, defined 4 Army worm, fall ...56, 59, 208, 209 Arsenate of lead 32 Arsenicals 30—34, 65, 137, 138 harmless 33, 34 Arsenic, white 33 Arsenite of copper 32 lime 33 Asparagus beetle, common ..93 — 96 work, figured x twelve-spotted ....96, 97 insects injuring 93 — 97 Autograplia brassiccr ....7, 140, 142 Bait for insects 54, 55 Barrel spray pumps ; 45 Bean cutworm 113 ladybird 109, 110 leaf-beetle 110, 111 leaf-roller 112 weevil, common 102 — 104 four-spotted 106 Beans and peas, insects in- juring 100—111 Beet aphides 129, 130 army worm 125 beetle. Western 123 insects injurint:s to ..120 — 130 leaf-beetle, larger 122, 123 webworm 125, 126 Beetles, defined 6 Bill-bugs, corn 195—199 Birds, beneficial 14 Bisulphid of carbon. 42, 102, 133, 167 Blister beetles 66—69, 124 Bollworm. figured xi see also Heliothis 113 Bordeaux mixture ....29, 55, 56, 65 Bran-mash 55, 138 Bruchus chinensis 104 — 106 obtectus 102—104 pisorum 100—102 irimaculatus 106 PAGE Brushing methods .. ..27, 116, 117 Bucket pumps 45 "Bud-worm" of corn 191 "Bugging" 27 Buhach, or pyrethrum 40 Burning over fields and waste lands 18 Butterflies, defined 7 Cabbage aphis 151 — 153 butterfly, Southern 139 flea-beetle. Western ..147, 148 insects injuring 131 — 154 looper 7, 140—142 maggot 131 — 135 webworm, imported ..142 — 144 worm, cross-striped 140 imported 136 — 139 Cantharis nuttalli 118, 119 Carbolic-acid emulsion .37, 108, 132 Carbon bisulphid, see Bisulphid of carbon Carncadcs messoria 242, 243 Carrot beetle 185—187 rust fly ... 176—179 Carrots, insects injurious to 184 — 188 Cassida bivittata 239 nigripcs 239, 240 Caterpillars, miscellaneous ..60 — 62 Celatoria diabrotica 157 Celery caterpillar 179, 180 insects injurious to ..176 — 186 leaf-tyer 180—182 looper 182, 183 Centipedes, briefly defined 5 Cerotoma trifurcata 110, 111 Chatocnema confints 240, 241 dcnticulata 212 piilicaria 211 Chinch bug, false 150, 151 Chrysomelidae 62 — 66 Clean farming 22, 158, 159, 167 Click beetles 80. 81 Cole crop insects 131 — 154 Coleoptera (beetles), defined ....6 Collecting insects, see also hand- picking 27 Compsomyia macellaria, figured . .8 Control of insects, natural ele- ments in 1 1 — 1 5 Cooperation in control of in- sects 23 — 25 Copidosoma truncateUa 142 Copper arsenite 32 Coptocycla bicolor 238 guttata 238, 239 Corimeleena piilicaria 183 259 26o INDEX PAGE Corn bill-bugs 195—199 cutworm 210, 211 ear worm . . 113, 207, 208 insects injuring 189 — 212 root-aphis 189, 190 root-worms 191 — 195 stalk-borer, larger 201—204 stalk-borer, smaller ..204 — 207 Corrosive sublimate 37, 38 Covering, cloth 27, 28 Cowpea weevil 104 — 106 Crioceris asparagi 93 — 96 12-piuictata 96, 97 Crop pests, general 49 — 91 rotation, see Rotation Crustacea, briefly defined 4 Cucumber beetle, striped ..156 — 159 twelve-spotted ..159, 191 — 193, 218 flea-beetle 218 insects injuring 155 Cultivation methods ..21, 132, 133, 138, 139 Cultural methods, see Farming methods Currant leaf hopper 85 Cutworm, corn 210, 211 dark-sided 246 spotted 210, 211 variegated 53, 54 Cutworms ..49—59, 113, 124, 145, 210, 211,_ 242, 243, 246 Cy!as formicariiAS _ 235, 236 Depressaria heracliana ....187, 188 Diabrotica longicornis .. . .194, 195 12-piinctata 159, 191—193 figured ^H** t-ittata 156 — 159 Diacrisia virginica -60 Piamond-back moth 144, 145 Diaphania livalinata 173 — 175 nitidalis 171 — 173 Diatrcea saccharalis 201 — 204 Diedrocephala versuta 117 Diptera, defined 8 Disking .21 Disonycha xanthomelana ..121, 122 Diversified agriculture .....20 Domestic animals, destroying insects '9 "Drill-worm" 191 Driving insects 68, 159 Eggplant flea-beetle 219 Elasmopalpus lignosellus ..204 — 207 Einpoasca Aavescens 85 Entomology, value of knowledge of 1-^3 Epicauta Icmniscata 67, 68 macxilata 68 marginata 124 pennsylvanica 220, 221 vittata 67 Epidapus scabiei 226 — 228 Epilachna borealis 160. 161 cornipta 109, 110 Epitrix cucumeris 217 — 219 fuscHla 219 parvula 219, 220 PAGE Enbadison schisoceri, figured ..241 Eiidamus proteus 112 Euphoria inda 209, 210 Euschistus rariolarius, figured ..10 Eutettix tenella 128 Eiithrips tritici, figured 10 Euxoa messoria 246 Evergestis rimosalis 140 Fall army worm 56 — 59 harrowing 170 plowing 21, 78, 82 Farming methods, to prevent insect injury ..16 — 25, 65, 66 Feltia annexa "■ ' ' i ^o Fertilizers, danger from organic. 108 mineral ^^^ "Fire bug" 1:J9 Fish-oil soap -'o Flea-beetles ..63—66, 121, 122, 146 — 149, 211, 212 Flies defined -^ Formalin • • • • • • ^° Fruit-chafer, brown 209, 210 Garden flea-hopper V^^f webworm 61, 6- Gas lime 34, 35 Granulated cutworm 53 Grasshoppers 69 — 73, 127 Greasy cutworm 52 Ground beetle, fiery, figured ....12 Gumbo, insects injuring 249 Hair-streak, gray 113, 114 Halticini 63 — 66 Halticus uhleri 118 Hand-picking ..27, 56, 108, 109, 132 Harlequin cabbage bug 148 — 150 Hcliophila (Leucania) umpuncta.59 Heliothis obsoleta 113, 207, 208, '33 234 Hellebore'.". 35, 108, 135 Hellula undalis 142—144 Hemiptera, defined 9 Heteroptera, defined 9 Hexapoda (insects) defined S Hippodamia convergens, figured ..6 Ilomoptera, defined 9 Honey-dew 84, 85 Hopper-dozers 27 Hot water, as insecticide. .38, 39, 138 Hymenoptera, defined 8 Insecticide apparatus 43 — 47 Insecticides 30—39, 78 applying 47 proprietary .•'^2, 43 Insects, injurious, determina- tion of xii injury, manifestations of X life history of 2 classification 3 — 6 natural elements in control of 11—15 predaceous 12 useful 14 Inspection, farm 22, 23 June beetles 73 — 79 Kerosene and sand 108 emulsion ..16, ZT , 65, 116, 138. 167, 178 INDEX 261 Knapsack sprayer 44 Lace-wing fly, figured 11 Lachnostcrna arcuata 76 cribrosa Tl farcta 77 fusca 76 Ladybird, convergent, figured .... 6 spotted 95 Ladybirds 13 Laphygma exigua 125 frugiperda ..56 — 59, 208, 209 Leaf-beetles 62 — 66, 121—124 -hoppers .85—87, 117, 127, 128 -miners 127, 153, 154 Lebia grandis 13, 217 Lepidoptera, defined 7 Lcptiiwtarsa deccmlineata .214 — 217 Lettuce earth-louse 249 insects injurious to ..248, 249 Ligyrus gibbosus 185 — 187 Lime 34 Lixus concavus 247 Locusts 69—73 London purple il Loxostege similalis 61, 62 sticticalis 125, 126 Lygus pratensis 87, 88 Macrobasis unicolor 119 Mancasellus brachyurus, figured ..4 May beetles 73 — 79 Mealy-bugs 243 Mechanical methods of destroy- ing insects 26 — 29 Megilla maculata 95 Melanoplus differentialis 71 femur-rubrum 70 spretus 9, 70, 71 Melanotus communis 80, 81 Melittia satyriniformis ....168 — 171 Meloida 66 — 69 Melon aphis ■. 85, 165—168 caterpillar 1 73 — 175 insects injuring 155 — 175 Millipedes, briefly defined 5 Milyas cinctus, figured 12 Mites, defined 4 Monocrepidiiis vespertinus, fig- ured 212 Monoxia conspwta 123 piincticollis 122, 123 Moths, defined 7 Murgantia histrionica ....148 — 150 Myriopoda, defined 5 Natural elements in control of insects 1 1 — 1 5 Nectarophora cucurbitce 165 destructor 114 — 117 erigeronensis 229 Negro bug, little 183 Neuroptera, defined 10 Nicotine extracts and powders . .41 Noctita clandestina 51 c-itignim 210, 211 Nozzles, spraying 47 Nysius angiistatus 150, 151 minu^us 151 Ogdoconta cinereola 113 Okra, insects injurious to 249 Oncometopia undata 249 Onion fly, black 245 insects injuring 244 — 246 maggot, imported 245 thrips 89, 90 Orthoplera, defined 9 Papaipcnia nitchi 199 — 201 Papilio polyxeiics 179, 180 Parasites, useful 14 Paris green 30 — 32 Parsley, insects injuring ..184 — 188 Parsnip leaf -miner 184, 185 webworm 187, 188 Parsnips, insects injuring .184 — 188 Pea aphis 114 — 117 moth Ill, 112 weevil 100-^102 Peas, insects injuring 100 — 119 Pegomya brassiccr 131 — 135 cepetorum 245 fusciceps 106—109, 135 Pemphigus bctcc 129 Pepper, insects injuring 250 Peridroma saucia 53, 54 Phadon ccruginosa I47 Phlegcthontius quiiiquemaculata 229—232 sexta 232, 233 Phlyctcrnia ferrugalis 180 — 182 Phthoriina-a opercutcUa ...224 — 226 Phyllotreta pusilla 147, 148 vittata 146, 147 Physopoda, defined 10 Pickle worm 171 Pie-plant, insects injuring. .246 — 248 Plant-bug, brown, figured 10 tarnished, figured 11 Plant-bugs ..10, 83, 87, 88, 117, . 118, 127, 128, 148—151 Planting to avoid insect injury 17, 158 Plant-lice, see Aphis and Aphides Plusia simplex 182, 183 Plutella macuHpennis 144, 145 Podisus maculiventris 95 Poisoned baits 54, 83 Poisons, contact 36 — 39 stomach 30, 35 Polistes bellicosus, figured 5 Pontia napi 139, 140 protodice 139 rapcp 136—139 Potato beetle, Colorado ..214 — 217 flea-beetle 217 — 219 insects injuring 213 — 228 scab gnat 226 stalk weevil 221 — 224 tuber worm 224 — 226 Potherb butterfly 139, 140 Preventives _ 16, 78, 79 Proprietary insecticides 42, 43 Protection of plants 55 Pruning, as insect remedy 28 Psita rosce 1 76 — 1 79 Psylliodes punctidata 248 Pteromalus puparum.lA, IS, 137, 138 Pyrethrum..39, 40, 65, 138, 159, 167. 262 INDEX PAGE Red-legged locust 70 Red spider 91 Repellents 28, 29 Rhizobius luctuccc 249 Rhopalosiphum dianthi ....151, 214 solani 229 Rhubarb curculio 247 flea-beetle 248 insects injuring 246 — 248 Rocky mountain locust ..9, 70, 71 Root-maggots 131 — 135 Rotation, crop 19, 79, 82, 83 Salsify, insects injuring 250 Scaptomysa Aaveola 153, 154 Scheele's green 32 Scliisocerus cbenits 241 privatus 241, 242 Screw-worm, figured 8 Seed-corn maggot ...106 — 109, 135 Semasia iiigricana Ill, 112 Sharpshooter, waved 249 Sigatphus curciiUonis 223 Soap, insecticide 38, 65, 167 Soldier-bug, bordered 12, 95 spined 95 Sowing, late 178 Sphenophorus aqualis 198 . callpsus 195 maidis 196, 197 ^ . "ea 197', 193 Spinach flea-beetle 121, 122 insects injuring 120 — 130 Sprayer, knapsack 44 Spraying 36, 37, 43—47 Spraying apparatus 43 — 47 Spring plowing 170 Squash bug 161—164 ladybird 160, 161 -vine borer 158 — 171 Stalk-borer, common 199 — 201 Stiretrns anchorago 95 Suffocation, insecticides which kill by 39 — 42 Sugar-beet leaf hopper 1 28 Sulphur .,. 41, 42 Sweet corn, insects injuring 189—212 Sweet-potato beetle, two-striped. 239 flea-beetle 240, 241 insects affecting 235 — 243 root-borer 235, 236 sawflies 241, 242 tortoise beetles 236 — 238 Syrphus ribesii, figured 13 Systena blanda 63, 64 taniata 64, 65 Tarnished plant-bug 1, 87, iS8 Tarred paper cards 133 — 135 Tetranychus bimaculatus 91 Thecla melinus 113, 114 Thousand-legged worms 5 Thrips 10, 89 — 91 tabaci 89, 90 tritici 90, 91 Tipliia itwrnata 78 Tobacco, as insecticide 40 flea-beetle 219, 220 Tomato fruit worm 233, 234 insects injurious to ...229 — 234 worms 229 — 233 Tortoise beetles 237 — 240 Trap crops .138, 139, 158, 159, 170 Trapping insects 28 Trichobaris trinotaia 221 — 224 Trichopoda pennipes 163, 164 Tritoxa Hexa 245 Turnip flea-beetle, striped .146, 147 leaf-miner, imported ..153, 154 Tychca brevicornis 130 N'ariegated cutworm 53, 54 Vermorel nozzle 47 Water-cress leaf-beetle 147 sowbug, illustrated 4 Whale-oil soap 38 Wheat thrips 90, 91 wireworm 80 White fly 175 White grubs 73—79, 130 Wireworms 79 — 83, 130, 21 "■ W-marked cutworm 51 Yellow bear 60 STANDARD BOOKS PUBLISHED BY ORANGE TUDD COMPANY NEW YORK CHICAGO i.39-441 Lafayette Street Marquette Building B OOKS sent to all :p arts of the tvorUl for catalog price Discounts for large quantities on afpli- catie Correspondence invited. Brief descriptive catalog free. Large illustrated catalog, six cents. Soils By Charles William Burkett, Director Kansas Agri- cultural Experiment Station. The most complete and popular work of the kind ever published. As a rule, a book of this sort is dry and uninteresting, but in this case it reads like a novel. The author has put uito it his individuality. The story of the properties of the soils, their improvement and manage- ment, as well as a discussion of the problems of crop growing and crop feeding, make this book equally valuable to the farmer, student and teacher. There are many illustrations of a practical character, each one suggesting some fundamental principle in soil manage- ment. 303 pages. 5^ X 8 inches. Cloth $1.25 Insects Injurious to Vegetables By Dr. F. H. Chittenden, of the United States Depart- ment of Agriculture. A complete, practical work giving descriptions of the more important insects attacking vegetables of all kinds with simple and inexpensive remedies to check and destroy them, together with timely suggestions to prevent their recurrence. A ready reference book for truckers, market- gardeners, farmers as well as others who grow vegetables m h small way for home use; a valuable guide for college and ex- periment station workers, school-teachers and others interested in entomology of nature study. Profusely illustrated. sVz x 8 inches. 300 pages. Cloth. . * • $i..SO The Cereals in America By Thomas F. Hunt, M.S., D.Agri., Professor of Agron- omy, Cornell University. If you raise five acres of any kind of grain you cannot afford to be without this book. It is in every way the best book on the subject that has ever been written. It treats of the cultivation and improvement of every grain crop raised in America in a thoroughly practical and accurate manner. The subject-matter includes a comprehensive and succinct treatise of wheat, maize, oats, barley, rye, rice, sorghum (kafir corn) and buckwheat, as related particularly to American conditions. First-hand knowledge has been the policy of the author in his work, and every crop treated is presented in the light of individual study of the plant. If you have this book you have the latest and best that has been written upon the subject. Illustrated. 450 pages. 5^/2 x 8 inches. Cloth $1.75 The Forage and Fiber Crops in America By Thomas F. Hunt. This book is exactly what its title indicates. It is indispensable to the farmer, student and teacher who wishes all the latest and most important information on the subject of forage and fiber crops. Like its famous com- panion, "The Cereals in America," by the same author, it treats of the cultivation and improvement of every one of the forage and fiber crops. With this book in hand, you have the latest and most up-to-date information available. Illus- trated. 428 pages. 514 X 8 inches. Cloth $1.75 The Book of Alfalfa History. Cultivation and Merits. Its Uses as a Forage and Fertilizer. The appearance of the Hon. F. D. Coburn's little book on Alfalfa a few years ago has been a profit revela- tion to thousands of farmers throughout the country, and the increasing demand for still more information on the subject has induced the author to prepare the present volume, which is by far the most authoritative, complete and valuable work on this forage crop published anywhere. It is printed on fine paper and illustrated with many full-page photographs that were taken with the especial view of their relation to the text. 336 pages. 6;^ x_9 inches. Bound in cloth, with gold stamp- ing. It is unquestionably the handsomest agricultural reference book that has ever been issued. Price, postpaid . . , $2.00 Clean Milk By S. D. Belcher, M.D. In this book the author sets forth practical methods for the exclusion of bacteria from milk, and how to prevent contamination of milk from the stable to the consumer. Illustrated. 5x7 inches. 146 pages, (^^l^tli ■' ■ - ^ **...... . $i.f,n Bean Culture By Glenn C. Sevey, B.S. A practical treatise on the pro- duction and marketing of beans. It includes the manner of growth, soils and fertilizers adapted, best varieties, seed selec- tion and breeding, planting, harvesting, insects and fungous pests, composition and feeding value : with a special chapter on markets b}' Albert W. Fulton. A practical book for the grower and student alike. Illustrated. 144 pages. 5x7 inches. Cloth $0.50 Celery Culture By W. R. Beattie. a practical guide for beginners and a standard reference of great interest to persons already engaged in celery growing. It contains many illustrations giving a clear conception of the practical side of celery culture. 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While the practical side has been emphasized, the scientific part has not been neglected, and the information given is of value, both to the grower and the student. Taken all in all, it is the most complete, reliable and authoritative book on the potato ever published in America. Illustrated. 200 pages. 5x7 inches. Cloth $0.75 Dwarf Fruit Trees By F. A. Waltgh. This interesting book describes in detail the several varieties of dwarf fruit trees, their propagation, planting, pruning, care and general management. Where there is a limited amount of ground to be devoted to orchard pur- poses, and where quick results are desired, this book will meet with a warm welcome. Illustrated. 112 pages. 5x7 inches. Cloth _ $0.50 Cabbage, Cauliflower and Allied Vegetables By C. L. Allen. A practical treatise on the various types and varieties of cabbage, cauliflower, broccoli, Brussels sprouts, kale, collards and kohl-rabi. An explanation is given of the requirements, conditions, cultivation and general management pertaining to the entire cabbage group. After this each class is treated separately and in detail. The chapter on seed raising is probably the most authoritative treatise on this subject ever published. Insects and fungi attacking this class of vegetables are given due attention. Illustrated. 126 pages. 5x7 inches. Cloth $0.50 Asparagus By F. M. Hexamer. This is the first book published in America which is exclusively devoted to the raising of aspara- gus for home use as well as for market. It is a practical and reliable treatise on the saving of the seed, raising of the plants, selection and preparation of the soil, planting, cultiva- tion, manuring, cutting, bunching, packing, marketing, canning and drying, insect enemies, fungous diseases and every require- ment to successful asparagus culture, special emphasis being given to the importance of asparagus as a farm and money crop. Illustrated. 174 pages. 5x7 inches. Cloth. , $0.50 The New Onion Culture By T. Greiner. Rewritten, greatly enlarged and brought up to date. A new method of growing onions of largest size and yield, on less land, than can be raised by the old plan. Thousands of farmers and gardeners and many experiment stations have given it practical trials which have proved a success. A complete guide in growing onions with the great- est profit, explaining the whys and wherefores. Illustrated. 5x7 inches. 140 pages. Cloth $0.50 The New Rhubarb Culture A complete guide to dark forcing and field culture. Part I — By J. E. Morse, the well-known Michigan trucker and originator of the now famous and extremely profitable new methods of dark forcing and field culture. Part II — Compiled by G. B. Fiske. Other methods practiced by the most experi- enced market gardeners, greenhouse men and experimenters in all parts of America. Illustrated. 130 pages. 5x7 inches. Cloth. $0.50 Farm Grasses of the United States of America By William Jasper Spillman. A practical treatise on the gr^ss crop, seeding and management of meadows and pastures, description of the best varieties, the seed and its impurities, grasses for special conditions, lawns and lawn grasses, etc., etc. In preparing this volume the author's object has been to present, in connected form, the main facts con- cerning the grasses grown on American farms. Every phase of the subject is viewed from the farmer's standpoint. Illus- trated. 248 pages. 5x7 inches. Cloth. . . . $1.00 The Book of Corn By Herbert Myrick, assisted by A. D. Shamel, E. A. Burnett, Albert W. Fulton, B. W. Snow, and other most capable specialists. A complete treatise on the culture, marketing and uses of maize in America -and elsewhere, for farmers, dealers and others. Illustrated. 372 pages. 5x7 inches. Cloth $1.50 The Hop — Its Culture and Care, Marketing and Manufacture By Herbert Myrick. A practical handbook on the most approved methods in growing, harvesting, curing and selling hops, and on the use and manufacture of hops. The result of years of research and observation, it is a volume destined to be an authority on this crop for many years to come. It takes up every detail from preparing the soil and laying out the yard, to curing and selling the crop. Every line represents the ripest judgment and experience of experts. Size, 5x8; pages, 300; illustrations, nearly 150; bound in cloth and gold; price, postpaid, $1.50 Tobacco Leaf By J. B. Killebrew and Herbert Myrick. Its Culture and Cure, Marketing and Manufacture. A practical handbook on the most approved methods in growing, harvesting, curing, packing and selling tobacco, with an account of the opera- tions in every department of tobacco manufacture. The contents of this book are based on actual experiments in field, curing barn, packing house, factory and laboratory. 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A timely up-to-date book on the practical application of the new methods for destroying insects with hydrocyanic acid gas and carbon bisulphid, the most powerful insecticides ever discovered. It is an indis- pensable book for farmers, fruit growers, nurserymen, garden- ers, florists, millers, grain dealers, transportation companies, college and experiment station workers, etc. Illustrated. 313 pages. 5x7 inches. Cloth $1.00 Diseases of Swine By Dr. R. A. Craig, Professor of Veterinary Medicine at the Purdue University. A concise, practical and popular guide to the prevention and treatment of the diseases of swine. With the discussions on each disease are given its causes, symptoms, treatment and means of prevention. Every part of the book impresses the reader with the fact that its writer is thoroughly and practically familiar with all the details upon which he treats. All technical and strictly scientific terms are avoided, so far as feasible, thus making the work at once available to the practical stock raiser as well as to the teacher and student. Illustrated. 5x7 inches. 190 pages. Cloth $0.75 Spraying Crops — Why, When and How By Clarence M. Weed, D.Sc. The present fourth edition has been rewritten and reset throughout to bring it thoroughly up to date, so that it embodies the latest practical information gleaned by fruit growers and experiment station workers. So much new information has come to light since the third edition was published that this is practically a new book, needed by those who have utilized the earlier editions, as well as by fruit growers and farmers generally. Illustrated. 136 pages. 5x7 inches. Cloth $0.50 Successful Fruit Culture By Samuel T. Maynard. A practical guide to the culti- vation and propagation of Fruits, written from the standpoint of the practical fruit grower who is striving to make his business profitable by growing the best fruit possible and at the least cost. It is up-to-date in every particular, and covers the entire practice of fruit culture, harvesting, storing, mar- keting, forcing, best varieties, etc., etc. It deals with principles first and with the practice afterwards, as the foundation, prin- ciples of plant growth and nourishment must always remain the same, while practice will vary according to the fruit grower's immediate conditions and environments. Illustrated. 265 pages. 5x7 inches. Cloth $1.00 Plums and Plum Culture By F. A. Waugh. A complete manual for fruit growers, nurserymen, farmers and gardeners, on all known varieties of plums and their successful management. This book marks an epoch in the horticultural literature of America. It is a complete monograph of the plums cultivated in and indigenous to North America. It will be found indispensable to the scientist seeking the most recent and authoritative informa- tion concerning this group, to the nurseryman who wishes to handle his varieties accurately and intellingently, and to the cultivator who would like to grow plums successfully. Illus- trated. 391 pages. 5x7 inches. Cloth. . . . $1.50 Fruit Harvesting, Storing, Marketing By F. A. Waugh. A practical guide to the picking, stor- ing, shipping and marketing of fruit. The principal subjects covered are the fruit market, fruit picking, sorting and pack- ing, the fruit storage, evaporating, canning, statistics of the fruit trade, fruit package laws, commission dealers and dealing, cold storage, etc., etc. No progressive fruit grower can afiford to be without this most valuable book. Illustrated. 232 pages. 5x7 inches. Cloth $1.00 Systematic Pomology By F, A. Waugh, professor of horticulture and landscape gardening in the Massachusetts agricultural college, formerly of the university of Vermont. This is the first book in the English language which has ever made the attempt at a com- plete and comprehensive treatment of systematic pomology. It presents clearly and in detail the whole method by which fruits are studied. The book is suitably illustrated. 288 pages. 5x7 inches. Cloth $i-oo Feeding Farm Animals By Professor Thomas Shaw. This book is intended alike for the student and the farmer. The author has succeeded in giving in regular and orderly sequence, and in language so simple that a child can understand it, the principles that govern the science and practice of feeding farm animals. Professor Shaw is certainly to be congratulated on the successful manner in which he has accomplished a most difficult task. His book is unquestionably the most practical work which has appeared on the subject of feeding farm animals. 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A complete exposition of important facts concerning the relation of bacteria to various problems related to milk. A book for the class- room, laboratorv, factory and farm. Equally useful to the teacher, student, factory man and practical dairyman. Fully illustrated with 83 original pictures. 340 pages. Cloth. 5^^ X 8 inches $1.25 Modern Methods of Testing Milk and Milk Products By L. L. VanSlyke. This is a clear and concise discussion of the approved methods of testing milk and milk products. All the questions involved in the various methods of testing milk and cream are handled with rare skill and yet in so plain a manner that they can be fully understood by all. The book should be in the hands of every dairyman, teacher or student. Illustrated. 214 pages. 5x7 "inches $0.75 Rural School Agriculture By Charles W. Davis. A book intended for the use of both teachers and pupils. Its aim is to enlist the interest of the boys of the farm and awaken in their minds the fact that the problems of the farm are great enough to command all the brain power they can summon. The book is a manual of exercises covering many phases of agriculture, and it may be used with any text-book of agriculture, or without a text- book. The exercises will enable the student to think, and to work out the scientific principles underlying some of the most important agricultural operations. The author feels that in the teaching of agriculture in the rural schools, the lalxjratory phase is almost entirely neglected. If an experiment helps the pupil to think, or makes his conceptions clearer, it fills a useful purpose, and eventually prepares for successful work upon the farm. The successful farmer of the future must be an experimenter in a small way. Following many of the exercises are a number of questions which prepare the way for further research work. The material needed for performing the experiments is simple, and can be devised by the teacher and pupils, or brought from the homes. Illustrated. 300 pages. Cloth. 5x7 inches. $1.00 Agriculture Through the Laboratory and School Garden By C. R. Jackson and Mrs. L. S. Daugherty. As its name implies, this book gives explicit directions for actual work in the laboratory and the school garden, through which agri- cultural principles may be taught. The author's aim has been to present actual experimental work in every phase of the subject possible, and to state the directions for such work so that the student can perform it independently of the teacher, and to state them in such a way that the results will not be suggested by these directions. One must perform the experi- ment to ascertain the result. It embodies in the text a com- prehensive, practical, scientific, yet simple discussion of such facts as are necessary to the understanding of many of the agricultural principles involved in every-day life. The book, although primarily intended for use in schools, is equally valuable to any one desiring to obtain in an easy and pleasing manner a general knowledge of elementary agriculture. Fully illustrated. 51^ x 8 inches. 462 pages. Cloth. Net . $1.50 Soil Physics Laboratory Guide By W. G. Stevenson and I. O. Schaub. A carefully out- lined series of experiments in soil physics. A portion of the experiments outlined in this guide have been used quite gen- erally in recent years. The exercises (of which there are 40) are listed in a logical order with reference to their relation to each other and the skill required on the part of the student. Illustrated. About 100 pages. 5x7 inches. Cloth. . $0.50 Farmer^s Cyclopedia of Aglriculture ^ ^ A Compendium of Agricultural Science and Pra£lice on Farm, Orchard and Garden Crops, and the Feeding and Diseases of Farm Animals • : • : 'By EARLEY VERNON WILCOX. Ph.D and CLARENCE BEAMAN SMITH, M.S Associate Editors in the Office of Experiment Stations, United States Department of Agriculture HIS is a new, pr.actical, and complete pres- entation of the whole subject of agricul- ture in its broadest sense. It is designed for the use of agriculturists who de- sire up-to-date, reliable information on all matters pertaining to crops and stock, but more particularly for the actual farmer. The volume contains Detailed directions for the culture of every important field, orchard, and g'aa-den crop grown in America, together with descriptions of their chief insect pests and fungous diseases, and remedies for their control. It contains an ac- count of modern methods in feeding and handling all farm stock, including poultry. The diseases which affect different farm animals and poultry are described, and the most recent remedies sug- gested for controlling them. Every bit of this vast mass of new and useful information is authoritative, practical, and easily found, and no effort has been spared to include all desirable details. There are between 6,000 and 7,000 topics covered in these references, and it contains 700 royal 8vo pages and nearly 500 suberb half-tone and other original illustrations, making the most perfect Cyclopedia of Agricul- ture ever attempted. Handsomely bound in cloth, ^3.50; half morocco (•Oery jamptaouj). ■f4-.50, postpaid ORANGE JUDD COMPANY, "' *Li:r.'.aWS.S "•' '.S.U & Tli-^IW > i 90^^ 00034 1131 ^