Winged insect

“ Such are the Ichneumons, beautiful winged insects, which perfidiously insert their eggs in the body of a living caterpillar, whose internal part serves at the same time for a cradle and for food. The young larva devours organ after organ, beginning with the least important, till the last serves for the formation of the last members of the winged insect.
More unfortunate are those which are kept under the bolts and bars of their host from their early youth to mature age; they have no participation in the great banquet of life, except it be in the pleasures of the table and of love. ”

“ If these larvae should be allowed to develop into a mature winged insect that would lay eggs, this particular insect would multiply itself hundreds of times over and it would take many more birds than at present exist to take over the big job of keeping the balance between necessary insect life and a surplus which would be destructive to all plant life. ”

“ In this last moult the tubercled skin splits on the back, and is soon worked off, the body in the winged insect having neither tubercles nor granulations. These winged insects are most abundant in August and September, but may be found as early as the first of July, and until the vines cease growing in the fall. The majority of them are females, with the abdomen large, and more or less elongate. ”

“ Armed with the above simple paraphernalia, viz. net to catch, boxes and pins to contain and detain, the insect hunter may sally forth on any fine summer's day, with a pretty sure prospect of sport, and the chance, at least, of a prize. Much depends, however, on the choice of a day, and the nature of the locality that is to form the hunting ground.
As to weather, it must be remembered that winged insects have a great objection to face a north, or north-east wind, during the prevalence of which you will probably find hardly one stirring, however prolific the locality may at other times be. ”

“ About twenty species of the Pyralides, one or two of the Pterophori, a few Crambi, about fifty of the Tortrices, and no less than two hundred of the Tineæ. The collector will do well to search fences and [Pg 332] tree trunks for these moths, whenever he has the opportunity; and also to use the net freely in wooded country, waste places, and along hedgerows, before and at dusk.
JUNE
There is a marked increase in winged insect life during this month. The early butterflies are disappearing, or perhaps have quite left us; but new species are taking their place. ”

“ Observers in other countries have noted that there is a summer migration of winged females to cruciferous plants, where colonies are established, and whence there is a return migration during the autumn to the original host. The wingless females are black, with part of the legs yellow, while the young individuals are pale in colour; the winged females have a green abdomen, from which arise the black “honey-tubes.” Since all the over-wintering eggs have hatched by the time the buds open, the insect can be then controlled by applications of nicotine-sulphate. ”

“ The jump is greater in proportion as the leg is longer.
To treat here in a general manner of the wings of insects would be useless. We shall refer to them at length in their proper place, when treating of the various types of winged insects.
In the perfect insect the abdomen does not carry either the wings or the legs. It is formed of nine segments, which are without appendages, with the exception of the posterior ones, which often carry small organs differing much in form and function. ”

“ The Orientals are very careful to gather in this crop at the exact time which experience has proved to be the best, namely, that in which the excrescence has attained its greatest size and weight. If there is any delay, the insect undergoes its metamorphosis, pierces the shell, and appears under its form of a winged insect. ”

“ In the winged insects they are of frequent occurrence, existing under great variety of form, varying greatly in position, and appearing usually to be in immediate relation with their active volant habits. Their presence is in direct adaptation to the needs and habits of their possessors, and being repellent, warning, or defensive structures, the odors they secrete being often exceedingly nauseous, they appear to have been called into existence in direct response to their biological environment. ”

“ Occasionally certain groups of winged insects evolved new types which had small wings or were wingless. The new types resulted because 34 the groups were subjected to environmental situations where wings were of little survival value. ”

“ Here we see that the feeding activities of the insect are carried on during the larval stage only; the may-fly in its winged condition takes no food, pairing and egg-laying form the whole of its appointed task. A similar though less extreme shortening of the imaginal life may be noticed in many endopterygote insects. For example, the bot- and warble-flies have the jaws so far reduced that they are unable to feed, and the parasitic life of the maggot (see p. 74) extending over eight or nine months in the body of the horse or ox, prepares for a winged existence of probably but a few days. ”

“ 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. ”

“ 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. ”

“ The Mallophaga, or Bird-lice, are degraded wingless insects, and are parasitic chiefly on birds, but also on mammals. In shape of body and character of the mouth-parts they are most nearly allied to the Psocidæ. The latter family includes both winged and wingless forms, the Book-mites belonging to the latter category. The winged forms may be illustrated by the common species, Psocus venosus (see Fig. 40) . The legs and antennæ are [25] long and slender and the wings are folded roof-like over the body when the insect is at rest. They feed on lichens and dry vegetation. ”

“ We are here supposed to have removed the soil on one side so as to give a view into the concreted earthen chambers where the pupæ are changing into full-grown beetles. You can see the much [Pg 29] longer legs of the adult insect beginning to develop, while the head assumes slowly its later form. The grubs remain in the cocoon through the winter, and emerge in spring as winged beetles, when they fly away with their brilliant wing-cases raised, in search of congenial mates and more dead field-mice. ”

“ Incidentally, this insect has made more positions for entomologists and has stimulated more interest in entomological work than all other species combined; in which respects it may not be considered an unmitigated pest.
As for plant-lice, their name is literally legion and their study Fig. 15. A winged plant-louse. is only begun. We find their eggs in winter and the insects themselves throughout the year. With the beginning of plant-growth the Aphids also begin development and the character of the infestation is as various as the plants or parts of plants attacked. ”

“ Frequently, as in the case of the aphids, many wingless generations intervene between two winged generations. A striking illustration of this fact is afforded by an aquatic bug, Velia currens, commonly to be seen skating over the surface of running water. The adults of Velia are nearly always wingless, but now and then the naturalist meets with a specimen provided with functional wings, the possession of which enables the insect to make its way to a fresh stream. ”

“ Winged insects are perhaps, of all, most admirably adapted for the special conditions found in one locality, and the barriers against their permanent displacement are numerous. Thus many insects require for their subsistence succulent vegetable food during the entire year, which, of course, confines them to tropical regions; some are dependent on mountain-vegetation; some subsist on water-plants; and yet others, as the Lepidoptera, in the larva state, are limited to a single species of plant. ”

“ Moreover there are whole orders of parasitic insects, such as the lice and fleas, which, showing clear affinity to orders of winged insects, are believed to be secondarily wingless. These orders are designated by Sharp 'Anapterygota.' And from the analogy of the periodic loss and recovery of wings in various generations of the same species, he has concluded that the gap between the exopterygote and the endopterygote method of development may have been bridged by an anapterygote condition ”

“ Still, in the case of all winged insects, there is one persistent difference between the young and the adult, and this is with respect to the development of the wings. The wings are always imper- fect or lacking in the young. ”

“ How long the scene of mutation continues is not known; some remain during the whole winter, more particularly those which quit the larva state in autumn, when a sudden cold checks their further operations, and consequently they remain in a torpid state, without any food, for several months. Some species of the beetle tribe go through all the stages of their existence in a season, while others employ near four years in the process, and live as winged insects a year. ”

“ In the winged insects, especially Lepidoptera, the number of moults is dependent on climate. Insects of wide distribution growing faster in warmer climates consequently shed their skins oftener; for example, the same species may moult once oftener in the southern than in the northern States, as in the case of Callosamia promethea, which in West Virginia is double-brooded. ”

“ Among the membranaceous or more transparent winged insects, the variety is endless, each genus differing essentially from the other; some appearing full of membranes or nerves, curiously disposed; others, again, with scarce any, like a clear piece of talc or isinglass; some exhibit a curious ground-work of points, which on close examination prove short hairs, while the nerves of others are furnished with little scales or feathers, as in some species of the gnat. The wings of many muscæ are coloured with black, brown, and white, in clouds, spots, stripes, &c. ”

“ The ancestors of the aphides were free winged insects; and, in certain stages of their existence, most living species of aphides possess at least some winged members. On the rose-bush, you can generally pick off a few such larger winged forms, side by side with the wee green wingless insects. But creatures which have taken to passing most of their life upon a single spot on a single plant hardly need the luxury of wings; and so, in nine cases out of ten, natural selection has dispensed with those needless encumbrances. ”

“ It is a general rule, that all winged insects pass through the larva and pupa state, before they assume their perfect form: there are also insects which have no wings, and yet undergo similar transformations, as the bed bug, the flea, &c. Other insects, which have no wings, and which always remain without them, never pass through the pupa state, but are subject to considerable changes, as well with respect to the number, as the figure of their parts; thus mites have four pair of feet, and two smaller ones at the fore part of the body, near the head ”

“ Means of Dispersal of Insects and the Barriers which Limit their Range.—Winged insects, as a whole, have perhaps more varied means of dispersal over the globe than any other highly organised animals. Many of them can fly immense distances, and the more delicate ones are liable to be carried by storms and hurricanes over a wide expanse of ocean. They are often met with far out at sea. ”

“ Winged insects have been mainly dispersed in the same way as birds, by their power of flight, aided by violent or long-continued winds. Being so small, and of such low specific gravity, they are occasionally carried to still greater distances; and thus no islands, however remote, are altogether without them. The eggs of insects, being often deposited in borings or in crevices of timber, may have been conveyed long distances by floating trees, as may the larvae of those species which feed on wood. Several cases have been published of insects coming on board ships at great distances from land ”

“ APTERA (Greek for “wingless”) , a term in zoological classification applied by Linnaeus to various groups of wingless arthropods, including some of the insects, the centipedes, the millipedes, the Arachnida (scorpions, spiders, &c.) and the Crustacea. In modern zoology the term has become restricted to the lowest order of the class Hexapoda or true insects. This order includes the bristle-tails and the springtails.
Many wingless insects—such as lice, fleas and certain earwigs and cockroaches—are placed in various orders together with winged insects to which they show evident relationships. ”

“ Some of the winged insects have elytra on their wings, as the melolontha; and others no elytra, as the bee. Insects do not direct their flight with their tail, and their wings have neither shaft nor division. ”

“ On the other hand, winged insects, such as bees, butterflies, and moths, making long excursions through the air, are admirably adapted for bringing pollen from distant plants. Hence plants spread their attractions for such insects, while they often contrive all sorts of ingenious devices for keeping undesirable ones, like ants, away from their flowers. ”