Insectivore

“ The foliage of all trees and shrubs should be vigorously beaten and the insects captured as they fly out. When a moth is taken, the collector will first turn the net half way round so as to close the entrance, and then, directly the insect ceases fluttering, he should carefully place one of the little boxes over it and slip on the lid. The box is then transferred to the right-hand pocket. He will soon learn to do this without in any way damaging the insect. On arrival at home, the insects should be immediately killed in the laurel bottle. ”

“ One can see insects stuck on them and vainly struggling to be free, and the hairs undoubtedly prevent green-fly and other such pests from interfering with the honey of the flower. In some of these cases it has been shown that the body of the insect is actually used as food, but that is more obvious with two interesting plants which specially devote themselves to the capture of insect prey. One of these is very often kept in the Boer farmhouses near Tulbagh, in South Africa, simply to attract the flies, which are a perfect pest in those dry valleys. ”

“ This type of insect gradually gave rise to the orders which now contain the largest number of species, including the beetles, moths, and flies. In many lines of this neuropteroid branch, as it is called, the larva has become adapted to a mode of life quite different from that of the adult. Many fly larvae, for example, live in rotting organic material or live as parasites within the tissues of other kinds of insects, whereas the adult flies often feed at flowers on pollen and nectar, visiting the site of the larval habitat only to lay eggs. ”

“ Without their aid it would in many cases be impossible for the agriculturist to hold his own against the ravages of his minute insect foes, whose habits are not sufficiently known to render artificial checks or destroying agents available. The females of all the species are constantly on the alert to discover the proper living food for their own larvae, which are hatched from the eggs they deposit in or on the eggs, larvae or pupae of other insects of all orders, chiefly Lepidoptera, the caterpillars of butterflies and moths being specially attacked (as also are spiders) . ”

“ In this process the entire old skin is shed, an operation well worth seeing. Under the old coat a new one has formed, which being larger, accommodates itself to the insect's increased size. The larval stage is in the case of many insects the active time when, if they are vegetable feeders, they injure crops.
When the larva has completed its growth it changes into a pupa. Some insects pass this third stage inside of silken cases they spin about themselves, others, after shedding the larval skin, find themselves each clad in a sort of horny coat of mail. We call these chrysalides. ”

“ As an agriculturist as well as naturalist I have been always interested in the insectivorous birds [76] as a great aid to man in the destruction of insects. I know of no bird that does not eat insects, except the goldfinch. I remember once examining the stomach of an American swift, it contained a mass of insects, six hundred and fifty mosquitoes and gnats which had been caught on the wing that day. Especially valuable is the purple martin because he can be attracted to our fields and orchards if the proper kind of house is made for him. ”

“ Many are so intimately connected with other insects during some part of their existence that they could not live without them; such are the parasitical hymenoptera and diptera, and those mimicking species whose welfare depends upon their being {34}mistaken for something else. Then again, insects have enemies in every stage of their existence—the egg, the larva, the pupa, and the perfect form; and the abundance of any one of these enemies may render their survival impossible in a country otherwise well suited to them. ”

“ Aquatic larvæ should be carried in tin boxes filled with wet moss or some water plant, for, if placed in corked vials with water, they die quickly.
Killing Specimens.—Specimens not intended for rearing should be killed immediately after capture unless for each specimen a separate vial or box can be provided. If a number of miscellaneous insects are put in the same vial the stronger specimens will, in a short time, crush or otherwise injure the more delicate ones or the predaceous species will devour any others they can master. ”

“ The hard substances commonly called captain's biscuits are the objects of attack, together with flour, peas, and similar articles of food, and the attacking insect is the larva of the meal-worm, the entomological title of which is Tenebrio molitor. In vain does the ship's cook, with all his art, prepare a soup composed of the richest ingredients, and calculated, as one would think, to gratify the taste of the greatest epicure. The larvæ have been beforehand with him; they have attacked and become mixed with the flour or the peas ”

“ As the sun goes down many species move which do not stir at other times. I watch the tops of the grass, the stems of the flowers, the twigs of the trees; I disturb leaves and low-growing plants with a short switch and secure each little moth that moves, taking each out of the net in a separate pill-box, selected according to the size of the insect, as he runs up the net to escape. Transferring the full boxes to the bag I continue the process until moths cease flying or night sets in. Many species can be taken with a lamp after dark. ”

“ Warned by the stench, which travels far and wide, a host of insects are flying hither; such insects as dissect the corpses of frogs, adders, lizards, hedgehogs, moles and field-mice—creatures that the peasant finds beneath his spade and throws disembowelled on the path. They fall upon the great leaf, whose livid purple gives it the appearance of a strip of putrid flesh; they dance with impatience, intoxicated by the corpse-like odour which to them is so delicious; they roll down its steep face and are engulfed in the capsule. After a few hours of hot sunlight the receptacle is full. ”

“ Don't let the soil get full of insect troubles; therefore, keep the soil open and aired and study it well.
"There are two general classes of insects known by the way they do their work. One kind gnaws at the plant really taking pieces of it into its system. This kind of insect has a mouth fitted to do this work. Grasshoppers and caterpillars are of this sort. The other kind sucks the juices from a plant. This, in some ways, is the worst sort. Plant lice belong here, as do mosquitoes, which prey on us. All the scale insects fasten themselves on plants, and suck out the life of the plants. ”

“ A certain kind of insect may live only on a certain kind of plant, and to obtain the insect the collector must search or sweep the plant, called the host plant.
Many obscure places harbor insects seldom found elsewhere. Among these are leaf mold and debris on the surface of the soil, particularly in woods; rotten logs and stumps, which should be turned over to reveal insects that hide under or around them, and then carefully searched or torn apart for others that live inside; in, under, and around dead animals; under boards and stones.
Trees sometimes yield valuable specimens. ”

“ The insects that trouble us most are: Canker-worm, tent-caterpillar, fringed-wing bud moth, handmaid-moth or yellow-necked caterpillar, roundheaded borer and the tussock-moth caterpillar on our trees; and codling-moth, gouger and tree cricket on and in our fruit. We spray annually, using a horse-power machine, illustrated in former reports of the State Horticultural Society, for the leaf-eating insects named, using London purple and clear water, sometimes adding lime. ”

“ Many insects, particularly dragon-flies, have brilliant coloring when fresh from the pupa, which is largely lost afterward. The time of laying and hatching [124] of eggs, the number from a single female, the character of the eggs, general habits, records of parasites and their mode of attack—all should be entered as observed. A great many species have the most curious life histories, which can not be ascertained except by continued and persevering observation, not only in the vivarium or insectary but in the field. ”

“ I have often kept specimens of these larvæ in vessels of water and noticed their predaceous habits; they feed on the larvæ of other water insects, but are not able to destroy fish, not being furnished with jaws or bodies nearly so strong as the perfect insect itself possesses. When the larva wishes to turn into its pupa state, it makes a round hole in the bank of the pond it inhabits, and there undergoes its change, turning into a full-grown beetle in about three [Pg 31] weeks' time. ”

“ There is a little apparatus [1] constructed for carrying this fluid safely to the field, and letting out a drop at a time into the box with the captured insect, taking care that the drop does not go on to the insect. Or a wide-mouthed bottle may be used, having at the bottom a pad of blotting-paper, or some absorbent substance, on which a few drops of chloroform may now and then be dropped. The insect being slipped into this, and the stopper or hand being placed over the bottle's mouth, insensibility (in the insect) follows immediately, and in a few minutes, at most, it is completely lifeless. ”

“ Here, I think, we have an explanation of the principle on which protection is undoubtedly afforded to certain insects by the possession of bright coloring on such parts of their wings or bodies as can be instantly covered and concealed at will. It is an undoubted fact, and one which must have been observed by nearly all collectors of insects abroad, and perhaps also in our own country, that it is more easy to follow with the eye the rapid movements of a more conspicuous insect soberly and uniformly colored than those of an insect capable of changing in an instant the appearance it presents. ”

“ It is well known that different mixtures, which are at first pure and apparently free from all insect life, will, in the course of their fermentation and subsequent impurity, generate peculiar species of animalcules. Thus all water and vegetable or animal matter, in a state of stagnation and decay, gives birth to insect life; likewise all substances of every denomination which are subjected to putrid fermentation. Unclean sewers, filthy hovels, unswept streets, unwashed clothes, are therefore breeders of animalcules, many of which are perfectly visible without microscopic aid. ”

“ With the change of climate, however, came a change in their taste for insects. They made their home in the country as well as the cities, and became seed and vegetable eaters, devouring the young buds on vines and trees, grass-seed, oats, rye, and other grains.
Their services in insect-killing are still not to be despised. A single pair of these Sparrows, under observation an entire day, were seen to convey to their young no less than forty grubs an hour, an average exceeding three thousand in the course of a week. ”

“ Moreover, insects are of great use as scavengers; such are the young or maggots of the house fly, the mosquitoes, and numerous other forms, that seem created only to vex us when [Pg 54] in the winged state. Still a larger proportion of insects are directly beneficial from their habit of attacking injurious species, such as the ichneumons (Fig. 43, the ichneumon of the American silk worm) and certain flies (Fig. 44, Tachina) ; also many carnivorous species of wasps beetles and flies, dragon flies and Aphis lions (Fig. 45, the lace-winged fly; adult, larva and eggs) . ”

“ The insect-eaters now existing are chiefly a few straggling forms of a once widely-spread group; while the rodents, on the contrary, are still a very numerous and varied family, spread all over the earth, and boasting of such intelligent forms as the squirrel, the beaver, and the rat. But here their advantages appear to end, while the insectivora point onwards not only to the bats, the only flying milk-givers, but also through the colugo to the lemurs, and thus onwards to the monkeys. ”

“ Before concluding the present chapter I should like to say a few words on the subject of rearing insects, which the entomologist will soon learn to regard as by far the most interesting method of acquiring specimens for his collection.
Members of the Coleoptera are probably the most difficult insects to rear in captivity. Their larvæ may be kept in ordinary jam-pots covered with perforated zinc, and filled with earth or rotten wood. The carnivorous species must, of course, be supplied with the animals on which they feed. Beetle larvæ are often some years in attaining maturity. ”

“ Why does the Insect construct the funnel at all? As a matter of protection it appears to be of little use, for the larvae are known to suffer from the attacks {294}of parasites as other Insects do. We have not the least reason for supposing that this mode of life for a larva is, so far as utility is concerned, better than a more simple and usual one. Indeed, extraordinary as this may appear, it is well known that other species of the same genus adopt a simple mode of life, laying their eggs in young fruits or buds. ”

“ It would be a simple matter to find abundant material for a large volume by making a study of the life-histories of the various insects that live upon or within the various tissues of this tree. The leaves alone provide a home for a remarkably large number of insect species scattered through a great many orders and families. The thickened blades seem to furnish an ideal opportunity for many larvae to get their living, and they are particularly useful to those which need to make a winter nest. ”