CURIOSITIES RESPECTING INSECTS.—(Continued.)

The Common House Fly.

Gordart has reckoned up forty-eight varieties of the fly, without including them all in this enumeration. The multitude of these lively insects, which the first genial sunshine calls forth into life, has limits which the human eye is incapable of exploring. The female fly is easily distinguishable from the male: she is larger than the latter, fuller in the body, of a lighter colour, and, when she is nearly ready to deposit her eggs, the abdomen is so transparent, that they may be perceived lying on both sides, opposite to each other. Nature has instructed her not to deposit her eggs in dry, but in damp substances, which keep them from being dried up, and at the same time afford nourishment to the maggot or worm. The latter issues from the egg generally in twenty-four hours, but, in the sun, within twelve hours after it is laid. About half an hour before, annular circles become visible in the egg, an undulatory motion succeeds, the egg opens at the end, and the worm makes its appearance. Its entrance into the world is extremely tedious; for the three or four minutes taken by the worm to work its way out of the egg, are, for it, certainly so many days. It is endowed, on the other hand, with vital powers, which enable it to defy inconveniences which cost other animals their lives. Nothing but turpentine, the general destroyer of insects, kills it in half an hour. On the fourteenth or fifteenth day, it begins to prepare for its transformation into a nymph, and in this form appears at first of a light yellow, and afterwards of a dark red. You would take it, in this state, for some kind of seed, rather than for the habitation of a living creature. The change of the nymph into a fly requires as much time as the preceding transformation. A thrust with the head then bursts the prison in which it is confined, and the fly, perfectly formed, sallies forth. The sun hastens its birth, which is then the business of but a moment; but in unfavourable weather, this probably painful operation often takes four or five hours. The insect is now as perfect as its parents, and not to be distinguished from them. As soon as it issues from the nymph, it flies away; and only those are unable to use their wings immediately, which have the misfortune to come out in gloomy weather.

Leuwenhock reckons, that every fly has eight thousand hexagons or eyes, on each of the hemispheres composing its face, and consequently sixteen thousand on both. M. Von Gleichen, a German naturalist, observes, that the law of retaliation is in some measure established, in regard to these animals; for if they annoy us, they are in their turn persecuted by others. Small yellow insects, discovered by means of the magnifying glass, crawling among the hairs that grow on their bodies, are supposed to be destined for this purpose.

The fecundity of flies is prodigious. On this head, the last-mentioned naturalist has made the following calculation:—

Another curious insect is, The Hessian Fly.—This is a very mischievous insect, which a few years ago appeared in North America, and whose depredations threatened then to destroy the crops of wheat in that country entirely. It is, in its perfect state, a small winged insect, but the mischief it does, is while in the form of a caterpillar; and the difficulty of destroying it is increased, by its being as yet unknown where it deposits its eggs, to be hatched before the first appearance of the caterpillars. These mischievous insects begin their depredations in autumn, as soon as the wheat begins to shoot up through the ground. They devour the tender leaf and stem with great voracity, and continue to do so till stopped by the frost; but no sooner is this obstacle removed by the warmth of the spring, than the fly appears again, laying its eggs now, as has been supposed, upon the stems of the wheat just beginning to spire. The caterpillars hatched from these eggs, perforate the stems of the remaining plants at the joints, and lodge themselves in the hollow within the corn, which shews no sign of disease till the ears begin to turn heavy. The stems then break, and being no longer able to perform their office in supporting and supplying the ears with nourishment, the corn perishes about the time that it goes into a milky state. These insects attack also rye, barley, and timothy-grass, though they seem to prefer wheat. The destruction occasioned by them, is described in the American Museum, (published at Philadelphia,) for Feb. 1787, in the following words:—

“It is well known that all the crops of wheat in all the land over which it has extended, have fallen before it, and that the farmers beyond it dread its approach; the prospect is, that unless means are discovered to prevent its progress, the whole continent will be overrun;—a calamity more to be dreaded, than the ravages of war.” This terrible insect appeared first in Long Island, during the American war, and was supposed to have been brought from Germany by the Hessians; whence its name. From thence it proceeded inland at the rate of about fifteen or twenty miles annually; and, in 1789, had reached two hundred miles from the place where it was first observed. At that time it continued to proceed with unabating increase; being apparently stopped neither by rivers nor mountains. In the fly state it is likewise exceedingly troublesome, by getting into houses in swarms, falling into victuals and drink, filling the windows, and flying perpetually into the candles.

The May Fly.—This insect is called the May fly, from its annual appearance in that month. It lies all the year, except a few days, at the bottom or sides of rivers, nearly resembling the nymph of the small libella; but when it is mature, it rises up to the surface of the water, and splits open its case; then, with great agility, up springs the new animal, having a slender body, with four black-veined, transparent, shining wings, with four black spots in the upper wings; the under wings are much smaller than the upper ones; and with three long hairs in its tail.

The husk it leaves behind floats upon the water. After this creature is discharged from the water, it flies about to find a proper place to fix on, (as trees, bushes, &c.) to wait for its approaching change, which is effected in two or three days.

The first hint I received of this wonderful operation, was by seeing their exuviÆ hanging on a hedge. I then collected a great many, and put them into boxes; and by strictly observing them, I could tell when they were ready for this surprising change.

I had the pleasure to shew my friends one, which I held in my fingers all the time it performed this great work; it was surprising to see how easily the back part of the fly split open, and produced the astonishing transformation. In the new fly, a remarkable difference is seen in their sexes, which is not so easy to be perceived in their first state, the male and female being much of a size; but afterwards the male is much the smallest, and the hairs of their tails much the longest.

When the females are about to deposit their eggs, they seek the rivers, keeping constantly playing up and down upon the water. It is very plainly seen, that every time they dart down, they eject a cluster of eggs, which appears like a little bluish speck, or a small drop of milk, as they sink to the bottom of the river. Thus they continue until they have spent their strength, being so weak, that they can rise no more, but fall a prey to the fish. But by much the greatest number perish on the waters, which are covered with them. This is the end of the females. The males never resort to the river, but, after a time, drop down, languish, and die, under the trees and bushes.

The species of libella abounds most with females, which is very necessary, considering the many enemies they have in their short appearance; for both birds and fishes are fond of them, and, no doubt, under water they are the prey of aquatic animals.

What is further surprising in this remarkable creature is, that during a life which consists only of three or four days, it eats nothing, and seems to have no apparatus for this purpose, but brings up with it, out of the water, sufficient support to enable it to shed its skin, and perform the principal ends of life with great vivacity.

The Vegetable Fly.—This is a very curious natural production, chiefly found in the West Indies. It resembles the drone, both in size and colour, more than any other British insect, excepting that it has no wings. “In the month of May, it buries itself in the earth, and begins to vegetate. By the end of July, the tree has arrived at its full growth, and resembles a coral branch; it is about three inches in height, and bears several little pods, which, dropping off, become worms, and thence flies, like the British caterpillar.” Such was the account originally given of this extraordinary production. But several boxes of these flies having been sent to Dr. Hill for examination, his report was as follows:—“There is in Martinique a fungus of the clavaria kind, different in species from those hitherto known. It produces soboles from its sides; I call it therefore clavaria sobolifera. It grows on putrid animal bodies, as our fungus (ex pede equino) from the dead horse’s hoof. The cicada is common in Martinique, and in its nymph state, in which the old authors call it tettigometra, it buries itself under the dead leaves, to await its change; and, when the season is unfavourable, many perish. The seeds of the clavaria find a proper bed in these dead insects, and grow. The tettigometra is among the cicada in the British Museum; the clavaria is but just now known. This is the fact, and all the fact; though the untaught inhabitants suppose a fly to vegetate, and though there is a Spanish drawing of the plants growing into a trifoliate tree; and it has been figured with the creature flying with this tree upon its back.”—Thus does ignorance delight in the marvellous!

The Boat Fly.—This insect, called Notonecta glauca, is thus described by Barbut. “It has a head somewhat round, of which the eyes seem to take up the greatest part. These eyes are brown, and very large, the rest of the head being yellow. In the fore-part it has a sharp trunk, that projects, and is inflected between the fore feet. On the sides are seen the antennÆ, very small, yellowish, and which spring from under the head. The thorax, which is broad, short, and smooth, is yellow on the fore, and black on the back part. The escutcheon is large, of a rough black, and as it were nappy. The elytra, rather large, and crossed over each other, are a mixture of brown and yellow, not unlike the colour of rust, which makes it look cloudy. The under part of the body is brown; and at the extremity of the abdomen are to be seen a few hairs. The feet, six in number, are of a light brown, the two hindermost having on the leg and tarsus hairs that give them the shape of fins, nor are they terminated by nails. The four anterior ones are somewhat flat, and serve the animal to swim with; but at their extremity they have nails, and no hairs. This insect is seen in stagnating waters, where it swims on its back, and presents its abdomen upwards; for which reason it has been called by the Greek name of notonecta. The hinder feet, longer than the rest, serve it as paddles. It is very nimble, and dives down when you go to take hold of it; after which, it rises again to the surface of the water. It must be cautiously handled, if one would avoid being pricked by it, for the point of its rostrum is exceedingly sharp, and intolerably painful, but it goes off in a few minutes. The larva very much resembles the perfect insect.”

Such is the account that Mr. Barbut gives of this beautiful nimble little creature. To this account, however, we shall add the following:—Its legs are long; when taken out of the water, it hops; it is very common in the ponds of water in Hyde Park, and in several other places about London. It is of a very particular form, being flattish at the belly, and rising to a ridge on the middle of the back; so that when it swims, which is almost always on the back, its body has much the resemblance of a boat in figure,—whence its vulgar name. It is eight lines long, three broad, and two and a half thick. The belly is jointed, striated, and, as Barbut observes, hairy. Nature has provided it with an offensive weapon resembling a sting, which it thrusts out when hurt, from a large opening at the tail. The head is large and hard; the eyes nearly of a triangular form. The nose is a long, green, hollow proboscis, ending in a hard and sharp point, which in its natural posture remains under the belly, and reaches to the middle pair of legs. The outer part of its wings are of a pale flesh-colour, with spots of a dead white; these are long, narrow, and somewhat transparent; they terminate in a roundish point, and perfectly cover the whole body. The triangular piece which stands between the top of the wings is hard, and perfectly black; the inner wings are broader and shorter than the outer ones; they are thin and perfectly transparent, and are of a pale pearl-colour. The hinder pair being greatly longer than all the rest, they serve as oars; and nature has tufted them with hair at the end for that purpose. This creature mostly lives in the water, where it preys on small insects, killing them, and sucking their juices with its proboscis, in the manner of the water scorpion and many other aquatic insects: it seizes its prey violently, and darts with incredible swiftness to a considerable distance after it.

Though it generally lives in the water, it sometimes, however, crawls out in good weather; and drying its wings by expanding them in the sun, takes flight, and becomes an inhabitant of the air, not to be known as the same creature, unless to those who had accurately observed it before: when tired of flying, or in danger of an enemy, it immediately plunges into the water. We are told that there are fourteen species of it, seven of which are common in Europe, in waters, &c.

Ephemeral Flies.—This species of insect is named ephemeral, because of its very short existence in the fly state. It is one of the most beautiful species of flies, and undergoes five changes. At first, the egg contains its vital principle; it comes forth a small caterpillar, which is transformed into a chrysalis, then into a nympha, and lastly, into a fly, which deposits its eggs upon the surface of water, where the sun’s rays bring them to life. Each egg produces a little red worm, which moves in a serpentine manner. They are found in abundance during the summer, in ponds and marshes; and as soon as cold weather sets in, the little worm makes for itself a shell or lodging, where it passes the winter; at the end of which it ceases to be a worm, and enters into its third state, that of a chrysalis. It then sleeps till spring, and gradually becomes a beautiful nympha, or a sort of mummy, something in the form of a fish. At the time of its metamorphosis, the nympha at first seems inactive and lifeless; in six days, the head appears, raising itself gradually above the surface of the water; the body next disengages itself slowly and by degrees, till at length the whole animal comes out of its shell. The new-born fly remains for some minutes motionless upon the water, then gradually revives, and feebly shakes its wings, then moves them quicker, and attempts first to walk, then to fly. As these insects are all hatched nearly at the same time, they are seen in swarms for a few hours flitting and playing upon the surface of the water; they then lay their eggs, and soon after die. Thus they terminate their short life in the space of a few hours, and the same day that saw them born, witnesses their death.

The Butterfly.

Behold, ye pilgrims of this earth, behold!
See all but man with unearn’d pleasure gay
See her bright robes the butterfly unfold,
Broke from her wintry tomb in prime of May!
What youthful bride can equal her array?
Who can with her for easy pleasure vie?
From mead to mead with gentle wing to stray,
From flower to flower on balmy gales to fly,
Is all she has to do beneath the radiant sky.
Thomson.

The first thing which fixes our attention on beholding these aËrial inhabitants, is, the clothing with which they are adorned. Yet some of them have nothing in this respect to engage our notice, their vestment is simple and uniform; others have a few ornaments on the wings; but with some, those ornaments amount to profusion, and they are covered with them all over. This last species will occupy us for a short interval. How beautiful are the gradations of colour which decorate them! what harmony in those spots which relieve the other parts of their attire! with what delicacy has nature pencilled them! But, whatever may be my admiration when I consider this insect by the naked eye, how greatly is it augmented, when I behold this beautiful object through the medium of the microscope! Would any one ever have imagined, that the wings of butterflies were furnished with feathers? Nothing, however, is more true; and what we commonly call dust, is found in reality to be feathers. Their structure and arrangement are adjusted to as perfect symmetry, as their colours are soft and brilliant. The parts which form the centre of these little feathers, and which immediately touch the wing, are the strongest; those, on the contrary, which compose the exterior circumference, are much more delicate, and of an extraordinary fineness. All these feathers have a quill at their base, but the superior part is more transparent than the quill from which it proceeds. If we lay hold of the wing too rudely, we destroy the most delicate part of the feathers; but if we remove all that we term dust, there remains only a thin transparent skin, where may be distinguished the little orifices in which the quill of each feather was lodged. This skin, from the nature of its texture, may be as easily discerned from the rest of the wing, as a fine gauze from the cloth on which it is fastened; it is more porous, more delicate, and seems as if embroidered by the needle; to complete its beauty, its extremity finishes by a fringe, whose minute threads succeed each other with the utmost regularity.

What are our most laboured dresses, what is all their boasted ornament, in comparison of that refined tissue with which nature has invested this simple insect? Our finest laces are only like coarse cloth, when brought to vie with that luxurious clothing which covers the wings of the butterfly; and our smallest thread, by their infinitely delicate fibres, swells into hempen cord. Such is the wonderful difference to be observed between the works of nature and those of art, when viewed through a microscope. The former are finished to all imaginable perfection; the others, even the most beautiful of their kind, appear incomplete and coarsely wrought. How fine a piece of delicate cambric appears to us! nothing more slender than the threads, nothing more uniform than the texture: and yet in the microscope these threads resemble hempen strings, and we should rather be tempted to believe that they had been interlaced by the hand of a basket-maker, than wrought on the loom of a skilful weaver.

What is most astonishing in this brilliant insect, is, that it proceeds from a worm, than which nothing has a more abject and vile appearance. Behold how the butterfly displays to the sun his splendid wings, how he sports in his rays, how he rejoices in his existence, and, in respiring the vernal airs, how he flutters in the meadow from flower to flower. His rich wings present to us the magnificence of the rainbow. How beautiful is he now, who but a little while ago crept a worm in the dust, in perpetual danger of being crushed to death! Who has raised him above the earth? Who has given to him the faculty of inhabiting the ethereal regions? Who has furnished him with his painted wings? It is God.

In down of ev’ry variegated dye,
Shines, flutt’ring soft, the gaudy butterfly;
That powder, which thy spoiling hand distains,
The form of quills and painted plumes contains:
Not courts can more magnificence express,
In all their blaze of gems and pomp of dress.
Browne.
Their wings, all glorious to behold,
Bedropt with azure, jet, and gold,
Wide they display; the spangled dew
Reflects their eyes and various hue.
Gay.

We shall now briefly describe The Metamorphoses of Insects. And first, The Butterfly:

From form to form they pass in wondrous change.
Virgil.

At the first exclusion from the egg, and for some months of its existence afterwards, the creature which is to become a butterfly, is a worm-like caterpillar, crawling upon sixteen short legs, greedily devouring leaves with two jaws, and seeing by means of twelve eyes, so minute, as to be nearly imperceptible without the aid of a microscope. We now view it furnished with wings capable of rapid and extensive flights; of its sixteen feet, ten have disappeared, and the remaining six are in most respects wholly unlike those to which they have succeeded; its jaws having vanished, are replaced by a curled-up proboscis, suited only for sipping liquid sweets; the form of its head is entirely changed, two long horns projecting from its upper surface; and, instead of twelve invisible eyes, you behold two, very large, and composed of at least twenty thousand convex lenses, each supposed to be a distinct and effective eye!

Were we to push our examination further, and, by dissection, to compare the internal conformation of the caterpillar with that of the butterfly, we should witness changes even more extraordinary. In the former we should find some thousands of muscles, which in the latter are replaced by others, of a form and structure entirely different. Nearly the whole body of the caterpillar is occupied by a capacious stomach. In the butterfly, this has become converted into an almost imperceptible thread-like viscus; and the abdomen is now filled by two large packets of eggs, or other organs, not visible in the first state. In the former, two spirally-convoluted tubes were filled with a silky gum; in the latter, both tubes and silk have almost totally vanished, and changes equally great have taken place in the economy and structure of the nerves and other organs.

What a surprising transformation! Nor was this all. The change from one form to the other was not direct; an intermediate state, not less singular, intervened. After casting its skin, even to its very jaws, several times, and attaining its full growth, the caterpillar attached itself to a leaf by a silken girth. Its body became greatly contracted; its skin once more split asunder, and disclosed an oviform mass, without exterior mouth, eyes, or limbs, and exhibiting no other symptom of life than a slight motion when touched. In this state of death-like torpor, and without tasting food, the insect existed for several months, until at length the tomb burst, and out of a case not more than an inch long, and a quarter of an inch in diameter, proceeded the butterfly, which covers a surface of nearly four inches square.

The Common Fly.—This winged insect, whose delicate palate selects out the choicest viands, one while extending his proboscis to the margin of a drop of wine, and then gaily flying to take a more solid repast from a pear or a peach; now gambolling with his comrades in the air, now gracefully carrying his furled wings with his taper feet;—was but the other day a disgusting grub, without wings, without legs, without eyes, wallowing, well pleased, in the midst of a mass of excrement.

The Greycoated Gnat.—This creature, whose humming salutation, while she makes her airy circles about our bed, gives terrific warning of the sanguinary operation in which she is ready to engage, was a few hours ago the inhabitant of a stagnant pool, more in shape like a fish than an insect. Then to have been taken out of the water would have been speedily fatal; now it could as little exist in any other element than air. Then it breathed through its tail; now through openings in its sides. Its shapeless head, in that period of its existence, is now exchanged for one adorned with elegantly tufted antennÆ, and furnished, instead of jaws, with an apparatus more artfully constructed than the cupping-glasses of the phlebotomist; an apparatus, which, at the same time that it strikes in the lancets, composes a tube for pumping up the flowing blood.

The Shardhorn Beetle.—This species of beetle, whose sullen hum, as he directs his droning flight close past our ears in our evening walk, was not in his infancy an inhabitant of air, the first period of his life being spent in gloomy solitude, as a grub, under the surface of the earth. The shapeless maggot, which we scarcely fail to meet with in some one of every handful of nuts we crack, would not always have grovelled in that humble state. If our unlucky intrusion upon its vaulted dwelling had not left it to perish in the wide world, it would have continued to reside there until its full growth had been attained. Then it would have gnawed itself an opening, and, having entered the earth, and passed a few months in a state of inaction, would at length have emerged an elegant beetle, furnished with a slender and very long ebony beak; two wings, and two wing-cases, ornamented with yellow bands; six feet; and in every respect unlike the worm from which it proceeded.

The Death-watch.—This appalling name is applied to a harmless, diminutive insect, because it emits a sound resembling the ticking of a watch, and is supposed to predict the death of some one of the family, in the house in which it is heard. Thus sings the muse of the witty Dean of St. Patrick on this subject:—

“————————————A wood worm
That lies in old wood, like a hare in her form:
With teeth or with claws, it will bite or will scratch,
And chambermaids christen this worm a death-watch;
Because like a watch it always cries click:
Then woe be to those in the house who are sick!
For, sure as a gun, they will give up the ghost,
If the maggot cries click, when it scratches the post:
But a kettle of scalding-hot water injected
Infallibly cures the timber affected;
The omen is broken, the danger is over,
The maggot will die, and the sick will recover.”

To add to the effect of this noise, it is said to be made only when there is a profound silence in an apartment, and every one is still.

Authors were formerly not agreed concerning the insect from which this sound of terror proceeded, some attributing it to a kind of woodlouse, and others to a spider; but it is now a received opinion, adopted upon satisfactory evidence, that it is produced by some little beetles belonging to the timber-boring genus, Anobium, F. Swammerdam observes, that a small beetle, which he had in his collection, having firmly fixed its fore-legs, and put its inflexed head between them, makes a continual noise in old pieces of wood, walls, and ceilings, which is sometimes so loud, that upon hearing it, people have fancied that hobgoblins, ghosts, or fairies, were wandering around them. Evidently this was one of the death-watches. Latreille observed Anobium striatum, F. produce the sound in question, by a stroke of its mandibles upon the wood, which was answered by a similar noise from within it. But the species whose proceedings have been most noticed by British observers, is, A. tessellatum, F. When spring is far advanced, these insects are said to commence their ticking, which is only a call to each other, to which, if no answer be returned, the animal repeats it in another place. It is thus produced: Raising itself upon its hind-legs, with the body somewhat inclined, it beats its head with great force and agility upon the plane of its position; and its strokes are so powerful, as to make a considerable impression if they fall upon any substance softer than wood. The general number of distinct strokes in succession, is from seven to nine or eleven; they follow each other quickly, and are repeated at uncertain intervals. In old houses, where these insects abound, they may be heard in warm weather during the whole day. The noise exactly resembles that produced by tapping moderately with the nail upon a table; and, when familiarized, the insect will answer very readily the tap of the nail.