S-fKU Niini3il 3SV51d 'iSOl dl, E3. 3AOW3il ;: ON OQ 3SVSId as rSC 7-- raR En, fcjr-o y ;^r - ir St \ ir-^ sr-^ * f- - — i. r ^ t \ sr-T- 1 *• Ul 'J- a> .', 5 ~r. I S n t £ H \: o ' S2 — r « n n S i' s — INSECTS AND INSECTICIDES ?, Difmin, NHK«>KMA'nONH OV J M 10 (JKLKJty CATl' Itl'I LLAll. liNSECTS AND INSFXTICIDES A Practical Manual CONCERNING Noxious Insects and the Methods of Preventino" Their Injuries BY Clarence ni. weed, n. sc. I'lolosisor ol" /i)oU>,u.v ami Kiilomoli>L;.v, Now Hainpshiio (."olh'ijo of Agriculture Hiul tlio MiMlianic Arts ILLUSTRATED SaOONO (I'iKX^ IS1£D) tCDiTION NEW YORK ORANGE JUDU COMPANY 185)5 ^5lo By THE Same Author FUNGI AND FUNGICIDES A Practical Manual Concei-ning the Fungous Diseases of Cultivated Plants and the Methods of Preventing their Ravages. Illustrated. Price, ,^1.00. SPRAYING CROPS AVhy, Wiien and How. Illustrated. Third (Revised) Edi- tion. Eleventh Thousand. 130 pages. Price, 25 cents. Orange Judd Company, New York, N, Y. TEN NEW ENGLAND BLOSSOMS AND THEIR INSECT VISITORS Illustrated. Houghton, Mifflin & Co., Boston and New York Copyright 1891 and 1895 3r CLARENCE M. WEED PREFACE This Yolume has been prepai^ed for the purpose of furnishing the farmer, the fruit grower, the floricultur- ist, and the housekeeper with a coucise account of the more important injurious insects with which they have to contend, together with a summary of the latest knowledge concerning the best methods of jn^e venting or counteracting the injuries of these pests. In its prepa- ration free use has been made of the information scat- tered through the literature of economic entomology; and, as a rule, it has been found impracticable to give to each author credit for first working out the life his- tories of the various species. In one way or another the contributions of nearly every American economic ento- mologist have been drawn upon ; but especial mention should be made of the help obtained from the publications of Dr. C. V. Riley, recently United States entomologist, whose remarkable investigations during the last quarter of a century have placed him foremost among the world's economic entomologists. Mention should also be made of the aid derived from the writings of Messrs. Bruner, Cook, Comstock, Fernald, Fletcher, Forbes, Garman, Gillette, Harvey, Howard, Lintner, Osborn, Packard, Saunders, Slingerland, and many others. The illustrations of this volume have also been gleaned from various sources. I am under obligations to the authorities of the Department of Agriculture and various experiment stations, particularly those of Illi- nois, Cornell University, Colorado, Kentucky, Nebraska, New Jersey and Ohio, — for the privilege of getting du- plicate electrotypes. The authors to whom each of VI lifSECTS AHD INSECTICIDES those figures that did not first appear in my own publi- cations should be credited, are indicated in the following list: After Eiley :— Plates III, IV, VI, XII, and figures 1-4, 8, 15, 23-27, 36-45, 59, 61, 63, 67, 69, 70, 72, 74-76, 78«, 79, 81-95, 97-103, 105, 119-121, 123, 124, 127-129, 133-139, 141, 144, 146-149, 150, 155, 157-162, 164-166, 168, 170, 3 72-176; after Lugger, fig. 5; after Osborn, figs. 169-171; after Garman, figs. 68, 71, 104; after Bruner, figs. 13, 14, 62, 80, 145 ; after Miss Ormerod, fig. 167 ; after Howard, figs. 46-50 ; after Comstock, fig. 141 ; after Lake, plate V, fig. 28 ; after Goff, fig. 132; after Smith, plate XV, figs. 9, 10, 122; after Slingerland, plates VII, X, figs. 30-34, 52-57, 60, 77, 78, 130, 131 ; after Marlatt, fig. 29 ; after Saunders, figs. 51, 116 ; after Packard, figs. 7, 22 ; after Lintner, figs. 16, 58 ; after Popenoe, fig. 108 ; after Gillette, plate VIII, fig. 66 ; after Bailey, fig. 19 ; after Galloway, fig. 18 ; after Forbes, figs. 64, 65, 143, 152-154 ; from Insect Life, figs. 12, 73 ; after Taschenberg, plate II, figs. 109-112. All the figures are natural size unless otherwise stated, and wherever a straight line occurs beside a mag- nified drawing, it represents the length of the specimen figured. I have attempted to make the discussions of life histories and remedies as plain and simple as possible, omitting, so far as practicable, all technical terms, and have included only such details as are necessary to a prac- tical understanding of the subjects treated of. In the present second edition the book has been thoroughly revised to date, and the latest available information incorporated. C. M. W. Nev) Hampshire College of Agriculture and Mechanic Arts. Durham, New Hampshire, April, 1895. CONTENTS Page. Introduction - 9 PART I Insects Affecting the Larger Fruits Apple 63 Plum 113 Pear 94 Peach 121 Cherry 128 PART II Insects Affecting Small Fruits Strawberry 137 Raspberry and Blackberry 159 Currants and Gooseberries 148 Grape 167 PART III Insects affecting Shade Trees, Ornamental Plants, and Flowers Shade Trees 189 Rose 215 Flowers 218 PART IV lifSECTS affecting VEGETABLES Tomato 225 Bean and Pea 242 Potato 228 Cabbage 245 Celery 234 Onion 261 Squash and Cucumber 235 Asparagus 263 PART V INSECTS AFFECTING CEREAL AND FORAGE CROPS Indian Corn 267 Clover 292 Wheat 278 Grass 299 PART VI Insect Pests of domestic Animals and the Household Insects Affecting Domestic Animals 313 Insect Pests of the Household 326 INSECTS AND INSECTICIDES INTPRODUCTIOK None of the changes modern civilization has made upon the earth is more evident to the American farmer than that of the increased difficulty of saving his crops from the ravages of noxious insects and parasitic funiri. Many of us have heard from our fathers and grand- fathers of the apples which once grew in abundance in yards and along highways, strangers alike to the codling moth, maggot or scab ; the luscious peaches free from worms and rot; the plums unmarked by the cur- culio, and the pears that had yet to learn the secret of becoming dwarfed, gnarly and cracked ; of the grapes that knew not how to rot and the potatoes whose leaves had neither been blighted nor bitten by the Colorado beetle. Now all is changed : every crop has foes that often gather the lion's share of the harvest. The enemies have come from the north and the south, the east and the west, from Europe and the islands of the sea, and in our own midst they have flocked from the forest to the field, deserting a wild plant for its cultivated congener or changing their habits to conform to a new environ- ment. This increase of noxious insects, however, is the natural result of the changed conditions of things. Among the principal factors tending toward it may be 1 2 INSECTS AND INSECTICIDES mentioned (1) the massing of crops in limited areas ; (2) the facilities for transporting insects long distances by vessels and railways carrying agricultural products ; (3) the abandoned farms and orchards that serve as breeding grounds; and (4) the destruction of forests and the cultivation of prairies. Considering each of these factors briefly, we find that the tendency of the first — that of the massing of crops in limited areas — toward increasing onr insect pests rests upon the biological law that the increase of any animal is limited by its food supply. Under the natural conditions existing on this continent before the advent of the white man, those insects which fed on wild plants had as a rule only a limited food supply. The apple maggot or raih'oad worm for example is supposed to have bred originally in the wild haws of the woods. The parent fly had then usually to find here and there an isolated tree bearing the fruit in which it deposited its eggs. Its chances of being caught by a bird or entrapped in a spider's web while on this search were very good, so that the scarcity of the food supply not only directly limited the number of individuals that could be produced, but by being scattered it increased the chances of the adult insects falling a prey to enemies. But in a modern apple orchard all this is changed : the food supply is almost unlimited, and is so massed together that the insect runs little risk in passing from fruit to fruit or from tree to tree. Hence it can multiply indefi- nitely unless there is some means of checking it. The same line of reasoning applies to a large proportion of our injurious insects. We are indebted to our commerce on sea and land for many of the most noxious insects. Brought to our shores from Europe, Asia or Australia by ships, many of these pests have found a land which for them was flow- ing with milk and honey, and in which their hereditary INTKODUCTIOJS^ 3 enemies had not yet gained a foothold. Consequently they have multiplied without let or hindrance; and by natural and artificial means — notably the railroad trains — they have rapidly overrun the country of their adoption. The abandoned or neglected fields and orchards all over the United States have proven a prolific breeding ground for many insect pests. Too often the efforts of painstaking farmers have been rendered unavailing by the proximity of such sources of infection. An orchard that has outlived its usefulness had better be converted into firewood than left to die uncared for. The destruction of forests has compelled certain in- sects to resort to cultivated crops for subsistence ; and in some cases a decided change in feeding habits has re- sulted. So also the bringing of the prairies into culti- vation has caused many insects which originally fed on wild grasses to resort to pastures and meadow lands. The operation of these various causes, together with the enormous powers of multiplication possessed by the insects themselves, have led to a constantly increasing injury to cultivated crops, until to-day these tiny foes exact a tribute of ten per cent, of the crop products of American agriculture. " They form an omnipresent host of taxgatherers, taking possession of the farmer's crops and enforcing their onerous demands without process of law, unless preventive measures are vigorously prose- cuted. They are no respecters of persons : like the rain they fall upon the fields of both the just and the unjust. ''The authorities best able to judge have estimated the annual loss in the United States due to these little pests at nearly half a billion dollars. Noxious insects, according to Dr. C. V. Riley, recently the distinguished entomologist of our National Department of Agriculture, occasion losses in the United States which are 'in the aggregate enormous, and have been variously estimated at from $300,000,000 to 1400,000,000 annually.' In 4 INSECTS AKD INSECTICIDES single states and single seasons tlie damage is often frightful in extent. During some of the great chinch- bug epidemics the loss in Illinois occasioned by this one insect has amounted to over 173,000,000 a year; and in seasons not marked by an outbreak of such a great crop pest the injury is much more severe than is ordinarily supposed. The official entomologist of the State just named, Professor S. A. Forbes, — after years of careful field observation and statistical study, — has recently ex- pressed his belief that Hhe insects of the State of Illinois derive as large a profit from the agriculture of this great agricultural State as do the farmers them- selves.' "* Fortunately, however, there is an extended silver lining to this dark cloud of insect injury. If these creatures have increased on every hand, our knowledge of methods of controlling them has also augmented with the passing years. Many of the remedies proposed ten or twenty years ago seem now foolish and impracticable. Within the last decade especially the progress has been phenomenal. It has been shown that many insects can be checkmated by a proper crop rotation ; that the nat- ural enemies of others can be used to destroy them ; and that others are easily killed by improved insecticides. But the most important advance has been the introduc- tion of the spraying machine, an apparatus by means of which insect-killing substances may be easily and rapidly distributed over the surfaces of trees, shrubs, vines and herbaceous plants. Its introduction into American hor- ticulture marks an advance almost as important as was marked by the advent of the improved cultivators into our agriculture. Before the latter were introduced the weeds that infest the soil were fought by the hand hoe, but now a single team does the work of many men. In *C. M. Weed, Popular Science Monthly, March, 1893. INSECT TRANSFORMATIONS 5 the same way, until recently, various laborious and par- tially effective methods were used in fighting noxious insects and destructive fungi; but now many foes of both these classes are fought on a large scale by the force pump and spray nozzle, and every season adds others to the list of those against which this method may be successfully used. With a large class of farmers and fruit growers, spraying has become a recognized part of the season's operations, and therein lies the chief promise of the method. When the belief becomes gen- eral that it is as important to save a crop from destruction by its foes as it is to produce it ; that fighting noxious worms must take its place as a farm process by the side of that of fighting noxious weeds ; that the parasitic plants which absorb the vitality of leaf and fruit are as danger- ous to the crop as the plants which dispute with it the possession of the soil, and when along with this recog- nition there is placed before the farming community a cheap and wholesale method of preventing the injuries of these organisms, — then the vast annual loss now suf- fered because of insects and fungi will be very greatly lessened. The pages which follow are devoted to a con- sideration of the more important of the first named of these enemies — the noxious insects — and to the methods of preventing their injuries. INSECT TRANSFORMATIONS Insects are distinguished from related animals by having three pairs of feet, fitted for locomotion, at- tached to a body divided into three principal parts — head, thorax and abdomen. A majority of them are also characterized by undergoing during their develop- ment a series of well-marked changes, or transforma- tions. Such insects exist in four distinct stages, namely : (1) the egg ; (2) the larva or caterpillar ; (3) the pupa or chrysalis ; and (4) the adult or imago. As an example 6 INSECTS AIs^D INSECTICIDES of these changes we may take the celery caterpillar, the transformations of which are illustrated in Plate I. The adult butterfly, a handsome, black creature, with yellow and blue markings on its wings (Plate I, e, /), deposits an egg on the underside of the celery leaf. Qliis egg {a) is a small, light yellow object, nearly spherical, though slightly flattened where it is attached to the leaf. A week or so after it has been laid there hatches from it a small caterpillar or ^^worm," less than one-tenth of an inch long, black, with two transverse white bands — one across the middle of the body and the other at the pos- terior extremity — and haying the back roughened with minute, black, projecting points. This little caterj^illar feeds upon the celery leaf, and within a few days so in- creases in size that it becomes necessary to shed its skin, or molt. For this purpose the skin splits along the back and the caterpillar crawls out, clothed in a new skin that had been formed beneath the old one. The color markings are somewhat different on this new covering. The caterpillar continues feeding and growing for several weeks, casting its skin at occasional intervals, and chang- ing considerably in color and markings. When full grown it is of the form and size indicated at b on the plate, the general color being pale green, with a series of transverse bands of black and yellow markings. When irritated it thrusts out, from a slit just back of the head, a pair of peculiar yellow Y-shaped organs, that emit a disagreeable odor. These organs on the caterpillar are represented at b, and at c is shown a front view of the head, with them extended. They doubtless serve as a protection from various enemies. The full-grown caterpillar becomes restless, and leaving the plant, seeks some sheltered situation in which to pupate, ^^ It first spins," says Dr. Harris, *' a little web or tuft of silk against the surface whereon it is rest- mg, and entangles the hooks of its hindmost feet in it, INSECT TRANSFORMATIONS CHIXCH BUG. Magnified. SO as to fix them securely to the spot ; it then proceeds to make a loop, or girth, of many silken threads, bent into the form of the letter U, the ends of which are fast- ened to the surface on which it rests on each side of the middle of its body ; and under this, when finished, it passes its head and gradually works the loop over its back, so as to sup- port the body and prevent it from falling downwards. Within twenty- four hours after it has taken its sta- tion, the caterpillar casts off its cat- erpillar skin, and becomes a chrysalis, or pupa (Plate I, d ) of a pale green, ocher-yellow, or ash-gray color, with two short ear-like projections above fig. i. the head, just below which, on the back, IS a little prominence like a pug nose. The chrys- alis hangs in the same way as the caterpillar, and remains m this state from nine to fifteen days, according to tlie temperature. When this period is terminated, the skin of the chrys- alis bursts open, *and the butterfly issues from it, clings to the empty shell till its c r a m p e d and a, b, eggs ; c, e,f, g, young droopiug W i n g S Magnified. have extended to their full dimen- sions, and have become dried, upon which it flies away in pursuit of companions and food." Besides celery this caterpillar feeds upon parsley, carrots, and related plants. FIG. 2. CHINCH BUG bugs, or nmyphs 8 IIH^SECTS AND INSECTICIDES The butterfly is known to entomologists as Papilio asterias. Insects which undergo such a marked series of changes as those above described are said to have complete transformations to distinguish them from those which do not undergo so marked a series of changes — those with incomjjlete transformations. In one stage of exist- ence— that of the chrysalis or pupa — insects of the first class take no food and are unable to move about. With these, also, the young or larva differs greatly in form and appearance from the adult. Thus, caterpillars are very unlike the butterflies and moths into which they de- velop, and larval honey bees differ greatly from the adults ; but with the insects of the second class this marked difference does not exist. The chinch bug fur- nishes a good illustration of these transformations. The adult bug (Fig. 1) deposits eggs (Fig. 2, a, d) about the roots of grass and grain. From these hatch young bugs (c) that do not differ in general form from the adults. They suck the sap from various plants of the grass fami- ly, gradually increasing in size, and molting at inter- vals. In a few weeks they become nearly full grown, but instead of changing to a quiet chrysalis state, they simply molt again and continue feeding as before. In these early stages, which correspond to the larva and chrysalis, they are called nymphs. The older nymphs {g) are nearly as large as the full-grown bugs, differing mainly in the absence of wings. In about a week they again molt and come forth as adult bugs. Grasshop- pers, crickets, and all true bugs, undergo these incom- plete transformations. BITING AND SUCKING INSECTS Insects take their food in two ways : some insects bite, others suck. The former, of which the Colorado potato beetle is an example, are provided with jaws by ENEMIES OF INJURIOUS INSECTS which they can gnaw the surface of the food plant. The latter have, instead, a pointed, tube-like beak which they can insert into the tissues of their host plant, and suck out the sap. On account of this difference in feeding habits some insects can be destroyed by coating their food plants with poison — the Colorado potato beetle for example — while others, like the plant lice or chinch bug, must be treated with some insecticide that kills by contact. NATURAL E:NEMIES OF INJURIOUS INSECTS Injurious insects have many natural enemies to con- tend with. Among the larger animals they are preyed upon by the *' fowls of the air and the fish of the sea ; " frogs lick them up with their viscid tongues, and toads are contin- ually sending them in search of the mystic jewel within theii* bodies, while snakes, lizards, moles, skunks, and a host of other animals are their con- stant enemies. But more de- structive than any or all of these are the foes of their own class — the predaceous and parasitic insects. Predaceous insects are those which attack other in- sects from the outside, devouring them bodily, or suck- ing out their lifeblood. The handsome little lady beetles, the two-winged robber flies, or the four-winged dragon flies furnish good examples of this class. So, also, do the black ground beetles, found everywhere un- der sticks and stones. Some of the largest of these are called caterpillar hunters, because they feed upon cankerworms, army worms, cutw^orms, and various other insect pests. One of these ground beetles is shown FIG. 3. GROUND BEETLE. a, larva ; b, beetle. 10 IKSECTS AND INSECTICIDES at Fig. 3, the larva being represented at the left, and the beetle at the right. Other predaceous insects live in ponds, lakes and rivers, devouring mosquitoes and re- lated creatures, while still others burrow through the earth and devour the insects found therein. Parasitic insects differ from their predaceous cousins in that they generally develop within the bodies of their victims and thus destroy them. These, also, are exceed- ingly numerous, both in individuals and species. A good illustration of the habits of this class is found in the small, four-winged, black fly (shown natural size and magnified at the right in Fig. 4), that destroys the com- mon grape caterpillar, an insect closely related to the familiar tomato worm or tobacco worm. This fly deposits a number of eggs beneath FIG. 4. CATERPILLAR WITH COCOONS OF ,. ,• . ,, pofpv. PARASITE. Adult parasite at light; ^^^® ^^^^ ^^ ^^^® ^^^®^ latter magnified. pillar, and thcSC CggS soon hatch into minute worms or maggots that absorb the body juices of the worm and develop at its expense. After a few weeks these maggots become full grown, and burrow their way out through the skin of their hapless and helpless host. They then spin their white silken cocoons (Fig. 4) upon its back. Within these cocoons they change to the pupal or chrysalis state. About two weeks later they again change, and the legless little mag- gots become transformed into neat and pretty black flies, with four wings and six legs, like the one which a few weeks before deposited in the caterpillar the eggs from which they developed. The borers that live in the stems of plants are gen- erally attacked by parasites that attach themselves to the skin on the outside, sucking the juices through the openings they make. Such are called external j)arasites ENEMIES OF INJUEIOUS INSECTS 11 to distinguish them from the internal parasites Just con- sidered. But these parasites are not always so successful as this, for they frequently furnish a partial illustration of the truth of Dean Swift's oft-quoted couplet: The httle fleas that do us tease Have other fleas that bite 'em, And these in turn have other fleas, And so it goes ad infinitum. These parasites are frequently subject to the attack of a still smaller parasite which destroys them as they destroyed their host. In such cases the first-mentioned spe- cies is called the primary par- asite, and the second a sec- ondary parasite. There are also foes of another kind from which injurious insects often suffer. These are the germs of contagious diseases, of a bacterial or fungous nature. The imported cabbage worm, for example, is frequently at- tacked by a bacterial disease — a sort of insect cholera — that destroys it in great num- bers. Similar diseases affect the army worm, the various cutworms, and many other ^^^^ chikch bugs affected insects. Diseases of a some- by fungus. what different nature, due to certain fungi other than bacteria, also attack many insects. For instance, the chinch bug is frequently destro3^ed in great numbers by a fungus that develops on the surface of the bug as a dense, white covering. This disease is illustrated at Fig. 5 : a number of dead bugs are shown on a wheat 12 INSECTS AND INSECTICIDES stalk on the left, while a single bug, much magnified, covered with the fungus, is represented at the right. THE OKDERS OF INSECTS It is frequently supj^osed that almost any sort of bugs, worms or spiders that fly or crawl about are in- sects, but correctly speaking a large proportion of these creatures are not insects at all. For example a spider is not an insect. Neither are the "thousand-legged worms" so often found under boards. In both these cases the creatures have too many legs to belong to the insect class. Spiders have eight legs, and the '^thousand legs" a great many more, while as already stated true insects possess but six. Thus by looking at Fig. 6 which represents a harvest spider or "daddy longlegs" the reader will see that there are four legs on each side, making eight in FIG. 6. HARVEST SPIDER all, whllc lu Fig. 7 which represents a centipede there are many more. But each of the fig- ures of insects shows only three pairs of legs. By count- ing the number of legs one can generally very easily tell whether one of these animals is an insect or some related creature. Insects proper are divided into a number of orders, the more important of which ^re briefly described in the following paragraphs. The lowest order of the Hexapoda — the class of true insects — is the Thysanura: it includes the peculiar minute insects commonly known as springtails, bristle- tails and fish moths. These little creatures are wingless and undergo no transformations — never getting beyond THE ORDERS OF lifSECTS 13 the larval stage ; some species have an aggregation of simple eyes on the head, but very few have compound eyes; the principal mouth parts are set back in the head. They inhabit a great variety of situations, being found abundantly under loose bark and boards lying on the ground. Some species, like the fish moth, live in houses or other dry places. ^^Many of them have a curious spring-like appendage attached to the tail, which is bent under the body, and by means of which the in- sects are enabled to make leaps that are enormous com- pared with their small size. Otheri ^ ^^^^ have long jointed m7m'i//iiHi> filaments at the end fig. i. centipede. of the body which serve no purpose that we know any- thing about. The insects are rarely seen on plants, but where an overflow occurs milHons of them are sometimes found upon the surface of the water, on which they hop about as easily as on land. Certain others are some- times found on the surface of snow, in midwinter. The species live on dead or decaying vegetable substances and upon fungi, and in turn furnish food for a great many kinds of predaceous forms." (Smith.) None of them are of material economic importance. The next higher order of insects is called the Pseu- doneuroptera. It includes the dragon flies. May flies, stone flies and similar forms. These insects have fonr membranous net-veiiied wings, with biting mouth parts and incomplete transformations. The life history of the common dragon fly may serve to illustrate the biol- ogy of this group. The eggs are laid on the stems or leaves of aquatic pkants by the adult dragon flies, and soon hatch into small larvae that live in the water, prey- ing upon mosquito ^^ wrigglers" and other aquatic in- sects. They are provided with a kind of trianguhir- shaped jaw^, with a sharp pair of scissors at the end ; THE ORDERS OF INSECTS 16 this is called the mask. It is usually concealed under the head of the larva, but when an insect comes within reach it is suddenly thrust out, grasps the victim and returns to its concealed position. The larva grows gradually, and finally crawls up out of the water on some reed, Avhen its skin splits open along the back and the adult dragon fly appears. These insects are preda- ceous in all stages of their existence. The order of insects to which grasshoppers, crick- ets, katydids and similar creatures belong is called the Orthoptera, a W'Ord meaning straight-winged. The insects of this order have four wings, the first pair being thickened, and, when at rest, overlapping the second, which are folded in longitudinal plaits. The transfor- mations are incomplete, the young resembling the adults in general appearance. The mouth parts are formed for biting rather than sucking. The first important family of the Orthoptera is that of the cockroaches {Blattidce). There are many species of them, the most abundant probably being the oriental cockroach and the so-called Croton bug. *' Cockroaches are very general feeders ; they destroy nearly all forms of provisions and injure many other kinds of merchan- dise. They often deface the covers of cloth-bound books, eating blotches upon them for the sake of the sizing used in their manufacture ; and I have had them eat even the gum from postage stamps. They thrive best in warm, damp situations ; in dwellings they pre- fer the kitchens and laundries, and the neighborhood of steam and water pipes. They are chiefly nocturnal insects. They conceal themselves during the day be- neath furniture or the floors, or within the spaces in the walls of a house ; and at night they emerge in search of food. The depressed form of their bodies enables them to enter small cracks in the floors or walls."* *Comstock. 16 IKSECTS AND Il^SECTICIDES After the cockroaches follow two families of peculiar insects. The first includes the soothsayers or praying mantes, and the second the walking sticks. The for- FIG. 8. BIRD GRASSHOPPER OR AMERICAN LOCUST. mer are found especially in warm climates, at least one species occurring commonly in our Southern States. FIG. 9. A KATYDID. The walking sticks also are most abundant in the trop- ics, although one species occurs in the Northern States. THE ORDERS OF INSECTS 17 The common grasshoppers or locusts belong to the family Aci'ididcB, a large group containing many injuri- ous species. The hind legs are long and stout, fitting the insect for jumping. The largest species inhabiting the United States is the bird grasshopper, or American locust, represented natural size in Fig. 8. This hand- some insect might readily be mistaken for a small bird when it is flying at a distance. It inhabits the Southern States, occasionally occurring as far north as Central Ohio. Accounts of other species will be found in the later pages of this book. The family Locustidce includes the long-horned grasshoppers and katydids. These insects especially abound during the late summer and early autumn FIG. 10. THE BLACK CRICKET. months, when their familiar sounds greet us on every side. Most of the insects of this family are green in color, to correspond with the herbage among which they live. The crickets which form the family Gryllidce are abundant everywhere in fields and meadows, and prob- ably do considerably more damage tlian they are usually credited with. In the Northern States the common 2 18 Il^SECTS AND INSECTICIDES black species generally winter oyer in the condition of eggs which are deposited in the ground. The climbing or tree crickets and the burrowing or mole crickets are abnormal members of this family. The order Hemiptera includes the true bugs. They have four wings, sucking mouth parts and incomplete transformations. Here belong the bark lice, the aphides, the tree hop23ers, the various plant bugs and many others. The most notorious plant-destroying species of this order is the chinch bug. The appearance of a t3^p- ical member of this order is represented in Fig. 11. The moths and butterflies form the order Lepidop- tera, or scaly-winged insects. Under the microscope the wings of these are seen to be cov- ered with minute scales which overlap one another. They have complete transformations and, in the adult state, sucking mouth parts. They are divided into a large number of families, the most important of which are the fol- lowing : The various families of butterflies are grouped together under the name fig. h. Rliopalocera. The adults are mostly lesser water bug. day fliers and the larvae, as a rule, live upon green vege- tation. The life history of the asterias butterfly already described is typical of this group. The family Sphingidce includes a considerable num- ber of injurious insects, of which the common tomato worm is a familiar example. The adults of this group are large-bodied moths, having loug sucking tubes, and strong wings adapted to swift flight. They fly at dusk, visiting flowers in search of nectar, and depositing eggs on their various food plants. The larvae are voracious, attaining a large size, and pupating in a hollow cell in the soil. THE OEDEES OF INSECTS 19 The family of silk-spinning moths, Bomhycidce, in- cludes a number of the most injurious insects affecting fruit and shade trees. The larvae of this group are hairy caterpillars, which feed upon leaves, and when full grown spin silken cocoons for protection in the pupal state. The tent caterpillar of the apple and cherry, the fall webworm, the tussock caterpillar, the cecropia and polyphemus moths and many similar insects belong here. The family of night-flying moths [NociuidcB) in- cludes a large number of very destructive species. The cutworms, army worm, wheat-head worm, zebra cater- pillar and many other destructive caterpillars belong here. In general the larvae have smooth skins, and pupate at or near the surface of 'the soil. The moths are of medium size, and as a rule fly only at night. There is a large family of small moths called Tor- tricidcB, the larvae of which are commonly known as leaf rollers. The normal habit of these little caterpillars is to feed upon the surface of leaves, which they roll into a protective covering ; sometimes they live singly, and sometimes a number live together in a common nest. These caterpillars attack the leaves of nearly all our fruit and ornamental trees, although as a rule they do little damage. Some s^^ecies, like the codling moth, feed upon fruit. The family of looping or measuring caterpillars, PhalaenidcBy includes the destructive cankerworm among its members. Many of the larvae of this group so closely resemble twigs as to be difficult to detect in their natural habitat. The adult moths have slender bodies and comparatively large wings, although some- times the females are wingless. To the Dijttera belong the two-winged flies ; the common house fly is an excellent example. These in- sects undergo complete transformations, have sucking 20 INSECTS AND INSECTICIDES mouth parts, and exhibit a great variety in their habits of life. Many live in filth of various kinds ; others are aquatic ; others develop") in plant tissues, and yet others are parasitic on the higher or lower animals. The Coleopte7'a or sheath-winged insects form the immense order which includes the beetles. The front wings are hardened into horny cases which cover and protect the mem- branous second pair ; the mouth parts are formed for biting and the transformations are complete. In I the larval state the beetles are com- monly called grubs. Many beetles are destructive to vegetation, while a few live upon decaying organic matter and others prey upon other insects. Only a few of the more important families can here be mentioned. The tiger beetles form a distinct family {Cecmdelidm) the members of which devour many other insects, being predaceous in both the larval and adult states. These beetles are no. 12. tiger beetle. often brightly colored and marked Magnified, with distinct spots. Their form when magnified is shown in Fig. 12. They are abundant in sandy situa- tions, and may commonly be seen running along country roads or by the side of streams. The ground beetles of the family CaraUdcB form one of the largest groups of this order. The commonest species of the family are the elongate black beetles found abundantly under boards and stones, resembling Fig. 3 h in general shape. These beetles vary much in habits: some of them, especially those belonging to the genus Harpalus and its allies, feed largely upon vegetation of THE ORDERS OF INSECTS 21 various kinds, while others, particularly those of the genus Calosoma and nearly related genera, are strictly carnivorous, being excellent examples of predaceous beetles. Many insects destructive to cultivated crops are found in the great family of leaf beetles or Chrijsome- lidce, which is said to include more than ten thousand described species. The most notorious Amer- ican member of this family is the Colorado t potato beetle, but there are many others, such as the corn-root worms, the various flea beetles, 1 the striped cucumber beetle, the asparagus beetle, and others equally injurious. The larvse of this group vary much in life history and appearance: some live exposed on leaves, others are leaf miners, and others live on roots under ground. A large number of injurious insects are found among the snout beetles of the family Cumulionidce and its allies. The plum and apple curculios, the bean and pea wee- vils, the various grain weevils, the corn bill bugs, the white-pine borer, and many others belong here. The larvae of these insects are usually footless grubs, and have varied feeding habits. The adults have a habit of dropping to the ground when disturbed, drawing their legs against the