-Rocky Mountain Locust (Caloptenus spretus). a, a, a, female in different positions, ovipositing; b, egg-pod extracted from ground, with the end broken open; c, a few eggs lying loose on the ground; d, e show the earth partially removed, to illustrate an egg-mass already in place, and one being piaced; f shows where such a mass has been covered up. (After Riley.)

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 ex traordinary capacity and powers; its hind-legs enɛ ble 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

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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 al' that is in it."-Bochart.

The earliest plague produced by the locusts, which has beer. 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.* 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. 1. 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. 1. 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,

* Hist. Nat. 1. xi. c. 29. A similar law was enacted in Lemnos, by which every one was compelled to bring a certain measure of locusts annually to the magistrates

Plin.

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 .as 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 Thaluba, 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