Amongst our most valuable domestic animals I shall be very unjust and ungrateful, if I do not enumerate those industrious little creatures the bees, from whose incessant labours and heaven-taught art we derive the two precious productions of honey and wax. They also are infested by numerous insect-enemies, some of which attack the bees themselves, while others despoil them of their treasures.—They have parasites of a peculiar genus, although at present regarded as belonging to Pediculus[262], and mites (Gamasus gymnopterorum) are frequently injurious to them. That universal plunderer the wasp, and his formidable congener the hornet, often seize and devour them, sometimes ripping open their body to come at the honey, and at others carrying off that part in which it is situated. The former frequently takes possession of a hive, having either destroyed or driven away its inhabitants, and consumes all the honey it contains. Nay there are certain idlers of their own species, called by apiarists corsair-bees, which plunder the hives of the industrious.—From the curious account which Latreille has given us of Philanthus apivorus, a wasp-like insect, it appears that great havoc is made by it of the unsuspecting workers, which it seizes while intent upon their daily labours, and carries off to feed its young[263]. Another insect, which one would not have suspected of marauding propensities, must here be introduced. Kuhn informs us, that long ago (in 1799) some monks who kept bees, observing that they made an unusual noise, lifted up the hive, when an animal flew out, which to their great surprise no doubt, for they at first took it for a bat, proved to be the death's-head hawk-moth (Acherontia Atropos), already celebrated as the innocent cause of alarm[264]; and he remembers that several, some years before, had been found dead in the bee-houses[265]. M. Huber, also, in 1804 discovered that it had made its way into his hives and those of his vicinity, and had robbed them of their honey. In Africa we are told it has the same propensity; which the Hottentots observing, in order to monopolize the honey of the wild bees, have persuaded the colonists that it inflicts a mortal wound[266]. This moth has the faculty of emitting a remarkable sound, which he supposes may produce an effect upon the bees of a hive somewhat similar to that caused by the voice of their queen, which as soon as uttered strikes them motionless, and thus it may be enabled to commit with impunity such devastation in the midst of myriads of armed bands[267]. The larvæ of two species of moth (Galleria Cereana, and Mellonella) exhibit equal hardihood with equal impunity. They indeed pass the whole of their initiatory state in the midst of the combs. Yet in spite of the stings of the bees of a whole republic, they continue their depredations unmolested, sheltering themselves in tubes made of grains of wax, and lined with silken tapestry, spun and wove by themselves, which the bees (however disposed they may be to revenge the mischief which they do them, by devouring, what to all other animals would be indigestible, their wax,) are unable to penetrate. These larvæ are sometimes so numerous in a hive, and commit such extensive ravages, as to force the poor bees to desert it and seek another habitation.
I shall not delay you longer upon this subject by detailing what wild animals suffer from insects, further than by observing that the two creatures of this description in which we are rather interested, the hare and the rabbit, do not escape their attack. The hare in Lapland is more tormented by the gnats than any other quadruped. To avoid this pest it is obliged to leave the cover of the woods in full day, and seek the plains: hence the hunters say, that of three litters which a hare produces in a year, the first dies by the cold, the second by gnats, and only the third escapes and comes to maturity[268].—We learn from the ingenious Mr. Clark, that the American rabbit and hare are infested by the largest species of Œstrus[269] yet discovered; and our domestic rabbits sometimes swarm with the bed-bug. This was the case with some kept by two young gentlemen at my house last summer to such a degree, that I found it necessary to have them killed.
Nor are the inhabitants of the waters sheltered by their peculiar element from these universal assailants. The larvæ of Dytisci fixing themselves by their suctorious mandibles to the body of fish, doubtless destroy an infinite number of the young fry of our ponds. Some species of salmon (Salmo Fario, L.) are the food of an animal which Linné has arranged under Pediculus; and probably many others of the finny tribes may, like the birds, have their peculiar parasites. Even shell-fish do not escape, for the Nymphon grossipes enters the shell of the muscle and devours its inhabitant.
I am, &c.
[LETTER VI.]
INJURIES CAUSED BY INSECTS.
INDIRECT INJURIES CONTINUED.
Having endeavoured to give you some idea of the mode in which insects establish and maintain their empire over man and his train of dependent animals, I shall next call your attention to his living vegetable possessions, whether the produce of the forest, the field, or the garden; whether necessary to him for his support, convenient for his use, or ministering to his comfort, pleasure and delight:—and here you will find these little creatures as busily engaged in the work of mischief as ever, destroying what is necessary, deranging what is convenient, marring what is beautiful, and turning what should give us pleasure into an object of disgust.