Chapter M: P. Huber is the only modern author that appears to have been witness to (3)

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.

CHAP. XXXI.

CURIOSITIES RESPECTING INSECTS.--(_Continued._)

_Locusts and Mosquitoes, and their Uses in the Creation;--from Kirby,
Spence, and Fothergill._

LOCUSTS.--If we could discover the use of every animal in the creation, we should gain a very clear insight into the grand designs of the Almighty, respecting creatures inferior to ourselves, and perceive the immediate cause and necessity of their existence, and how far we have a right to interfere with their economy. That man should ever attain the whole extent of this knowledge, in this state of existence, can scarcely be hoped for; but, that he may learn much, there can be no doubt.

Because the utility of some animals, in a general view, is not palpably obvious, we ought not pettishly or hopelessly to give up the inquiry. Some of the most numerous are apparently the most noxious, and the least useful, as the locust (_gryllus migratorius_) for example. It has never been my fortune to visit countries subject to the devastations of these insects; and the travellers who describe them, seem, either through want of inclination, or astonishment at the desolating effects produced by their incursions, unable to give those facts which an industrious and attentive naturalist, with enlarged views, might collect and apply to some useful purpose; for there can be no doubt that Infinite Wisdom would not have permitted these insects to be so numerous as they are, if their existence was not absolutely necessary. To look at a locust in a cabinet of insects, we should not, at first sight, deem it capable of being the source of so much evil to mankind as stands on record against it. Yet, although this animal be not very tremendous for its size, nor very terrific in its appearance, it is the very same whose ravages have been the theme of naturalists and historians in all ages, and, upon a close examination, it will be found to be peculiarly fitted and furnished for the execution of its office.

It is armed with two pair of very strong jaws, the upper terminating in short, and the lower in long teeth, by which it can both lacerate and grind its food; its stomach is of extraordinary capacity and powers; its hind-legs enable it to leap to a considerable distance, and its ample vans are calculated to catch the wind as sails, and so carry it sometimes over the sea; and although a single individual can effect but little evil, yet, when the entire surface of a country is covered by them, and every one makes bare the spot on which it stands, the mischief produced may be as extensive as their numbers. So well do the Arabians know their power, that they make a locust say to Mahomet, "We are the army of the Great God; we produce ninety-nine eggs: if the hundred were completed, we should consume the whole earth, and all that is in it."--_Bochart._

The earliest plague produced by the locusts, which has been recorded, appears also to have been the most direful in its immediate effects, that ever was inflicted upon any nation. It is that with which the Egyptian tyrant and his people were visited for their oppression of the Israelites. Only conceive of a country so covered by them, that no one can see the face of the ground--a whole land darkened, and all its produce, whether herb or trees, so devoured, that not the least vestige of green is left in either.--_Exod._ x. 5, 14, 15. But it is not necessary to enlarge upon a history, the circumstances of which are so well known. To this species of devastation, Africa in general seems always to have been peculiarly subject. This may be gathered from the law in Cyrenaica mentioned by Pliny, by which the inhabitants were enjoined to destroy the locusts in three different states, three times in the year; first their eggs, then their young, and lastly the perfect insect.[17] And not without reason was such a law enacted; for Orosius tells us, that in the year of the world 3,800, Africa was infested by such infinite myriads of these animals, that, having devoured every green thing, after flying off to sea they were drowned, and, being cast upon the shore, they emitted a stench greater than could have been produced by the carcases of 100,000 men!--_Oros. contra Pag._ l. v. c. 2. St. Augustine also mentions a plague to have arisen in that country from the same cause, which destroyed no less than 800,000 persons (_octoginta hominum millia_) in the kingdom of Masanissa alone, and many more in the territories bordering upon the sea.--_Less._ l. 247. note 46. From Africa this plague was occasionally imported into Italy and Spain; and an historian quoted in Mouffet relates, that in the year 591 an infinite army of locusts, of a size unusually large, grievously ravaged part of Italy; and being at last cast into the sea, from their stench arose a pestilence which carried off near a million of men and beasts. In the Venetian territory also, in the year 1478, more than 30,000 persons are said to have perished in a famine occasioned by these terrific scourges. Many other instances of their devastations in Europe, in France, Spain, Italy, Germany, and other countries, are recorded by the same author. In 1650 a cloud of them was seen to enter Russia in three different places, which from thence passed over into Poland and Lithuania, where the air was darkened by their numbers. In some places they were seen lying dead, heaped one upon another to the depth of four feet; in others they covered the surface like a black cloth; the trees bent with their weight; and the damage they did exceeded all computation.--_Bingley_, iii. 258. At a later period, in Languedoc, when the sun became hot, they took wing, and fell upon the corn, devouring both leaf and ear, and that with such expedition, that in three hours they would consume a whole field. After having eaten up the corn, they attacked the vines, the pulse, the willows, and lastly, the hemp, notwithstanding its bitterness.--_Philos. Trans._ 1686. Sir H. Davy informs us (_Elements of Agricultural Chemistry_, 233.) that the French government in 1813 issued a decree with a view to occasion the destruction of grasshoppers.

Even this happy island, so remarkably distinguished by its exemption from most of those scourges to which other nations are exposed, was once alarmed by the appearance of locusts. In 1748 they were observed here in considerable numbers, but providentially they soon perished without propagating. These were evidently stragglers from the vast swarms which in the preceding year did such infinite damage in Wallachia, Moldavia, Transylvania, Hungary, and Poland. One of these swarms, which entered Transylvania in August, was several hundred fathoms in width, (at Vienna the breadth of one of them was three miles,) and extended to so great a length, as to be four hours in passing over the Red Tower; and such was its density, that it totally intercepted the solar light, so that when they flew low, one person could not see another at the distance of twenty paces.--_Philos. Trans._ xlvi. 30. A similar account has been given by Major Moor, long resident in India. He relates, that when at Poonah, he was witness to an immense army of locusts which ravaged the Mahratta country, and was supposed to come from Arabia: this, if correct, is a strong proof of their power to pass the sea under favourable circumstances. The column they composed, extended five hundred miles; and so compact was it, when on the wing, that, like an eclipse, it completely hid the sun, so that no shadow was cast by any object; and some lofty tombs, distant from his residence not more than two hundred yards, were rendered quite invisible. This was not the _Gryllus migratorius, L._ but a red species; which circumstance much increased the horror of the scene, for, clustering upon the trees after they had stripped them of their foliage, they imparted to them a sanguine hue. The peach was the last tree they touched.

Dr. Clarke, to give some idea of the infinite numbers of these animals, compares them to a flight of snow when the flakes are carried obliquely by the wind. They covered his carriage and horses; and the Tartars assert, that people are sometimes suffocated by them. The whole face of nature might have been described as covered by a living veil. They consisted of two species, _G. tartaricus_, and _migratorius, L._; the first is almost twice the size of the second, and, because it precedes it, is called by the Tartars, the herald or messenger.--_Travels_, i. 348. The account of another traveller, Mr. Barrow, of their ravages in the southern parts of Africa, in 1784, and 1797, is still more striking: an area of nearly two thousand square miles might be said literally to be covered by them. When driven into the sea by a N. W. wind, they formed upon the shore, for fifty miles, a bank three or four feet high; and when the wind was S. E. the stench was so powerful, as to be smelt at the distance of a hundred and fifty miles.--_Travels_, &c. 257.

From 1778 to 1780, the empire of Morocco was terribly devastated by them; every green thing was eaten up, not even the bitter bark of the orange and pomegranate escaping. A most dreadful famine ensued: the poor were seen to wander over the country, deriving a miserable subsistence from the roots of plants; and women and children followed the camels, from whose dung they picked the undigested grains of barley, which they devoured with avidity: in consequence of this, vast numbers perished, and the roads and streets exhibited the unburied carcases of the dead. On this sad occasion, fathers sold their children, and husbands their wives.--_Southey's Thalaba_, i. 171.

When they visit a country, (says Mr. Jackson, speaking of the same empire,) it behoves every one to lay in provision for a famine, for they stay from three to seven years. When they have devoured all other vegetables, they attack the trees, consuming first the leaves and then the bark. From Mogadar to Tangier, before the plague in 1799, the face of the earth was covered by them: at that time a singular incident occurred at El Arisch. The whole region from the confines of Sahara was ravaged by them; but on the other side of the river El Kos, not one of them was to be seen, though there was nothing to prevent their flying over it. Till then, they had proceeded northward; but, upon arriving at its banks, they turned to the east, though all the country north of Arisch was full of pulse, fruits, and grain, exhibiting a most striking contrast to the desolation of the adjoining district. At length they were all carried by a violent hurricane into the western ocean; the shore, as in former instances, was covered by their carcases, and a pestilence was caused by the horrid stench which they emitted: but when this evil ceased, their devastations were followed by a most abundant crop. The Arabs of the desert, "whose hands are against every man," _Gen._ xvi. 12. and who rejoice in the evil that befalls other nations, when they behold the clouds of locusts proceeding from the north, are filled with gladness, anticipating a general mortality, which they call _el khere_, (the benediction;) for, when a country is thus laid waste, they emerge from their arid deserts, and pitch their tents in the desolated plains.--_Jackson's Travels in Morocco_, 54.

The noise the locusts make when engaged in the work of destruction, has been compared to the sound of a flame of fire driven by the wind, and the effect of their bite to that of fire.--_Bochart._ A poet of our own day has very strikingly described the noise produced by their flight and approach:--

Onward they came, a dark continuous cloud
Of congregated myriads, numberless,
The rushing of whose wings was as the sound
Of a broad river, headlong in its course
Plung'd from a mountain summit, or the roar
Of a wild ocean in the autumn storm,
Shattering its billows on a shore of rocks!
_Southey's Thalaba_, i. 169.

But no account of the appearance and ravages of these terrific insects, for correctness and sublimity, comes near to that of the prophet Joel: "A day of darkness and of gloominess, a day of clouds and of thick darkness, as the morning spread upon the mountains: a great people and a strong; there hath not been ever the like, neither shall be any more after it, even to the years of many generations. A fire devoureth before them; and behind them a flame burneth: the land is as the garden of Eden before them, and behind them a desolate wilderness; yea, and nothing shall escape them. The appearance of them is as the appearance of horses; and as horsemen, so shall they run. Like the noise of chariots[18] on the tops of mountains shall they leap, like the noise of a flame of fire that devoureth the stubble, as a strong people set in battle-array. Before their face the people shall be much pained; all faces shall gather blackness. They shall run like mighty men; they shall climb the wall like men of war; and they shall march every one on his ways, and they shall not break their ranks: neither shall one thrust another; they shall walk every one in his path: and when they fall upon the sword, they shall not be wounded. They shall run to and fro in the city; they shall run upon the wall, they shall climb up upon the houses; they shall enter in at the windows like a thief. The earth shall quake before them, the heavens shall tremble: the sun and the moon shall be dark, and the stars shall withdraw their shining!" The usual way in which they are destroyed, is also noticed by the prophet. "I will remove far off from you the northern army, and will drive him into a land barren and desolate, with his face toward the east sea, and his hinder part toward the utmost sea, and his stink shall come up, because he hath done great things!"--_Joel_ ii. 2-10, 20.

The best method of destroying locusts, would be to recommend them as an article of food. In the Crimea, they are often eaten by the inhabitants. Some French emigrants, who had been directed in this manner, assured me, that when fried, they were very palatable and very wholesome. The Arabs, according to Hasselquist, eat them roasted, and are glad to get them.

It is quite certain that there is nothing endued by nature with peculiar functions, in vain; and it is equally certain, that matter, however modified, whether in the form of animated or inanimated bodies, is continually undergoing change. The more deeply we investigate the works of creation, the more strong will be our conviction of these truths.

We know that many animals, and particularly insects, have apparently no other employment, than that of clearing or purifying the surface of the earth of superfluous matter, the residuum of decayed bodies, or of reconverting it into useful forms, as I shall attempt to illustrate hereafter. Now, if we survey those regions which give birth to, and support, the vast clouds of locusts alluded to, our view will be confined principally to the extensive deserts of Africa and Asia; the vegetation of many of which, according to the reports of travellers, is abundant and luxuriant, beyond the conception of those who have not beheld them; insomuch, that the crops of grass, and other annual vegetables, absolutely load the earth; and these, perishing upon each other, would form an impenetrable, putrid mass, if not consumed by some animals appointed for the purpose.

That locusts support existence by vegetable food, is well known; but whether they have no other object than to consume the superabundant produce of the regions they frequent, and to procreate, is not so easily proved. One who has had no opportunity of witnessing their manners, from their birth to their final destruction, can scarcely be able positively to decide; but I have no doubt that an intelligent naturalist, (governed by the principles this chapter is intended, in some measure, to illustrate,) with the necessary opportunities, such as Dr. Shaw, in particular, had, would be able to get at facts that would indisputably prove the existence of locusts to be a blessing rather than a curse.

Whatever may be the direct object of their existence, locusts are of great use to many other animals, for there are some, particularly birds, that entirely prey upon them; and, if man himself refuses this food, it is rather from the prejudice, perhaps, of an absurd education, than from any improper or bad quality of the food itself.[19] The inhabitants of several eastern nations have a relish for this diet: and it is recorded of him who cried in the wilderness, "Prepare ye the way of the Lord," that "his meat was locusts and wild honey."--_Matthew_ iii. 4. After this, we cannot listen to the feeble remonstrances of any modern epicure.

MOSQUITOES, AND THEIR USES.--The mosquito is accounted one of the most noxious and the most numerous of insects; at least of such as are esteemed noxious by the vulgar and the ignorant. In some countries, indeed, their numbers, and the effects produced by them, are wonderful. There is no instance on record more striking than the following, as related by Dr. Clarke:--

"No contrivance on our part could prevent millions of mosquitoes from filling the inside of our carriage, which, in spite of gloves, clothes, and handkerchiefs, rendered our bodies one entire wound. The Cossacks light numerous fires, to drive them from the cattle during the night; but so insatiate is their thirst of blood, that hundreds will attack a person attempting to shelter himself even in the midst of smoke. At the same time, the noise they make in flying cannot be conceived by persons who have only been accustomed to the humming of such insects in our country."--"Almost exhausted by fatigue, pain, and heat, I sought shelter in the carriage, sitting in water and mud. It was the most sultry night I ever experienced; not a breath of air was stirring; nor could I venture to open the windows, though almost suffocated, through fear of the mosquitoes. Swarms, nevertheless, found their way to my hiding-place; and when I opened my mouth, it was filled with them. My head was bound in handkerchiefs; yet they forced their way into my ears and nostrils. In the midst of this torment, I succeeded in lighting a lamp over the sword-case; which was instantly extinguished by such a prodigious number of these insects, that their dead bodies actually remained heaped in a large cone over the burner for several days afterward: and I know not any mode of description which can convey a more adequate idea of their afflicting visitation, than by simply relating this fact: to the truth of which, those who travelled with me, and who are now living, bear indisputable testimony."

Those who have laboured under so painful a visitation, as that to which this lively account refers, may not perhaps be so ready to admit the general utility of these irritating insects, though their usefulness is more evident, and far more easily proved, than that of the locust, or indeed of most other animals of a similar nature. Bred in the midst of stagnant pools, of bogs, and marshes, in regions unwholesome to man, and where the effluvia arising from animal bodies, and from rank decaying vegetable substances, are so abundant, as to form thick pestilential vapours, that would inflict almost instant destruction on the human inhabitant, and most other creatures, if not removed as quickly as they were formed;--bred in such regions, and gifted with functions and propensities directed to the proper ends, the mosquito supports its existence by consuming the noxious particles exhaled from the swamps; and the bodies of animals, as rapidly as they are generated;--thereby preventing that horrible putrefaction of the air, and consequent pestilence, which would infallibly take place, if the mosquitoes, and similar insects, were not employed to purify the atmosphere.

CHAP. XXXII.

CURIOSITIES RESPECTING INSECTS.--(_Concluded._)

_Animalcules--The Cheese Mite--The Hydra, or Polypes._

The smallest creature in existence
Has limbs and sinews, blood, and heart, and brain,
Life and her proper functions to sustain,
Through the whole fabric, smaller than a grain!
What more can our penurious reason grant
To the large whale, or castled elephant;--
To those enormous terrors of the Nile,
The crested snake, and long-tail'd crocodile;--
Than that all differ but in shape and name,
Each destin'd to a less or larger frame?
_Prior's Solomon._

ANIMALCULES.

The microscope discovers legions of animalcules in most liquors, as water, vinegar, beer, dew, &c. They are also found in rain, and several chalybeate waters, and in infusions of both animal and vegetable substances, as the seminal fluids of animals, pepper, oats, wheat, and other grain, tea, &c. &c. The contemplation of animalcules has rendered the term, _infinitely_ small bodies, extremely familiar to us. A mite was anciently thought the limits of littleness; but we are not now surprised, to be told of animals twenty-seven millions of times smaller than a mite. Minute animals are found proportionably much stronger, more active and vivacious, than large ones. The spring of a flea in its leap, how vastly does it outskip any thing the larger animals are capable of! A mite, how vastly swifter does it run than a race-horse! M. De. L'Isle has given the computation of the velocity of a little creature, scarcely visible by its smallness; which he found to run three inches in half a second: supposing now its feet to be the fifteenth part of a line, it must make five hundred steps in the space of three inches; that is, it must shift its legs five hundred times in a second, or in the ordinary pulsation of an artery. The excessive minuteness of microscopical animalcules conceals them from the human eye. One of the wonders of modern philosophy is, to have invented means for bringing objects, to us so imperceptible, under our cognizance and inspection: creatures, a thousand times too little to be able to affect our sense, should seem to have been very safe; yet we have extended our views over animals, to whom these would be mountains. In reality, most of our microscopical animalcules are of so small a magnitude, that through a lens, whose focal distance is the tenth-part of an inch, they only appear as so many points; that is, their parts cannot be distinguished, so that they appear from the vertex of that lens under an angle not exceeding a minute.

If we investigate the magnitude of such an object, it will be found nearly equal to 3/100000 of an inch long. Supposing, therefore, these animalcules of a cubic figure, that is, of the same length, breadth, and thickness, their magnitude would be expressed by the cube of the fraction 3/100000, that is, by the number 27/1000,000,000,000,000 that is, so many parts of a cubic inch, is each animalcule equal to. Leuwenhoek calculates, that a thousand millions of animalcules, which are discovered in common water, are not altogether so large as a grain of sand. In the milt of a single cod-fish, there are more animals than there are upon the whole earth; for a grain of sand is bigger than four millions of them. The white matter that sticks to the teeth also abounds with animalcules of various figures, to which vinegar is fatal; and it is known, that vinegar contains animalcules in the shape of eels. In short, according to this author, there is scarcely any thing which corrupts, without producing animalcules. Animalcules are said to be the cause of various disorders. The itch is known to be a disorder arising from the irritation of a species of animalcules found in the pustules of the body; when the communication of it by contact from one to another is easily conceived, as also the reason of the cure being effected by cutaneous applications.

In the Philosophical Transactions, vol. 89, is a curious account of animalcules produced from an infusion of potatoes, and another of hemp-seed, by the late Mr. Ellis.

"On the 25th of May, 1768," he says, "Fahrenheit's thermometer 70°, I boiled a potato in the New-River water, till it was reduced to a mealy consistence: I put part of it, with an equal proportion of the boiling liquor, into a cylindrical glass vessel, that held something less than half a wine pint, and immediately covered it close with a glass cover. At the same time I sliced an unboiled potato, and, as near as I could judge, put the same quantity into a glass vessel of the same kind, with the same proportion of New-River water, not boiled; and, covering it with a glass cover, placed both vessels together. On the 26th of May, twenty-four hours afterwards, I examined a small drop of each by the first magnifier of Wilson's microscope, whose focal distance is reckoned 1/50th part of an inch; and, to my amazement, they were both full of animalcules, of a linear shape, very distinguishable, moving to and fro with great celerity, so that there appeared to be more particles of animal than vegetable life in each drop. This experiment I have repeatedly tried, and always found it to succeed in proportion to the heat of the circumambient air; so that even in winter, if the liquors are kept properly warm for two or three days, the experiment will succeed. I procured hemp-seed from different seedsmen, in different parts of the town; some of it I put into the New-River water, some into distilled water, and some into very hard pump-water: the result was, that in proportion to the heat of the weather, or warmth in which they were kept, there was an appearance of millions of minute animalcules in all the infusions; and, some time after, oval ones made their appearance, much larger than the first, which still continued; these wriggled to and fro in an undulatory motion, turning themselves round very quick all the time they moved forwards."