fc-c • -P I Digitized by tine Internet Arciiive in 2010 witii funding from Boston Library Consortium IVIember Libraries Iittp://www.archive.org/details/insectlifeintrod1901coms Plate I. Plate I.— THE CECROPIA MOTH. (See page 195.) % ,HTOM AT' EDITION IN COLORS INSECT LIFE AN INTRODUCTION TO NATURE-STUDY AND A GUIDE FOR TEACHERS, STUDENTS, AND OTHERS INTER- ESTED IN OUT-OF-DOOR LIFE By JOHN HENRY COMSTOCK /{ PROFESSOR OF ENTOMOLOGY IN COR- NELL UNIVERSITY AND IN LELAND STANFORD JUNIOR UNIVERSITY : : : WITH FULL-PAGE PLATES FROM LIFE REPRODUCING INSECTS IN NATURAL COLORS, AND WITH MANY ORIGINAL ILLUSTRATIONS ENGRAVED BY ANNA BOTSFORD COMSTOCK, MEMBER OF THE SOCIETY OF AMERICAN WOOD ENGRAVERS :::::::::::::: BOSTON COLLEGE LliJKAKr CHESTNUT H^LL, MASS. NEW YORK D. APPLETON AND COMPANY 1901 6til56 Copyright, 1897, 1901, By D. APPLETON AND COMPANY. CIS May, 1901. CONTENTS. PAGE Introduction . i PART I. LESSONS IN INSECT LIFE. CHAPTER I. — The parts of an insect 9 II. — The beginning of a collection and a study of the METAMORPHOSES OF INSECTS 22 III. — The CLASSIFICATION OF INSECTS AND THEIR NEAR RELA- TIVES 51 IV. — Pond life . . 87 V. — Brook life 144 VI. — Orchard life . . 166 VII. — Forest life 186 VIII. — Roadside life 221 PART II. THE COLLECTION AND PRESERVATION OF SPECIMENS. I. — The collection of specimens 284 II. — The preservation of specimens ..... 294 III. — On labeling specimens and taking notes . . . 315 IV. — The breeding of insects 326 V. — Miscellaneous lists . 336 LIST OF PLATES TO FACE PLATE PAGE I. — The Cecropia Moth .... Frontispiece II.— The Tomato-worm Moth ...... 40 III.— Some Sphinx Moths 80 IV.— Beetles 85 v.— A Pond 87 VI.— A Brook I44 VII. — Dandelions and a Locust ...... 166 VIII.— Forest and Orchard Moths 174 IX.— A Forest Aisle 188 X. — Some Forest Moths 197 XI. — Under-wing Moths 204 XII. — Long-horned Beetles 215 XIII.— Roadside Butterflies . . . . . . .221 XIV. — Tiger-moths 239 XV.— Swallow-tail Butterflies . . • . , . .243 XVI.— Butterflies 246 XVII.— Butterflies .* 252 XVIII.— Caterpillars . . . . . . . ■ .328 INSECT LIFE INTRODUCTION. This book was written to meet the demand for a work which will be an aid to teachers of Nature study in the public schools, students in the higher schools, and others interested in outdoor life. Amons: all the classes of animals none is more available for study than insects. Their abundance make it easy to obtain specimens ; they may be found wherever man can live, and at all seasons. Not only are insects numerous as individuals, but the number of species is far greater than that of all other animals taken together. The ease with which living insects can be kept in confinement, and the smallness of the expense in- volved in preserving specimens, add greatly to the availability of insects as subjects for Nature study. No enterprising teacher need hesitate to undertake this study on account of lack of specimens or of apparatus ; with a little encouragement the pupils will furnish these, and the teacher need not trouble the school board with requests for an appropriation. Although at present most adults have been taught to shun insects, most children are easily interested in them. The wonderful transformations of insects, their 2 INSECT LIFE. beauty, and the high development of their instinctive powers render them attractive subjects of study. Any one can find out something new regarding in- sect architecture — the ways in which these creatures build nests for themselves or for their young ; it is easy to observe remarkable feats of engineering, examples of foresight, wonderful industry, unremit- ting care of young, tragedies, and even war and slavery. Insects are no longer thought to be unworthy of serious consideration. We have learned that all life is linked together in such a way that no part of the chain is unimportant. Frequently upon the action of some of these minute beings depends the material success or failure of a large section of our country. But insects are of interest to us for other reasons than the influence they may have upon our material welfare ; the study of them is a fruitful field for in- tellectual growth. It is not a small matter to be able to view intelligently the facts presented by the insect world, to know something of what is going on around us; and so rich is this field that no one gains more than a mere smattering concerning it. We know as yet comparatively little about the minute structure of insects ; the transformations and habits of the greater number of species have not been studied ; and the blood relationship of the various groups of insects is very imperfectly under- stood. If, therefore, one would learn something of the action of the laws that govern the life and de- velopment of organized beings, and at the same time experience the pleasure derived from original inves- tigation, he can not find a better field than is offered INTRODUCTION. 3 by the study of insects. But it is not necessary that one should have the tastes and leisure required for careful scientific investigation in order to profit by this study. It can be made a recreation, a source of entertainment when we are tired, and a pleasant occupation for our thoughts when we walk. The desire to know more of the creatures about us is growing rapidly ; Nature study is being intro- duced generally in schools of all grades, and every- where lovers of out-of-door life are learning to ex- perience the pleasure of a more intimate acquaintance with their surroundings. It is hoped that this will be made easier by this book. Its chief object is to serve as a guide for those who wish to acquire a knowledge of insects from a study of the insects themselves ; it is intended to lie open before the observer while the subject of study is examined. The needs of the beginner in the study of insects, be he old or young, have been kept constantly in mind. The teacher of children who is preparing a lesson, the youth who is studying by himself, and the adult who adds to the pleasure of his outing by learning something new to him — all need to approach Nature by the same path. For this reason an elemen- tary, didactic form of treatm.ent has been adopted, although the book is intended for adults as well as for younger pupils. It is not expected that the teacher will take a class through the book from beginning to end ; for Nature study to be most successful must be varied : each locality and each season will afford different subjects for study. With young pupils it is best to begin with obser- 4 INSECT LIFE. vations on living insects. When practicable, excur- sions into the fields should be made for this purpose. Suggestions as to what insects are most likely to be found in different localities are given in the chapters on Pond Life, Brook Life, Orchard Life, Forest Life, and Roadside Life. But in most cases it will be necessary to make the observations in the schoolroom. For this a breed- ing cage or an aquarium will be needed. Directions for making these are given in Chapter IV, pages 326-335- At first an aquarium will be found more useful than a breeding cage, for the constant movement in a well-stocked aquarium is sure to excite interest. If the pupils are furnished with an insect net (see page 285), they can keep the aquarium supplied with living insects. In the chapters on Pond Life and on Brook Life the more common aquatic insects are described and directions are given for their study. During the winter, cocoons of the giant silkworms can be collected (see pages 188-197) and kept till the adult moths emerge, affording good material for les- sons on the transformations of insects. At the same time, and in early spring, the eggs of the apple-tree tent caterpillar can be found on apple trees and on wild cherry, and later the growth and transforma- tions of the insect observed (see pages 168-171). At an early period in the course, a home-made breeding cage (see page 327) should be provided ; and during the summer months it will be easy to keep it stocked with some of the insects described in the chapters on Orchard Life, Forest Life, and Road- side Life. INTRODUCTION. 5 While the pupils are becoming familiar with the life of insects, they can be taught something of their structure and of their classification ; but with young pupils these subjects should be subordinated to the study of the activities of insects. In the first eight lessons (pages 9-21) the parts of an insect that can be seen without dissection are described. A locust or grasshopper is used as an example, and serves as a type ; in later chapters considerable attention is given to the more obvious modifications of structure corre- lated with the peculiar habits of the insects described. So much of structure as is desirable for the pupils to learn can be taught incidentally while they are observing the habits of the insects. After the school has been supplied with an aqua- rium and one or more breeding cages, provision should be made for preserving a collection of insects. Nothing will more surely maintain an interest in Na- ture study than a growing collection of insects made by the pupils themselves. Do not buy a collection ; the specimens that a class can collect in a single sum- mer day will be worth more as a stimulus to personal observation than a purchased collection. In Chapter II (pages 22-50) are given several lessons for begin- ners on collecting and preserving specimens ; and in Part II (pages 2^84-325) are suggestions for more advanced work in this direction. In a word, the Nature-study work should not be a fixed, definite course ; the most available objects of the locality and season should be selected for study, and these observed from as many points of view as possible. One day observe habits ; another, study structure ; and later learn something of classification 5 INSECT LIFE. by putting the specimens in their proper place in a collection. The Nature study can be made an aid to work in language and in drawing ; many suggestions for this are given throughout the book. With an aquarium, a breeding cage, and a few boxes for preserving specimens, all of which can be procured with little expense, both teacher and pupils will find the Nature-study period the most enjoyable part of the day. Everything possible should be done to make this study a recreation which the pupils will enjoy outside of school hours. If each has a collection, this will be an easy matter. Do not discourage the pupils by re- quiring them to memorize abstract statements con- cerning insects. Let their knowledge of the subject be based on personal observations. The statements in the book are merely to aid the pupils in their study of the specimens ; personal observation should be the real source of their information. The development of the habit of ascertaining facts for themselves is one of the greatest benefits the pupils will derive from this study. In preparing the lessons an effort has been made to combine the verification method and the interro- gation method of laboratory work in such a way as to obtain the desirable results of both systems and to give variety to the work. When the former method is used, the teacher will be able in most cases to determine if the pupil has correctly verified the statements made in the text by examining the draw- ings he is required to make or the account he is asked to write. INTRODUCTION. 7 It is obvious that, in order properly to direct work of this kind, the teacher should be thoroughly acquainted with the subjects studied by the pupils. The difficulties that have been in the way of the teachers who have tried to obtain a systematic knowl- edge of insects is doubtless the chief reason that in- sect life has not been studied more in the public schools. An appreciation of these difficulties led the author and the illustrator of this book to prepare first, for the use of teachers, a comprehensive text- book, by means of which the teacher can easily pre- pare himself to direct the study of his pupils. This is entitled "A Manual for the Study of Insects."^ In this study, perhaps more than in any other taught in the secondary schools, the pleasure of con- stantly learning something new can be shared by the teacher with the pupils. The writer has had an un- usually broad experience in teaching this subject, but he has never yet taken a class into the field without finding something new to him. In this connection we wish to urge the importance of perfect sincerity. The teacher should frankly say, " I do not know," when asked a question that he can not answer, and it will be well if he will add, " We will try to find out." Teach the pupils early that any one by intelligent endeavor can add to the sum of knowledge. While the chief end of this study is the training of the powers of observation and the careful ascer- taining of facts in a scientific manner, it seems to us to be well to encourage somewhat an imaginative view * Published by the Comstock Publishing Company, Ithaca, N. Y. 8 INSECT LIFE. of the subject. For this purpose we have included some poetical references to insects. We believe that the reading of these by the pupils will both stimulate their love of a poetical form of expression and bring them in closer sympathy with the world of life around us. PART I. LESSONS IN INSECT LIFE. CHAPTER I. THE PARTS OF AN INSECT. 'OOK at an insect and you will find a creature with parts which are very different from those of the animals with which we are more familiar. Although it can see, hear, eat, and walk, its eyes, ears, mouth, and legs are not like the corresponding organs of the higher animals. It is necessary, therefore, at the beginning of our study of insect life, to learn something of the structure of insects. We will not attempt at first, however, to make a thor- ough study of insect anatomy, but will merely select one kind of insect,, and study the principal divisions of the body as seen from the outside. Having done this, we will be able to see in our later studies in what ways the parts of other kinds of insects have been modified in form to fit them for their modes of life. Thus, for example, we will find that an insect which catches its prey by running has legs of a different shape than those of an insect that 9 10 INSECT LIFE. swims through the water ; and an insect that sucks the blood from its victims has a different kind of mouth than one that chews up the leaves of plants. It is also important that w^e should know the names of the principal parts of the body of an insect, so that we may understand descriptions of insects, and be able to write descriptions ourselves. We have selected locusts, or grasshoppers as they are more commonly called, for the subject of these introductory lessonSo We have done this because locusts are quite large, and are common in all parts of our country ; and, too, the parts of the body in these insects are comparatively simple. In the course of these lessons the following things will be needed : A supply of locusts,"^ blank paper and pencils for making notes and drawings, one or more cyanide bottles (see page 286) for killing the specimens collected by the pupils, a lens, cardboard and mucilage for mounting dissections, and scissors. A compound microscope is very desirable, but not absolutely necessary. * It is best, when practicable, that the pupils should collect these for themselves. But in the case of city schools, or when the work is begun at a season of the year when these insects are not readily found, the teacher should have on hand a supply of locusts preserved in alcohol. These can be collected beforehand or obtained of some dealer in labora- tory supplies. The best way to collect them is by sweeping (see page 291) the grass in a dry meadow or pasture in late summer or early autumn. In this way a pint or more of locusts can be collected in a short time. These can be preserved in alcohol in an ordinary glass can, such as is used for preserving fruit. There should be more than enough alcohol to cover the insects, and after they have been in it for twenty-four hours it should be poured off and fresh alcohol substituted. A list of dealers in laboratory supplies is given at the close of this volume for the conven- ience of those who wish to purchase specimens. THE PARTS OF A LOCUST. II Fig. I. — A locust. LESSON I. THE PARTS OF A LOCUST. Collection of Specimens and a General View of the Body. 1. Collect several locusts or short-horned grass- hoppers and bring them to the school. They can be carried in a small box or wide-mouthed bottle. Fig. I represents one of these insects. 2. If living locusts are collected, kill them by leaving them in a cyanide bottle for a half hour or more. Note. — If the pupils can not find living locusts at the time this lesson is taken, preserved specimens will be furnished by the teacher. 3. Count the legs and the wings of the locusts, and make a note of the number of each on a sheet of paper headed Notes on the Parts of a Locust. 4. Study the body of the insect and observe that it is composed of three portions: first, the head ; sec- ond, a stout portion to which the legs and wings are attached, the Fig. 2. — Wasp, with head, tho- rax, and abdomen separated. Fig. 3. — Side view of locust with wings removed. thorax ; and, third, the hinder part of the body or abdomen iab-do' men). In a locust the division between the thorax and 2 12 INSECT LIFE. the abdomen is not well marked. Fig. 2 represents a wasp with the three regions of the body separated, and in Fig. 3 a locust is represented with its wings re- moved so as to show the extent of each of these regions. 5. Make a copy on your sheet of notes of the figure of a side view of a locust. LliSSON II. THE PARTS OF A LOCUST (CONTINUED). The Head, except the Mouth-parts. The head is the first of the three regions of the body. It contains the brain of the insect and other important organs ; but in these lessons we will study only the outside parts of it. The head bears the antennse, the eyes, and the mouth-parts. 1. The antenncE {cm-ten' nee) are the two long, slen- der organs attached to the head in front of the large eyes. Make a drawing of one of them. The singu- lar form of the word antennse is antenna (an-ten'na). 2. Study the large eyes which are situated one on each side of the head. Examine them with a lens, .A^ .^>^ jbt^ also with a microscope if you have the use of one. The surface of the eye when much magnified resem- bles honeycomb in appearance (Fig. 4). Each of the six-sided divisions FiG.T-P^ ^com- o^ the large eye is a complete eye, pound eye, greatly hcncc the larp^c cvcs are compound enlarged. o ./ i^^va^^^^^^^^^^^ eyes. 3. In addition to the two large compound eyes a locust has three simple eyes. There is one of these THE PARTS OF A LOCUST. 1 3 just in front of the upper part of each compound eye, and the third is in a hollow near the middle of the face of the locust ; find each of these. Note. — The simple eyes are usually called the ocelli {o-cel'li). This term is also applied frequently to the little eyes, or ommatidia, of which the compound eyes are composed ; but if nothing is said to indicate that the parts of a compound eye are meant, the term ocelli always refers to the simple eyes. In the same way the term eyes usually refers to the compound eyes alone. The singular form of ocelli is ocellus {p-cel lus). 4. Make a drawing of the front side of the head showing the position of the antennas, the eyes, and the ocelli. LESSON III. THE PARTS OF A LOCUST (CONTINUED), The Mouth-parts. 1. Attached to the lower edge of the front side of the head of the locust is a movable flap ; this is the upper lip or labrum {la' brinn). Carefully remove it with a knife and save it. 2. By removing the upper lip there is exposed a pair of horny jaws ; these are the mandibles {inan'di- bles). The mandibles open sidewise instead of up and down like the jaws of higher animals. Carefully re- move the mandibles. This can be done by separating them with a pin, and turning each one sidewise till it breaks from the head. Save the mandibles. 3. By the removal of the mandibles there is ex- posed a second pair of jaws, which, like the mandi- bles, open sidewise. These are the maxillce {max- il'lce). The singular form of maxillse is maxilla (max- il'la). The maxillse, unlike the mandibles, are very complicated organs, each maxilla consisting of sev- 14 INSECT LIFE. eral parts. Leave the maxillas attached to the head till later. 4. Remove the head of the locust and pin it with the hinder side uppermost to a piece of cork or block of wood. 5. With the head in this position the flaplike lower lip or labium {la'bi-uni) can be easily seen. Like the maxillse, the labium consists of several parts. 6. Lift the free end of the labium with a pin and observe the tonguelike organ which arises from the inner side of it, and pro- jects between the maxillse ; this is the hypopharynx (Jiy- po-phar' ynx). 7. Remove the labium and the hypopharynx and save them. 8. After the removal of the labium it will be easier to remove the maxillas than before. Remove them and save them. 9. Arrange the mouth- parts on a card as shown in Fig. 5 and gum them in place. 10. The five-jointed appendages of the maxillae are the maxillary palpi. The singular of palpi is palpus. 11. The three-jointed appendages of the lower lip or labium are the labial palpi. Review. — The mouth-parts of a locust consist of an upper lip, the labrum ; an under lip, the labium; Fig, 5. — The mouth-parts of a lo- cust : 8, labrum ; 10, mandibles ; II, maxillse; ii ^, maxillary- palpi ; 12, labium ; 12 d^ labial palpi ; 13, hypopharynx. THE PARTS OF A LOCUST. 15 two pairs of jaws, the maitdibles and the maxillce ; and a tonguelike organ, the hypopharynx. The jaws open sidewise instead of up and down, as do the jaws of the higher animals. The upper pair of jaws are called the mandibles ; the lower pair of jaws the maxillce. Each maxilla bears a palpus ; these are the maxillary palpi. The labium bears a pair of palpi ; these are the labial palpi. LESSON IV. THE PARTS OF A LOCUST (CONTINUED). The Appendages of the Thorax, the Legs. The thorax is the middle one of the three regions of the body (see Lesson I and Fig. 3). The append- ages of the thorax are three pairs of legs and two pairs of wings. In this lesson we will study the legs. 1. Study carefully one of the fore legs of the locust and observe that it is composed of several parts or segments. Each of these segments of the leg has a distinct name. As these names are often used in descriptions of insects, it is necessary to learn them. 2. The first segment of the legs, the one that is joined to the body, is nearly globular in outline ; this is the coxa {cox' a). 3. The second segment of the leg is much smaller than the coxa ; this is the trochanter (tro-chan'ter). 4. The third segment of the leg is the principal one ; this is t\\Q femur {fe'mur). Its name is the same as that of the principal bone in the human leg. 5. The fourth segment of the leg is nearly as long 1 6 INSECT LIFE. as the femur, but it is more slender; it is called the tibia {tib'i-d). This name is the same as the name of the principal bone between the knee and ankle of the human leg. 6. All of the leg of the locust beyond the tibia is the foot or tarsus {tar'sus). This part consists of three segments in the locust, but the number of seg- ments in the tarsus differs in different kinds of in- sects. 7. The last segment of the tarsus bears a pair of claws. These are called the tarsal claws. 8. Find each of the parts named above in each of the legs of the locust. 9. Make a drawing of one of the fore legs and name the parts. 10. The plurals of the terms are as follows : coxa, coxge ; trochanter, trochanters ; femur, femora (fem'- o-ra) ; tibia, tibise ; tarsus, tarsi. LESSON V. THE PARTS OF A LOCUST (CONTINUED). The Appendages of the Thorax^ the Wings. 1. Remove the two wings of one side, spread them out on a card, and gum them in place. 2. Study the wings and observe that each is com- posed of a membrane strengthened by a framework of thicker lines. These thickened lines composing the framework are called the veins of the wings. The term vein used in this connection is not very appro- priate, but as it is in general use it would not be well to attempt to change it. THE PARTS OF A LOCUST. 17 3. Observe the strong, longitudinal veins, and the numerous smaller cross-veins. 4. The portions of the membrane bounded by the veins are called the cells. 5. Cut a piece about one fourth inch square from one of the wings not removed from the body, mount it on a card, and make a careful drawing of the veins and cells. Label the drawing as follows : Fragment of the zving of a locust showing the veins and the cells. 6. Write a description of the wings of a locust ; describe first the general features of the wings, and then state how the two wings of one side differ from each other. LESSON VI. THE PARTS OF A LOCUST (CONTINUED). The Thorax. 1. In this lesson we are to study the parts of the thorax, but before beginning this study the pupil should examine the abdomen and observe that the body wall of that region is composed of several ring- like segments. 2. Like the abdomen, the entire body of an insect is made up of a series of segments, but it is not so easy to distinguish "the separate segments in the head and thorax as it is in the abdomen, 3. The segments of which the head is composed are grown together so completely that the head ap- pears to consist of a single segment. 4. The thorax consists of three segments, which we will try to distinguish. Observe that the first pair of legs are borne by a ringlike part which can l8 INSECT LIFE. be separated from the remainder of the thorax. This is the first of the segments of the thorax. 5. Separate the first segment of the thorax from the remainder of this region. Observe that the belly or ventral 's>\d.Q is small, while the upper or dorsal ^\diQ is large, being composed of the large sunbonnet- shaped piece which is just back of the head. 6. The first segment of the thorax is called the prothorax {^pro-tho' rax). 7. Make a drawing of a side view of the prothorax representing the left side. 8. The portion of the thorax remaining consists of two segments closely grown together. These are the second and third thoracic segments. The second thoracic segment bears the second pair of legs and the first pair of wings ; the third thoracic segment bears the third pair of legs and the second pair of wings. Study the specimen and try to make out the limits of these segments. 9. The second or middle thoracic segment is called the mesothorax (ines-o-tho'rax). The third or last tho- racic segment is called the metathorax {inet-a-tho'rax). 10. Remove the wings and make a drawing of the left side of these two segments. 11. Observe that the greater part of each side of these two segments consists of four large, oblique pieces. The first two of these pieces belong to the mesothorax, the last two to the metathorax. Review, — The body of an insect consists of a series of segments ; of these the first three behind the head form the thorax. The three segments of the thorax are called the prothorax, the mesothorax, and the meta- thorax respectively. THE PARTS OF A LOCUST. 19 LESSON VII. THE PARTS OF A LOCUST (CONTINUED). The Abdomen. The abdomen is that portion of the body which is behind the thorax. In a locust the thorax and ab- domen are so closely connected that it requires care- ful study to determine where one ends and the other begins. 1. Examine the ventral or belly side of the body and determine which is the first abdominal segment. The front edge of this segment is dovetailed into the metathorax, so that at first sight it appears to be a part of the thorax. 2. Examine the upper or dorsal part of the first abdominal segment ; this is widely separated from the ventral part by the cavities for the insertion of the hind legs. 3. Observe the ears ; these are situated one on each side of the first abdominal segment. Each is a large opening in the body wall which is closed by a very delicate membrane (see Fig. 3). Locusts differ from other insects in having ears in this position. 4. Examine the seven abdominal segments follow- ing the first ; each* of these is ringlike in form. 5. Find the breathing holes or spiracles. There is a row of them on each side of the bod}^ The first one on each side that is in the abdomen is just in front of the ear. In the seven following abdominal segments there is one on each side of each segment near the lower front corner of the upper part of the segment. 20 INSECT LIFE. Note. — In addition to the abdominal spiracles, there are two pairs of spiracles which belong to the thorax : one of these is situated in the membrane between the prothorax and mesothorax ; the other just above and a little back of the insertion of the middle pair of legs. The first of these two pairs is covered by the free margin of the prothorax, which can be cut away with scissors. 6. Examiae several specimens of locusts and ob- serve that in some the hind or caudal end of the body tapers to the end and bears four pointed and curved, horny pieces, and that in others this end of the body is terminated by a single, large, hood-shaped plate. Those in which the body ends in four pieces are females ; the others are males. 7. The four pieces at the caudal end of the body of the female are for making holes in the ground or in soft w^ood in which the eggs are laid, and are called the ovipositor. 8. In using the ovipositor the insect pushes it into the ground and then spreads the pieces apart ; by re- peating this operation many times a deep hole is made in which the eggs are laid. 9. Make a drawing of the left side of the abdo- men ; represent carefully the position of the ear and of the spiracles. Use either a male or female, but state under the drawing which sex it represents. LESSON VIII. THE PARTS OF A LOCUST (CONTINUED). Review. The following table illustrates the relations of the parts of a locust that have been studied in the pre- ceding lessons. The pupils should learn this table THE PARTS OF A LOCUST. 21 SO that they can write it without referring to the book : Antennae. Compound eyes. Simple eyes or ocelli. f Labrum. I Mandibles. Head. Mouth-parts, -i Maxilla and maxillary palpi. Thorax. -{ Labium and labial palpi Prothorax and first pair of legs. second pair of legs, first pair of wings, third pair of legs, second pair of wings. \ veins. Mesothorax and Metathorax and Wing Leg Abdomen. I cells. Coxa. Trochanter. Femur. Tibia. (^ Tarsus and claws. ( ears (in locusts only). The abdomen bears •< spiracles. ( ovipositor. CHAPTER II. THE BEGINNING OF A COLLECTION AND A STUDY OF THE ^lETAMORPHOSES OF INSECTS. HE mere reading of books about natural objects will do but little toward forming an intimate acquaintance with Nature. If one w^ould really know about the creatures that are near us wherever we go, he must study them directly, and not depend on what others have said about them. It is for this reason that these first lessons in Insect Life are based on the study of specimens that the pupils have collected for themselves. It will be far better for the pupils to learn a few things at first hand than to memorize a great mass of information from books. In most places it is comparatively easy to find insects. The pupils can collect them while going to and from school or during recess ; or a class may be excused for an hour or two occasionally to make longer trips, under the direction of one of the older pupils : but, when possible, the teacher should accom- pany the pupils in their excursions. More insects will be found on w^arm days when the sun is shining than at other times. 22 THE BEGINNING OF A COLLECTION. 23 In the case of city schools that are remote from parks or other good collecting fields, excursions into country places can be made on Saturdays, and the specimens collected on such an excursion can be kept for study till the following Monday. Much more progress in attaining real knowledge will be made in this way than by daily recitations based on a study of a book about insects. With a little effort living insects can be kept in breeding cages or aquaria, so that the specimens col- lected on a single excursion may serve for daily ob- servations for a long time. Each pupil should be encouraged to make a per- manent collection for himself. With such a collec- tion there is little danger of his losing his interest in the subject ; and the facts that he has learned will be remembered more easily. Moreover, the making of additions to a collection and the frequent rearranging of it will be a source of great pleasure and instruction. If for any reason it is impracticable for the pupils to make private collections, a collection should be made for the school. If the specimens in such a col- lection are labeled with the names of the collectors, the pupils will be stimulated to make additions to it. And if, as soon as the older pupils have learned to handle specimens carefully, each is appointed curator of some group of insects, a personal interest in the collection will be stimulated, and each wall acquire a more thorough knowledge of the group collected than he would otherwise. The group assigned to a student may be some order or family of insects, or an artificial group based on habits. Some experience with the local con- 24 INSECT LIFE. ditions in each school will be necessary for the teacher to be able to select the more available groups. Even when the pupils make private collections it will be well to have each one, after he has become familiar with the different orders, select some one of them as his specialty, and study that one more thor- oughly. In this way he will be forced to do more careful collecting in order to add to his collection constantly, and he will thus learn more about the habits of the insects collected. Before beginning the work the teacher should decide what apparatus is to be used, and make pro- vision for obtaining that part of it which the pupils are not to make for themselves, so that the work shall not be delayed by lack of material. Although there are many things that are desira- ble for carrying on this work, much can be accom- plished with very little material and that which is inexpensive. The following lists will aid the teacher in deciding what to get : — Necessary Supplies for Pupils. Cyanide bottles. See page 286. Pins. See page 295. Empty cigar-boxes. See page 306. Cork or pith. See page 309. Additional Supplies desirable for Pupils. Insect nets. See page 285. Glass-topped cases. See page 306. Coddington lenses. See below. Vials. Alcohol. THE BEGINNING OF A COLLECTION. 25 Desirable Supplies foi' the School. Cabinet for insect cases. See page 294. Pliers or pinning forceps. See page 299. Cases, pins, vials, and alcohol. Microscope. See below. Supplies for mounting microscopic objects. See page 300. At least the teacher should possess a lens. 01 the cheaper lenses the form known as the Codding- ton lenses I have found to be the best. These are commonly kept by stationers or jewelers. They can also be procured of any dealer in optical instruments. See list of dealers at the end of this volume. If a microscope be procured for the school, care should be taken to get one provided with what is known as the society screw, so that objectives of any of the more prominent makers can be used on it. If the funds at the disposal of the school will only admit of the purchase of a microscope with a single objec- tive, a three-fourths-inch objective will be found as useful as any for entomological work, and perhaps later a one-fifth-inch objective or others can be added. Price lists of microscopes will be furnished by deal- ers in optical instruments. Most dealers make discounts from thtir list prices when furnishing schools. In preparing the above suggestions we have tried to keep in mind the needs and the ability of supply- ing these needs of both teachers in the smaller schools, where there may be no funds to spend for apparatus, and of teachers in the larger schools, where even costly apparatus can be purchased. 25 INSECT LIFE. LESSON IX. PREPARATION FOR A COLLECTING TRIP. Havinof learned somethins: about the structure of a locust, which was taken as a t3^pical insect, we are ready to begin the study of other insects. In doing this we will first learn how to collect and preserve specimens ; after that we will study the classification of insects and the life histories of some of them. The forms of insects are numberless, and their ways are as varied as are their forms. As we walk over the fields they spring up before us or scurry away through the grass. Some fly lazily here and there ; others dart back and forth with the rapidity of thought. We crush them under foot by a careless step ; we find them on every shrub and tree ; and the streams and ponds are peopled by them. Let us approach their study with kindly feelings, bent on learning what we can concerning them and their ways, and putting aside the false notion that many of us have been taught that these creatures are to be despised. The great majority of them can be regarded as our friends, for they are of service to us ; others, while not actually beneficial, do us no appreciable harm ; a few, and they are only a few compared with the great number that make up the insect world, interfere with our happiness. These we are forced to fight ; but the combat is one of self- defense and not a war against an enemy that harms us maliciously. In making a collection for study it will be neces- sary for us to kill specimens ; but we will do this as PREPARATION FOR A COLLECTING TRIP. 27 humanely as possible, and will not destroy more than we need for our work. The objects of this lesson are two : first, the suggesting of a proper spirit in which to take up this work ; and, second, the getting ready for our first field trip, so that when the time comes to start there will be no delay. The most important thing to carry with you into the field is a good pair of eyes. Without these but little will be accomplished. Of the various kinds of collecting apparatus the most important is a cyanide bottle. Each pupil, if possible, should have one of these. On page 286 will be found directions for making them. In addition to a cyanide bottle it will be well if each one has an insect net, although much can be done without a net. See page 285 for a description of an insect net. No other apparatus is needed for the first field trip, but it will be well if some provision be made at once for preserving the insects that you are going to collect. The following are the more important things needed for this: 1. An insect case or empty cigar-boxes. Read what is said on pages 306 to 310 regarding these, and note especially what'is said on page 310 regarding the use of corn pith for lining cigar-boxes. 2. A supply of insect pins or, if these can not be obtained, a paper of ordinary pins. Read what is said on this subject on pages 295 to 299. 28 INSECT LIFE. LESSON X. THE FIRST COLLECTING TRIP. Material needed for the Excursion. — " A sharp pair of eyes," a cyanide bottle, and an insect net if you have one. Where to look for Specimens. — On flowers and leaves, on the surface of the ground, under stones and pieces of w^ood lying on the ground, in rotten stumps, and under the bark of decaying logs and trees. What to collect. — We plan to study all kinds of insects and also some animals that are not true in- sects, but are closely related to them. It will be best, however, on this first excursion to collect only winged insects. Other forms may be collected and studied later in the course. Suggestions. — Do not leave your cyanide bottle open unnecessarily, for if you do it will lose its strength in a short time. With proper care a cyanide bottle will last several months. Do not hold your face near the open cyanide bottle so as to breathe the fumes that escape from it. With ordinary care there is no danger in the use of a cyanide bottle. You can take bees and wasps from flowers with- out danger of being stung by shutting them into the bottle with the cork. Take the bottle in one hand and the cork in the other, and bring the two together quickly, one on each side of the insect. The insects collected can be left in the cyanide bottles or on damp sand in a jar or tight box till THE FIRST COLLECTING TRIP. 29 the following day. If the excursion is made on Saturday the insects can be kept soft in this way till Monday. Fig. 6. — Poison ivy. (Note that the leaflets are in threes, and that each has only a single midrib. ) If a cyanide bottle is wet inside it should be wiped out and a piece of blotting paper placed in it. But if the dampness is due to the dissolving of the cyanide it is better to put enough dry plaster of Paris Fig. 7, — Virginia creeper. (Note that the leaflets are in fives.) into the bottle to absorb the liquid ; sprinkle the plaster of Paris carefully on top of the layer of cement in the bottom of the bottle, so that the whole shall form one solid layer. To the Teacher. — If poison ivy or poison oak abounds in the region where the pupils are to col- 30 INSECT LIFE. lect, the plant should be made known to them. They should also be able to distinguish between F.G. 8.— Clematii (Note that the leaflets are in threes, like the poison ivy, but each leaflet has several midribs.) poison ivy and the harmless Virginia creeper and clematis. See Figs. 6, 7, and 8.* LESSON XI. ON MOUNTING SPECIMENS. 1. Take the specimens that were collected on the first collecting trip, and which have been kept moist either by being left in the cyanide bottle or in a closed vessel upon damp sand, and spread them out before you. If the directions were followed, they are all winged. 2. Select one of the larger specimens and observe * The writer, who is extremely susceptible to the poison of poison oak and poison ivy, has experienced great relief when poisoned by bath- ing the affected parts frequently with a lotion made of one part tincture of grindelia and four parts water. Prompt and frequent application of this lotion will prevent the appearance of the pustules characteristic of this disease ; if the application be not made soon enough for this, the injury can be kept from spreading by a thorough oxidi persistent use of the lotion. ON MOUNTING SPECIMENS. 31 that, as with the locust, the body consists of three main parts — the head, the thorax, and the abdomen. 3. In pinning insects most specimens should be pinned through the middle of the thorax. Read the section on pinning insects on page 297. 4. Pin four or five of the larger specimens in this way, leaving about one fourth of the length of the pin above the back of the insect. If insect pins be used, avoid using the smaller sizes, as they are easily bent. Insects that are too small to be pinned with No. 3 Klager pins should be mounted on cards as described later. 5. Ascertain if you have any beetles in your col- lection. Beetles have a pair of wing-covers in the place of the front wings. These wing - covers are thick and horny, and meet in a straight line down the back of the in- sect, forming a hard case, beneath which the hind wings are folded. Fig. 9 represents a beetle. 6. Separate the beetles in your collection from the other specimens. 7. In pinning beetles the pin should be put through the right wing-cover at a point about one fourth the length of the wing-cover from its base (see Fig. 10). 8. Pin all the beetles in your collection that are large enough to be pinned. Fig. g. — A beetle. 22 * INSECT LIFE. 9. Pin any other winged insects you have that are large enough to be pinned, remembering that except in case of beetles the insects should be pinned through the middle of the thorax. 10. If there remain some in- sects that are too small to be pinned, they should be mounted on cardboard points, as described on page 298. 11. Count the legs on each specimen in your collection. (It is supposed that you have only winged specimens.) How many legs do winged insects have? The shrilling locust slowly sheathes His dagger voice, and creeps away Beneath the brooding leaves where breathes The zephyr of the dying day : One naked star has waded through The purple shallows of the night. And faltering as falls the dew It drips its misty light. O'er garden blooms, On tides of musk. The beetle booms adown the glooms And bumps along the dusk. The katydid is rasping at The silence from the tangled broom : On drunken wings the flitting bat Goes staggering athwart the gloom : The toadstool bulges through the weeds ; And lavishly to left and right The fireflies, like golden seeds, Are sown about the night. THE SECOND COLLECTING TRIP. 33 O'er slumb'rous blooms. On floods of musk, The beetle booms adown the glooms And bumps along the dusk. Jiunes Whitcomb Riley. "^ LESSON XII. THE SECOND COLLECTING TRIP. 1. Review carefully the directions on page 28. 2. On this excursion the pupils should collect any true insects — that is, those having only six feet — that they may find ; but the especial object of the excur- FlG. II. — Nymph of Melanoplus^ first stage. (After Emerton.) Fig. 12. — Nymph of Melanoplus, second stage. (After Emerton.) Fig. 13. — Nymph of Melanoplus, third stage. (After Emerton.) Fig. 14. — Nymph of Melanoplus, fourth stage. (After Emerton.) sion is to get a set of specimens illustrating the growth of either crickets or locusts or bugs. Select whichever of these is most common, and get as com- * From Old-fashioned Roses, by permission of the Bowen-Merrill Co. 34 INSECT LIFE. plete a series as possible representing the changes from the very young insect without any wings, through the different stages of wing-growth up to the adult insect. The accompanying figures (Figs. 11-16) represent the transformations of a common locust. Note that Fig. 15. — Nymph of Mzlanoplus^ Fig. i6. — Melanoplus^ adult, fifth stage. (After Emerton.) the figures of the younger stages are enlarged. The hair line represents in each case the length of the insect. LESSON XIII. INCOMPLETE METAMORPHOSIS. Nearly all insects undergo great changes in form while getting their growth. Thus, caterpillars in time become butterflies or millers ; grubs when fully developed are beetles; and maggots are the young of two-winged flies. In the case of butterflies, millers, beetles, and two-winged flies, the fully developed insects bear but little resemblance in form to the 3^oung. It would be difficult to find two adult insects that differ more in form than do a butterfly and the caterpiUar from which it was developed. But in the case of certain other insects, the changes undergone during the life of the insect are not nearly so great as with INCOMPLETE METAMORPHOSIS. 35 these. Thus the young locust resembles the adult in form to a great extent, except that it lacks wings ; and the same thing is true of crickets, bugs, and many other insects. Those insects which, like butterflies, millers, bee- tles, and flies, undergo a complete change of form while getting their growth are said to undergo a complete metamorphosis. Insects which, like locusts, crickets, and bugs, do not change greatly in form except by the gradual growth of wings are said to undergo an incomplete metaynor pilosis. Let us study more carefully the changes of an insect with an incomplete metamorphosis. 1. Pin the specimens that were collected on the last excursion. If some are too small to pin, mount them on cardboard points. 2. Select those that were collected to illustrate the changes in form from the very young insect without any wings through the different stages of wing-growth up to the adult insect. 3. Determine how many stages of growth are represented by these, and place together the speci- mens illustrating each stage. The young of insects that undergo an incomplete metamorphosis are termed nymphs. 4. Make an outline drawing of the thorax and wings, when they are present, of each stage. Draw either the dorsal or a side view, whichever will show best the development of the wings. 36 INSECT LIFE. LESSON XIV. MOLTING. 1. Take a locust that has been killed by being placed in a cyanide bottle or in alcohol and cut the abdomen in two, near the middle of it. 2. Observe that the hard parts of the body are on the outside, and that there is no internal skeleton, as in our own bodies. This fact makes necessary a peculiar feature in the growth of insects and of the other animals that are closely related to them. The body of an insect is inclosed in a firm case, which, as it does not in- crease in size, becomes too tight for the insect as the insect grows. To meet this difficulty the outer hard layer of the skin is shed. The inner soft layer of the skin then stretches so as to accommodate the increased size of the insect ; later this soft skin, which is now on the outside, becomes hard, so as to serve as a protection to the insect. In time this skin also becomes too tight, but another soft skin has been formed beneath it, and the hard skin can be shed like the other, of sheddinof the skin is termed Fig. Ty. — The cast skin of a nymph of a dragon-fly. This process molting. Insects differ greatly as to the number of times that they molt ; some pass through only three or OBSERVATION OF INCOMPLETE METAMORPHOSIS. 37 four molts, while others shed their skin twenty times or more. It is at the time of molting that changes in the form of the body take place. Fig. 17 represents the cast skin of a nymph of a dragon-fly. LESSON XV. OBSERVATION OF INCOMPLETE METAMORPHOSIS. 1 . Collect a considerable number — fifteen or twenty or more — of nymphs of locusts or crickets, and place them in a breeding cage. See page 327 for directions for making inexpensive breeding cages. 2. Put a sod of growing grass in the cage for the insects to feed upon, and replace it with a fresh one when necessary. 3. Endeavor to rear the nymphs, and make notes on their changes. 4. Examine the cage daily, and when cast skins are found, study them and preserve specimens for your collection. 5. Preserve a specimen of each of the nymph stages, and label it with the date on which it was taken. 6. Observe that, although the changes between the different nymph stages are slight, the change be- tween the last nymph stage and the adult is a marked one, there being a great increase in the size of the wings at this time. 38 INSECT LIFE. THE GRASSHOPPER AND THE CRICKET. Green little vaulter in the sunny grass, Catching your heart up at the feel of June, . Sole voice that's heard amid the lazy noon. When even the bees lag at the summoning brass ; And you, warm little housekeeper, who class With those who think the candles come too soon, Loving the fire, and with your tricksome tune Nick the glad silent moments as they pass ; Oh, sweet and tiny cousins, that belong One to the fields, the other to the hearth. Both have your sunshine ; both, though small, are strong At your clear hearts ; and both were sent on earth To sing in thoughtful ears this natural song : Indoors and out, summer and winter — Mirth. Leigh Hunt. LESSON XVL OBSERVATION OF COMPLETE METAMORPHOSIS AND DEFINITION OF TERMS. And what's a butterfly ? At best, He's but a caterpillar, drest. — John Gay. 1. Collect some caterpillars, and, keeping them alive, put them in a breeding cage to rear. See pages 327 to 330 for directions for making breeding cages. 2. Keep the caterpillars supplied with food, giv- ing them the same kind of plant as that on which they were found, and keep only one kind of cater- pillar in a single breeding cage. Most of the com- mon hairy caterpillars found running over the surface of the ground will feed on grass and many other plants, but other caterpillars will starve if not fed on their proper food plant. OBSERVATION OF COMPLETE METAMORPHOSIS. 39 !NOTE. — Among the more available kinds of caterpillars for use in this lesson are the following : The common green cabbage-worms ; the green worm, ringed with black and spotted with yellow, that eats the leaves of caraway ; and the large yellow and black one found on milk- weed. The transformations of each of these can be observed in a com- paratively short time if the study begins early enough in the season. The autumn broods of the first two pass the winter in the pupa state. 3. Begin a series of notes on each kind of cater- pillar under observation, giving each a number and numbering the notes to correspond. (See Part II, Chapter III.) Begin each note with the date on which it was made. Record everything that you observe regarding the habits and transformations of Fig, 18. — Larva and pupa of a butterfly. the insects. Try to observe the molting of the in- sects and each of the transformations. 4. All caterpillars hatch from eggs. If you suc- ceed in rearing adult insects and will keep some of them caged for a time you may be able to get eggs. 40 INSECT LIFE, But many insects will not lay in confinement. They are more apt to lay in confinement if caged with a growing food plant of the larva. 5. Caterpillars and the corresponding stage of other insects with a complete metamorphosis are called larvcE. The singular form of this word is larva. 6. When a larva is full grown it molts its skin and appears in a very different form. This third stage (the ^g^ being the first and the larva the sec- ond) is called \h^ pupa. The plural of pupa is pupce. In Fig. 18 there are represented two larvae on the upper edge of a fragment of a leaf and a pupa sus- pended from the lower edge. The pupse of butter- flies are sometimes called chrysalids.^ 7. Some larvae before changing to the pupa state spin about the body a silken case within which the pupa -A large cocoon within a rolled leaf. State is paSSCd. Such a case is called a cocoon. Sometimes a leaf is fastened about the cocoon (Fig. 19) ; and some hairy caterpillars make their cocoons largely of their own hair, fastening it to- gether with a thin layer of silk. 8. Following the pupa state is the adult or imago state. Fig. ic * There are two forms of this word : first, chrysalid, with the plural chrysalids ; and, second, chrysalis, with the plural chrysalides. The singular form of the second and the plural form of the first are in more common use. HTOM M^O l/QT 3HT— .II staj^ Plate II.— THE TOMATO-WORM MOTH. Phlegethontius celus. Plate II. BEETLES OR COLEOPTERA. 41 LESSON XVII. REVIEW OF TERMS USED IN DESCRIBING THE METAMOR- PHOSES OF INSECTS. Kinds of Metamorphosis. Names of Stages. /. Development without metamorphosis. This has not been described in these Egg. lessons, and it occurs only in a single \ Immature insect. order of insects, the Thysanura (see Adult. page 63). [Egg. II. Incomplete 7netamorp hosts. < Nymph (several stages). (^ Adult or ijnago. Egg. larva. Pupa. (The pupa is sometimes inclosed in a cocoon^ ^ Adult or imago. III. Complete metamorphosis. LESSON XVIII. BEETLES OR COLEOPTERA (Co-le-op'te-ra). While the pupils are observing the development of the insects in their breeding cages, which will probably require a long time, the work of making a collection can be continued. 1. Collect as many kinds of beetles as you can and mount them as directed in Lesson XL Beetles can be found under stones and pieces of wood lying on the ground, under the loose bark of dead trees, logs, and stumps, and on the foliage of plants. 2. The beetles, of which there are many thousand kinds, constitute what is termed by naturalists an Order. There are several orders of insects ; the one composed of beetles is named the Coleoptera. This ^2 INSECT LIFE. name is from two Greek words : one, kolcos, meaning a sheath, and the other, //^r^, meaning wings. It re- fers to the fact that in this order in place of the front wings there are two horny sheaths which cover the hind wings. 3. Prepare a label like that given below. 4. Pin this label into the upper left-hand corner of your case, and arrange your beetles below the label in rows extending from left to right, putting only one kind of beetle in a row. 5. As you collect more beetles place them with these, putting each kind in its proper row. 6. Select one of the larger beetles in your collec- tion and make a drawing representing the dorsal view of it. LESSON XIX. THE ORDER COLEOPTERA (CONTINUED). 1. Carry a small cyanide bottle in your pocket, and, whenever you have an opportunity, collect any beetles that you can find, and add them to your col- lection. 2. Observe that in each kind of beetle the wings are always of the same size. The wings of these in- sects are not gradually developed as they are with locusts, crickets, and bugs ; but the young of beetles THE ORDER COLEOPTERA. 43 are grubs which undergo a complete metamorphosis in the course of their development. 3. Select one of the larger beetles, and examine its wing-covers, or elytra, as they are called. Remove them, and note their structure. How do the elytra of beetles differ from the front wings of locusts? 4. Study the hind wings. How does the folding of the hind wings of a beetle differ from that of the hind wings of a locust ? 5. Mount the elytra and hind wings of the beetle on a card. 6. Study the mouth-parts of the beetle, dissecting them out, and mounting them on a card as was done with the mouth -parts of a locust in Lesson III. Label each of the mouth-parts. 7. Remove some of the upper rows of beetles in your case so as to make room for the two cards just prepared, and place the cards immediately below the label for the order. Then rearrange the beetles be, low the cards. 8. We have now observed the more important characteristics of the order Coleoptera or beetles, which are as follows : Order Coleoptera. — The members of this order have a pair of horny wing- covers, called elytra, zvhich meet iji a straight line down the back, and beneath which there is a siftgle pair of membranous wings. The mouth-parts are formed for biting. The metamorphosis is complete. 44 INSECT LIFE. LESSON XX. THE TRANSFORMATIONS OF A BEETLE. 1. Find a potato field infested with the Colorado potato-beetle. Fig. 20 represents the adult of this insect. 2. If this species is not in your collection, collect some of the adult beetles for it. 3. Search for the larva of this potato- beetle. It is a thick, plump grub, strong- ly arched above, and of a pale yellow color, with two rows of black spots on each side. 4. Search also for the eggs of this in- sect. These are yellow in color and are laid in clusters on the leaves of the potato. 5. Take the eggs and larva to the school alive and put them in a breeding cage. Keep the larvae sup- plied with fresh potato leaves and watch their de- velopment, keeping notes on it. Put a few of the eggs and larvae in alcohol and preserve them in your collection. 6. When full grown, the larvse go into the ground to transform ; there should on this account be a layer of soil in the bottom of the cage. 7. After the larvae have gone into the ground to transform, some of the cocoons should be dug up and preserved in the collection. 8. When the beetles begin to emerge from the ground, dig up some of the cocoons and remove pupas from them for the collection. 9. Arrange the specimens of this species in your A COLLECTING TRIP. 45 collection in the following order, eggs, larv^, co- coons, pupge, adults, and label each group. LESSON XXI. A COLLECTING TRIP. 1. Review carefully the directions and sugges- tions given for the first collecting trip in Lesson X. 2. The special object of this trip is to learn to collect insects by sweeping grass and beating the foliage of herbs and shrubs with an insect net. See page 290 for directions for the use of insect nets. Great care should be taken to procure the speci- mens in as good condition as possible. Empty your net frequently, so that the specimens shall not be in- jured by the sweeping or beating. LESSON XXIL MOUNTING OF SPECIMENS. If the sweeping and beating of the last trip were successful, there will be considerable work to be done in mounting specimens. Before doing this read pages 297 to 299, and then endeavor to mount your specimens in as good condition as possible and pre- serve them for future study. LESSON XXIII. ON COLLECTING BUTTERFLIES. Owing to the dustlike covering with which but- terflies and moths, or millers, are clothed, and which 46 INSECT LIFE. is easily injured, it is necessary to make a special study of the methods of collecting these insects ; for if the specimens are not handled properly, they will be of very little use for study. We will first study the collecting of butterflies. 1. For collecting butterflies an insect net and a collecting box are necessary. The pupils doubtless have insect nets before this lesson is reached ; the collecting boxes can be made of empty cigar boxes, as described on page 287. 2. In addition to the net and collecting box a bottle of chloroform with a brush fitted into the cork (Fig. 21) is very desirable, although not absolutely necessary. 3. It is seldom best to attempt to run down a butterfly and catch it on the wing. Fol- low the insect quietly until it alights, and catch it while at rest. 4. The removal of the insect from the net should be done with very great care, for here lies the greatest danger of injury to the specimen. Fig. 21. ^^ the butterfly is a small one, it can be taken from the net by placing the mouth of an open cyanide bottle over it ; in this way touch- ing the specimen with the fingers is avoided. If the specimen is too large for this, the net should be held in such a way that the insect can not flutter and thus injure its wings. Try to have it come to rest with its wings folded over its back, for the lower side of the wings are not so easily injured as is the upper side. Then take the fold of the net con- taining the butterfly between the thumb and finger ON SPREADING BUTTERFLIES. 47 of one hand and pinch the thorax of the insect. This can be done in such a way as to kill the insect at once without crushing the specimen. It can then be removed from the net and pinned and placed into the collecting box. If the collector has a bottle of chloroform and brush, as soon as the insect is at rest in a fold of the net it can be killed by wetting its thorax with chloro- form. This is done by putting the wet brush on the net where it rests against the thorax of the insect. The butterfly can then be removed and pinned into the collecting box. 5. Read paragraph on folded papers for butter- flies, page 287. 6. Go into the field and collect some butterflies. Try to secure them in perfect condition rather than to try to get a large number. 7. If you have time to spread the butterflies when you return from the field, pass at once to the next lesson; but if not, put the specimens on damp sand in a tightly closed jar or box and leave them till the following day. See paragraph on relaxing insects, page 305. LESSON XXIV. ON SPREADING BUTTERFLIES. Read the directions for making spreading boards and for spreading insects on pages 303 to 305, and then spread the butterflies that you have collected. ^8 INSECT LIFE. LESSON XXV. THE STRUCTURE OF BUTTERFLIES. 1. Take a butterfly that has just been killed or one that has been relaxed in a damping- jar, and pin it so that it can be handled without rubbing the colors from the wings. 2. Examine the compound eyes with a lens or microscope, and make a drawing illustrating the structure of the surface ; only a small portion of one eye need be represented, but show this greatly en- larged. 3. Observe on the lower side of the head two forward-projecting organs. These are the feelers of the lower lip or labial palpi. 4. Observe an organ that is coiled up between the labial palpi. If the butterfly has been recently killed or is thoroughly relaxed, this organ can be straightened out by using a pin. It is the sucking- tube by means of which the insect extracts nectar from flowers. It is composed of two parallel parts closely united, but with a channel between them through which the nectar is sucked. These two parts are the maxillae, which have become greatly developed and modified to fit them for sucking. The other mouth-parts, except the labial palpi, are poorly developed. 5. Remove the head and gum it with the maxillas uncoiled to a card which is large enough to receive the two wings of one side also. 6. Remove the two wings of one side and gum them to the card with the head. THE STRUCTURE OF BUTTERFLIES. 49 7. Study the clothing- of the wings. It is neces- sary to use at least a lens for this ; if there is a micro- scope in the school it should be used for this study. It will be found that the dust covering the wings and body is composed of scales, which are of regular form ; and that in butter- flies these scales are ar- ranged in regular order upon the wings. Fig. 22 represents part of a wing of a butterfly greatly magnified. In the upper part of the figure the membrane of the wing is represented with the scales removed. 8. The butterflies, to- gether with the moths, or Fig. 22.— Part of win^ of butterfly, greatly magnified. millers, and the skippers, which are insects that re- semble butterflies, constitute an order w^hich is named the Lepidoptera. This name is from two Greek words : lepis, a scale, and pterojt, a wing. It refers to the scaly covering of the wings and body. 9. Make a copy of the following label, and fasten it in your collection above the specimens of Lepi- doptera : 1 so INSECT LIFE. lo. Place the card bearing the head and wings of a butterfl}' immediately below this label. LESSON XXVI. ON COLLECTING MOTHS. 1. The fact that moths, or millers as they are often called, do not fold their wings above the body like butterflies makes it impracticable to kill speci- mens by pinching the thorax. Very large specimens can be killed by chloroform, as described in Lesson XXIII ; but most specimens should be taken from the net by placing the mouth of an open cyanide bottle over them. Never touch a specimen with the fingers if it can be avoided. 2. Do not carry moths in a cyanide bottle with other insects. It is best to have a separate bottle for Lepidoptera, for they are liable to be injured by rub- bing against other insects ; and the specimens of other insects w^ill be soiled by the scales from the butterflies or moths. 3. Many moths can be collected in the fields by day, but much larger numbers can be taken at night at lights or at sweetened baits. Read the sections on sugaring and on collecting at lights on pages 292 to 293. 4. Collect as many kinds of moths as possible, taking especial pains to get the specimens in good condition. 5. Carefully spread one or more specimens of each kind ; other specimens may be simply pinned and left till winter, when they can be relaxed and spread. CHAPTER III, THE CLASSIFICATION OF INSECTS AND THEIR NEAR RELATIVES. N the course of the lessons in the preced- ing chapter, a beginning was made in the classification of insects. The sub- ject can now be taken up in a more systematic manner. It is not, how- ever, the purpose of this book to car- ry the classification of insects further than to the orders, although in the chapters following this a few easily recognized families will be studied. It is believed that it is better for the pupils that are beginning this study to devote the greater part of their time to the study of the structure and habits of insects ; later, the classification can be carried farther with the aid of more advanced manuals written for that purpose. The collector of insects is sure to meet many small animals that, although not true insects, are closely allied to them. It is important, therefore, that the characteristics of these near relatives of in- sects should be pointed out, which we will briefly do, before discussing the orders of insects. 51 52 INSECT LIFE, The Classes of the Branch Arthropoda. In the study of the parts of a locust (see Lesson VI) it was learned that the body of an insect is com- posed of a series of more or less similar rings or seg- ments joined together. This fact is also true of the bodies of certain other animals that are not insects ; thus, if the body of a scorpion, a centipede, or a lob- ster be examined, it will be found to resemble that of an insect in this respect. There is another charac- teristic in which these animals resemble insects — namely, some of the segments of the body bear jointed legs. All the animals possessing these two character- istics are classed together as the branch Arthropoda {Ar-throp' o-dd) of the animal kingdom, the term branch being applied to each of the principal divi- sions of the animal kingdom. A similar segmented form of the body is char- acteristic of worms, but these are distinguished from the Arthropoda by the absence of legs. It should be remembered that many animals commonly called w^orms, as the tomato-worm, apple-worm, etc., are not true worms, but are the larvse of insects. The angle worm is the most familiar example of a true worm. The principal divisions of a branch of the animal kingdom are called classes. The more common rep- resentatives of the branch Arthropoda are distributed among four classes. These are the Crustacea, the Arachnida, the Myriapoda, and the Hexapoda. The last of these comprises the insects, the first three the near relatives of insects. CLASSIFICATION OF INSECTS. 53 The following table will enable the student to dis- tinguish the classes of the Arthropoda."^ TABLE OF CLASSES OF THE ARTHROPODA. A. With two pairs of antennse and at least five pairs of legs. Aquatic animals breathing by gills. Page 53 Crustacea. AA. With one pair of antennae or with none. Air-breathing animals. The number of legs varies from six to many. B. Without antennae and with four pairs of legs, although the maxillary palpi are often leglike in form, making the animal appear to have five pairs of legs. Page 55 , Arachnida. BB. With antenna. C. With more than three pairs of legs ; and without wings. Page 57 M YRIAPODA. CC. With only three pairs of legs, and usually with wings in the adult state. Page 58 Hexapoda. Class Crustacea (Crus-ta'ce-a). The Crustaceans {Crus-ta' ce-ans^. The most familiar illustrations of the Crustacea are the crayfishes, the lobsters, the shrimps, and the * The following is the method of using the analytical tables given in this book : Read carefully the statement of characteristics given opposite A and AA respectively, and by examining the animal to be classified de- termine which is true of this animal. This will indicate in which division of the table the name of the group to which the animal belongs is to be looked for. If this division of the table is subdivided, pass to B and BB (also to BBB if it occurs) in this division and determine in a like manner under which the animal belongs. Continue in this way, passing to the letters C, D, E, etc., in regular order till the name of the group is reached. Then turn to the page indicated and read the description of the group given there, comparing the specimens with the description. It should be borne in mind that an analytical table is merely an aid to the determination of groups. As the groups that we recognize are not always sharply limited in nature, we can not expect to be able in every case to find characters that will serve to distinctly separate them in a table. Therefore when a student has determined by the aid of a key to what 54 INSECT LIFE. crabs. Crayfishes (Fig. 23) abound in our brooks, and are often improperly called crabs. The lob- sters, the shrimps, and the true crabs live in- salt water. The Crustacea are distinguished from all other Arthro- pods by having two pairs of antennas and by their mode of respiration, being the only ones that breathe by true gills. Many insects live in water and are furnished with gill- like organs, but these are tracheal gills. True gills are for the purification of blood, while tracheal gills are for the purification of the air con- tained in the air ves- sels or trachese of an insect. The former contains a large num- ber of blood vessels, the latter a large number of air vessels. There are minute Crustacea common in ponds and streams. Three of the more abundant of these Fig. 23. — A crayfish. Fig. 24. — Crustacea : a, Cypris ; b, Cyclops ; c, Daphnia. Fig. 25. A sow-bug. group a species seems to belong, he should verify this determination by a study of the characters of that group given in the detailed discussion of it. CLASSIFICATION OF INSECTS. 55 are shown greatly enlarged in Fig. 24 ; they fre- quently occur in aquaria in which aquatic plants are growing. The sow-bugs (Fig. 25) are also Crustacea. They live about water-soaked wood ; with these only one pair of antennae are well developed. Class Arachnida (A-rach'ni-da). The Arachnids {A-rach'nids). To this class belong the spiders, scorpions, har- vestmen, mites, and certain other less common forms. These animals differ from the other classes of the branch Arthropoda in having no antennse. They have four pairs of legs fitted for walking, and many of them have very large maxillary palpi, which re- semble legs. The head and thorax are closely united, forming a region which is called the ceph- alothorax {ceph-a-lo-tho' rax). These characteristics are easily seen in spiders (Fig. 26). The most common rep- resentatives of the class Arach- nida are the spiders. These are extremely interesting ani- fig. 26.— a spider. mals on ac- count of the high development of their instinc- tive powers. An account of the habits of some of the common species is given in the chapter on Road- side Life. 56 INSECT LIFE. The harvestmen (Fig. 27) are also abundant in most parts of our country. These leed on small in- Fig. 27. — Aharvestman. sects, especially aphids, and are perfectly harmless. They are sometimes called ''grandfather graybeards." Scorpions (Fig. 28) are common in the southern portions of the United States, but are not found in the North. They feed upon spiders and large insects, which they seize with the large pincers of their palpi, and sting to death with a poison sting, w^hich is at the hind end of the body. The mites are mostly very small. They differ from other Fig. 28, — A scorpion. Fig. 29. — An itch mite : a, from below ; b, from above. Arachnids in having the abdomen fused with the cephalothorax (Fi< Certain velvety red species CLASSIFICATION OF INSECTS. 57 often attract attention on account of their red color, and other species are often found para- sitic on insects. The annoying para- sites that are known as ticks (Fig. 30), and which are common in the warmer parts of our country, are mites. The sheep-tick, however, is a wingless fly. Fig. 30. — The cattle-tick, female. Class Myriapoda (Myr-i-ap'o-da). The Myriapods [Myr'i-a-pods). This class includes the centipedes and the milli- pedes, both of which are commonly called thousand- legged worms. The members of this class have a distinct head which bears a single pair of antennas. The body is long, and consists of similar seg- ments, which are not grouped into regions, and each segment of the body bears one or two pairs of legs. The centipedes (Fig. 31) have only a single pair of legs to each segment. Representatives of many species of these are common. The poison glands open through the claws of the first pair of legs, which are bent forward Fig. 31. — A centipede. Fig. 32.— a millipede. The centipedes so as to act with the mouth-parts, feed on insects. The millipedes (Fig. 32) differ from the centipedes in having two pairs of legs on each of the body seg- ments except the first three. The millipedes, as a 58 INSECT LIFE. rule, live in damp places, and feed on decaying vege- table matter. They are harmless, except that occa- sionally they feed upon growing plants. Class Hexapoda (Hex-ap'o-da). The Insects. Insects differ from the other classes of the Arthrop- oda in having only three pairs of legs, and usually in having wings in the adult state. The}^ have a sin- gle pair of antennas, and the segments of the body are grouped into three regions : head, thorax, and abdomen. The name Hexapoda is from two Greek words : hex, six, and pous, foot. Numerous examples of in- sects are figured in the following portions of this chapter. THE ORDERS OF THE CLASS HEXAPODA. The class Hexapoda, or insects, is divided into nineteen orders. In our Manual for the Study of In. sects these orders and the families of which they are composed are discussed in detail, but in these first lessons we can only briefly refer to each order. The following table is taken from the Manual. This table of orders is merely intended to aid the pupil in determining to which of the orders a specimen that he is examining belongs. No effort has been made to indicate in the table the relation of the orders to each other. CLASSIFICATION OF INSECTS. 59 TABLE FOR DETERMINING THE ORDERS OF HEXAPODA.* {^This table includes only adult insects.) A. Wingless or with rudimentary wings. B. Mandibles and maxillae retracted within the cavity of the head so that only their apices are visible. Page 63 Thysanura. BB. Mandibles and maxillae more or less prominent and fitted for biting. (See BBB also.) C. Head with long, trunklike beak. {Boreus.) Page 78, Mecoptera. CC. Head not prolonged into a trunk. D. Louselike insects of small size ; body less than one sixth inch in length. E. Antennae with not more than five segments. (Bird-lice.) Page 69 Mallophaga. EE. Antennae with many segments. (Book-lice.) Page 68. CORRODENTIA. DD. Insects of various forms, but not louselike, and, except in the case of some ants, with the body more than one sixth inch in length. E. Abdomen with short, conical, compressed, many-jointed caudal appendages. {Cockroaches.) Page 70, . .Orthoptera. EE. Abdomen without jointed caudal appendages. F. Legs fitted for jumping. ( Wingtess locusts, grasshoppers, and crickets.) Page 70 Orthoptera. FF. Legs fitted for running. G. Abdomen broadly joined to the thorax. H. Body linear. {Walking-sticksl) Page 70. Orthoptera. HH. Body white and somewhat antlike in form. {Ter- mes.) Page 67 Isopter A. HHH. Body neither linear nor antlike in form. ( Wing- less firefly et at) Page 85 Coleoptera. GG. Base of abdomen strongly constricted. {A tits et at.). Page 85 Hymenoptera. BBB. Mouth-parts formed for sucking. C. Small abnormal insects in which the body is either scalelike or gall-like in form, or grublike and clothed with wax. The waxy * See note at bottom of page 53. 6o INSECT LIFE. covering may be in the form of powder, of large tufts or plates, of a continuous layer or of a thin scale, beneath which the insect lives. {Coccidce.) Page 75 Hemiptera. CC. Body more or less covered with minute scales, or with thick long hairs. Prothorax not free (i. e., closely united with the meso- thorax). Mouth-parts usually consisting of a long " tongue " rolled beneath the head. Page 80 Lepidoptera. CCC. Body naked, or with isolated or bristlelike hairs. D, Prothorax not well developed, inconspicuous or invisible from above. Tarsi five-jointed. Mouth-parts developed into an unjointed trunk ; palpi present. Page 83 Diptera. DD. Prothorax well developed. E. Body strongly compressed ; tarsi five-jointed, {Fleas^ Page 84 Siphonaptera. EE. Body not compressed ; tarsi one-, two-, or three-jointed. F. Last joint of tarsi bladderlike or hooflike at the tip ; mouth parts forming a triangular, unjointed beak ; palpi present. Page 74 Physopoda. FF. Last joint of tarsi not bladderlike, and furnished with one or two claws ; mouth parts forming a slender, usually jointed beak ; palpi apparently wanting. Page 75. Hemiptera. AA. Winged, (The wing-covers, elytra, of beetles and of earwigs are counted as wings in this table,) B. With two wings. C. Wings horny, leathery, or parchmentlike. D, Mouth-parts formed for sucking. Wings leathery, shortened, or membranous at the tip. Page 75 Hemiptera. DD. Mouth-parts formed for biting. Jaws distinct. E. Wings horny, without veins. Hind legs not fitted for jumping. Page 85 Coleoptera. EE, Wings parchmentlike, with a network of veins. Hind legs fitted for jumping. Page 70 Orthoptera. CC. Wings membranous. D. Abdomen with caudal filaments. Mouth-parts rudimentary. E. Halteres wanting. Page 64 Ephemerida. EE. Halteres present (males of Coccidce). Page 75, Hemiptera. DD, Abdomen without caudal filaments, Halteres in place of second wings. Mouth-parts formed for sucking. Page 83. Diptera. CLASSIFICATION OF INSECTS. 6l BB. With four wings. . , C. The two pairs of wings unlike in structure. D. Front wings leathery at base, and membranous at tip, often overlapping. Mouth-parts formed for sucking. Page 75. Hemiptera. DD. Front wings of same texture throughout. E. Front wings horny or leathery, being veinless wing covers. {Elytm.) F. Abdomen with caudal appendages in form of movable for- ceps. Page 69 EUPLEXOPTERA. FF. Abdomen without forceplike appendages. Page 85. COLEOPTERA, EE. Front wings leathery or parchmentlike, with a network of veins. F. Under wings not folded. Mouth-parts formed for suck- ing. Page 75 Hemiptera, FF. Under wings folded lengthwise. Mouth-parts formed for biting. Page 70 Orthoptera. CC. The two pairs of wings similar, membranous. D. Last joint of tarsi bladderlike or hooflike at the tip. Page 74. Physopoda. DD. Last joint of tarsi not bladderlike. E. Wings entirely or for the greater part clothed with scales. Mouth-parts formed for sucking. Page 80 Lepidoptera. EE. Wings naked, transparent, or thinly clothed with hairs. F. Mouth-parts arising from the hinder part of the lower surface of the head, and consisting of bristlelike organs in- closed in a jointed sheath. {Ho77ioptera.) Page 75. Hemiptera. FF. Mouth-parts in normal position. Mandibles not bristle- like. G. Wings net-veined, with many veins and cross-veins. H. Tarsi consisting of less than five segments. I. Antennae inconspicuous, awl-shaped, short, and slen- der. J. First and second pairs of wings nearly the same length ; tarsi three-jointed. Page 65 . . .Odonata. JJ. Second pair of wings either small or wanting ; tarsi four-jointed. Page 64 Ephemerida. II. Antennae usually conspicuous, setiform, filiform clavate, capitate, or pectinate. 62 INSECT LIFE. J. Tarsi two- or three-jointed, K. Second pair of wings the smaller. Page 68. CORRODENTIA. KK. Second pair of wings broader, or at least of the same size as the first pair. Page 66, Plecoptera. J J, Tarsi four-jointed ; wings equal. Page 67. ISOPTERA. HH. Tarsi consisting of five segments. I. Abdomen with setiform, many-jointed anal fila- ments. {Certain May-flies?) Page 64. .Ephemerida. II, Abdomen without many-jointed anal filaments, J. Head prolonged into a trunklike beak. Page 78. Mecoptera. JJ. Head not prolonged into a beak. Page 77. Neuroptera. GG. Wings with branching veins and comparatively few cross veins, or veinless. H. Tarsi two- or three-jointed. I. Posterior wings smaller than the anterior. Page 68. CORRODENTIA. II. Posterior wings as large as or larger than the ante- rior ones. {Certain stone-flies.) Page 66. Plecoptera. HH. Tarsi four- or five-jointed. I. Abdomen with setiform, many-jointed anal fila- ments. {Certain May -flies?) Page 64. Ephemerida. II, Abdomen without many-jointed anal filaments. J. Prothorax horny. First wings larger than the second, naked or imperceptibly hairy. Second wings without, or with few, usually simple, veins. Jaws (mandibles) well developed. Palpi small. Page 85 Hymenoptera. JJ. Prothorax membranous or, at the most, parch- mentlike. Second wings as large as or larger than the first, folded lengthwise, with many branching veins. First wings naked or thinly clothed with hair. Jaws (mandibles) inconspicuous. Palpi long. Mothlike insects. Page 79. Trichoptera, CLASSIFICATION OF INSECTS. 63 List of Orders of the Thysanura. EpheMerida. Odonata. Plecoptera. Isoptera. corrodentia. Mallophaga. euplexoptera. Orthoptera Physopoda. Hexapoda. Hemiptera. Neuroptera. Mecoptera. Trichoptera. Lepidoptera. Diptera. SiPHONAPTERA. Coleoptera. Hymenoptera. Order Thysanura (Thys-a-nu'ra). Bristletails, Springtails^ Fish-moths^ and others. The members of this order are wingless insects which undergo no metamorphosis, the larval form being retained hy the adult. The mandibles and max- illcB are retracted within the cavity of the head, so that only their tips are visible ; they have, hozvever, some free- dom of motion, and can be used for biting and chewing soft substances. True compound eyes are rarely present ; but in some genera there is a group of simple eyes on each side of the head. The abdomen is sometimes fur7iished with rudimentary legs. A familiar example of this order is the fish-moth (Fig-. 33), which often does damage to starched cloth- ing, bookbindings, and sometimes loosens wall paper by eating- out the paste. The hair line at the left of the figure indicates the length of the insect. The fish-moth is one of the bristletails, which are l-IG. 33. — The fish- moth. 64 INSECT LIFE. Fig. 34. - A springtail. SO called on account of the bristles at the hind end of the body. Fig. 34 represents one of the springtails. In these insects there is a taillike organ, which is bent under the insect when it is at rest, and by which it can leap several feet. Spring- tails are abundant in damp places, among decaying veg- etation ; but they are com- monly overlooked on account of their minute size. The name Thysanura is from two Greek words : thysanos, a tassel, and otira, the tail. Order Ephemerida (Eph-e-mer'i-da). The May-flies. The members of this order have delicate membranous wings with a fine network of veins ; the fore wings are large and the hi7id wings are much smaller^ or zvanting. The mouth- parts are rudimentary. The 7net morphosis is incomplete. The name of this order is from the Greek word epJieme- ros, lasting but a day. It was given to these insects on ac- count of the shortness of their lives after reaching the adult state. Fig. 35 represents a common species. Work on May-flies is outlined in the chapter on Pond Life. fig. 35.— a May-fly. CLASSIFICATION OF INSECTS. 65 Order Odonata (Od-o-na'ta). The Dragon- files and Damsel-fiies. The members of this order have four membranous wings which are finely netted ivitJi veins ; the hind wings Fig. 36. — A dragon-fly. are as large or larger than the fore wings, and each wing has 7iear the middle of its front margin a joint like structure — the nodus. The mouth-parts are formed for biting. The metamor- phosis is incomplete. The name of this order is evidently from the Greek word odons, a tooth ; but the reason for applying- it to these insects is obscure. It may refer to the tusklike form of the abdomen. Fig. 36 represents a dragon- fly, and Fig. 37 a damsel-fly Work on these insects is out- lined in the chapter on Pond Life. Fig. 37. — A damsel-fly, 66 INSECT LIFE. Order Plecoptera (Ple-cop'te-ra). T/ie Sto7ie-fiies. The members of this order have four membranous wings ^ ivith comparatively few or with many cross-veins ; the hind zvings are much larger than the fore wings, and are folded in plaits and lie upon the abdomen when at rest. The mouth-parts are of tJie biting type of structure, but are frequently poorly developed. The metamorphosis is incomplete. The name of this order is from two Greek words: plecos, plaited, and pteron, a wing. It refers to the way in which the hind wing^s are Fig. 38. — A stone-fly. Fig. 39. — A nymph of a stone-fly. folded when at rest. Fig. 38 represents one of the larger members of this order with the wings of one side spread, and Fig. 39 represents a nymph. Work on these insects is outlined in the chapter on Brook Life. CLASSIFICATION OF INSECTS. 67 Order Isoptera (I-sop'te-ra). The Termites or White-ants. The members of this order are social insects. Each species consists of several distinct castes, of which only the "'kings'' and the '' qneeiis'' are winged. These have four long, narrozv wings, zvhich are soviezvhat leathery in structure, and zvhicJi are furnished with numerous but more or less indistinct veins. The two pairs of wings are similar in form and structure, and are laid flat upon the back when not in use. The mouthparts are formed for bit- ing. The metamorphosis is incomplete. The termites are commonly called white-ants on account of their light color and the fact that they live in large com- munities like ants. They are, however, not at all closely related to the true ants. They can be distinguished from ants at a glance by the absence of a slender waist between the thorax and ab- domen (Fig. 40). The termites that occur in the United States are ^fe;£/ usually found in old logs and stumps, or in the ground under stones. Dur- ing the greater part of the year only the workers (Fig. zjo) and the soldiers (Fig. 41) are found in the nest. But during early summer the winged forms, the newly developed kings and Aqueen. Fig. 40. A worker. Fig. 41. A soldier. 6% INSECT LIFE. queens, also occur. A mature, egg-lajing- queen is presumably present in each nest ; but this form of our common species has not yet been found. Fig. 42 represents an egg-laying queen of an African species. The name of this order is from two Greek words : isos, equal, and pteron, a wing. It refers to the fact that the two pairs of wings are similar in form and structure. Order Corrodentia (Cor-ro-den'ti-a). The Psocids (^Fsoc'ids) and the Book-lice. The winged members of this order have four mem- branous wings ^ with the veins prominent, but with com- paratively few cross-veins ; the fore wings are larger than tJie hind wings ; and both pairs when not in use are placed rooflike over the body, being almost vertical, and not folded in plaits. The mouth-parts are formed for biting. The metamorphosis is incomplete. The winged members of this order feed upon lichens and are found on the trunks of trees and on fences ; they often occur in swarms. Fig. 43 represents a common form with its wings spread. The most familiar repre- sentative of the wingless forms is the book-louse (Fig. 44). This is a minute insect which occurs be- tween the leaves of old books and on papered walls of houses. Fig. 43. — A psocid. Fig. 44. — A book- louse. CLASSIFICATION OF INSECTS. 69 The name of this order is from the Latin word corrodere, to gnaw, and refers to the gnawing habits of these insects. Order Mallophaga (Mal-loph'a-ga). The Bird- lice. The members of this order are zuijigless parasitic in- sects, zvith biting mouth-parts. The metamorphosis is incomplete. The bird-lice are common on poultry and other birds. They differ from the true lice in having bit- ing mouth-parts, and in feeding upon either feathers, hair, or the skin, w^hile the true lice have sucking mouth-parts and feed upon blood. Fig. 45 represents a specie's which infests poultry. The name of the order is from two Greek words : mallos, wool, and phagein, to eat. Although some species infest sheep fig. 45. and goats, feeding upon their w^ool, by far ^^ird-icuse. the greater number live among the feathers of birds. Order Euplexoptera (Eu-plex-op'te-ra). The Earwigs. The members of this order have apparently four wings ; the first pair of which are leathery, very small, zuithout veins, and whe?t at rest meet in a straight line on the back ; the second pair are large, with radiati?tg veins, and when at rest are folded both lengthwise and cross-wise. The mouthparts are formed for biting. The caudal end of the body is furnished zvith a pair of appendages zuhich resemble forceps. The metamorphosis is incomplete. These are long and narrow insects, resembling 70 INSECT LIFE. rove beetles in the form of the body and in the short- ness of the wing covers, but easily distinguished by having a pair of forceps, at the end of the body (Fig. 46). The common name, earwig, has reference to a widely spread fancy that these in- sects creep into the ears of sleeping persons. The earwigs are rare in the north- eastern United States, but are more often found in the South and on the Pacific coast. In Europe they are common, and are often troublesome pests, feeding upon the corollas of flowers, fruits, and other vegetable substances. Fig. 46.— An earwig. j • r 1 he name 01 the order is from three Greek words : eu, \nq\\, pleko, to fold, ?ir\d pter 071, wing. It refers to the unusual folding of the hind Order Orthoptera (Or-thop'te-ra). Cockroaches, Crickets, Grasshoppers, and Others. The members of this order have four luings : the first pair are thickened, and overlap when at rest ; the second pair are thinner, and are folded in plaits like a fan. The mouth-parts are formed for biting. The metamor- phosis is incomplete. The name of the order is from two Greek words : ortJios, straight, and pteron, a wing. It refers to the longitudinal folding of the hind wings. This order includes only six families, and as they are among our most common insects we will briefly refer to each of them. CLASSIFICATION OF INSECTS. 71 Family Blattid^ (Blat'ti-dae). — The body is oval when seen from above, and is very flat ; the three pairs of legs are similar in form ; the insects run rapidly. They are commonly known as cock- roaches. Some are winged (Fig. 47), others are wingless (Fig. 48). Family Mantid^ (Man'ti-dse). — The prothorax is very long and slender; the first pair of legs are very different from the others and are fitted for grasping. These insects feed on other insects, which they seize with their fore legs. The suppliant attitude w^hich they assume while lying in wait for Fig. 47. The Croton. bug. Fig. A wingless cockroach. Fig. 49. — A praying-mantis. their prey (Fig. 49) has given them the name of pray- ing mantes, the name of the typical genus being Mantis. Family Phasmid.^ (Phas'mi-dse). — The body is very long and slender; the three pairs of legs are 72 INSECT LIFE. similar in form, and are also very long and slender; the insects walk slowly. This family includes the well-known walking sticks (Fig. 50). Family AcRiDiD^ (A-crid'- i-d^e). — There are three fami- lies of this order in which the hind legs are very much Fig. 51.— a locust. stouter or very much longer, or both stouter and longer, than the other pairs, being fitted for jumping. This is the first ol these three fami- lies. In this family the an- tennas are shorter than the Fig. 52, — A locust. body. The ovipositor is short and composed of four separate plates. The tarsi are three-jointed. The mem- bers of the family are known as locusts or short-horned grasshoppers (Figs. 51 and . Family Locustid^e (Lo-cus^ti-dse). — This is the second of the three families of jumping Orthoptera. Fig. 50. — A walking-stick. CLASSIFICATION OF INSECTS. 73 In this family the antennae are very slender and longer than the body. (This is also true of crickets.) The ovipositor is sword- shaped. The tarsi are four- jointed. The family as a whole are called the true grasshoppers or the long- horned grasshoppers. Some of the smaller species (Fig. 53) are known as meadow- grasshoppers, and a few of the larger species are called katydids (Fig. 54). It should be observed that, owing to an unfortunate application of names, Fig. 53. —A meadow-grasshopper. Fig, 54.— The angular-winged katydid and its eggs. 74 INSECT LIFE. the locusts do not belong to the Locustidge, but to the Acrididce. Family Gryllid.e (Gryrii-dse).— This is the last of the three families of jumping Orthoptera. With these insects the antennas, like those of the long-horned grasshoppers, are very slen- der and longer than the body, except in the mole- FlG. 55. — A cricket. Fig. 56.— a cricket. crickets. The ovipositor is spear-shaped when ex- erted. The tarsi are three-jointed. The members of this family are known as crickets (Figs. 55 and 56). Order Physopoda (Phy-sop'o-da). Thf'ips. The members of this order have four wings ; these are similar in form, long, 7tarrow, menibranous^ not folded, with but few or 710 veins, and only rarely with cross-veins ; they are fringed with long hairs, and are laid horizontally along the back when at rest. The meta- morphosis is incomplete. The mouth-parts are probably used chiefly for sucking ; they are intermediate i7t for 771 betwee7i those of the sucki7tg and those of the biting in- sects. TJie tarsi are one- or twofointed a7id bladderlike at tip. The name Physopoda is from two Greek CLASSIFICATION OF INSECTS. 75 words : physao, to blow up, and pons, a foot. It re- fers to the curious bladderlike feet of these insects. The species of thrips are very minute insects. Fig. 57 represents one of them greatly enlarged, with the wings of one side spread. They can be easily found by pulling to pieces the blossoms of clover or daisies. Some species are black, others are light brown. The wing- less nymphs of our common black species are bright red. f^^- 57.-A thrips.. Order Hemiptera (He-mip'te-ra). Bugs^ Lice, Aphids, ajid others. The winged members of this order have four wings ; in one suborder the first pair of wings are thickened at the base, with thinner extremities which overlap on the back ; in another suborder the first pair of wings are of the same thickness throughout, and usu- ally slope at the sides of the body. The mouthparts are formed for sucking. The metamorphosis is incom- plete. The name Hemiptera is from two Greek words: hemi, half, and pteron, a wing. It was suggested by the form of the first pair of wings in the true bugs. Here the basal half of these organs is thickened somewhat like the wing covers of beetles, only the terminal half being winglike. The second pair of wings are membranous, and when at rest are folded beneath the first pair. Within this order are grouped insects that differ greatly in form and appearance. These are dis- ^6 INSECT LIFE. tributed among three suborders, which can be sep- arated by the following table : A. Wingless Hemiptera, parasitic upon man and other mammals, with a fleshy unjointed beak II. Parasitica. A A. Hemiptera with or without wings, but with a jointed beak. B. First pair of wings thickened at the base, with thinner extremities, which overlap on the back ; beak arising from the front part of the head (Fig. 58) , I. Heteroptera. BB. Wings of the same thickness throughout, and usually sloping at the sides of the body ; beak arising from the hinder part of the lower side of the head (Fig. 59) III. Homoptera. Suborder Heteroptera (Het-e-rop'te-ra). This suborder includes the true bugs, of which the squash- bug (Fig. 60) and the common ^^'^1^ stink-bugs (Fig. 61) are well- FiG, 58.— Head of an hete- ropterous insect. Fig. 59.— Head of an homopte- rous insect. Fig. 60.— The Fig. 61.— A squash-bug. stink-bug. known examples. Several families of this suborder are discussed in the chapters on Pond Life and on Brook Life. Suborder Parasita (Par-a-si'ta). — This suborder is represented in the United States by only one family, the Pediculidse (Ped-i-cu'li-dse). This family comprises the true lice (Fig. 62), which differ from the bird lice of the order Mallophaga in having sucking mouth parts. The true lice live on the skin of mammals CLASSIFICATION OF INSECTS. 77 and suck their blood. There are several ^species that infest man. Suborder Homoptera (Ho-mop'te-ra).— The Ho- moptera includes insects of widely diversified form, but which agree, however, in having- the wings when present of the same thickness through- out, and usually sloping roof-like at the sides of the body when at rest, and in having the beak arise from the hinder part of the lower side of the head (Fig. 59). Among the more common representatives of this suborder are the cicadas (Fig. 63) and the spittle-insects and the tree-hop- pers, described in the chapter on Roadside Life. The common ^^' ^'^ plant-lice, or aphids, and the scale-bugs are also members of this suborder. Order Neuroptera (Neu-rop'te-ra). The Dobson, Aphis-lions^ Ant-lions, and Others. . The members of this order have foiir zvings ; these are membranous and furnished with numerous veins, and usually zuith many cross-veins. The head is not pro- longed into a beak. The mouth-parts are formed for biting. The metamorphosis is complete. The name of this order is from two Greek words : neuron, a nerve, and pteron, a wing. It refers to the numerous nerves, or veins as they are more com- monly called, with which the wings are furnished. When the name Neuroptera was first used it was 7^ INSECT LIFE. applied to a much larger group of insects than now, a group which has since been divided into many orders. So that now, while the name expresses a character which is true of the order, it is also true of many others.* One of the more conspicuous members of the order is Polystcechotes punctatus {Pol-ys-toech' o-tes punc- ta'tiis), which is repre- sented by Fig. 64. To this order also belong Corydalis (see page 153) and the V\Q. 6^.— Polystcechotes punctatus. Aphis-lio7lS {?>QQ \)digQ I 78). Order Mf.coptera (Me-cop'te-ra). The Scorpion-flies and Others. The 7neinbers of this order have four zvings ; these are membranous and furnished with numerous veins. The head is prolonged into a beak, at the end of which biting mouthparts are situated. The metamorphosis is complete. This is a small order composed of very remark- able insects. The most striking character common to all is the shape of the head, which is prolonged into a beak w^ith jaws at the end (Fig. 65). The name Mecoptera is from two Greek words : mecos, length, and pteron, a wing. The members of the genus Panorpa Fig. 65.— Head {Pa-nor'pa) (Fig. 66) are called scorpion- o^^^^coipion- * The Neuroptera of the older entomologists included the following orders : Thysanura, Ephemerida, Odonata, Plecoptera, Isoptera, Corro- dentia, Mallophaga, Neuroptera, Mecoptera, and Trichoptera. CLASSIFICATION OF INSECTS. 79 flies on account of the peculiar form of the caudal part of the abdomen of the male (Fig. 6^). This at first sight suggests the corresponding part of a scorpion, but in reality the two are very different. Very closely allied to the scorpion-flies are the insects of the genus Bittacus {Bit'- ta-cus). Fig. 66.— a scorpion-fly. Fig. 67. Tail of a scorpion- fly. These insects have long narrow wings, long legs, and a slender abdomen. They resemble crane- flies very closely when on the wing. In this genus the caudal appendages of the male are not enlarged as in Panorpa. The species of the genus Boreus {Bo're- iis) are remarkable for occurring on snow in the winter in our Northern States. In this genus the females are wingless, while the males have rudimentary wings. Order Trichoptera (Tri-chop'te-ra). The Caddice-flies or Caddice-worms. The members of this order have four wings ; these are membrafiotcs, furnished with numerous longitudinal veins, but with only few cross-veins, and are more or less densely clothed with hairs. The mouth-parts are rudi- TYientary. The metamorphosis is complete. Fig. 68.— a caddice-fly. Fig. 69. — A caddice-worm. This order is composed of the caddice-flies and caddice-worms (Figs. 6Z and 69), which are discussed 8o INSECT LIFE. in the chapter on Brook Life. The name of the order is from two Greek words: thrix, a \\?ivc, pteron, a winof. It refers to the fact that the wino:s are clothed with hair. Order Lepidoptera (Lep-i-dop'te-ra). The Moths, or Millers, the Skippers, and the Butte)- flies. The members of this order have four wings ; these are membranous and covered with overlapping scales. The mouth-parts are formed for sucking. The meta- inorpJwsis is complete. The name of this order is from two Greek words : lepis, a scale, and pteron, a wing. It refers to the fact that the wings of these insects are covered with scales. Every lad that lives in the country knows that the wings of moths and butterflies are covered with dust, which comes off upon one's lin- ofers when these insects are handled. This dust when examined with a microscope is found to be composed of very minute Fig. 70.— Part of a win? of a butter- i r v-pp-nlar form fly, greatly magnified. The scales SCalCS 01 rCgUldr lOrm, were removed froni a portion of ^^^^ when a wiuo^ is looked the specimen figured. o at in the same way the scaks are seen arranged with more or less regularity upon it (Fig. 70). The body, the legs, and other ap- pendages are also covered with scales. This order has been discussed in Lessons XXIII to XXV, and several representatives of it are de- M^' ..^W"... .aqjBirg no e.i; . isqg joddA arlT .i .?JnBlq it>; =:3qBi^ ,23lqq43 no Bvizl sflT .V^Wfi--^^ TiWfi^'iW/l .^luiq^iioQ banisv-jiifiQ sriT .£ .sq£i^ no abasj; ■ YTiadv^ong arfj fans sliloijevanori risud ariJ no abaa^ no sbasl B-ftBl 3riT twaiw w^n^-^wk ,xnijiq8 suaaaX arlT .g .339DBfdiil boB SqBI-g Plate III.— SOME SPHINX MOTHS. FIGURE 1. The Abbot Sphinx, Thyreus abboti. The larva feeds on grape. 2. The White-lined Sphinx, Deilephila lineata. The larva feeds on apples, grapes, and many other plants. 3. The Dark-veined Deilephila, Deilephila gallii. The larva feeds on grape. 4. The Bumblebee Hawk-moth, Hemarps diffinis. The larva feeds on the bush honeysuckle and the snowberry. 5. The Nessus Sphinx, Amphion nessMs. The larva feeds on grape and rubiaceae. Plate III. CLASSIFICATION OF INSECTS. 8l scribed in the chapters following this one. The principal divisions of the Lepidoptera that are ap- propriately discussed here are three : The moths, the skippers, and the butterflies. The Moths. — These are the insects commonly called millers. Most of the species fly by night and are frequently attracted to lights. When at rest the Fig. 71. — A moth with threadlike antennas. wings are either wrapped around the body, or are spread horizontally, or are folded rooflike on the abdomen ; they are not held in a vertical position above the body. The antennas of moths are of vari- FiG. 72. — A moth with featherlike antenn£e. ous forms ; they are usually threadlike or featherlike ; only in rare cases are they enlarged toward the tip (Figs. 71, 72). The Skippers. — The skippers are so called on ac- 82 INSECT LIFE. count of their peculiar mode of flight. They fly in the daytime and dart suddenly from place to place. When at rest they usually hold the wings erect in a vertical position like butterflies; often the fore wings are thus held while the hind wings are extended horizontally. The antennae are threadlike, and en- larged toward the tip ; but in most cases the extreme tip is pointed and recurved, forming a hook. The Fig. 73.— a skipper. FiG. 74. — A skipper. abdomen is usually stout, resembling that of a moth rather than that of a butterfly (Figs. 73, 74). Fig. 75. — The goat-weed butterfly. The Butterflies. — The butterflies fly by day, and when at rest they fold the wings together above the back in a vertical position. The antennas are thread- CLASSIFICATION OF INSECTS. 83 like with a club at the tip, which is never recurved so as to form a hook. The abdomen is slender (Figs. 75, 76). Fig. 76, — The banded-purple butterfly. Order Diptera (Dip'te-ra). The Flies. The members of this order have only two wings ; these are borne by the mesothorax. The metathorax is furnished zvith a pair of knobbed threads — the halteres. The month-parts are formed for sucking. The meta- morphosis is complete. To the order Diptera belong all insects that are properly termed flies, and only these. The word " fly " forms a part of many compound names of in- sects of other orders, as butterfly, stone-fly, May-fl}^ and Chalcis-fly ; but when used alone, it is correctly applied only to dipterous insects. To some flies other common names have been applied, as mosquito, gnat, and midge. The name Diptera is from two Greek words : dis^ two, and pteron, a wing. It was suggested by the fact that the flies are distinguished by the possession 84 INSECT LIFE. of a single pair of wings ; for no fly has more than two wings, and only a few are wingless. The common house-fly is the best-known repre- sentative of this or- der. Fig. "jj repre- sents a crane-fly, so called on account of its long legs. In this figure the halteres, which represent the hind wings in this or- der, are well shown. Several families of flies are referred to in the following chap- FiG. 77.— A crane-fly. tcr. Order Siphonaptera (Siph-o-nap'te-ra). The Fleas. The members of this order are practically wingless^ the wings being represented only by minute scaly plates. The mouthparts are formed for sucking. The meta- morphosis is complete. The name of the order is from two Greek words : si- phon, a tube, and pteros, wingless. It refers to the form of the mouth and to the wingless condition of the in- sects. Fig. 78 represents the j^^ ri_„ J ' i. 1 Fig. 78. — The dog-flea and its dog-flea and its larva. ' larva. Plate IV. Plate IV.— BEETLES. FIGURE 1. The Six-spotted Tiger-beetle, Cicindela sexguttata. See page 270. 2. The Searcher, Calosoma scrutator. A predaceous beetle. 3. Caloptero7t reticulatum, a diurnal member of the firefly family. 4. ChlcEtiius sericeus, a ground-beetle. 5. Brachynus fumaits, a bombardier beetle. 6. The Round-headed Apple-tree Borer, Saperda Candida. 7. The Poplar Borer, Saperda calcarata. 8. The Cloaked Knotty-horn, Desmocerus palliatiis. The larva bores in the pith of elder. 9. Buprestis fdsciata^ one of the metallic wood-borers. TO. The Spotted Pelidnota, Pelidnota punctata. It feeds on the leaves of grape. 11. Dicerca divartcata, one of the metallic wood-borers ; the larva bores in peach, cherry, beech, and maple. 12. A burying beetle, N'ecrophorus. 13. PhancBus carnifex, male ; one of the tumble-bugs. 14. Fhancsus carnifex, female. HrTR- 3f{j no :.-—'■ .f lori- ; ■:1jSC )1J -driT ■SJ t;;.T .01 ^iSl ^^ IJ 4U iVjUCi i .- '-'^ "^ .Vi'SijS'.'SisV^'- al^rnsj .X'iViS^^^Si-) z ■.';;'5i5'^X5S\^ •■H CLASSIFICATION OF INSECTS. Order Coleoptera (Co-le-op'te-ra). The Beetles. 85 The members of this order have a pair of horny wing- covers, called elytra, which meet in a straight line down the back, and beneath which there is a single pair of ineni- branous wings. The mouthparts are formed for biting. The metamorphosis is complete. Beetles can be readily distinguished from all other insects except earwigs by the possession of horny, veinless wing-covers, which meet in a straight line down the back (Fig. 79); and they differ from earwigs in lacking the pincer- like appendages at the tail end of the body characteristic of those insects (see page 70). Fia 79- a beetle. Beetles also differ from ear- wigs in having a complete metamorphosis. The name of the order Coleoptera is from two Greek words : coleos, a sheath, and pteron, a wing. It refers to the sheathlike structure of the elytra (el^y-tra) or wing-covers, which were formerly be- lieved to be modified wings. This order has been studied in Lessons XVIII to XX, and several families are described in the foUow^- ing chapters. Order Hymenoptera (Hy-me-nop'te-ra). Bees, Wasps, Ants, and Others. The members of this order have four wings ; tiiese are membraitous, and furnished with comparatively few or 86 INSECT LIFE. zvitJi no transverse veins. The hind wings are smaller than the fore wings. The mouth- parts are formed for biting and sucking. The abdomen in the female is usually fur?iisJied zvith a sting, piercer, or saw. The metamorphosis is complete. The bees, wasps, and ants are among the better- known insects, and will serve to give an idea of the characteristic appearance of the members of this order. They are chiefly insects of small or moderate size, and many of them abound wher- ever flowers bloom. From the Fig. 8o.— An ichneumon-fly. earliest timcs they havc been favorites with students of the habits of animals, for among them we find the most wonderful developments of instinctive powers. Many volumes have been written regarding their ways, and much remains to be discovered, even concerning our most common species. The name of the order is from two Greek words : hymeit, membrane, 2ind pteron, a wing. It refers to the fact that the wings are of a delicate membranous tex- FlG, 8i. — An ensign-fly. Fig. 82, — A digger-wasp. ture ; but this characteristic is not distinctive, for it is possessed by the wings of many other insects. Figs. 80, 81, and 82 represent members of this order. Plate V. A POND. CHAPTER IV. POND LIFE. F all delightful fields for Nature study none can surpass in interest a well- stocked pond, for there is a pecul- iar fascination in the study of pond life. Even to one who knows lit- tle about Nature, a pretty pond, partly shaded by trees and fringed with water-plants, is a source of de- light. What pleasure when one is tired to lie on a grassy bank and watch the ripples chase each other over the water, or to thread one's way through a rank growth of sedges and rushes to where the cat-tail flags rear their tall spikes, and the sweet-scented water-lilies lift themselves above their shield-shaped leaves, or to fioat in a boat and watch the clouds above and their doubles in the mirror below ! Such experiences bring rest and a feeling of har- mony with Nature. But a keener enjoyment comes with a more intimate acquaintance with the forms of life that abound in these places, when one can look upon each kind of water-plant as an old friend, and know something of the ways of the creatures that glide over the surface or swim beneath. 87 SS INSECT LIFE. There is a pond that we love to visit when we are tired with work at our desks. It is a long", narrow one that winds beneath overhanging trees, and is margined with a dense growth of water-plants. Over this pond dragon-flies hawk at midges ; on a dead tree near the bank a kingfisher has his perch, from which on our approach he swoops down twirl- ing his watchman's rattle ; sometimes in the swamp near by we frighten up a bittern ; and in the shal- lows near the shore the great blue heron loves to fish, standing knee-deep in the water watching pa- tiently for his victims. Here, too, occur large colonies of whirligig-bee- tles, which chase each other round and round as if at play ; water-striders skim over the surface ; the marsh-treader glides on its stiltlike legs among the rushes and floating leaves ; and, beneath the surface, water- boatmen, back -swimmers, water- scorpions, diving -beetles, and many other strange creatures abound. We go to this pond and watch these creatures in their homes and then we bring some of them to our study, where we put them in aquaria, and try to learn more about their ways. Similar ponds can be found in most country places, and the following pages of this chapter are written to aid others in making similar studies. In the studies of life histories the pupil should be very careful in his observations ; it is easy to make mistakes. Do not be satisfied with seeing a thing once, but observe it over and over again. Make sure you are right and then look again. This is the only way in which good scientific work can be done, and POND LIFE. 89 every pupil can be a scientific observer if he has eyes and will use them properly. INSECTS THAT FLY OVER PONDS. The Dragon-flies, or Darning-needles, and THE Damsel-flies {Field Work), — It is a field day, and we find ourselves near our favorite pond, drawn here by a charm we do not care to resist. We are seated on a convenient log on the bank. Below us lies the water without a ripple on its surface, and whether we look up or look down we see the same beautiful foliage of the graceful trees that line the shores. Fringing the bank beyond is a bed of lilies, whose shields float on the surface, and at our feet great arrowlike leaves point upward. Not a breath stirs a branch, and so still is it that it seems as if no living thing were here except the invisible, silent stream of life within twig and leaf. Suddenly there shoots over the pond that swiftest of w^inged crea- tures, a dragon-fly. So rapid is its flight that we can hardly follow it with our sight. Back and forth it goes, when, discovering strangers, it darts in front of us and suddenly stops in midair. Here it hangs for a moment motionless, except for its rapidly vibrating wings, and then as suddenly darts away. What a pity that children should be taught to fear this beautiful, harmless creature by the silly legend that it will sew up their eyes and ears ! The habits of dragon-flies are such that they can be studied only in the field ; the roomiest of breed- ing cages would offer slight scope for the powers of these insects. We must therefore watch them while free if we would learn what they do. 90 INSECT LIFE. Yonder flies a tiny insect, a midge or a mosquito ; as we watch it, a dragon-fly darts at it and it is gone. Now that we have learned what to watch for, we see insect after insect destroyed by the rapacious crea- ture ; no wonder that it is called a dragon. Other dragon-flies have come to our pond. Some of them are behaving quite differently from the one that is hawking mosquitoes. They soar over the pond, and at frequent intervals swoop down and touch the water with the tip of the abdomen. Why do they do this? Are they at play splashing the water like a child? No, these are females laying their eggs. The young of dragon-flies lead a very different life from that of the adult. They live be- neath the water upon the bottom of the pond or stream as the case may be ; and the adult places her eggs in such a position that when the young hatch they will be in their proper element. Not all dragon-flies lay their eggs as these are doing. On one occasion the writer, in company with his class, saw a dragon-fly poising herself in the air a short distance above the point where a water-plant emerged from the water. At frequent intervals the insect descended with a swift curved movement, pushing the end of her abdomen into the water. On examination a large cluster of eggs was found at- tached to the plant just below the surface. And Prof. Uhler has observed a dragon-fly alight upon a reed, and, pushing the end of her body below the surface of the water, glue a bunch of eggs to the submerged stem. The dragon-flies that we have been observing hold their wings spread out stifBy when at rest (Fig. PONU LIFE. 91 83). But there are certain insects, abundant about a ditch near this pond, which resemble these dragon- FlG. 83. flies very closely in structure, but differ in that they fold their wings parallel with the body when resting (Fig. 84). They have not the great powers of flight possessed by the dragon-flies that do not fold their wings, but flit airily from plant to plant. The more gentle hab- its of these insects have led the French to call them demoiselles or damsels. English writers heretofore have classed both of these kinds of insects under the name dra- gon-flies, but in the following pages we will restrict the name dragon-flies to those that hold their wings spread out and term those that fold their wings dam- sel-flies. There is a great variety of damsel-flies. Some have nearly fig. 84. Q2 INSECT LIFE. colorless wings and comparatively dull-colored bod- ies, while others have shiny-black wings and brilliant, metallic-green or blue bodies. The damsel-flies la}^ their eggs in a remarkable manner. These insects have well-developed oviposi- tors with which they can make incisions in the stems or leaves of plants ; and some of the species at least, when they wish to lay their eggs, crawl down the stems of aquatic plants and lay their eggs in them be- neath the water. Can it be that the habit of folding their wangs when they are not in use is correlated with the pecul- iar egg-laying habits of these insects? Certainly it would be difficult for them to creep beneath the water were their wings expanded like those of dragon-flies. Let those who have accompanied us on this field trip try to learn something new about dragon-flies and damsel-flies. This they can do by patiently watching. They can learn upon what kinds of in- sects these creatures feed ; they can observe differ- ences in their modes of flight, and in the regions which each prefers to haunt; and they can ascertain more than we now know regarding the various ways in w^hich they lay their eggs. As soon as an observa- tion is made, it should be recorded in a notebook or on slips of paper carried for this purpose. After observations have been made on one of these insects, that particular one should be captured if possible, so that the record of the observation may be completed by determining the particular species observed. Other specimens should be taken for study at school and for preservation in your collection. POND LIFE, 93 It is exceedingly difficult to catch dragon-flies while they are on the wing. Watch them till one ahghts, and then approach it quietly till within reach of it and capture it with a very quick sweep of the net. Damsel-flies, however, are easily captured. The Habits of Dragon-flies and Damsel- flies {School Work). — Write an account of an excur- sion that you have made yourself to a pond or stream, and include in it the observations that you made on dragon-flies and damsel-flies. State also in this account whether you believe these insects to be injurious or beneficial to man, and the reasons for this belief. Copy the following label and place it above the dragon-flies and damsel-flies in your collection : "^ Order Odonata (Od-o-na'ta). The Dragon- flies and Dajnsel flies. Blue draofon-flies knitting- To and fro in the sun, With sidelong jerk flitting Sink down on the rushes, And, motionless sitting. With level wings swinging On green tasseled rushes. To dream in the sun. — Lowell. The Structure of Dragon-flies {School Work). — Select for study one of the large dragon-flies col- lected on the last field day, one of those that hold the wings spread out when at rest. If you failed to * In writing these labels, underscore the word in capitals with two lines, and the words in italics with a single line. See example, page 42. 94 INSECT LIFE. get any, borrow one of some more successful collec- tor. Do not touch the specimen itself, lest 3^ou break it, but handle it by means of the pin with which it is pinned. 1. Observe the general appearance of the insect, noting the large head, the slender neck, the stout thorax, the broadly expanded wings, and the long, slender abdomen. 2. Study the head, noting its shape, the puffed out front portion, the concave hinder side, and the large compound eyes. 3. Examine the compound eyes with a lens or microscope, and make a drawing illustrating the struc- ture of the surface ; only a small portion of one eye need be represented, but show this greatly enlarged. State the proportion of the surface of the head occu- pied by the compound eyes. 4. Find the simple eyes, using a lens for this pur- pose ; they are situated in the triangular space be- tween the compound eyes and the puffed out front portion of the head. How many of them are there? 5. Observe the antennae ; these are very small, and are situated in the same triangular space as the simple eyes. Each antenna consists of a stouter basal part and a slender, bristlelike part composed of several segments. Make a drawing of one antenna greatly enlarged. 6. Make a drawing of the head seen from above, representing each of the parts already mentioned. Make the drawing large enough so that the simple eyes and antenna can be well shown. 7. Study the lower side of the head and make a drawing of the mouth-parts that can be seen without POND LIFE. 95 dissection. These are the upper lip or labrum, the tips of the mandibles, and the lower lip or labium. The maxillge are usually concealed when the mouth is closed. The labium is very large and ends in three broad flaps, one below the mouth and one on each side ; the one below the mouth is sometimes more or less split on the middle line, and each of the side flaps bears a slender appendage ; sometimes, however, these appendages are very minute. 8. Study the parts of the head already examined with a view to seeing how they are fitted to their use. The most conspicuous parts are the very large eyes ; evidently the sense of sight is exceedingly im- portant to these insects; note also that the shape of the eyes is such that the insect can see in all direc- tions without making any movement of the head or body. Regarding the simple eyes, we can only say that three well-developed ones are present ; no one has yet discovered the peculiar use of these eyes as distinguished from that of the compound eyes, but it seems as if they must have a function different from that of the compound eyes, else why should an insect with such highly developed compound eyes possess simple eyes also. In many insects the sense of smell is believed to have its seat in the antennas ; if that is so in dragon-flies, it is evident that com- paratively little use is made of this sense by these in- sects, for the antennse are so slightly developed as to be little more than rudimentary organs ; but it is not strange that insects so well provided with organs of sight should have little use for organs of smell in hawking their prey or in seeking their mates. The mouth -parts are admirably fitted for seizing and 96 INSECT LIFE. holding the small insects upon which the dragon-flies feed. It is also probable that the freedom of move- ment of the head resulting from the slenderness of the neck is of great use to these insects in seizing their prey. 9. Study the peculiar features of the thorax, not- ing the following points : Its large size — this is neces- sary to give room for the large and powerful mus- cles that move the wings. The position of the legs — these are situated much farther forward than is usual with insects, all of the legs being nearer the head than the wings. The legs are used but little for walking, their chief use being for clinging to some support and, perhaps, for seizing prey. With most insects the middle and hind pairs of legs are attached to the thorax farther back than are the correspond- ing wings, and consequently the side pieces of the thorax between the wangs, and these legs slope back- ward and downward from the wings. This is shown in Fig. 85, which represents a side view of a locust with its wings re- moved. In a dragon-fly these side pieces of the tho- rax slope forzvard and downward. Make a drawing of a side view of a dragon-fly, illustrating this point ; the wings need not be represented, and only the bases of the legs need be shown, as is done in the figure of a locust. 10. Examine the legs of the dragon-fly, noting the spines borne by the femur and tibia. Consider the possible use of these spines in catching and hold- FiG. 85. POND LIFE. 97 ing prey. Make a drawing of one of these legs and label the following parts: coxa, trochanter, femur, tibia, tarsus, and claws. 11. Study the wings. These wings are of espe- cial interest, for, judging by the powers of fiight of these insects, they must be extremely well fitted for their use. Although large they are very light ; yet notwithstanding their lightness they are strong, be- ing strengthened by a large number of veins and veinlets, and the margin of the wing is strengthened throughout by an ambient vein. Near the middle of the length of the frontal (costal) margin of each wing there is a jointlike structure : this is called the nodus ; this structure is characteristic of the wings of dragon-flies and damsel-fiies, but its use is not known. The front part of each wing, which is the part where the greatest strength is required, is folded in plaits somewhat like a fan. This adds greatly to the strength of the wing. Take a flat piece of writing paper and observe how easily it can be bent. Now, fold this piece of paper like a fan and see how much stiffer it is. Study the cross-veins extending back from vein I (i. e., the front margin of the wing) and note that some of them extend straight across the furrow to vein III (the second vein from the margin), and are in the form of triangular braces that tend to preserve the form of the furrow. 12. The abdomen is long, and usually quite slen- der. The necessity for the great length of the abdo- men is not quite clear ; it may be that the abdomen serves to steady the flight like the shaft of an arrow ; and, too, there may exist a relation between the form of the wings and that of the abdomen. With most gS INSECT LIFE. swiftly flying insects, as the bees, wasps, hawk-moths, and others, the hind wings are reduced in size, and thus there is a concentration of the powers of flight to a region near the front end of the body, which adds to its efficiency, for the opposite arrangement would result like an effort to shoot an arrow with the wrong end forward ; with dragon-flies the hind wings are as large as or larger than the fore wings, but the great length of the abdomen results in the flight organs as a whole being comparatively near the front end of the body. It should also be observed that the form of the abdomen is well fitted for the pecul- iar method of laying the eggs. In the males of dragon-flies there is a slit in the lower side of the second abdominal segment, which contains an organ furnished with hooks. Dragon-flies and damsel-flies differ from all other insects in the position of this organ of the males. Determine the sex of each of your specimens and label them male or female as the case may be. 13. Make a sketch of the dragon-fly seen from above. The Structure of Damsel-flies {School Work)^ — Compare the structure of a damsel-fly with that of the dragon-fly already studied. Note especially the form of the head with the eyes projecting like the oarlocks of an outrigged skiff, the shape of the wings, the position of the wings when at rest, and the form of the ovipositor of the females. Make a sketch of the head seen from above. Make a sketch showing the outline of each of the wings of one side. Deter- mine the sex of each of your specimens and label them. POND LIFE. 99 The May-flies {Field Work). — Let us continue our study of the insects that fly over ponds. In many places, at certain periods of the year, the most abundant of these are the May-flies. These are very fragile insects with large, del- icate fore wings, with the hind wings much smaller or want- ing, and with the abdomen furnished at its caudal end with either two or three many- jointed, threadlike appendages (Fig. 86). Although a few May-flies can be found at almost any time during the warmer parts of the year, in each locality there are certain periods dur- ing which they are much more abundant than at other times ; then they are apt to appear in great swarms. This period is as likely to be in June or July as in May, despite the common name of these insects. It is at such times that a study should be made of their habits. If you find that May-flies are abundant at any time and you have not already made a study of them, it will be worth while to postpone the study of any other in- sects and devote your attention to these, for no other insects described in these lessons have so short a pe- riod of flight as the May-flies. While in. the field take notes on the following points : — I. The flight of these insects — contrast it with that of dragon-flies. Fig. 86. 100 INSECT LIFE. 2. The food of May-flies — can you find any that are catching other insects or that are feeding on plants? 3. The young of May-flies live in the water. Try to observe the emergence of the insects from the water. 4. If you succeed in observing the emergence of the winged insect from the water, collect the empty nymph skin and, if possible, the winged individual that emerged from it. These should be preserved together in your collection ; they will serve to con- nect the adult with its early stages. 5. May-flies differ from all other insects in that they shed the skin once after they are able to fly. The winged May -fly when it emerges from the water is not a fully developed adult, but is what is termed a subimago. The subimago state is of short duration ; sometimes it lasts only a few minutes, but in other species it lasts twenty-four hours or more. Watch the May-flies that are resting on plants or other objects near the shore and try to observe the molting of the subimago. If you succeed, collect the adult or imago and the empty subimago skin, and preserve them together in your collection. Even if you fail to observe the molting, you ought to be able to collect subimago skins if the May-flies are at all abundant. 6. Endeavor to observe the laying of the eggs. Some May-flies lay their eggs in masses; specimens are often found in which there project from the cau- dal end of the body two parallel, subcylindrical masses of eggs, for in these insects the two oviducts open separately. POND LIFE. lOi 7. In the evening, examine the street lamps or other lights, and note the extent to which the May- flies are attracted to them. The Habits of May-flies {School Work). — Write an account of what you have learned regarding May- flies. Copy the following label and place it above the May-flies in your collection (see footnote, page 93):- Order Ephemerida (Eph-e-mer'i-da). T/ie May -flies. The Structure of May-flies {School Work).— It is quite difficult to preserve specimens of May- flies in good condition for study, as they shrivel greatly on drying. We will call attention, therefore, to only a few of the more important points in the structure of these insects. 1. Study the head and observe the following: The very large compound eyes — in dried specimens these are apt to be more or less shriveled, and in some kinds of May-flies each compound eye is di- vided into two distinct parts ; the simple eyes or ocelli — in some of our more common species these are much larger than is usual with insects; the mouth- parts — these are absent or represented by minute rudiments. May-flies take no food during their very short existence in the adult state. Make a sketch of the head seen from above. 2. Study the wings and make a sketch showing the outline of each of the two wings of one side. 3. Write out a statement of the points of resem- blance and the points of difference between the wings of May-flies and those of dragon-flies. 102 INSECT LIFE. 4. Make a sketch of a May-fly seen from above. The Stone-flies [Field Work). — Among the in- sects that are common flying about ponds and streams are the stone-flies. Fig. 87 represents one of our larger species with the wings of one side spread out. When at rest these in- sects fold their wings upon the back, as shown on the left side of the figure. Most of our species are much smaller than the one represented here, but they can be recognized as stone-flies by their resemblance in form to this one. The body is flattened, elongate, and with the sides nearly parallel ; the prothorax is large ; the antennae are long, tapering, and many jointed ; in most species the caudal end of the abdomen is furnished with two slender appendages. Stone-flies are so called because they pass their early stages beneath stones in streams and ponds. 1. Collect as many kinds of stone-flies as you can, saving several specimens of each kind. 2. Make notes on their powers of flight. 3. Make notes on the localities in which they occur. 4. Try to discover the method in which they lay their eggs. pond life. 103 The Structure and Habits of Stone-flies {School Work). — Write an account of what you have learned regarding- stone-flies. Describe first the ap- pearance of these insects ; illustrate this by two sketches, one showing the appearance of the insect as seen from above with the wings closed, the other an enlarged view of the head and prothorax as seen from above, and compare the eyes and antennas with those of dragon-flies and May-flies. In the second part of the account state what you have learned regarding the habitat and habits of stone-flies. Copy the following label and place it above the stone-flies in your collection (see footnote, page 3) : Order Plecoptera (Ple-cop'te-ra). The Stone flies. Other Insects that fly Over Ponds {Field Work). — During the field days, when you are studying pond life collect any insects that you find flying over ponds or resting near them. These should be care- fully pinned, labeled, and preserved in your collec- tion for future study. INSECTS THAT LIVE ON THE SURFACE OF WATER. In the excursions that have been made for the purpose of studying pond life, the pupils have proba- bly observed certain insects running over the sur- face of the water as if it were a firm pavement. We purpose to study carefully some of these insects, but before doing so it will be well to endeavor to understand how it is that these creatures can per- form the apparent miracle of walking upon water. I04 INSECT LIFE. The Surface-film of Water (School Work). — One of the astonishing facts to be learned by the study of pond life is that many insects are able to walk upon water, and equally strange is the fact that certain other insects that live within water can hang from its upper surface without any effort to keep themselves there, although their bodies are heavier than water. These things seem to contradict the well-known law of Nature that an object can not float in a liquid unless it is lighter than that liquid. And in truth it is a fact that under certain conditions objects that are much heavier than the liquid upon which they are placed will float. This phenomenon is due to the presence of what has been termed the surface-film of liquids. It has been shown by many experiments, some of which are given below, that on the surface of water, and other liquids also, there is a film of the liquid which tends to contract as if it were a membrane stretched equally in all directions. The explanation of the for- mation of this film is a difficult matter, which can not be undertaken here. It is discussed in the more ad- vanced works on physics and in some of the larger cyclopaedias under the head of capillary attraction. The action of the surface-film can be seen by the following experiments : Experiment i. — Take a fine needle and carefully lay it on the surface of a glass of water. To do this hold the needle in a horizontal position and bring it as near the water as you can without touching the water and then drop the needle. If the experiment be performed with sufficient care, the needle will POND LIFE. 105 float. Steel is seven times heavier than water ; never- theless, in this experiment we see a piece of steel floating on the surface of water. Experiment 2. — Take a needle that you have caused to float on the water and wet it thoroughly. Now you will be unable to make it float so long as it is wet. This experiment indicates that one of the con- ditions of floating of a heavy object is that it shall not be wet by the liquid. Experiment J. — Take needles of different sizes or short pieces of different sizes of wire, and, having them perfectly dry, try to make them float. In this experiment it is well to lay the piece of w4re across the tines of a fork and lower it gently into the water. It will be found that only the smaller needles or pieces of wire will float. This experiment indicates that a second condition of the floating of a heavy object is that it shall be comparatively small. Experime7it 4.. — Take a glass of water and place it on a stand so that you can look through the side of the glass at the surface of the water both from above and below. Place a needle upon the water, the larger the needle the better, provided it will float. By studying the floating object carefully it will be seen that it rests in a little hollow with sloping sides, the surface of the water being indented as if it were covered with a membrane stretched across it. There are many other interesting phenomena that are explained by a knowledge of the action of the surface-film of liquids, but their study belongs to the subject of physics ; only so much has been introduced here as is necessary to understand what we will see in our study of pond life. Io6 INSECT LIFE. The Water-striders (Field WorE):—'^o\\ that we have studied the surface-fihn of water, let us visit some pond or stream and observe those insects that live upon it. Chief among these are the water- striders, the long-legged creatures that skate over the surface as if they had no weight. There are a good many species of water-striders, and several quite distinct types, differing in size, in the form of the body, and in the relative length of the legs. One of the more common forms is represented by Fig. 88. Try to find some of these, for ow- ing to their larger size it will be easier to ob- serve them than other kinds ; but if you are unable to find these, study any water-striders that you can find and make notes for an account of them. 1. Water-striders live upon both ponds and streams ; if you are observing them upon a stream, note what portions of the stream they prefer. 2. Do they occur singly or in colonies? 3. Are they shy or otherwise? 4. Are they disturbed by fish ? To determine this watch them w^here there are fish, and throw grasshoppers or other insects into the water and note if the fish are more apt to jump at these than at the water-striders. 5. Throw some insect into the water where there are no fish, but near some water-striders, and note the actions of the latter. What is likely to happen A water- strider. POND LIFE. 107 to an insect that falls into the water where there are water-striders? 6. Watch the water-striders and learn if they will jump from the water to catch insects that fly near it. 7. Remain quiet at the shore of the pond or stream till the water-striders approach near enough to be observed closely and determine what portions of the body rest upon the water. 8. Observe the dimples in the water where the feet rest on the surface. 9. When the sun is shining- brightly, find some water-striders where the water is shallow and ob- serve on the bottom of the pool the shadows of the dimples in the water made by the feet of the insects. Note that each shadow is surrounded by a golden ring of light. The more advanced pupils should be able to explain the cause of this ring of light. Note that there is no ring of light about the shadow cast by the body ; why is this so ? 10. Make a sketch showing the outline of the body and the position of each of the legs and the an- tennae when the insect is at rest. 11. Discover which pair of legs are the chief organs of locomotion in the striding of these insects. 12. Collect as many kinds of water-striders as possible, saving several specimens of each species. Kill them in your cyanide bottle and then pin them on your return home. Water-striders are dimorphic — that is, there are two distinct forms of fully developed individuals in each species. One form is winged, the other wing- less. Try to procure both the winged and the wing- less form of each species collected. The presence I08 INSECT LIFE. of winged forms probably enables these insects to spread overland from one pond or stream to another, but the conditions under which winged forms occur are not well understood. Sometimes a third form occurs in which the adult has short wings. It should be remembered that the nymphs of the winged forms have short wing-pads, but these differ in appearance from perfect wings. The Families of Water-striders (School Work). — There are two closely related families of bugs the members of either of which could well be called water-striders on account of their mode of life. In one family the legs are much longer than in the other, and better fitted for the gliding motion characteristic of water-striders ; the members of this family are termed *'the water-striders." In the other family the legs are shorter and fitted for running rather than rowing ; as the body is broadest across the prothorax in these insects, they are termed " the broad-shoul- dered water-striders." Separate from the others those specimens of water- striders in your collection in which the second and third pairs of legs are extremely long and slender, and in which the body is widest back of the pro- thorax. If this family is well represented in your locality, you should have some species in which the body is long and slender, as in Fig. 88, and also some smaller species in which the body is oval in outline. Copy the following label and fasten it above the place where the water-striders are to be put in your collection : — Order Hemiptera (He-mip'te-ra). The Bugs. POND LIFE. lOQ Place immediately below this label the following one, and then arrange the water-striders just selected beneath this second label ; put each species of water- strider in a row by itself: — Family Hydrobatid.^ (Hyd-ro-bat'i-dae). The Water-striders. Fig. 89 represents a member of the second family of water-striders, somewhat enlarged. These insects can be distinguished from the true water-striders by their comparatively short legs and broad prothorax. If you have any specimens of this fami- ly arrange them just after the true water-striders and below the follow- Fig. 89. — a broad- 1 , 1 shouldered water- ing label :— strider. Family Veliid^ (Ve-li'i-dae). The Broad-shouldered Water-striders. The Habits of Water-striders {School Work). — Write an account of what you have learned regard- ing water-striders. The Structure of Water-striders {School Work). — Select one of the true water-striders, prefer- ably a large one like that represented by Fig 88, and study the following parts. I. The body is covered with microscopic hairs, those on the lower side are longer and usually silvery white in color. These doubtless form a waterproof coating, and add much to the beauty of the insects, causing them to appear like white-bottomed boats when on the water. jIO INSECT LIFE. 2. The head is inserted in the prothorax up to the base of the eyes. The eyes, though small com- pared with those of the dragon-fly, are really quite large and prominent ; their shape and position are such that the insect can readily see in all directions. The antennse are long and consist of four segments. The beak arises from the forward end of the head ; when not in use it usually extends backward between the fore legs. It consists of four segments; the sec- ond segment, however, is quite short and liable to be overlooked. A bristlelike piercing organ can usually be seen protruding from the tip of the beak. Make a drawing of a side view of the head, show- ing the form of the head, eyes, antennas, and beak. 3. Study the position and form of the legs. The fore legs are placed well forward, and are stouter than the others ; they are used for seizing and hold- ing the prey. The middle and hind legs are placed far back, and are the chief organs of locomotion, the middle legs being used as oars and the hind legs as rudders. A striking peculiarity of the legs in the two families of water-striders is that the last segment of the tarsus is split at the end and the claws are in- serted in this cleft ; this is most easily seen in the stouter fore legs than in the threadlike middle and hind legs of the true water-striders. In the broad- shouldered water-striders it is easily seen on any of the legs. Make a drawing of the tarsus of one of the legs, showing this peculiarity. 4. Make a drawing of the lower side of the abdo- men, noting carefully the form of the segments near the caudal end. POND LIFE. Ill 5. Study all the specimens you have of water- striders and see if you can separate the sexes. The Whirligig-beetles {Field Work).~'^o lad who has loitered much by ponds or wandered along the margins of brooks with open eyes can have failed to see the whirligig-beetles, those social fel- lows that gather in large numbers and chase each other round and round in graceful curves with wonderful rapidity. These beetles are oval or ellip- tical in form, more or less flattened, and usually of a very brilliant, bluish-black color above, wath a metallic luster ; one of our common forms is represented by Fig. 90, but some of the smal- ler species are proportionally longer and more convex. Seek for specimens of whirligig-beetles on the surface of the ponds and streams in your locality and, when found, watch them carefully, note- book in hand, and record all that you can see of their ways. Take with you on this field trip some empty bot- tles, in which to bring home living specimens, and an insect net ; you will need the latter in catching these wary creatures. Note the peculiar odor emitted by the insects when caught ; this is caused by the milky fluid which the insects emit from various joints of the body, and is probably a means of defense. As these insects can be easily kept alive in aquaria, we will make a more careful study of their habits in confinement. Comparatively few whirligig-beetles can be found in the spring ; these are individuals that have sur- 112 INSECT LIFE. vived the winter. A new generation begins to appear early in the summer, and they are most abundant late in August or early in September. As cold weather comes on they disappear, bury- ing themselves in mud at the roots of water plants for their winter sleep. But they can be kept active in aquaria in warm rooms long after all have disappeared from the surface of ponds and streams. On your return from the field trip prepare an aquarium with sand or gravel in the bottom and a few water plants anchored in this soil. Put the living whirligig-beetles into this aquarium, and cover it so that the insects can not escape. Put in a killing bottle some specimens to be used for a study of the structure of these insects. The Structure of Whirligig-beetles {School Work). — I. Pin the specimens in your killing bottle, so that they may be easily handled without injury to them, putting the pin through the right wing-cover a short distance from its base. 2. Study the appearance of one of these insects when seen from above. Note that the hinder part of the body is covered by a pair of horny wing-cov- ers or elytra, which meet in a straight line along the middle of the back. This type of wing-covers is the mark "by which beetles are most easily recog- nized. 3. Study the head as seen from above and make a drawing of this view, showing the following parts : The upper lip — a horny fiap projecting from the ex- treme front end of the head ; the clypeus — a narrow piece extending crosswise between the upper lip and POND LIFE. 11^ the chief part of the head ; the antennge — these are unusually short and thick (Fig. 91 represents one of the antennae of a whirligig-beetle greatly enlarged) ; the compound eyes — these are quite prominent, and are situated a consider- able distance from the margin of the head. 4. Study the head as seen from below, a very remarkable thing will be seen — namely, a pair of large compound eyes in addition to the pair already observed on the upper side of the head. It should be said, however, that these insects really have only two compound eyes, like other insects ; but each eye is divided within the head, one part extend- ing to the upper surface of the head and the other to the lower surface. What peculiarity in the mode of life of the whirligig-beetles renders this arrangement of eyes desirable ? 5. Study the mouth-parts and observe that in- stead of a beak for sucking, as with the water-strid- ers, these insects have jaws fitted for biting. 6. Make a drawing of one of the front legs, and label the following parts : coxa, trochanter, femur, tibia, tarsus, claws. 7. The sexes of whirligig-beetles can be distin- guished by the fact that in the males the segments of the tarsus of the fore legs are flattened and furnished with a spongy cushion of hairs beneath, while in the females the segments are more nearly cylindrical and do not bear cushions. Separate the sexes of these insects in your collection. 8. Study the middle and hind legs and observe their strangely modified form. While the fore legs are oarlike in form, these are modified into short and 114 INSECT LIFE. very broad paddles. Fig. 92 represents the form of one of these. 9. Remove with a pin one of the wing-covers and observe the large membranous wing compactly folded beneath it. Although these insects are commonly seen only on Fig. 92. ^ water, they have good powers of flight, and migrate from pond to pond by means of their wings. I have taken them at electric lights far from any water. 10. The various kinds of beetles taken together constitute the order Coleoptera, and the whirligig- beetles form the family Gyrinidas of this order. Write the two following labels and place them above the whirligig-beetles in your collection : — Order Coleoptera (Co-le-op'te-ra). The Beetles. Family Gyrinid^ (Gy-rin'i-dae). The Whirligig-beetles. The Habits of Whirligig- beetles {^School Work). — Watch the living specimens that you have in an aquarium and learn all you can of their habits. The following are some of the points to be observed : Compare their attitude when at rest with that of a water-strider. Describe their method of locomotion. Describe their actions when frightened. Can you see any indications of their method of breathing when under water? How do they remain beneath the water? How do they rise to the surface? In what way do the beetles endeavor to escape from the water? Try to discover what they will eat — POND LIFE. 115 there is some difference of opinion among scientific writers on this point. After observing these insects at intervals for sev- eral days write an account of what you have learned regarding them. INSECTS THAT REST AT THE SURFACE BUT SWIM BENEATH. In our studies of pond life up to this time we have observed some of the insects that fi}^ over ponds and some that live upon the surface of water, but a far greater number of insects live within the water. Some of these are fitted for a purely aquatic life, but many find it necessary to come to the surface from time to time to get a supply of air. This latter class of insects, as a rule, rest at the sur- face in such a position that they have access to the air above the water, and only swim beneath when alarmed or when in search of food. It is this class of insects, those that rest at the surface but swim be- neath, that we are to study now. A Collecting Trip. — Provide yourselves with insect nets and a supply of empty bottles for bring- ing back living insects. Go to some pond or stream, and, resting quietly on the shore, try to observe some of the insects that live within the water but rest at the surface. If there is no convenient pond and you go to a stream for this purpose, choose the more quiet portions of the stream, and preferably the deeper pools and those in which plants are growing. Approach the water very quietly so as not to frighten the insects. Often when nothing is to be seen at first the observer will be rewarded by a sight of the desired objects if he will sit very still for a time. Il6 INSECT LIFE. After learning what you can by watching, sweep the vegetation beneath the surface of the water with your net, and in this w^ay collect as many kinds of insects as possible. Put the insects into clean bot- tles so that they may be kept alive. On your return prepare several aquaria with sand or gravel on the bottom and aquatic plants anchored in the sand ; if practicable prepare as many aquaria as you have kinds of insects, so that one kind shall not destroy another. But in order to observe pre- daceous insects capture their prey it is necessary to put other insects with them when you are ready to make the observation. After the insects have been placed in the aquaria you will soon be able to learn which ones belong to the class that rest at the surface but swim beneath. The Predaceous Diving-beetles {School Work). — If a collecting trip like that outlined above is a successful one, there are almost sure to be several kinds of beetles among the insects collected. These can be recognized by the horny wing-covers, w^hich meet in a straight line along the middle of the back. If we omit certain small beetles which are not likely to be studied by the beginner, the beetles collected in this way will represent only two families ; one of these families is the Dytiscidse, or predaceous diving- beetles. The members of this family can be recog- nized by the fact that when at rest they hang head downward with the tip of the abdomen at the sur- face of the water. Figs. 93 and 94 represent two of the larger members of this family. There are, how- ever, many small species, measuring less than one fourth of an inch in length, which can be found in POND LIFE. 11^ almost any pond. If you can obtain specimens of the larger ones, they will be best for the purposes of study. Some specimens should be kept alive in aquaria for a study of their habits, and some should be killed and pinned for a study of their structure. Place the pinned speci- mens when not in use in . Fig. 93. Fig. 94. your collection under a copy of the following label and immediately after the whirligig-beetles : — ^ Family Dytiscid^ (Dy-tis'ci-dae). T/ie Predaceous Diving-beetles. Whenever convenient to do so, watch the diving- beetles and learn all you can regarding their habits. Make a memorandum of whatever you learn ; the hints given on page 1 14 for the study of the whirligig- beetles will be useful here. As these diving-beetles are predaceous, they may be fed with other insects or bits of raw meat. If properly cared for, they can be kept alive in aquaria for a long time, even several years. The Structure of the Predaceous Diving- beetles {School Work). — Select for study specimens of the largest species of predaceous diving-beetles in your collection and observe the form of the following parts : — * No effort is made in these outlines to indicate a natural sequence of the families studied. It will be sufficient for the purposes of begin- ners to place each family under the order to which it belongs, placing first those studied first. IlS INSECT LIFE. 1. The body as a whole. Observe its evenly rounded outlines, and consider how well fitted it is for gliding through the water. 2. The antenucG. These are inserted immediately in front of the eyes, and are threadlike in form, each consistino- of twelve similar ses:- ments (Fig. 95). The form of the antennae is an important characteristic of these insects, for by it they can be distinguished from the Fig q:; ^vater-scavenger beetles, which they closely resemble in general appearance. 3. The hind legs. These are fitted especially for swimming, being long and more or less oarlike ; the tarsus is flattened and fringed with hairs, and the segments of it taper evenly from its base to the claws. ^lake a drawing of one of these legs. 4. The middle legs. These do not differ greatly from the usual form of the legs of insects, except that in the males of certain species the first three segments of the tarsus are much wider than the others and furnished with cushions beneath. 5. The fore legs. In the females these legs are also of the usual form. But in the males of our com- mon larger species the first three segments of the tarsus are dilated and form a circular disk, upon the under side of which are little cuplike suckers. These suckers differ in size and arrans^ement in different genera ; Fig. 96 represents a tarsus of Dytisais {Dy- tis'oiis). 6. Examine the fore legs of all of your pinned specimens of the larger diving-beetles and separate the sexes of each species. 7. If your collection is sufficiently full, you will POND LIFE. 119 be able to observe that in some species there are two kinds of females, one havins: smooth wino^-covers, and another in which the wing-cov- ers are furnished with a number of deep furrows (Fig. 94). 8. Study the eyes and compare them with those of the whirligig- beetles. . Fig. 96. 9. Kemove one wmg-cover and observe the large wing folded beneath it. These beetles can fiy well, and thus migrate from pond to pond. 10. Remove the wing and observe the spiracles or breathing holes on the back near the side of the body. 11. How do these insects breathe when under water ? The Habits and Structure of the Preda- CEOUS Diving-beetles {School Work). — Write an ac- count of what you have learned regarding these in- sects. The Water-tigers {Field and School Work). — These rapacious creatures are the larv^ of the pre- daceous diving-beetles, and are found in the ponds frequented by these beetles. In sweeping submerged plants for the pond insects already described one is quite apt to obtain water -tigers also. They are elongated, spindle-form grubs, with large sickle- shaped mandibles. Fig. 97 represents one of our larger species. Put the specimens that you collect into an aquarium in which plants are growing, so that the larvas can crawl to and from the surface 'easily. I20 INSECT LIFE. Learn what you can regarding the habits and structure of these larvae. Observe their favorite Fig. 97. — A water-tiger. attitude when at rest. Learn how they obtain air. Place other aquatic insects with them, and observe their predaceous habits and their method of sucking the blood of their victims. Note their methods of locomotion. In studying their structure, observe the peculiar form of their mandibles ; these are large, sickle- shaped, and hollow, with a slitlike opening near the tip. They are admirably fitted for holding the prey and at the same time sucking the blood from its body, as the hollow of the mandibles communicates with the mouth. Observe the spiracles along the sides of the abdomen ; these are used but little if at all during the larval stage. The last pair of spiracles are just beneath the tip of the last abdominal seg- ment ; it is throusfh these that the larva obtains its supply of air. Preserve one or more specimens in alcohol and put them with the predaceous diving-beetles in 3^our collection. The Water-scavenger Beetles {School Work). — The water-scavenger beetles are common in quiet pools, where they may be found swimming through the water or crawling among the plants growing on the bottom. If the collecting trip outlined on page POND LIFE. 121 Fig. 98. — A water- scaven- ger beetle. 115, was a successful one, there are probably speci- mens of these beetles in your aquaria ; but if you do not already have specimens, go into the field again and sweep plants growing beneath water with an insect net until you get specimens. Fig. 98 represents the largest ^ of our water-scavenger beetles ; 0 but we have in this country many ^ smaller species, and the majority of them measure less than one half inch in length. The members of this family differ in habits from other com- mon aquatic beetles by the fact that when they rest at the surface of the water they keep the head end of the body uppermost. The most easily observed difference in structure is in the form of the antennae. These are club-shaped (Fig. 99) ; they are inserted immediately ^^^^^^^ in front of the eyes, and are usually ^ concealed beneath the eyes and pro- N^ thorax. Care must be taken not to iG- 99- mistake the very long maxillary palpi for the antennae; these palpi arise from the side of the mouth, and are only three- or four-jointed. Select one of the larger species of water-scavenger beetles and make a study of living specimens in an aquarium, and of the structure of pinned specimens. Study especially the method in which they obtain air, and the manner in which they carry it when be- neath the water. 9 122 INSECT LIFE. Observe their food habits. These beetles are sup- posed to live chiefly upon decaying vegetation in the water, but some of them'have been known to feed upon other insects and upon snails. Arrange your pinned specimens under a copy of the following label and immediately after the Dyti- scidge : — Family Hydrophilid^ (Hyd-ro-phiri-dae). The Water-scavenger Beetles. The members of this family form cases in which the eggs are laid. Fig. lOO represents one of these cases attached to a leaf. If you find similar cases preserve them in your col- lection with the beetles of this family, or place them in an aquarium and try to rear the young. The Larvae of Water-scavenger Beetles {Field and School Work). — The larvae of the water -scavensrer beetles tiG. lOO. ^ live beneath the surface in ponds inhabi- ted by the adults, and may be captured by a sweep- ing net in the same way as the adults. As the}^ thrive well in aquaria, their habits can be easily observed. They bear some resemblance to water-tigers (Fig. 97), but they can be distinguished from them by the following characters: the body is more plump; the mandibles are not so slender, are not tubular, and are usually furnished with one or more teeth ; and the abdomen, in all the species that I have studied, is furnished with backward-projecting spines or with filaments, or with both. Study the habits of these larvae. Observe the POND LIFE. 123 method of respiration, the ways of locomotion, and the nature of their food. Offer them both livins: and dead insects, snails, and meat. Preserve one or more larvse in alcohol, and put them with the adults in your collection. The Back-swimmers (School J>F^r/^).— When the different kinds of insects that you have collected by sweeping submerged plants have been placed in aquaria, you will be able to recognize the back-swim- mers by the fact that they swim up- side down. One of these insects is represented back uppermost by Fig. lOI. The back-swimmers love to float at the surface of the water. Here they hang motion- less, back downward in a slanting position, with the tip of the abdomen at the surface, and the head con- siderably submerged. When in this position the fore and middle legs are slightly bent, so that the claws are at the surface, as if the insect were clinging to the ceiling of its room ; while the longer, oar-like hind legs are nearly straight, and project down into the water somewhat ; here they are held in the posi- tion of the beginning of a stroke, as if the creature were waiting for the word go ; and they can go quick- ly and rapidly like an expert sculler. Often they will swim to the bottom of the pond, where, clinging to a stone or plant, they will rest quietly, apparently as much at home as when at the surface. In their journeys from one part of the aquarium to another, they are forced to keep their oars in con- stant motion. For these topsy-turvy creatures carry a load which is so light that the moment they stop 124 INSECT LIFE. rowing they fall upward. This load is a film of air, which can be seen shining through their wings like burnished silver. Knowing this, we can under- stand how the back-swimmers can remain so long at the bottom of the aquarium without strangling. Occasionally these insects v/ill float on the surface of the water with the back uppermost ; when in this position they can leap into the air from the water and take flight. It is necessary, therefore, to keep aquaria containing them covered, in order to prevent their escape. Let us study these creatures more closely : 1. Kill two or three specimens by putting them into a cyanide bottle. In handling back-swimmers care must be taken or they will inflict painful stings with their sharp and powerful beaks. 2. When those in the killing bottle are dead, pin them so that they can be handled conveniently. Put the pin through the three-cornered piece on the mid- dle of the back (the scutellum), so as not to fasten the wings down. 3. Hold the insect back downward and note the boat-shaped form of the body, the middle of the back representing the keel. 4. Study the head and observe the following parts : The eyes — these are very large, and each has two large scallops in the outer (lateral) side. The antennae — these are often so concealed that it is diffi= cult to see them ; each is situated just behind that scallop of the eye of the same side which is nearest the mouth. The beak — this projects backward be- tween the legs. What insects already studied have similar mouth-parts ? To w^hat order do they belong ? POND LIFE. 125 5. Study the legs and observe that the fore and middle legs are furnished with claws, and are fitted for clinging to plants and stones and for seizing prey, while the hind legs are destitute of claws and are fitted for swimming. Make a drawing of one of the hind legs, also one of a fore or middle leg. 6. Study the wings. These are closely folded over the back of the abdomen. The fore wings are thick and heavy at the base, while the tips are thinner and overlap. This type of wing is found only in the order Hemiptera or bugs. Carefully spread the fore wings apart with a pin and observe the hind wings, which are beneath them ; these are very thin and transparent ; they are stiffened by a few stout veins, and are folded lengthwise on the back of the abdo- men ; in a recently killed specimen they can be spread with a pin. Like most other pond insects that we have studied, the back-swimmers can leave the water and fly to some other pond if they do not like their surroundings. They do not have this free- dom, however, until they are grown up. Early in the summer back-swimmers are found that have no wings ; these are the young ones, the nymphs, on which the wings have not yet grown. If you have wingless specimens in 3^our collection, label them Nymphs. 7. Study the belly side of the abdomen. Along the middle line there is a prominent ridge which is thickly clothed with hairs, and, on each side between this ridge and the edge of the body there is a deep furrow. Along the upper edge of the outside of this furrow, and a short distance from the side of the body, there is a fringe of long hairs. Wet a pin and 126 INSECT LIFE. with it carefully brush these hairs toward the side of the body so as to uncover the furrow. When this is done there can be seen on the sloping outer side of the furrow a small hole in each of the segments of the abdomen ; these are the spiracles or breathing holes. Note that the ridge on the middle of the belly ends behind in a sharp, projecting point ; and that on each side the edge of the body bearing the fringe of hairs also ends behind in a similar point, between which and the tip of the abdomen there is quite a space. This space serves as an opening to an air-chamber between the wings and the abdomen. 8. Take from the aquarium two or three living specimens and put them into a tumbler which is nearly filled with water. Be careful not to be stung while doing this. 9. While a specimen is resting quietly at the sur- face of the water, study it with a lens. Make a draw- ing showing the arrangement of the hairs on the abdomen of the living specimen while in the water; this arrangement is very different from that seen on the pinned specimens already studied. 10. Observe, on the living specimen in the water, the hole near the tip of the body through which the air passes into the chambers beneath the fringes of hairs and into the air-chamber between the wings and the abdomen. 11. Study the pinned specimens again, and make sure that you understand how the air can pass to the chambers referred to in the preceding para- graph. 12. On the pinned specimens study the first ab- dominal segment on the belly side, and observe the POND LIFE. 127 little furrow on each side ; these are air-passages extending- between the chambers on the belly side of the abdomen to that beneath the wings. (In addition to the spiracles in the abdomen there are spiracles in the thorax ; but as these are exceed- ingly difficult to find, they will not be described here.) 13. Observe living specimens in water and note that they carry air among the hairs on the lower side of the thorax, and in the spaces between the head and prothorax and between the prothorax and the mesothorax. In fact, a large part of the body is en- veloped with air. But the most capacious air-cham- bers are those inclosed by the fringes of hairs on the belly side of the abdomen. It is to the buoyant ac- tion of the air in these that the insect owes its pecul- iar position in the water. 14. If you will watch with a lens living specimens in a glass of water you will be able to see them force the air out of the chambers beneath the fringes of hair, using their hind legs for this purpose, and sometimes an entire fringe will be lifted like a lid. 15. Watch living specimens as they rise to the surface from the depths of the aquarium, and see how they bump against the surface film. 16. Throw living flies into the water where the back -swimmers are and see what the back -swim- mers will do. If flies are abundant in the room, observe the fate of those that come to drink from the water. 17. Kill and pin several specimens of each species of back-swimmers that you have collected, and ar- range them in your collection under a copy of the 128 INSECT LIFE. following label, and immediately after the water- striders, for these insects also belong to the order Hemiptera : — Family Notonectid^ (No-to-nec'ti-dse). The Back-sivimmers. An Essay on Back- swimmers {School Work). — Write an account of what you have learned regard- inof back-swimmers. The Water-scorpions (Field and School Work). — Among the strange insects that live in ponds, but come to the surface to obtain air, are the water-scor- pions. These are not so com- mon as the back- swimmers, but as they are found in simi- lar situations, there may be specimens among those insects in your aquaria collected by sweeping the stems of sub- merged plants. If not, search for them in the places whereback- swimmers are found. There are two quite different kinds of water- scorpions in this country. In one of these, called Nepa (Ne'pa), the body is flat and broad (Fig. 102) ; in the other, called Ranatra (Ran' a-trci), the body is long and very slender (Fig. 103). In both, the hind end Fig. 102. POND LIFE. 29 of the body is furnished with a pair of long, slender, horny appendages. Each of these is grooved on the inner side, so that when they are held together they form a tube through which air can be drawn. They are represented in this position in the figure of Ncpa and separate in that of Ranatra. Another interesting feature in the structure of water-scorpions is the form of the fore legs. These are fitted for grasping, and are of such form that each is a complete organ by itself. The coxa is long (in the case of Ranatra it is very long, so that it ap- pears like a femur), and the femur is furnished with a groove into which the tibia and tarsus fit like the blade of a pocket-knife into the handle. The resemblance in form to a scorpion is quite striking in the case of Nepa (Fig. 102), but it is much less so with Ranatra. If you succeed in obtaining water-scorpions, keep them in an aquarium and observe their habits. Study their method of obtaining air, the way in which they seize their prey, their modes of locomotion, and any other features of their life history that you can observe. The body of Nepa is very flat, enabling the insect to hide beneath stones and rubbish on the bottom of ponds. With Ranatra the slender form of the body and the dirt with which it is usually covered causes the insect to resemble a dirty stick. This resem- blance doubtless aids the insect greatly in the cap- ture of its prey. Adult water-scorpions have well-developed wings which reach nearly to the end of the abdomen ; if you find wingless individuals, or some with short wing-pads, label them as nymphs. I30 INSECT LIFE. The water-scorpions belong to the order Hemip- tera. Place your pinned specimens under a copy of the following label and immediately after the back- swimmers : — • Family Nepid^ (Nep'i-dae). The Water-scoi'pions. The Giant Water-bugs {Field and School Work). — These are common insects in quiet ponds. Fig. 104 represents one of the larger species, and Fig 105 a smaller one. All of them can fly well in the adult state, and some are frequent- ly attracted to lights in great numbers. These are known in some parts of the country as " electric- light bugs." The mem- bers of this family are pre- daceous. Their fore legs are fig. 105.— Giant fitted for seiz. -=""-b"s.^-''-- ing prey and resemble somewhat those of the water- scorpions. These insects can be easily kept in aquaria and are good subjects for study. The outlines already given for the study of other pond insects will afford suggestions for work on these. A striking feature in the life history of many of the giant water-bugs is Fig. 104. — Giant water-bug', Belostoina. POND LIFE. 131 that the female fastens her eggs on the top of her own back with a thin layer of w^aterproof glue, which she secretes for this purpose. Fig. 106 represents a species found in the far West. The pinned specimens in your collection should be placed after the water-scorpions under a copy of the following label : — Family Belostomid^ (Bel-os-tom'i-dae). The Giant Water-bugs. Fig. 106. — Female, with eggs, Serphus, The Wrigglers {Field Work).— The wrigglers, or " wigglers," as they are more commonly called, are so well known that it is hardly neces- sary to describe their form that they may be rec- ognized. They abound through- out the warmer part of the year in ponds, in ditches choked with fall- en leaves, and in pools in swampy places. But usu- ally they are most Fig. 107. — A glass of water containing eggs, larvae, CaSlly lOUna lU CX- and pup^ of mosquitoes. ^^^^^ rCCCptaclcS of rain-water, in watering-troughs, and in other sim- 32 INSECT LIFE. ilar places. There are two forms of them : one are the larvse of mosquitoes, the other the pupge of the same insects ; both are represented in Fig. 107. Collect some wrigglers and put them in a glass of water where you can observe them. This aquarium should be kept covered when jou are not studying the insects in it. The Larv^ of Mosquitoes {School Work).— In the study of wrigglers begin with the larvae ; these are of the form shown at a in Fig. 108. 1. Note that when a larva is at rest it hangs from the surface with its head down ; several are shown in this position in Fig. 107. 2. Note that when a larva is disturbed it swims away with a wriggling motion or quietly sinks toward the bottom. 3. Note that a larva can sink without any appar- ent effort, while in order to regain the surface it is forced to exert itself violently. Evidently the body of the insect is heavier than water. 4. Let us see if we can discover the means by which the larva keeps itself at the surface without any effort, although the body is heavier than water. Note that the true hind end of the body, the last abdominal segment, is not at the surface, but is turned to one side, and that what really reaches the surface is the end of a tube borne by the next-to-the- last segment. This is the breathing-tube of the larva. If the pupil has the use of a microscope, a larva should be mounted on a glass slip and the structure of this breathing-tube examined. It will Fig. 108. — Mosquitoes. a, larva ; b, pupa. POND LIFE. 133 be found to bear at its hinder-end a rosette of five platelike lobes ; this is shown at a in Fig-. 109. This rosette can be seen imperfectly with a good lens. When a larva reaches the surface it spreads out the rosette upon the surface film, w^hich buoys it up in the same way that we have seen a needle supported by this film (see experiment i, pag-e 104). The body fig. 109.— «, end of f 1 , -1 ^'^ ^ i • breathing- tube of 01 the larva is only slightly heavier larva; ^ breath- than the water, and the buoyant effect -g-t"be of pupa. of the surface film on the rosette is sufficient to over- come this difference. 5. Consider the adaptations in structure to the mode of life of this insect : The form of the respira- tory tube enables it to rest at the surface of the water, where it can get a supply of air, w^hile the greater weight of the fore end of the body causes it to hang down into the water in a position suited to collect- ing the minute particles of decaying vegetation scat- tered through the water and upon which the insect feeds. This position is also one that enables the in- sect to start quickly on its wriggling journey when alarmed. 6. If the student has the use of a microscope, it will be well for him to make at this point a larger r.nd more detailed figure of a larva than that given above, which was introduced merely to show the general form of these insects in this stage. The Pup^ of Mosquitoes {School Work).— The larvas of mosquitoes develop rapidly, and after a few molts change into club-shaped pupas, the head and thorax being greatly enlarged in this stage. The J 34 INSECT LIFE. general form of the pupse is shown at b in Fig. io8. Usually larvas and pupae are found at the same time, but if you have only larvse you can obtain pupse by keeping the larvae in water till they trans- form. 1. Note and describe the differences between the larvae and the pupse in the following respects : The form of the body. The position of the insect when at rest. The number and position of the breathing- tubes. (The structure of a breathing-tube of a pupa, as seen through a microscope, is shown at b in Fig. 109.) 2. Note that the pupae of mosquitoes are active, swimming with a wriggling motion similar to that of the larvae. It is a very unusual thing for insects that have a complete metamorphosis (see page 35) to be active in the pupa state. 3. Observe the wing-pads on the sides of the thorax, also the leaflike appendages at the tail end of the body, with which the insect swims. 4. If you have an opportunity to do so, study the pupa with a microscope and make a large, detailed drawing of it. 5. How does the pupa make use of the surface film of water? The Emergence of Mosquitoes. — The pupa state of mosquitoes lasts only a few days, then the skin splits down the back, and the winged mosquito carefully works itself out and cautiously balances itself on the cast skin, using it as a raft, until its wings are hardened so that it can fly away. Collect many wrigglers, and, keeping them in water, try to observe the emergence of the adult. POND LIFE. 135 Adult MosQUixoES.—The form of mosquitoes is very well known, but there are certain mosquitolike insects that are liable to be mistaken for members of this family. Mosquitoes differ from these, however, in having a fringe of scalelike hairs on the margin of the wing and also on each of the wing-veins. Fig. '-•tlVlii'll'iltipi Fig 1 10. — Wing of mosquito. 1 10 represents the wing of a mosquito as seen through a microscope. The sexes of mosquitoes can be distinguished by the form of the antennae ; at m in Fig. in is repre- sented the antenna of a male, and/ the antenna of a female. It is only the females that sing and bite ; the males are mute and live on the juices of plants. The eggs are laid side by side in a boat-shaped mass on the surface of the water. One of these is repre- sented floating in Fig. 107. By col- lecting a mass of this kind and putting it in a vessel of water, the complete life history of these insects can be observed. Mosquitoes belong to the order of two-winged insects or flies. Collect some adults and, if you have very slender pins, pin them ; if not, mount them on Fig. Ill of mosquitoes, m, male ; /, female. 136 INSECT LIFE. cardboard points. Copy the following labels, and arrange your specimens under them : — Order Diptera (Dip'te-ra). The Flies. Family Culicid^ (Cu-lic'i-dae). The Mosquitoes. Write up the life history of a mosquito, and place specimens of the eggs, larvae, and pupse in alcohol in your collection with the adults. INSECTS THAT REST AT THE BOTTOM. As a rule, it is rather difficult to watch in the field the habits of insects that live at the bottom of ponds; but in most cases these insects can be kept in aquaria, and there studied without difficulty. By searching ponds or the quiet portions of streams, some of these insects may be seen crawling over the bottom, and can then be taken with the hand. But a more rapid way of collecting them is by sweeping the bottom of the pond and submerged plants with an insect net. If the work outlined in the preceding pages has been carried out, it is more than probable that some of these insects are al- ready in your aquaria. If not, seek for them in the field. The Habits of Water-boatmen {School Work). — These are oval, gray and black, mottled bugs, usually less than half an inch in length ; they occur in the streams, ponds, and lakes of the whole United States. The characteristic form and markings of these in- sects are shown in Fig. 112. Very little difficulty will be had in finding these insects in almost any lo- POND LIFE. 13^ cality where there are ponds of water, and thej are very easily kept in aquaria. 1. Remove a few specimens from the aquarium, and place them in a glass of water in the bottom of which there is a layer of gravel or small pebbles. If several specimens are placed in the glass, some of them may come to rest near enough the side of the glass so that they may be studied with a lens. 2. Note that the favorite at- ^_ Fig. T12. titude of a water-boatman is clinging to a pebble at the bottom of the aquarium by the tips of the middle legs, with the fore legs bent up under the head and the hind legs stretched out sidewise like oars. This is a very different at- titude from that assumed by their near relatives, the back-swimmers. 3. Note that there is a thick layer of air covering the entire belly or ventral side of the body. Some- times this layer of air extends down the legs nearly or quite to the ends of the coxse, and often there is a strip of air on the outside of the outer edge of each upper wing. The spaces between the head and pro- thorax, the prothorax and mesothorax, and between the wings and abdomen are also filled with air. These masses of air can be seen when the insect bends its body. 4. By watching these insects carefully, you will be able to see that sometimes one will lift its wings slightly, thus drawing the air from the ventral side of the body up under the wings ; and, on the other 138 INSECT LIFE. hand, they frequently rub their hind legs down their backs, thus forcing the air from under the wings to the ventral surface of the body. 5. Note that while a water-boatman is resting near the bottom of the aquarium, it frequently moves its oarlike hind legs backward with a quick sweeping motion, causing a current of water to flow over the layer of air on the ventral side of the body. Although the water-boatmen breathe air, w^hich they carry with them in a way very similar to that of the back-swimmers, they are able to remain under water without going to the surface to renew the sup- ply of air for a very long period. This, I think, is explained by the fact that the air on the lower side of the body and along the outer edge of the wing- covers is in direct contact with the water, so that it can be purified by the air that is mixed with the water. And probably it is to insure this purification of the layer of air that the insect causes a current of water to flow over it by the sweeping motion of its hind legs. This also explains the reason for forcing the air out from under the wings and drawing it back again. Sometimes, however, the insects dart to the sur- face and return to the bottom as if going after a fresh supply of air ; but the movement is so rapid and the stay at the surface is so short that I have been unable to determine the manner of taking the air. 6. Observe the mode of life of these insects as completely as possible, and write an account of them. The Structure of Water-boatmen {School Work). — Kill and pin some specimens, and study their structure. POND LIFE. 139 1. Note that the head overlaps the prothorax in- stead of being inserted in it, as is usually the case with insects. 2. Observe the very large, three-cornered eyes. The antennas are very small, and are concealed under the backward-projecting edge of the side of the head. 3. Observe the lower part of the front of the head ; it tapers to a blunt point, but it is not pro- longed into a slender beak, as is usual with bugs ; near the tip of the head there is a small opening, through which the sucking mouth-parts are pushed when in use. 4. The prothorax is conspicuous above, and is marked by transverse stripes ; on the sides it is very short, and below it is almost completely covered by the head ; this brings the fore legs very near to the mouth. 5. Make a drawing of one of the fore legs ; note that the tarsus consists of a single segment, is scoop- like in form, and bears a comblike fringe of bristles. 6. Make a drawing of a middle leg, and note the very long, slender tarsal claws. What is the use of these claws? 7. Make a drawing of a hind leg. What are these legs fitted for ? 8. Study the lower side of the abdomen of sev- eral specimens. In the females the segments are of the usual form, but in the males some of them, and especially the last four, are very unsymmetrical, being, upon one side, broken into irregular-shaped frao;-ments. The cause of this is not known. 9. Indicate by labels the sexes of your pinned specimens. I40 INSECT LIFE. lo. Place the pinned specimens in your collection with the Hemiptera under a copy of the following label :— Family Corisid^ (Co-ris'i-dae). The Wate7'-boatmen. The Nymphs of Damsel-flies {Field Work). — The nymphs of damsel-flies are truly aquatic, having gill-like organs which enable them to live in water without coming to the surface from time to time for a supply of air. They may be found in those ponds or streams about which the adults fly, and are most abundant among the stems of submerged plants. Fig. 113 will enable you to recognize these insects when found. CoUectspecimens of these nymphs and place them in aquaria for study. The Habits and Structure OF THE Nymphs of Damsel-flies {School Work). — The nymphs of dam- sel-flies are easily reared in aquaria in which the water is kept pure by growing plants. Frequently tiny ones will appear in such aquaria from eggs that were in the stems of the plants when they were collected. In such cases it is easy to watch the entire life history of the insect after it leaves the Qgg. We will not outline such a study, for the pupil who has made the observations on pond life already indicated will be able to direct his own studies ; and independent original observations are much more Fig. ii^. — N^'inph of damssl-fly. POND LIFE. 141 enjoyable than prescribed work. We will, however, explain two striking peculiarities in the structure of these insects : 1. Remove the nymph from the water and exam- ine its mouth-parts. The lower side of the head will be seen to be covered by a broad flap ; this is the greatly developed lower lip or labium, and is termed in these insects the mask. With a pin lift the end of the mask away from the head, and observe that it is very long and is hinged in such a w^ay that it can be pushed out a considerable distance in front of the head. Note also that it is furnished with hooks at the end. This is the organ by which the nymph seizes its prey. Try to observe the nymphs in your aquarium catch other insects. A similar organ is possessed by the nymphs of dragon-flies, and is represented in Fig. 115. 2. Observe the leaflike organs at the hind end of the body. These are the tracheal gills, the organs by means of which the insect breathes during its life in the water. Fig. 114 represents a tracheal gill of a damsel-fly greatly enlarged. These organs are called tracheal gills because the tracheae or air- vessels extend into them, and the air con- tained in the tracheae is purified by the water (or rather by the air in the water) that bathes the gills. While with true gills, as those of ^^^- "4- fishes and lobsters, etc., the gill contains vessels car- rying blood to be purified. 3. Preserve specimens of nymphs of damsel-flies in alcohol and put them in your collection with the adults. 1^2 INSECT LIFE. 4. Write an account of what you have learned about these insects. The Habits and Structure of the Nymphs OF Dragon-flies {Field and School Work). — The nymphs of dragon-fiies are found in the same situa- tions as those of damsel-flies ; they are also found crawling over the bottoms of ponds and streams where there are no plants growing. They vary greatly in form, some being slender while others are very broad. They resemble the nymphs of damsel- flies in having a mask and in their use of this organ ; but they differ in lacking the external tracheal gills. Fig. 115 represents one of these nymphs. Collect specimens of these nymphs and place them in aquaria for study. Also preserve some in alcohol in your collec- tion with the adult dragon -flies. When P^^ ^^ collectingthese, search for cast skins along the shores of the pond or stream. Preserve speci- mens of the cast skins in your collection. We will call attention to only one feature in the structure and habits of these creatures, leaving the pupil to discover other things for himself : The nymphs of dragon-flies possess tracheal gills of very unusual form. These are situated within the body, and consist of a large number of tracheae rami- fying in the walls of the hind part of the intestine — the rectum. The nymph drawls water into this part of the intestine through the opening at the hind end of the body ; and this water, bathing the walls of the rectum, purifies the air in the tracheas POND LIFE. 143 in the same way that the air in the trachese of an ordinary tracheal gill is purified. By watching a living specimen it can be seen to alternately draw in the water and force it out again. This arrangement serves as an organ of locomo- tion as well as an organ of respiration. For the insect, by suddenly forcing out the water from the rectum, can cause itself to shoot forward. The jet of water forced out from the rectum when the insect jumps forward is most easily seen when the insect is on the bottom of the aquarium ; in such a case the fine dirt will be disturbed by it for a considerable distance back of the insect. If you can find a large number of nymphs of dragon-flies, do so, and, keeping them in aquaria, try to observe the emergence of the adult. Of this Tennyson wrote : To-day I saw the dragon-fly Come from the wells where he did lie, An inner impulse rent the veil Of his old husk ; from head to tail Came out clear plates of sapphire mail. He dried his wings : like gauze they grew, Through crofts and pastures wet with dew A living flash of light he flew. CHAPTER V. BROOK LIFE. N a deep ravine, where a hill stream tumbles down a stairway of rocks, is one of our favorite resorts on Satur- days. A dense forest growth covers the sides of the ravine, and shuts out all the world besides ; but at midday, when the sun shines brightly, the light streams down through the narrow opening above the creek. This is the time to watch the ways of the crea- tures clinging to the rocks in the rapids, or living in the quiet pools below. Many a holiday have we waded up this stream, bottles and lens in hand, coaxing Nature to yield up some of her secrets. ' Here we have watched the caddice-worms drag their log houses over the bottoms of the pools ; here the brinks of the falls bear great patches of a living carpet of wriggling black-fly larvse ; and here we discovered how the net-winged midges leave the water, unfold their wings, and take flight. It is a rich collecting field ; the cool, pure water of the brook and the rush of the torrents affording a home 144 Plate VI. A BROOK. BROOK LIFE. 145 for many creatures that can not live in the warmer and more quiet streams of the valley below. In the following pages are mentioned some of the insects that may be found in similar streams — that is, in streams flowing rapidly over stones. Most of these insects occur rarely or not at all in quiet, sluggish streams, flowing over sandy bottoms, through level stretches of country. In such streams are found the insects described in the chapter on Pond Life. In our hill stream, too, there occur many of the pond insects, for during its course there are quiet bays and broad, still waters, which seem perfectly suited to their needs. Little brook, sing to me : Sing about a bumblebee That tumbled from a lily- bell, and grumbled mumblingly Because he wet the film Of his wings, and had to swim, While the water-bugs raced round and laughed at him ! Little brook, sing a song Of a leaf that sailed along Down the golden-braided center of your current swift and strong, And a dragon-fly that lit On the tilting rim of it. And rode away and wasn't scared a bit. James Whitcomb Riley. ^ INSECTS THAT LIVE BENEATH STONES IN RAPIDS. There is no collecting field that is more certain to yield returns than the bed of a rapidly flowing stream of pure water. Lift the stones from such a * From Old-fashioned Roses, by permission of the Bowen-Merrill Co. 146 INSECT LIFE. Stream at any season of the year and you will find nymphs and larvae of various kinds clinging to their lower surface. If before lifting the stones you will place a net in the stream just below^ them, other in- sects that live beneath the stones will be swept into it by the current. A great variety of insects live in such places, the kinds differing in different localities. But there are certain families that are almost sure to be represented in any rapidly flowing stream ; they are the stone- flies, the May-flies, and the caddice-worms. These and a few others are described below. Most of these insects are not easily kept in aquaria without running water. But if you can place an aqua- rium under a faucet, and keep the water from over- flowing by the use of a constant-level siphon (see page 331), you may be able to preserve living speci- mens for study. If vou are unable to do this, study the insects as well as you can in the field, and bring back speci- mens for your collection and for a study of their structure. The Nymphs of Stoxe-flies [Field and School Work). — In most localities the insects that occur in greatest numbers on the lower side of stones in the beds of streams are the nymphs of stone-flies, and it was probably this fact that suggested their common name. Usually the first stone lifted from a riff will be found to bear several of these insects clinging to it, or scurrying over its surface in their efforts to escape. When at rest the very flat body is closely applied to the stone, while the legs, antenuce, and caudal setce radiate from it on the surface of the BROOK LIFE. 147 stone. In our common forms there is a tuft of hair- like tracheal gills just behind the base of each leg, and the more mature individuals have conspicuous wing-pads (Fig. 116). These general characteristics will enable the pupil to recognize these insects. Specimens should be collected and taken to school for a more careful study of their structure. Look also for empty nymph skins ; these will be found clinging to stones and other ob- jects on the shores of the stream, where they were left when the adults emerofcd. Pin the empty nymph skins and preserve the nymphs in al- cohol. Put both in your collec- tion with the adult stone-flies (see page 103). In the study of the structure of these insects note the follow- ing : The nymphs resemble the adults to a consid- erable degree, except that they lack wings. The order Plecoptera, or stone-flies, is a good example of those orders, the members of which undergo an incomplete metamorphosis. The body is greatly flattened ; in this way the insect is well fitted for creeping under stones. The legs are flattened and fringed with hairs, fitting the insect for swimming as well as for creeping. The tarsi are each furnished with tzvo claws. The organs of special sense are well developed, there being large compound eyes, three simple eyes, and long antennge. The mouth is fur- FlG. 116. — Nymph of stone-fly. 148 INSECT LIFE. nished with strong, toothed mandibles (it is some- times necessary to cut away the upper lip in order to see them well), and the caudal end of the body is furnished with two large setae. The number and position of the tufts of tracheal gills differ in different species. The nymphs of stone-fiies are carnivorous. ^ The Nymphs of May-flies {Field and School Work). — These are also found beneath stones in the beds of rapidly flowing streams, but they also oc- cur in many other situations. Some live in the banks of streams, where they excavate burrows for shelter; others live in slowly moving waters and conceal themselves by covering the body with mud ; and still others swim among water plants. But in regions where there are rapidly flowing streams, those that live under stones will be most easily found. As a rule, the body is not flattened to so great an extent as with the nymphs of stone-flies ; the tracheal gills are usually more or less platelike in form, al- though sometimes they are threadlike and tufted ; and the tarsi end in a single claw. Fig. 117 represents one of our most com- mon species. Study the structure of a nymph, and compare it with that of the nymph of a stone-fly. Fig. 117.— Preserve specimens in alcohol, and put ^Ai^y^fl?^ them in your collection with the adult May- flies (see page loi). The Caddice-WORMS {Field and School Work).— When the writer was a lad, before he had heard of BROOK LIFE. 149 Nature study — before the study of insects except as a part of zoology was taught in any school in this country — he began his study of caddice-worms. It was not a thorough study — in fact, he w^ould have been surprised to have heard it called study at all. To him it w^as fun, after a long tussle with a hard Latin lesson, to run over the long bridge across the river and on to the swamp near the lake where the Azaleas blossomed, and to lie face down on the bank of a stream and watch the curious worms that had tiny log houses about their bodies. It was his first introduction to a field of study that has since happily occupied the greater part of his time for several decades. Probably for this rea- son he always expe- riences a thrill of pleasure when he is permitted to intro- fig. 118. duce these little architects to other Nature-loving youngsters. This was a sluggish stream, and the caddice- worms found there built cases of fragments of partly decayed wood, like that shown in Fig. 118. Later, in another quiet stream where grass was growing in the water, there were found other cad- dice-worms, which built cases having: a still greater resemblance to log houses. These cases were composed of tiny lengths of grass laid crosswise (Fig. 119). They iG. 119. ^j.g rough-appearing structures, but within they are smooth and lined with silk — an excellent protection to the soft-bodied larvae that occupy them. Caddice-worms, like either of these described I50 INSECT LIFE. above, can be kept in aquaria, and are excellent sub- jects for study. In swiftly flowing streams, and especially in those in which the water is cool, there may be found many other kinds. Several of these build cases of small stones or grains of sand. Some of the cases are very regular in form ; others consist of a central tube with large stones fastened on two sides of it (Fig. 120); Fig. 120. Fig. 121. Fig. 122. and one kind, built of fine sand, is coiled so as to resemble the shell of a snail (Fig. 121). In all of these the material of which the case is made is fastened together by silk, which the larvas spin from the mouth in the same manner as caterpil- lars. In some species the case is composed entirely of silk. Fig. 122 represents the form of such a case made by a larva that lives among eel-grass in a lake. Before transforming to pupas, the caddice-worms partly close their cases so as to keep out intruders, but openings are left for the inflow of water for breathinsf. The adults are known as caddice-flies ; they are mothlike insects, which are often attracted to lights at night. Fig. 68, page 79, represents one of them. Collect as many kinds of caddice-worms as possi- ble. Keep alive some of those that will live in aquaria, and study their habits. Remove some from their cases, and study their BROOK LIFE. 151 structure. Note especially the following : The great length of the legs, which enables the larva to pull itself along without exposing much of its body ; the firmer covering of the fore part of the body which is exposed while the insect is walking ; the softer texture and paler color of the protected parts of the body ; the number, form, and position of the tracheal gills ; and the hooks at the hind end of the body by which the larva holds itself within its case. Preserve larvae with their cases in alcohol, and mount empty cases on cards. Try to rear pup2e and adults from larvas kept in aquaria. Place specimens of larvas, cases, pupse, and adults in your collection under a copy of the following label :— Order Trichoptera (Tri-chop'te-ra). The Caddice-flies or Caddice-worins. Write an account of your observations on these insects, and illustrate it with sketches of their cases. The Net-building Caddice-worms {Field a^id School Work), — In lifting stones from a stream where the current flows swiftly, the collector often finds attached to the lower side of the stones little masses of pebbles which are fastened to each other and to the larger stone by threads of silk. These are the homes of the net-building caddice-worms. Pull these rude habitations apart and the owners will be found in more or less perfect tubes of silk. Very little respect for the architectural skill of these builders is commanded by their dwellings. But if one looks a little farther something will be found that is sure to excite admiration. The dweller with- 152 INSECT LIFE. Fig. [23. — Net of a net-building caddice-worm. in this rude retreat is a fisherman, and stretched be- tween two stones near-by can be seen his net. This is made of silk. It is usually funnel-shaped, opening up-stream, and in the center of it there is a portion composed of threads of silk extending in two directions at right angles to each other, so as to form meshes of surprising regu- larity. It is as if a spider had stretched a small web in the water where the cur- rent is swiftest (Fig. 123). These nets occur in rap- ids between stones, but in many places they are to be found in greater numbers along the brinks of falls. Here they are built upon the surface of the rock, in the form of semi-elliptical cups, which are kept distended by the current. Much of the coating of dirt with which these rocks are clothed in summer is due to its being caught in these nets. It is usually difficult to procure specimens of these nets for preservation ; sometimes, however, one can be found attached to the surface of a single small stone or to a piece of wood in such a way that it can be removed from the water without injury to it. Find some net-building caddice-worms and learn all you can regarding their ways ; collect specimens for your collection and for study ; compare their structure with that of other caddice-worms ; pre- serve specimens of larvas in alcohol ; and dry, if pos- sible, some of their nests and nets. Write an account of these insects. BROOK LIFE.. 153 Fig. 124. — A wa- ter-penny. The Water-pennies {Field J^^^r^).— These are strange larvae, which are rarely recognized as insects by the young collector. They are very flat, circular in outline, and about five sixteenths of an inch in diameter. They are found clinging to the lower surface of stones in rapid streams. Fig. 124 represents one greatly enlarged. They are larvag of beetles of the genus Psephenus {Pse- pJie'niis), and are merely mentioned here so that the stu- dent of brook life may know what they are. The Dobson or Horned Co- RYDALIS {Field Work). — If a net or a wire screen be held with one edge close to the bottom below some stones lifted with a hoe or garden rake, many of the insects living under the stones will be swept into the net or upon the screen, and can thus be captured. One of the insects that is often caught in this way is the dobson, the ugly creature represented by Fig. 125. This larva is well known in many parts of the United States, as it is used extensively by anglers for bait, especially for bass, and in spite of its dis- agreeable appearance it is in some respects very in- teresting to students of Nature study. Fig. 125. — The dobson. 154 INSECT LIFE. It will not thrive in an ordinary aquarium, but it can be kept alive in one through which there is a current of well-aerated water flowing. If such an aquarium is lacking, specimens can be kept alive on damp sand or in a box with freshly cut grass, for this is a truly amphibious species. As this insect lives nearly three years in the larval state, larvse can be found at any season of the year. In the latter part of May or early in June the full-grown larvse leave the water, and each makes a cell under a stone or some other object on or near the bank of the stream. Here they soon change to pupge. These are white and have prominent wing- pads. In about a month after the larva leaves the water the adult insect ap- pears. Fig. 1 26 represents the male, which has re- markably long mandibles. The female resembles the male, except that the man- dibles are comparatively short. Soon after the adults appear the eggs are laid. These are attached to stones or other objects overhanging the water; they are laid in blotchlike masses which are chalky-white in color, and measure from half an inch to nearly an Fig. 126. — The adult dobson or horned Corydalis, male. BROOK LIFE. 155 inch in diameter. A single mass contains from two thousand to three thousand eggs. When the larvse hatch they at once find their way into the water, where they remain until full grown. The best time to study this insect is late in the spring and early in the summer, for at this season all stages of it can be found. Try to get larvae, pupse, adults, and eggs, and preserve them in your collec- tion under a copy of the following label : — Order Neuroptera (Neu-rop'te-ra). Family Sialid^ (Si-al'i-dae), The adult dobson is known as the horned Cory- dalis, its scientific name being Corydalis cornuta. The Structure of the Dobson {School Work).— Put a larva in a cyanide bottle one or two hours be- fore it is needed for study, as it requires considerable time to kill these insects. 1. Lay the specimen on its back and make a draw- ing of the ventral surface. 2. Name the parts and appendages of the body shown in this view. The long, tapering appendages on the sides of the abdomen may be termed the lateral filaments ; the tufts of hairlike appendages near the bases of the lateral filaments are tracheal gills, and at the hind end of the body there is a pair oi prole gs. Each proleg is furnished with a pair of claws. Note that in addition to the tracheal gills this larva has well-developed spiracles. Make a drawing of a spiracle as seen through a lens. Note especially the lid by which the opening of the spiracle is closed. State the number of spiracles and the position of 156 INSECT LIFE. each pair. Consider how well fitted this insect is both for life in the water and on the land. A more detailed account of the structure of this larva is given in The Elements of Insect Anatom}^ by Comstock and Kellogg. The Near Relatives of the Dobson or Cory- DALIS {Field Work). — In searching for the dobson the pupil is apt to find certain other members of the same family which live in similar situations. Some of these resemble Corydalis very closely, except that they are smaller when full grown and do not have tufts of tracheal gills ; these belong to the genus Chauliodes {Chau-li' o-des). A still smaller larva which is similar in form and also lacks tracheal gills is Sialis {Si' a lis) ; this differs from both of the preceding in having at the hind end of the body a long, tapering appendage instead of a pair of prolegs. Place any specimens that you may get of either of these in your collection under the family Sialidce (see page 155). INSECTS THAT LIVE EXPOSED IN TORRENTS. There are many insects that find in rapids places best fitted for their existence, but most of these are more or less protected from the rush of the water by the fact that they live beneath stones. Some insects, however, scorn any protection, but live exposed where the water flows the swiftest ; two of these are mentioned below. The Black-flies {Field Work), — The larvse of the black-flies should be sought in streams flowing down steep descents. If present, they are easily found, for they occur clustered together in large numbers, form- ing a black coating over the rocks. They prefer the BROOK LIFE. 157 Fig. 127.— Cocoon and larva of a black-fly. brinks of falls and places where the slanting bed-rock is washed clean by a swift flow of water, but some- times they cling to pieces of wood or small stones that are firmly fixed in the rapids. When the larvas are fully grown they spin boot- shaped cocoons within which the pupa state is passed ; these are firmly fastened to the rock upon which the larvae lived. In Fig. 127 there are represented a larva and a cocoon. 1. Find a cluster of larvse and take notes on the following: The way in which they keep their place in the swift current. (It is the tail end by which they are usually fastened to rock.) Their method of locomotion, and the action of the fan-shaped or- gans attached to the head. 2. Collect larvas and cocoons and try to keep them alive in water. These insects can not be reared in aquaria unless they are placed under a jet of water, but they can be kept alive several hours, thus giving some opportunity for watching their habits in con- finement. 3. Look for the eggs of the black-flies. These are yellowish or brownish and occur in patches in situations similar to those inhabited by the larvse. 4. Look also for adults. These occur in swarms, hovering over the brinks of falls and dashing back and forth through the spray. Sometimes they may be seen darting into the water and out again ; at such times they are laying their eggs. Fig. 128 represents one of these flies somewhat 158 INSECT LIFE. enlarged, and Fig. 129 represents an antenna much more enlarged. The peculiar venation of the wings is sufficient to distinguish black- flies from all others. The Black - flies {School Work). — Prepare for your collec- tion as complete a series as pos- FiG. 128. ., , , „ ^ sible 01 the dmerent stap:es of , . . . , pi- 1 • Fig. 129. these msects, pmnmg the rlies and preserving the eggs, larvse, and cocoons with pupse in alcohol. Place them with other Diptera under a copy of the following label : — Family Simuliid^ (Sim-u-li'i-d^). The Black-flies. Watch living larvae in a glass of water and ob- serve the following : The disklike sucker, fringed with hooks at the caudal end of the body. The fleshy proleg situated just back of the head ; this ends in a sucker fringed with hooks. The thread of silk spun from the mouth. The fan-shaped organs borne by the head. And the three delicate, much-branched tracheal gills, which are pushed out from between the last two abdominal segments. Write an account of what you have learned re- garding black-flies, including a description of the methods of locomotion of the larvse and the prob- able method by w^hich the larvas obtain their food. It has been found by examining the stomachs of these larvas that they feed on microscopic aquatic plants and bits of tissue of larger plants. The Net-winged Midges (Field and School Work). — These insects occur in situations similar to those BROOK LIFE. 159 Fig. 130. — Net-winged midges ; a, larva, dorsal view ; (5, larva, ven- tral view inhabited by the black-flies, but as they are compara- tively rare insects they are merely mentioned here. In Fig. 130 a represents a larva seen from above, b a larva seen from below, and c a side view of the pupa. As these are the strang- est of all insect larvge they should be carefully studied if found. A full account of their habits and transfor- _^ „ - • ^ „ ■ ^ • • trai view ; c, puparium. mations is given in our . - f f Manual for the Study of Insects. The}^ belong to the order Diptera and to the family Blepharocerid^ (Bleph-a-ro-cer^i-das). INSECTS OF BROOKSIDES. In the study of brook life the pupil will hardly fail to observe many insects about the shores of the streams. The presence of the greater part of them in such situations is not due to the proximity of water, but is largely a matter of chance. Any forest, orchard, or roadside insect may be found near a brook if its proper food occurs there. Some of these insects are described in subsequent chapters. Here mention is made of a few of those that prefer the vicinity of water and are rarely found elsewhere. The '^YiO'^Y.-^^5Q^ {Field and School Work). — These abound in the vicinity of streams and lakes and upon damp soils. They are small bugs, of dark colors with white or yellow markings, and with long Fig l5o INSECT LIFE. antennas. Fig. 131 will aid in recognizing them. The shore-bugs take flight quickly when disturbed, but alight after flying a short distance ; some species dig burrows and live for a part of the time beneath the ground. Collect specimens and put them in your collection under a copy of the following label: — Family Saldid^ (Sal'di-dae). The S hoi' e -bugs. The Toad-shaped Bugs {Field and School Work), — There is sometimes found on the margins of streams or in marshes where the soil is moist a cu- rious bug, which, on account of its short and broad body and projecting eyes, reminds one of a toad (Fig. 132). If you find speci- mens of these, observe the color of the soil Fig. 132. I'll r 1 1 upon which they are lound and compare it with that of the insects, for this species exhibits con- siderable variation in coloring, and its colors are usu- ally protective. The toad-shaped bugs belong to the order Hemip- tera. Label your specimens as follows : — Family Galgulid^ (Gal-gu'li-dae). The Toad' shaped Bugs. The Pine-cone Willow-gall {Field and School Work). — The wanderer by the brookside often sees a crop of cones borne by willows, and if he is care- less he is apt to pass them by, thinking that they, like the cones of pines and spruces, contain the seeds of the plant. But the observant student knows that the seeds of willows are borne in catkins, which differ greatly in shape from these conelike growths. BROOK LIFE. l6l These cone-shaped objects belong to that class of vegetable growths termed galls. There are very many kinds of these ; and upon some plants, as oaks, for example, they are very abundant. Galls are produced by insects in this way. The female gall-producing insect stings the plant and lays ain egg in the wound. It is believed that in some cases there is deposited with the egg a drop of poison, which causes the growth of the gall. But in other cases the gall does not begin to develop until the larva hatches from the egg and begins to feed upon the tissue of the plant. Evidently if there is a poison in such cases it must be secreted by the larva. The explanation of why galls grow is not yet clear ; but we know this much, that each species of gall-making insect makes a par- ticular kind of gall. Hence one versed in this subject can tell by the form and structure of a gall what species of insect produced it. The gall serves as a home and food for the larva de- veloped within it. Let us return to the pine-cone wil- low-gall (Fig. 133). This differs in Fig. 133.— The pine-cone willow-gall. shape and in the manner of its growth from most galls. (Other types of galls will be described in later l52 INSECT LIFE. chapters.) It is produced by a small gall-gnat, which lays an egg in the tip of a branch of willow. A mag- got hatches from this egg and lives in the heart of the bud, which ceases to grow in length ; but, strange- ly enough, leaves continue to be developed, and they, crowded together, form the cone-shaped gall. Collect specimens of the pine-cone willow-gall and, splitting them open in the middle, find the larv26 that produced them. In early spring the adult gall-gnats can be reared by keeping the galls in breeding cages. There is a guest gall-gnat that lays its eggs be., tween the scales of the pine-cone willow-gall, and the larvae hatched from these develop in this place. Seek for specimens of these larvse, and in early spring try to breed the adults. Both of these gall-gnats pass the winter in the larval state within the galls. The larvas can be found within the galls at any time during the summer, fall, or winter; but in order to breed the adults, it is best to leave the galls on the plants till early spring. There are several kinds of insects, among them certain long-horned grasshoppers, that deposit their eggs between the leaves of the pine-cone willow-gall ; the young, however, leave the galls as soon as they are hatched. Gall-making species are found in several of the orders of insects. The two gall-gnats mentioned here belong to the order Diptera. Place specimens in your collection with other Diptera under a copy of the following label : — Family Cecidomyiid^ (Cec-i-do-my-i'i-dae). T/ie Gall-gnats. BROOK LIFE. 163 The Alder-blight {Field and School Work). — One often finds on the trunks and branches of alders growing" on the margins of streams large patches of snowy-white matter. These patches are composed of many insects crowded together and covered with a downy excretion. Such insects are known as woolly- aphids. There are several kinds of common woolly- aphids. That which lives on the alder is known as the alder-blight, another kind living on beech trees is called the beech-tree blight, and a third kind, infesting apple trees, is the woolly-aphis-of-the-apple. All of these secrete large quantities of honey-dew. Each aphid has its beak inserted into the bark of the infested tree. By cutting off a section of an in- fested branch and putting it in a cyanide bottle, the insects can be killed, and most of them will remain clinging to the branch. It can then be pinned into the collection. The aphids belong to the order Hemiptera ; place specimens under the following label :— Family Aphidid^e (A-phid'i-dae). T/ie Plajit-lice or Aphids {Aph'ids). The Wanderer {Field aiid School Work).— The name wanderer has been applied to a butterfly (Fig. 134) that is found only in limited localities, al- though it occurs from Maine to Florida and westward to Kansas. It prefers the borders of streams pio. 134. -The wanderer. and marshy places where alder grows ; and now that its life history is known, this fact is explained. The caterpillars of nearly all but- 164 INSECT LIFE. terflies feed on plants, but the larva of this species is truly carnivorous, feeding on the wooUy-aphids known as the alder-blight. If the alder-blight is common in your locality, search colonies of it for the larvag of this butterfly. They will be found burrowing through the downy mass, and their paths will be marked by the remains of their victims. They resemble grubs more than ordinary caterpillars, and are more or less covered with the white excretion of the plant-lice. Their legs and prolegs are short and small, allowing the body to be closely pressed to the bark of the branch. By collecting these caterpillars and feeding them with the alder-blight, the transformations of the butterfly can be easily observed. If you do this, save speci- mens of larvae, pupse, pupa skins, and adults for your collection. This species should be labeled as fol- lows : — Order Lepidoptera (Lep-i-dop'te ra). The Moths, the Skippers, and the Butterflies. Family Lyc^nid^ (Ly-caen'i-dae). The Gossamer-winged Butterflies. The Grouse-locusts {Field and School Work).— There is a group of small locusts the members of which are remarkable for the shape of the pronotum. This projects back- ward like a little roof over the wings. Fig. 135. and often extends beyond Ihe end of A grouse-locust. -^ ttt- 1 1 the abdomen (rig. 135). Vvith these insects the fore wings are in the shape of small, rough scales, the hind wings being protected by the pro- notum. BROOK LIFE. 165 The grouse-locusts are commonly found in low, wet places and on the borders of streams. They prefer the broad gravelly stretches where there is little or no vegetation, the low banks that are swept by the water when the streams are high. They vary greatly in color, their color being usually similar to that of the soil on which they live. They are very active, and hence difficult to catch without the use of a net. In studying these insects in the field note especially the protective nature of their colors. Pre- pare one or more specimens for your collection by spreading the wings so as to show the relative size of the fore and hind wings. Label them as follows : — Order Orthoptera (Or-thop'te-ra). Cockroaches^ Crickets^ Grasshoppers, and Others. Family Acridid^ (A-crid'i-dae). The Locusts, or Short-horned Grasshoppers, CHAPTER VI. ORCHARD LIFE. An orchard is an excellent place for Nature study. Here live many kinds of tiny creatures, each kind with its own peculiar mode of life. Some have comparatively simple life histories, merely eating and growing- and final- ly laying eggs for another generation ; but others undergo wonderful transfor- mations, and still others exhibit an in- stinct that seems much like reason. And even those that appear to live the most humdrum existence are well worthy of careful study, for their lives are never as simple as they seem at first sight. By a study of orchard life there may be learned also much that is of immediate practical importance ; some of the most dreaded insect pests infest fruit trees. A thorough knowledge of the ways of these depredators enables us to plan successful- ly methods of destroying them, and thus to prevent their ravages. Knotgrasiand To Carry ou this study it is not neces- hSitie^Gaf^rf- ^^^3^ ^^ ^^ ^^ ^ large orchard. Except in idea poiygoni. a city, almost every dwelling-house has i66 Plate VII. DANDELIONS AND A LOCUST. ORCHARD LIFE. 167 some fruit trees about it, and these are sure to be in- fested by some of the insects described in this chap- ter. And the boys and girls that live in cities can find fruit trees with a little effort. This chapter is restricted to insects infesting fruit trees. Many other kinds of insects may be found on grass and other herbage about orchards ; some of these are described in the chapter on Road- side Life. Under the high-top sweeting-, Many a playmate came to share The sports of our merry meeting: Zigzag butterflies, many a pair, Doubled and danced in the sunny air ; The yellov/ wasp was a visitor there ; The cricket chirped from his grassy lair ; Even the squirrel would sometimes dare Look down upon us, with curious stare ; The bees plied fearless their honeyed care Almost beside us, nor seemed aware Of human presence ; and when the glare Of day was done, and the eve was fair. The fireflies glimmered everywhere. Like diamond-sparkles in beauty's hair. In the boughs of the high-top sweeting. The humming-bird, with his gem-bright eye. Paused there to sip the clover. Or whizzed like a rifle-bullet by ; The katydid, with its rasping dry. Made forever the same reply. Which laughing voices would still deny ; And the beautiful four-winged dragon-fly Darted among us, now low, now high, And we sprang aside with a startled cry, Fearing the fancied savagery Of the harmless and playful rover. l68 INSECT LIFE. The flying grasshopper clacked his wings. Like castanets gayly beating ; The toad hopped by us, with jolting springs ; The yellow spider that spins and swings Swayed on its ladder of silken strings ; The shy cicada, whose noon-voice rings So piercing shrill that it almost stings The sense of hearing, and all the things Which the fervid northern summer brings — The world that buzzes and crawls and sings — Were friends of the high-top sweeting. Elizabeth Akers.'^ INSECTS INFESTING FOLIAGE. The Apple-tree Tent-caterpillar {Field and School Work). — In early spring, as soon as the leaves begin to expand, conspicuous webs may be found on the branches of apple and other trees. The begin- ning of such a web is represented in the upper part of Fig. 137. These webs are the "tents" of the apple-tree tent-caterpillar — an insect that is social while in the caterpillar state. Each colony consists of the larvae that have hatched from a cluster of eggs deposited b}^ a moth on a twig near the place where the web is afterward built. Such a cluster of eggs is represented above the web in the figure. Usually, however, the tent is built much farther from the ^gg^ cluster than is shown here. 1. Search for egg-clusters on the twigs of apple before the leaves af)pear ; they can be found at any time during the winter or early spring. 2. If egg-clusters are found, examine them from * From The High-top Sweeting, by permission of Messrs. Charles Scribner's Sons. ORCHARD LIFE. 169 day to day and ascertain the date of hatching of the larvae. 3. If the larvae hatch before the leaf-buds open, ascertain upon what the larvae feed at this time. Fig. 137. — The apple-tree tent-caterpillar, eggs, tent, larva, cocoons, and adult. 4. If. egg-clusters are not found, search for webs. Upon what kinds of trees other than apple can these be found ? 5. If possible, find a specimen in a convenient place to study — where it can be examined daily. If none is found near the school or the home of the pupil, or near some street between the tw^o, cut off a I^O INSECT LIFE. branch bearing a tent, and tie it to a branch of another tree of the same kind in a convenient place. 6. Describe the position, form, and structure of one of these tents. Of what is it made ? Where does the substance of which it is made come from ? How is the tent held in place ? How is it increased in size ? Make a picture of a tent. 7. Describe one of the caterpillars that lives in this tent (see page 325). 8. Upon what do the caterpillars feed ? At what time of the day do they feed ? How far do they go for their food ? 9. Are the paths over which the caterpillars go to and from their food marked in any way ? If so, how ? 10. The way in which this pest is usually fought is by destroying the caterpillars in their tents. Can this be done better at one time of day than another? If so, when ? 11. Search for the remains of the cluster of eggs from which a colony of tent-caterpillars have hatched. Carefully describe this cluster. Make a picture of it. Preserve the specimen for your collection. 12. Put a branch of the kind of tree upon which the caterpillars are feeding in water in a breeding cage. Select a branch which bears many leaves. Place fifteen or twenty caterpillars on this branch, in order to keep them confined, and thus be able to observe their transformations. Put fresh branches in the cage when necessary to keep the larvse sup- plied with food. 13. What do the caterpillars do when full grown? Observe their actions in your breeding cage and in the field. ORCHARD LIFE. 171 14. Preserve some caterpillars in alcohol, and put them in your collection near the cluster of eggs. 15. Observe and describe the making- of cocoons. Note the date when the cocoons are made. 16. After you are familiar with the appearance of the cocoons, look for them out of doors, and find out where they are made. 17. Open a cocoon a few days after it is made, and describe the pupa. 18. Preserve a pupa in alcohol, and put it next to the larvse in your collection. 19. Watch for the appearance of the adult moths, and thus determine the duration of the pupa state. 20. Preserve specimens of the cocoons and moths. First kill the moths by putting them in the killing bottle, then pin and spread them. When dry, take them from the spreading board, and put them in the collection with the other specimens illustrating the transformations of the species. Try to get both sexes of the moth ; the females are larger than the males, and have narrower antennae. 21. Make a picture of the moth. 22. Write an account of the life history of this insect. 23. Arrange the specimens of the apple-tree tent- caterpillar in your collection under a copy of the following labels : — Order Lepidoptera (Lep-i-dop'te-ra). The Moths ^ the Skippers^ and the Butterflies. Family LASiocAMPiDiE (Las-i-o-cam'pi-dae). The Lasiocampids i^Las-i-o-cam'pids). J ^2 INSECT LIFE. Note. — There are several species of tent-caterpillars in the United States. The most common one east of the Rocky Mountains is the one figured above — the apple-tree tent-caterpillar, Clisiocampa americana {Clis-i-o-cani pa a-nier-i-cd no). Another species that occurs in this region is the tent-caterpillar-of-the-forest, Clisiocampa disstria {C. dis'stri-a). The larva of this species differs in having a row of spots along the middle of the back instead of a continuous, narrovi' line. This species will an- swer just as well for the work outlined above as the apple-tree tent- caterpillar. The more common tent-caterpillars of the Pacific coast are Clisio- campa calif arnica (C. cal-i-for ni-ca), whose webs may be found on oaks in March and April, and Clisiocampa constricta (C. con-sl?icta), which in- fests fruit trees later in the season. The caterpillars of the last-named species do not make tents, although they live in colonies. Other Leaf-eating Caterpillars (Fie/d and School Work). — There are many kinds of caterpillars that feed on the foliage of other fruit trees, any one of which will serve as a good subject for study. It would take too much space to describe many of these and to outline the method of study of them, as has been done above for the tent-caterpillars. The fol- lowing brief outline will be all that is necessary for the pupils that have carefully studied several of the insects already described : — 1. Collect larvse found feeding on the foliage of fruit trees. Try to get several specimens of each kind, and note carefully upon what they were feed- ing. 2. Put each kind of larva into a separate breeding cage (see pages 327 to 330 for descriptions of breeding cages), and feed each with leaves from the kind of tree on which it was found. Keep the food fresh by placing the stems in water, and renew it daily. 3. Make careful notes on the habits of the insects, and describe each stage in their development. ORCHARD LIFE. 173 4. Save specimens for your collection of anything illustrating- the habits of the species and specimens of each of the stages in the development of the species. Arrange these specimens in your collection, labeled as fully as you can. 5. Write an account of what you have learned. The following are some of the more common of the orchard insects that feed on foliao^e : — The yellow-necked apple-tree- worm, Datana minis- tra {Da-ta'na mi-nis'trd). — This caterpillar has the Fig. 138. — The yellow-necked apple-tree-worm. curious habit of assuming the attitude shown in Fig. 138. It feeds on forest trees as well as fruit trees. It remains throughout the winter in the pupa state. Fig. 139 represents the adult. There are sev- eral closely allied species which feed on forest trees. The red -humped ap- ple-worm, Gidemasia con- fig. 139. 174 INSECT LIFE. cinna {CEd-e-ma' si-a con-cin'nd). — The larva of the spe- cies has a coral-red head, and there is a hump of the same color on the back of the first abdominal Fig. 140.— The red-humped apple-worm segment (Fig. 140). This species passes the winter in the pupa state, and the adults appear in June and July. The measuring-worms. — There are many kinds of _^ these. Fig. 141 represents one of them. They are called measuring-worms on account of the curious way in which they walk. The most important species that infest fruit trees are known Fig. 141.— A measuring- worm. as canker-worms. 1 here are two species of canker-worms, which are very similar in appearance and habits. In both the adult female is wingless (Fig. 142), while the male (Fig. 143) has well-devel- oped wings. The white-marked tussock-moth, No- tolophus leucostigma {No-tol' o-phus leu-co- stig' md).—l:\)S.'s^ caterpillar (Fig. 144) is Fig. 142.— Fe- male canker- worm. ,1 .-j^i^i "-loB. 3tJiJ-iioB9' fiquq 714 ^ gil ; tjlams't ,. ^. : ji moil gnrjoaioiq ni^Is B7Tl4 aril -..._trl:-. 'rl =, H .BidiorfquH lo ^i^viiuLoiIj no £V7£i J) 1 Ayn'\ ,gin3rniq3 9niv-=iq-f:iO sriT iigiiV' btiB sqBi^ 'io e9VJ5t)I sr; ■.rfj no r . _ 3f{T .v;u>v. .,-=A^-u^x-A\ ,rifo, Plate VIII.— FOREST AND ORCHARD MOTHS. FIGURE I, 2, and 3. The Peach-tree Borer, Sannina exitiosa. Fig. i, male ; Fig. 2, female ; Fig. 3, cocoon with empty pupa skin projecting from it. 4. The Eight-spotted Forester, Alypia octomaculata. The larva feeds on grape and Virginia creeper. The Morning Forester, Alypia matuta. The Pearl Wood-nymph, Euthisanotia tmio. The larva feeds on the leaves of Euphorbia. The Grape-vine Epimenis, Psychonwrpha epinienis. The larva feeds on the leaves of grape and Virginia creeper. The Maia-moth, Hemileuca maia. The larva feeds on the leaves of oak. The White-marked Tussock-moth, Notolophus leiicostigma. See page 174; also Plate XVIII, Fig. 8. The Well-marked Tussock-moth, Notolophus definita. See Plate XVIII, Fig. 7, for the larva. Plate VIII. \ ORCHARD LIFE. 175 common on both fruit and forest trees ; it is an ex- ceedingly beautiful larva, being ornamented with bright colors. The adult fe- male is wingless, and lays her eggs in a frothy mass on her cocoon. The male (Fig. 145) has well-developed wings. The Plant - lice or Aphids {Field and School Work). — The plant-lice or aphids are minute insects which live by sucking the sap from the more tender portions of plants. They usually occur clustered Fig. 143. — Male canker-worm. Fig. 144. — The white-marked tussock-moth, larva. together in large numbers, and may be either winged or wingless (Fig. 146). Many kinds of aphids can be found in any orchard ; among the more common Fig. 146. — A gjoup of aphids. 176 INSECT LIFE, species are the green ones that are very abundant some years on the tips of branches of apple, and the dark-colored ones that cause the leaves of peach and cherry to curl, thus forming tubes within which they live. Find a colony of aphids in a convenient place where they can be observed from day to day, take notes on their habits and structure, and finally write an account of what you have learned. The following suggestions will aid you in this study: — 1. Observe the form of the body. Usually there are two forms of individuals in a colony — one wing- less, the other winged. Usually the greater num- ber of individuals are w^ingless, and these never develop wings. But as aphids increase in numbers very rapidly, there is danger of the destruction of the food-plant and a consequent destruction of the colony. To avoid this danger, from time to time individuals are born that develop wings. These fly away, and start new colonies in fresh localities. The nymphs of the winged form can be recognized by their wing-pads. 2. Observe the reproduction of aphids. Both the wingless and the winged forms referred to in the preceding paragraph give birth to living young. In some species the young aphid pro- duced in this way is inclosed in a soft shell, but usually not. The birth of the young aphids can be easily seen with a hand lens at any time during the warmer part of the year in almost any colony of aphids. 3. The two forms of aphids that are being consid- ered now consist each of a single sex, all of the indi- ORCHARD LIFE. I77 viduals being females. As these females reproduce without pairing-, they are termed agamic ia-gani'ic). (The word agamic is from two Greek words, mean- ing without marriage.) The two forms are designated as the wingless agamic form and the ivinged agamic form respectively ; the latter is often called the mi- grating form. 4. Collect specimens of the following forms of the species that you are studying, and preserve them in alcohol: — Full-grown wingless agamic females, nymphs of the wingless agamic form, winged agamic females, and nymphs of the winged agamic form. 5. Generally on the setting in of cold weather, or in some cases on the failure of nourishment, the weather being still warm, there is produced a gen- eration including individuals of both sexes. These are known as the sexual forms. The males may be either winged or wingless, but these true females are always wingless. The sexual forms pair, and the female produces one or more eggs. It is in the ^gg state that the species usually pass the win- ter. 6. In the autumn watch for the appearance of the sexual forms and for eggs. 7. Study the agamic forms, and note if there is a pair of tubes on the back of the sixth abdominal seg- ment. Sometimes these are represented by tubercles and sometimes they are wanting. 8. It has been generally believed that through these tubes or tubercles the sweet, transparent fluid, which is known as honey-dew, is excreted. But it has been recently discovered that the honey-dew comes from the hind opening of the alimentary 178 INSECT LIFE. canal* Try to observe the excretion of honey- dew. 9. Find a colony of aphids that is attended by ants, and determine why the ants are there. INSECTS THAT PREY UPON APHIDS. The Aphis-lions {Field and School Work). — Look among colonies of aphids for aphis-lions. These are spindle-shaped larvae, with very long, slender, curved jaws ; one of these larvae is represented on the lower left leaf in Fig. 147. The aphis-hons are most easily Fig. 147.— Eggs, larva, cocoon, and adult of Chrysopa. found in those colonies of aphids that live within curled leaves. I. Remove a small branch bearing a colony of * M. Biirgen. Der Honigtau. Jenaische Zeitschrift, Bd. xxv (1891), s. 387-428. ORCHARD LIFE. 179 aphids and place it in water or wet sand in a breed- ing- cage. Tie a wad of cotton about the branch so that aphis-lions can not easily escape from it. 2. Collect several aphis-lions and place them among the aphids, and observe their habits. If the aphids are destroyed before the aphis-lions get their growth and spin cocoons, transfer the aphis-lions to a new colony of aphids. 3. When the aphis-lions have made cocoons, transfer the cocoons to a wide-mouthed bottle cov- ered with netting, and leave them there till the adults emerge. The adult aphis-lion is called a lace- w^inged-fiy. 4. Search for eggs of lace-winged-flies. They can be found on the leaves of trees and bushes, attached by long, slender stalks, as shown in the figure. 5. Prepare a set of specimens illustrating the transformations of lace-winged-flies or aphis-lions, and label them as follows : — Order Neuroptera (Neu-rop'te-ra). Family Chrysopid^e (Chry-sop'i-dae). The Lace-winged- flies or Aphis-lions. The Lady-bugs {Field and School Work). — The insects that are commonly called lady-bugs are small beetles which are more or less nearly hemi- spherical in form, and generally red or yellow with black spots, or black, with white, red, or yellow spots. Fig. 148 represents a com- mon species. Lady-bugs, both in the adult and larval states, feed on aphids, other small in^ sects, and the eggs of insects. The object of this i8o INSECT LIFE. lesson is to have the pupils observe the transforma- tions of some common species of lady-bug-. 1. Collect larvse of lady-bugs and place them in a breeding cage with a colony of aphids, put- ting onl}^ one kind in a cage. These larvse can be found in the same situations as the aphis-lions (see preceding lesson), and resem- ble them somewhat in form. They are not Fig. 149. g^ slender as the aphis-lions, and their jaws are shorter. Fig. 149 represents a common species. The breeding cage should be arranged and cared for the same as for aphis-lions. 2. Ascertain the method in which lady-bugs pass the pupa state; it is an unusual one. Fig. 150 rep- resents a pupa. 3. Prepare a set of specimens illustrating the transformations of a species of lady-bug, and place it with 3'Our Coleoptera, labeled as follows : — Fig. 150. Family Coccinellid/e (Coc-ci-nel'li-dse). The Lady-bugs. INSECTS INFESTING FRUIT. The CodliN-MOTH {Field and School Work). — The most important pest of the apple is the '' worm " that is frequently found feeding within the fruit near its core. This " worm " of wormy apples is the larva of a tiny moth, which is known as the codlin- moth (Fig. 151). I. Carefully examine a number of wormy apples by cutting them to pieces, and. write an account of Fig. 151. ORCHARD LIFE. l8l the injury to them. Where does the larva enter the iruit? Where is the injury chiefly done? Where does the larva emerge from the fruit? 2. In what place is it probable that the eggs of this insect are laid, judging by the observations that you have made on the habits of the larvas? 3. Collect a large number of the larvse by remov- ing them from wormy apples, and place them in a tightly closed jellj^-glass or other small cage. Put some pieces of apple in the cage to serve as food. Put also some small pieces of bark in the cage so that the larvas may hide under them. 4. Describe the larva, and preserve some speci- mens in alcohol. 5. Observe the larvae daily until they make their cocoons, and then describe the cocoons. Note date when the cocoons are made, so as to determine the length of time spent by the insect in its cocoon. 6. Try to find similar cocoons under loose bark on apple trees. 7. Empty cocoons of this insect are often found under loose bark that has been pierced by a wood- pecker in order to feed on the insects. Preserve specimens of such pieces of bark and cocoons. 8. Scrape the loose bark from the trunk of an apple tree, and then take a piece of wrapping paper long enough to reach around the trunk and fold it so as to make a band about three inches wide, and fasten this band about the trunk. The band can be fastened in place with a tack or with a cord. Look beneath this band once a week, and collect the larvas and pupas that you find there, keeping a record of the number found each week. 13 l82 INSECT LIFE. Note. — At one time fruit-growers fought the codlin-raoth by collect- incr the larvae and pupoe in this way and destroying them. It has been found, however, that a better way is to spray the apple trees just after the blossoms fall with Paris-green-water. By this means the larvae are poisoned before they eat their way into the young fruit. 9. Examine the cage containing cocoons daily in order to determine the date of emergence of the moths. 10. There is more than one generation of this in- sect each year. Determine by breeding the number of generations in your locality, and the method of passing the winter. 11. Write an account of the life history of this insect. 12. Prepare a set of specimens illustrating the transformations of this species, place them with the Lepidoptera in your collection, and label them as fol- lows : — Superfamily Tortricina (Tor-tri-ci'na). The Tortricids [Tor'tri-cids). Carpocapsa pomonella {Car-po-cap' sa pom-o-neVla). The Codlin-moth. The Plum-CURCULIO {Field and School Work). — The plum-curculio is the insect that stings immature plums, laying eggs in them, from which hatch grubs, that cause the fruit to fall prematurely. This insect also infests the peach, nectarine, apri- cot, and cherry. In the case of the cherry the in- fested fruit does not fall, but ripens with the larvas in it, the larvas being the well-known '' worm " of " wormy cherries." The study of this insect should begin early in the season, for the eggs are laid in the young fruit. ORCHARD LIFE. 1 83 I. Search for the eggs in any of the fruits named above. Their presence can be easily determined by a peculiar mark made by the female when laying her eggs. A hole is made through the skin of the fruit, and into this hole the egg is put. The insect then makes a crescent-shaped incision partly surrounding the one containing the egg. 2. If the dot and crescent mark is found on the fruit, search should be made for the adult insects. These are most easily found early in the season, and can be readily obtained by spreading a cloth under an infested tree and jarring the tree. The adults will drop to the ground feigning death. Specimens should be pinned for your collection. The adult is a beetle. It is about one fifth of an inch in length, and is dark brown spotted with black, yellow, and white. The wing-covers are rough, and the head is prolonged into a snout, which is bent back under the prothorax when at rest. 3. Preserve in alcohol specimens of fruit showing the dot and crescent mark. Cherries will be most available for this on account of their small size. Pre- serve also specimens of the larvas. 4. Describe the way in which the larvas injure the fruit. 5. Place infested fruit in a breeding cage on a layer of earth ; determine method of passing the pupa state ; preserve specimens of pupas ; and breed the adult insect, so as to determine whether the in- sects that you collected by jarring are really the adult of this species. 6. Write an account of the habits and appearance of this insect. 1 84 INSECT LIFE. 7. Label your specimens properly. The species belongs to the order Coleoptera ; the family CuRCU- LIONID^ (Cur-cu-li-on'i-dse), The Curculios {Cur-cu' li-os) or Weevils ; and the specific name of this curculio is Conotracheliis nenuphar {Con-o-tra-che' lus nen'u-phor). The Pomace-flies {Field and School Work). — There are several species of small flies, the larvse of which live in decaying fruit ; and as these insects are often abundant about pomace in cider-mills and wineries, they have been termed pomace-flies. Usually the larvse of these flies can be found in decaying fruit in any orchard during the autumn. And as they develop very rapidly, they are excellent subjects for study. In the case of one species which I studied, the complete life cycle occupied only from eleven to seventeen days. 1. Place in a breeding cage some decaying apples or other fruit in which there are maggots, There should be a layer of earth in the breeding cage, as some species of pomace-flies pass the pupa state in the ground. 2. Study the larva carefully and write a description of it. Note especially the form of the first pair of spiracles, which project near the head of the body, as these present the most obvious specific distinctions of the larvse of the different species. The form of the caudal end of the body should be carefully studied also. The skin of these larvse is so transparent that the larger tracheae, or breathing tubes, can be easily seen through it with a low power of the microscope. Make a drawing representing an entire larva, and more detailed drawings representing each end of the body. ORCHARD LIFE. 185 3. When the larvse are full grown, determine where the pupa state is passed, and make a drawing- of the puparium. The pupa state of most flies, in- cluding the pomace-flies, is passed within the dried skin of the larva. This dried skin, which serves the purposes of a cocoon, is termed a puparium i^pu-pa'- ri-um). 4. Put some puparia in a vial in order to deter- mine the duration of the pupa state. 5. When the adult flies emerge in your breeding cage, save some specimens for your collection, and put some living ones in a cage with decaying fruit which is not infested. If you have more than one species of pomace-flies, put the different species in different cages. Try to discover the eggs when they are laid, and to determine the duration of each stage of the insect. 6. Write an account of the pomace-flies that you have studied. 7. Prepare a set of specimens for your collection. The pomace-flies belong to the order Diptera, the family MusciD^ (Mus'ci-dae), and to the genus Dro- sophila {Dro-sopJi' i-lci). ^^^ H m i^^i H CHAPTER VII. FOREST LIFE. DELIGHTFUL place for the study of in. sect life, especially on a hot summer day, is the margin of a forest. Here abound innumerable species, exhibiting- the great- est variety of habits. And the charm of a holiday spent in the shade can be increased mani- fold by watching and collecting them. The best places for the study of forest insects are the edges of woods, groves, isolated forest trees growing in open fields or by roadsides, and fringes of trees along the banks of streams. The depths of dense forests are inhabited b}^ a much smaller number of kinds of insects than the places just named. In the chapters on Pond Life, Brook Life, and Orchard Life detailed directions have been given for the study of the insects mentioned. But by the time the student has reached this chapter he should have become sufficiently familiar with the methods of study to be able to plan his own investigations ; hence the chief object of this chapter is to point out subjects for study. 'Tis a woodland enchanted ! The great August noonlight, i86 FOREST LIFE. jg? Through myriad rifts slanted, Leaf and bole thickly sprinkles With flickering gold ; There, in warm August gloaming, With quick, silent brightenings. From meadow-lands roaming. The firefly twinkles His fitful heat-lightnings. — Lowell. THE LARGER LEAF-EATING CATERPILLARS. The Giant Silkivorms. The largest of the leaf-eating insects found on our forest trees are the giant silkworms. There are several species of these, and some of them can be found in almost any of the inhabited portions of our country. These larvae frequently attract attention on ac- count of their large size, and the adults are favorites with young collectors, being the most showy of moths. It is easy to rear these insects, beginning with either eggs, larvae, or pupae. The following general directions for breeding will apply to any of the species : — E-ggs of the Giant Silkworms. — The eggs of the giant silkworm moths, being of large size, are fre- quently found attached to leaves of the trees upon which the larvae feed, but they are more often ob- tained from moths kept in confinement. When a female moth is captured it is usually only necessary to place her in a breeding cage, and keep her alive for a few days, in order to obtain fertile eggs. The females of this family of moths can be recognized by 1 88 INSECT LIFE, the fact that the antennas are not so large as are the antennae of the males. In case a female moth is bred from a cocoon, it is necessary that she should be al- lowed to mate with a male in order that her eggs be fertilized. It there be no males in the cage with her, males can usually be obtained by leaving the cage near an open window for a day or two. Frequently under such conditions males will come to the cage in large numbers. Having obtained eggs, it is neces- sary to ascertain the food plant of the larva ; the more common food plants of each of the species is given below. LarvcB of the Giant Silkzvorms. — These larvae can be found throughout the summer months, but they are more frequently observed in the latter part of the season, when they are nearly or quite full grown. The collection of them is greatly facilitated by searching beneath the trees on which they live for the pellets of excrement which drop to the ground from where they are feeding. In collecting them, note carefully their food plant. Cocoons of the Giant Silkworms. — The pupa state of the giant silk-worms is passed within dense silken cocoons, which have suggested their popular name. All of our species pass the winter in this state, and several of them fasten their cocoons to the branches of trees ; consequently it is during the winter months, ■while the trees are bare, that the cocoons are most often collected. Cocoons which are collected during the winter should be stored in a cool place till spring, so that the adults shall not emerge before it is possi- ble to find food for the larvas that will hatch from their eggs. Even when it is not desired to breed a Plate IX. A FOREST AISLE. FOREST LIFE. 189 second generation, it is undesirable to keep the cocoons during the winter months in a warm, dry room, for there is apt to be insufficient moisture in the air of such a room for the perfect development of the insects. Classification of the Giant Silkworms. — The giant silkworms, being the larvse of moths, belong to the order Lepidoptera. These moths constitute the family Saturniid^ (Sat-ur-ni'i-dse). The scientific name of each of the species mentioned below is given after the popular name. The following are the more common North American species : — The Io-MOTH, Automeris io {Au-tom'e-ris i'o). — This is the most common of the smaller species of the family. The female is represented by Fig. 152. In this sex the ground color of the fore wings is Fig. 152. — The io-moth. purplish red. The male differs greatly in appear- ance, being somewhat smaller and of a deep yellow color, but it can be easily recognized by its general resemblance to the female in other respects. 190 INSECT LIFE. Fig. 153. — Larva of the io-moth. The larva (Fig. 153) is one that the student should learn to recognize in order that he may avoid han- dling it, for it is armed with spines the prick of which is venom- ous. It is green, with a broad brown or reddish stripe, edged be- low with white on each side of the abdomen ; the spines are tipped with black. It feeds on the leaves of apple, cherr}^ willowy elm, currant, and many other plants. The cocoon is thin ; it is usually surrounded by leaves, and made near the ground. The adults sometimes emerge in the au- tumn, but usually not till spring. The Polyphemus-moth, Telea polyphemus {Te'le-a pol-y-phe' vius). — This is a 3'ellowish or brownish moth, with a windowlike spot in each wing. There is a gray band on the front margin of the fore wings, and near the outer margin of both pairs of wings there is a dusky band, edged without with pink: the fore wings are crossed by a broken dusty or reddish line near the base, edged within with white or pink. The transparent spot on each wing is divided by a vein and encircled by yellow and black rings. The wings expand from five to six inches. The larva (Fig. 154) feeds on oak, basswood, but- ternut, elm, maple, apple, plum, and other trees. When full grown, it measures three inches or more in length. It is of a light green color, with an oblique yellow line on each side of each abdominal segment except the first and last ; the last segment is bordered FOREST LIFE. IQI by a purplish brown V-shaped mark. The tubercles on the body are small, of an orange color, with me- FiG. 154.— Larva of the Polyphemus-moth. tallic reflections. The cocoon (Fig. 155) is dense and usually inclosed in a leaf. Sometimes it is fastened to a twig, but ordinari- ly it falls to the ground with the ^^ leaves in the au- tumn. Observe and Fig. 155.— Cocoon of the Polyphemus-moth. 192 INSECT LIFE. describe the method of exit of the adult from the cocoon. The Luna-moth, Tropcea luna {Tro-pce'a lu'nd).— This is the most beautiful of the giant silkworm moths. Its wings are of a delicate light green color, with a purple-brown band on the front edge of the Fig. 156.— The luna-moth. fore wings. It can be easily recognized by Fig. 156. The larva feeds on the leaves of walnut, hickory, FOREST LIFE. 193 and other forest trees. It measures when full grown about three inches in length. It is pale bluish green, with a pearl-colored head. It has a pale yel- low stripe along each side of the body, and a trans- verse yellow line on the back between each two abdominal segments. The cocoon resembles that of the preceding species in form, but is very thin, con- taining but little silk. It is found on the surface of the ground beneath the trees on which the larv^ feed. The Promethea-MOTH, Callosamia prometJiea {Cal- lo-sa' mi-a pro-me' the-d). — The female moth of this spe- cies can be recognized by Fig. 157. The male differs Fig. 157. — The Promethea-moth, female. so greatly from the female that it is liable to be mis- taken for a distinct species. It is blackish, with the transverse lines very faint, and with the spot near the center of each wing wanting or very faintly indi- 194 INSECT LIFE. cated. The fore wings also differ markedly in shape from those of the female, the apex of each being much more distinctly sickle-shaped. We have ob- tained forty males of this species in a single after- noon by placing a cage containing living females near an open window. They fly most in the lat- ter part of the afternoon. The larva when full-grown measures two inches or more in length. It is of a clear and pale bluish green color ; the legs and oval shield are yellowish, and the body is armed with longitudi- nal rows of tubercles. The tubercles are black, polished, wartlike elevations, excepting two each on the second and third thoracic segments, which are larger and rich coral-red, and one sim- ilar in size to these, but of a yellow color, on the eighth abdominal seg- ment. This larva feeds on the leaves of a large proportion of our common fruit and forest trees, but we have found it most frequently on wild cher- ry and ash and on lilac. The cocoons can be easily collected during the win- ter from these trees. The cocoon is Fig. is8.-Cocoon greatly elongated, and is inclosed in a cfU|ePromethea- ^^^^^ ^^^ petiolc of which is SCCUrcly fastened to the branch by a band of silk extending from the cocoon (Fig. 158). At the FOREST LIFE. 195 Upper end of the cocoon there is a conical, valve- like arrangement, which allows the adult to emerge without the necessity of making a hole through the cocoon. Cut one of your cocoons in two cross- wise so as to see this valve. The Cecropia-MOTH, Samia cecropia {Sa'ini-a ce- cro'pi-d). — This is the largest of our giant silkworm. Fig. 159. — The Cecropia-moth. moths, the wings expanding from five to six inches and a half. It can be recognized by Fig. 159. The larva is known to feed on at least fifty species of 14 96 INSECT LIFE. plants, including apple, plum, and the more common forest trees. When full grown it measures from three to four inches in length, and is dull bluish green in color. The body is armed with six rows of tuber- cles, extending nearly its entire length, and there is an additional short row on each side of the ventral aspect of the first five segments following the head. The tubercles on the second and third thoracic seg- ments are larger than the others, and are coral red. The other dorsal tubercles are yellow, excepting those of the first thoracic and last abdominal seg- ments, which, with the lateral tubercles, are blue ; all are armed with black bristles. The cocoon (Fig. 'Zri^.'zr "-.r'^^'l Fig. i6o. — Cocoon of the Cecropia-moth. 1 60) is securely fastened to a branch of the food plant, where it is easily found during the winter months. The Ceanothus Silkworm, Samia califomica. — The Cecropia-moth is not found on the Pacific coast, but its place is taken by a closely allied species simi- lar in size and markings, but differing in having the ground color of the wings reddish or dusky brown. The larva feeds on Ceanothus : the cocoon resembles ■ "^'W^-'-s^r^^ Plate X. Plate X.— SOME FOREST MOTHS. FIGURE 1. The Imperial-moth, Basilona ifuperialis. The larva feeds on hickory, butternut, and other forest trees. See page 197. 2. The lo-moth, AvJomeris to. Male. See page 1S9 for figure of the female. 3. The Rosy Dryocampa, Dryocampa rttbicunda. The larva is the green-striped maple-worm. 4. The Crinkled Flannel-moth, Megalopyge crispata. The larva feeds on oak, elm, apple, and raspberry. xaa^oi: mi T'lnhD aril 4. FOREST LIFE. 197 that of the Cecropia-moth, except that the ends are usually free from the branch to which the cocoon is attached. THE ROYAL-MOTHS. The royal-moths constitute a family, the ClTHE- RONIID.^ (Cith-e-ro-ni'i-dse), which is closely alHed to the giant silkworms. The species are of medium or large size, and some of them are among the more common forest insects. The larvse are armed with horns or spines, of which those on the second thorac- ic segment, and sometimes also those on the third, are long and curved. These caterpillars eat the leaves of forest trees, and go into the ground to transform, which they do without making cocoons. The rings of the pupa bear little notched ridges, the teeth of which, together with some strong prickles at the hind end of the body, assist it in forcing its way upward out of the earth. The following are the more common species: — Fig. 161,— Larva of the imperial-moth. The I MPERI AL-MOTH, Basilona imperialis {Bas-Uo'na im-pe-ri-a' lis). — The full-grown larva of this species iqS INSECT LIFE. k .-- > 'K ' ^/■<"} ^\%i FOREST LIFE. 199 (Fig. 161) measures from three to four inches in length. It feeds on hickory, butternut, and other forest trees. The moth expands from four to five inches and a half. It is sulphur-yellow, banded and speckled with purplish brown. The Regal-moth, Cither onia regalis (CitJi-e-ro' ni-a re-ga'lis). — This is the largest and most magnificent of the royal-moths (Fig. 162). The fore wings are olive- colored, spotted with yellow, and with a more or less distinctly marked band outside the middle olive. The wings expand from four to six inches. The larva, when full grown, measures from four to five inches in length, and can be recognized by the very long, spiny horns with which it is armed. Those of the mesothorax and metathorax are much longer than the others ; of these, there are four on each segment ; the intermediate ones measure about three fifths of an inch in length. The larva feeds on hickory, walnut, and various other trees. The Anisota Oak-worms. — There are several smaller royal-moths belonging to the genus Anisota {Aii'i-so'td), the larvae of which feed on oak. Fig. i6-t,.—A}iisota, male. Fig. 164. — A?tisota^ female. These larvae are more or less striped and armed with spines. In the adult state the sexes differ greatly in 200 INSECT LIFE. appearance. The male and female of a common spe- cies are represented by Figs. 163 and 164. THE LARGER NEST-BUILDING CATERPILLARS. Many species of caterpillars make nests within which they live. The greater number of these be- long to the group described below as leaf-rollers — a group composed chiefly of very small species. A few of the larger caterpillars also make nests. The more common species of these are the following : — The Tent-caterpillars. — See page 172 for a reference to these. The Fall Web-worm, Hyphantria ainea {Hy^ phan'tri-a cu'nc-d). — A very common sight in autumn in all parts of our country is large, ugly webs inclos- inof branches of fruit or forest trees. These webs are especially common on apple and on ash. Each web is the residence of a colony of larvae which have hatched from a cluster of eggs laid on a leaf by a snow-white moth. There is a variety of this moth in which the fore wings are thickly studded with dark brown specks. Every gradation exists between this form and those that are spotless. The species win- ters in the pupa state, and the moths emerge during May or June. The webs made by this insect should not be confounded with those made by the apple-tree tent-caterpillar. The webs of the fall web-worm are made in the autumn, and are much lighter in texture, being extended over all of the leaves fed upon by the colony. The Scallop-SHELL Moth, Calocalpa undidata [Cal-o-cal'pa ii7t-d2i-la'td). — This is a pretty moth, with its yellow wings crossed by so many fine, zigzag, FOREST LIFE. 20 1 dark brown lines that it is hard to tell which of the two is the ground color (Fig. 165). It lays its eggs in a cluster on a leaf near the tip of a twig of cher- ry, usually wild cherry. The larvae make a snug nest by fastening together the leaves at the end of the twigi and within this nest (Fig. 166) they live, adding new leaves to the outside as more food is needed. The leaves die and become brown, and thus render the nest con- spicuous. The larvae are black above, with four white stripes, and flesh- colored below. When full grown they descend to the ground to transform, and pass the winter in the pupa state. Fig. 165. —The scallop- shell moth. Fig. 166. — Nest of larvae of the scallop- shell moth, and eggs of moth enlarged. The Mocha-stone Moths, Ichthyiira [Ich-thy- u'rd). — There often occur on poplar and willow nests of the form shown in Fig. 167. Each of these nests 202 INSECT LIFE. contains a colony of larvae — the young of a moth of the genus Ichthyura, of which there are several spe- FiG. 167.— Eggs, larva, and nest of a mocha-stone moth. cies in this country. The moths are brownish gray, w^ith the fore wings crossed by irregular whitish lines (Fig. 168). It was these peculiar markings, re- sembling somewhat those of a moss-agate, that sug- gested the popular name given above. In the case of our most common species, the nests are found in midsummer or later. The larvse, when young, feed within the nest, but when they become large they leave the nest at night to feed on other leaves. The cocoons are made under leaves or other rub- bish on the ground, and the adults do not emerge until the following summer. These insects can be easily bred by placing a nest in a breeding cage and putting fresh branches of the food plant next to the nest as often as necessary. The Silver-spotted Skipper, Epargyreus tityrus {Ep-ar-gy' re-US tit'y-rus). — If one will lie on his back in Fig. 168. — A mocha-stone moth. FOREST LIFE. 203 late July or in September under the low hanging branches of some locust tree, and look so that the leaves are clearly outlined against the sky, he may see that the fernlike regularity of some of the com- pound leaves is interrupted, several of the leaflets being fastened together with silk so as to make a little tube, which serves as a home for the builder. These tubes are made in various ways ; sometimes the tips of several pairs of opposite leaflets are brought to- gether below the leaf-stalk and fastened with silk, and the overlapping edges of the leaflets on each side fastened in the same way ; thus is formed a roomy chamber, within which the architect lives. The remains of such a nest is represented in Fig. 169. When this specimen was collected late one Fig. 169.— Nest of a larva of the silver-spotted skipper. afternoon, the leaflets were all present on the stem ; but when I went to photograph it the next morning I found that the caterpillar during the night, having nothing else to feed upon, had eaten the leaflets at both ends of the nest. These nests are made by the larva of the silver- spotted skipper, a butterflylike insect which flies from 204 INSECT LIFE. Larva of the silver-spotted skipper. flower to flower with a skipping motion (see page 8i for the characteristics of the skippers). This skipper is dark chocolate-brown, with a row of yellow spots extending across the fore wing, and with a large, silvery white spot on the lower side of the hind wing. The larva is a curious creature, with a large head, a slen- der neck, and a spindle-shaped body (Fig. 170), and will serve as a type of the family Hesperiid^ (Hes- pe-ri'i-dse), which includes our common skippers ; for the larvas of this family can be recognized by this peculiar form, and most of them live concealed in a folded leaf or in a nest made of several leaves fastened together. The Bag-worms, family Psychid^ (Psy'chi-dse). — The bag-worms are those caterpillars that have the curious habit of building each for itself a silken sac covered with little twigs within which it lives (Figs. 171 and 172). When the caterpillar washes to move from one place to an- other, it pushes forth the front end of its body and creeps along, carrying its house with it. It is said that the spe- cies that inhabit Ceylon are believed by the natives to be composed of individ- uals who, in a previous incarnation, were human beings and stole kindling- wood, and who now atone for the theft by repeating the act as an insect. 'fJ -AA:. fi^sO .1 f f . ^me^ .\\'3-v ri\v>'i