Adult insect

“ The adult insect is necessarily the reproductive stage, but in most cases it must support itself as well; the immature insect bas no other direct object in lire than that of feeding and of preparing itself for its transformation into the adult. ”

“ The caterpillar differs markedly from the butterfly. As we pursue our studies of insect growth and transformation we shall find that in some cases the difference between young and adult is much greater—as for example between the maggot and the house-fly, in others far less—as between the young and full-grown grasshopper or plant-bug. It is evidently wise to begin a general survey of the subject with some of those simpler cases in which the differences between the young and adult insect are comparatively slight. ”

“ Adult moths and butterflies have no mandibles or have mere rudiments of them (Fig. ?63) , but the jaws are often quite visible in the pupae (Fig. ? 59 H, Md) , and the pupa of one moth has long, toothed mandibles which it uses to liberate itself from the cocoon before transforming to the adult. The structural changes that accompany the transfor- mation of the larva into an adult insect are by no means confined to the outside of the body. Much internal re- organization goes on which involves changes in the tissues themselves. ”

“ Out of the pupa, whether it be cocoon, chrysalis, or just plain pupa case, comes the adult. The main business of adult insects is to reproduce their kind. After the eggs are laid there is little excuse for their living. In the case of a great many kinds of insects death follows soon after. There [395] are some noted exceptions to this rule as for instance the wasps which build with so much skill and patience the homes in which to rear their young, the ants and the bees, both social and solitary, which carry on such a complicated home life. ”

“ In the holometabolous insects there is a resting, quiescent stage during the pupal period, when the insect takes no food. In this respect the more specialized insects differ from other metamorphic animals. The larva has an abundant supply of fat lasting through pupal life, while in the quiescent pupa, respiration and circulation is much lessened, the animal being as a rule motionless. This resting stage is also necessary for the histolysis and formation of the adult body from the imaginal buds present in the larva. ”

“ Here they feed upon the liquids or tissues of the now helpless insect and grow to maturity in from ten to thirty days. Meanwhile, however, the grasshopper bas died; and when the parasites are full grown, they leave the dead body and bury themselves in the earth to a depth of from two to six inches. Here they undergo the transformation that will give them the form of their parents, and when they attain this stage they issue from the earth as adult winged flies. Thus, one insect is destroyed that another may live. ”

“ B, C, D, larva, pupa, and adult worker of l/espula maculiJrons. The worker is a non- reproductive female and uses her oviposi- tor as a sting
most of the activities and structures of the animal, in- cluding its adaptation to its environment, its modes of locomotion, its devices for avoiding enemies, its means of obtaining food. Hence, in studying any young insect, we must understand that we are dealing almost exclusively with characters that are adaptive to the feeding function. When we observe the life of any caterpillar we soon realize that its principal business is that of eating. ”

“ As soon as such expansions would be of even slight use to the insect as breathing organs, the question as to their permanency would be settled. Organs so useful both for flight and aëration of the blood would be still further developed, until they would become permanent structures, genuine wings. They would thus be readily transmitted, and being of more use in adult life during the season of reproduction, they would be still further developed, and thus those insects which could fly the best, i.e. which had the strongest wings, would be most successful in the struggle for existence. ”

“ For the most part these insect parasites are small four-winged flies, although many of them are two-winged flies. In either case the life stages show a series of changes much like those of the butterflies themselves. Each parasite exists first as an egg, second as a larva, third as a pupa, and fourth as an adult fly. ”

“ The adult feeds savagely on other insects, killing them with powerful jaws—which can also nip your finger. The larvae are called “doodlebugs” and live in upright burrows in the sand, allowing their jaws to extend above ground to capture unsuspecting prey.
Click Beetles (Elateridae) When turned over, the insect snaps back upright First body segment as broad as the last
Click Beetles are so named because of the resounding “click” they make when snapping up into the air after being overturned. The adults are strict vegetarians, so look for them on plants. ”

“ Generally speaking, all adult insects have wings, and all winged insects are adults. There are exceptions to this, but they will take their places when the time comes. The young of the insects belonging to certain orders resemble their parents enough so as to be placed where they belong at a glance. This is true of the grasshoppers, katydids, and crickets, of the true bugs which include the squash-bugs, the chinch-bug, the stink-bug and others. ”

“ Thus it is an almost ideal spot for all sorts of insects to lay their eggs. There is a high probability that the great majority of them will hatch. As the young rise from the water they are attracted by the star-filled heavens overhead. They fly toward them as moths to a lamp. The same is true of many of the small adult insects, some of which are essentially microscopic. ”

“ INSECT METAMORPHOSIS
it is provided with food by the parents. Sorne of the wasps store paralyzed insects in the cells of the nest for the young to feed on; the bees give their young a diet of honey and pollen, with an adrnixture of a secretion from a pair of glands in their own bodies. The grubs have noth- ing to do but to eat; they have no legs, eyes, or antennae; each is a rnere body with a rnouth and a stornach. The adult bees consume rnuch honey, which, like its con- stituent, nectar, is an energy-forrning food ”

“ Though gradation in size may be a sign of successive ages in certain insects, the presence of functioning wings denotes that growth has ceased; in the case of wingless insects, the characters of maturity may be less conspicuous. Although there may be at times a fairly wide range in size among fully-grown individuals of the one species, such variation is not due to age, but to certain factors influencing the insect during growth, such as the abundance or scarcity of food supply, and favourable or unfavourable climatic conditions. ”

“ Small insects have, as a rule, shorter lives than large ones; those whose larvae devour highly nutritive food generally develop more quickly than those which have to live on dry, poor, substances; life-cycles follow one another most rapidly in summer weather when temperature is high and food plentiful.
In early chapters we have already noticed the long aquatic life of the larva and nymph of a dragon-fly, relatively a large insect, and the rapid multiplication of the repeated summer broods of virgin aphids (p. 18) . ”

“ The pupa being disengaged from its skin, assumes a different form, in which it is dignified with the name of a beetle, and acquires a distinction of sex, being either male or female. The insect now begins to enjoy a life far preferable to its former state of existence; from living in dirt and filth, under briars and thorns, it raises itself towards the skies, plays in the sun-beam, rejoices in its existence, and is nourished with the oozing liquors of flowers. ”

“ The price, then, of a good collection is eternal vigilance. Most insects, when exposed for any length of time to strong light, fade or lose color, and the only way to prevent such achromatism is to exclude the light.
Insect pests affecting collections include Psocidæ, Mites, Tineidæ, Coleoptera of the families Ptinidæ and Dermestidæ, these last being the most injurious. ”

“ What we call parasitism in insects is really a kind of hunting. The Mutilla, for instance, is a huntress, and her prey is the grub of another kind of Wasp, just as the game of this other kind of Wasp may be a Caterpillar or a Beetle. When it comes to this, we are all hunters, or thieves, whichever way you look at it, and Man the greatest of all. He steals the milk from the Calf, he steals the honey from the children of the Bee, just as the Gray Fly takes the food of the Wasps’ babies. She does it to feed her children; and Man helps himself to everything he can find to feed his. ”

“ These later stages, comprising the greater part of the larval history, are adapted for an inquiline or a parasitic life, where shelter is assured and food abundant, while the short-lived, active condition enables the newly-hatched insect to make its way to the spot favourable for its future development, clinging, for example, in the case of an oil-beetle’s larva, to the hairs of a bee as she flies towards her nest. ”

“ In yon grey wall at the end of the lawn, just above the climbing rose-bush, there are now seven hungry infants in one small cradle, each one, some one says, able to consume its own weight of insect food every day. I am inclined to believe that it must be so, while trying to count the visits paid to the nest in one hour by the parent tits--those small tits that do the gardener so much harm! We know, on good authority, that the spider has a "nutty flavour"; and most insects in the larval stage afford succulent and toothsome, or at all events beaksome, morsels. ”

“ When I catch an insect I do it by throwing my tongue forward, out of my mouth. I have an idea the insects consider my treatment of them rather rough. If I didn't eat them, the wood-boring ones, would destroy all the trees. My bill isn't strong enough to bore in the hard wood; I only injure the bark, no matter what some people may say. The wood-eating beetles, caterpillars, spiders, daddy longlegs, grass-hoppers, and flies, are all grist for my mill—or bill, rather. ”

“ Others, and this is the most common mode of parasitism, attack the insect in its larva state; others, in the pupa state, and still others in the perfect, or imago state. Dr. Leidy has shown that the wood-devouring species of beetle, Passalus cornutus, and some Myriopods, or "thousand legs," are, in some cases, tenanted by myriads of microscopic plants and worms which luxuriate in the alimentary canal, while the "caterpillar-fungus" attacks sickly caterpillars, filling out their bodies, and sending out shoots into the air, so that the insect looks as if transformed into a vegetable. ”

“ The young do not look at all like the adults. In many [393] cases as, for example, the dragon fly and the mosquito, they are fitted in the immature stages to a life in the water. They must, on this account, have organs for swimming, for aquatic breathing, and for getting a living in the water. The forms of these young insects are just as varied as those of the adults, but they do not resemble the winged ones in the least. The life history collection must contain specimens of the immature forms of insect life as well as adults if it is to be most useful and complete. ”

“ But the very first time that you notice the male insect flying about on a warm summer’s evening you will see why the title was given to it; for it keeps on suddenly appearing and disappearing, over and over again, just as if it had the power of making itself visible or invisible whenever it chose. The fact is that the upper surface of the wings is glossy white, while the lower is dark brown, and that as the insect flies you can see the one and not the other. So every time that the wings are lowered the moth appears; and every time that they are raised it disappears. ”

“ When this is finished, all except a round hole, it brings seven or eight caterpillars or spiders, each of which is rendered insensible, but not killed, by the fluid from its sting. These it deposits in the cell, and then one of its own larvae, which, as it grows, finds food quite fresh. The insects are in a state of coma, but the presence of vitality prevents putridity, or that drying up which would otherwise take place in this climate. By the time the young insect is full grown and its wings completely developed, the food is done. ”

“ Many insects are polygoneutic, that is, the species is represented by two or more annual broods, or generations, and thousands of individuals may, by careful treatment, be reared from the eggs of a single female. In the case of the higher animals the development and multiplication of individuals takes place but slowly, and it is obvious, therefore, that there is in the domain of insect life a far more convenient field for the investigation of the great problems of variation in animal forms, than among the vertebrate animals. ”

“ The food is chiefly insects but considerable numbers of spiders and daddy-long-legs also are eaten. Beetles, caterpillars, and ants are the larger classes of insect food, but moths, flies, bugs, and a few hymenoptera also are eaten. Among forest enemies that have been found in stomachs of this species are round-headed wood borers, leaf beetles, flea beetles, weevils, bark beetles, leaf hoppers, and jumping plant lice. ”

“ Certain insects (also certain Batrachians, reptiles, &c.) are unpalatable to the rapacious kinds; it is therefore a direct advantage to these unpalatable species to be distinguishable from all the persecuted, and the more conspicuous and well-known they are, the less likely are they to be mistaken by birds, insectivorous mammals, &c., for eatable kinds and caught or injured. Hence we find that many such species have acquired for their protection very brilliant or strongly-contrasted colours--warning colours--which insect-eaters come to know. ”