I have on a former occasion given you some account of the devastation produced by the white ants, or Termites, the species of which constitute the first class of perfect societies[40]; I shall now relate to you some further particulars of their history, which will, I hope, give you a better opinion of them.
The majority of these animals are natives of tropical countries, though two species are indigenous to Europe; one of which, thought to have been imported, is come so near to us as Bourdeaux. The fullest account hitherto given of their history is that of Mr. Smeathman, in the Philosophical Transactions for 1781; which, since it has in many particulars been confirmed by the observations of succeeding naturalists, though in some things he was evidently mistaken, I shall abridge for you, correcting him where he appears to be in error, and adding from Latreille, and the MS. of a French naturalist resident on the spot, kindly furnished by Professor Hooker, what they have observed with respect to those of Bourdeaux and Ceylon. The white ants, though they belong to the Neuroptera order, borrow their instinct from the hymenopterous social tribes, and in conjunction with the ants (Formica) connect the two orders. Their societies consist of five different descriptions of individuals—workers or larvæ—nymphs or pupæ—neuters or soldiers—males and females.
1. The workers or larvæ, answering to the hymenopterous neuters, are the most numerous and at the same time most active part of the community; upon whom devolves the office of erecting and repairing the buildings, collecting provisions, attending upon the female, conveying the eggs when laid to what Smeathman calls the nurseries, and feeding the young larvæ till they are old enough to take care of themselves. They are distinguished from the soldiers by their diminutive size, by their round heads and shorter mandibles.
2. The nymphs or pupæ. These were not noticed by Smeathman, who mistook the neuters for them:—they differ in nothing from the larvæ, and probably are equally active, except that they have rudiments of wings, or rather the wings folded up in cases (Pterothecæ). They were first observed by Latreille; nor did they escape the author of the MS. above alluded to, who mistook them for a different kind of larvæ.
3. The neuters, erroneously called by Smeathman pupæ. These are much less numerous than the workers, bearing the proportion of one to one hundred, and exceeding them greatly in bulk. They are also distinguishable by their long and large head, armed with very long subulate mandibles. Their office is that of sentinels; and when the nest is attacked, to them is committed the task of defending it. These neuters are quite unlike those in the Hymenoptera perfect societies, which seem to be a kind of abortive females, and there is nothing analogous to them in any other department of Entomology.
4. and 5. Males and females, or the insects arrived at their state of perfection, and capable of continuing the species. There is only one of each in every separate society; they are exempted from all participation in the labours and employments occupying the rest of the community, that they may be wholly devoted to the furnishing of constant accessions to the population of the colony. Though at their first disclosure from the pupa they have four wings, like the female ants they soon cast them; but they may then be distinguished from the blind larvæ, pupæ, and neuters, by their large and prominent eyes[41].
The first establishment of a colony of Termites takes place in the following manner. In the evening, soon after the first tornado, which at the latter end of the dry season proclaims the approach of the ensuing rains, these animals, having attained to their perfect state, in which they are furnished and adorned with two pair of wings, emerge from their clay-built citadels by myriads and myriads to seek their fortune. Borne on these ample wings, and carried by the wind, they fill the air, entering the houses, extinguishing the lights, and even sometimes being driven on board the ships that are not far from the shore. The next morning they are discovered covering the surface of the earth and waters: deprived of the wings which before enabled them to avoid their numerous enemies, and which are only calculated to carry them a few hours, and looking like large maggots; from the most active, industrious, and rapacious, they are now become the most helpless and cowardly beings in nature, and the prey of innumerable enemies, to the smallest of which they make not the least resistance. Insects, especially ants, which are always on the hunt for them, leaving no place unexplored; birds, reptiles, beasts, and even man himself, look upon this event as their harvest, and, as you have been told before, make them their food; so that scarcely a single pair in many millions get into a place of safety, fulfill the first law of nature, and lay the foundation of a new community. At this time they are seen running upon the ground, the male after the female, and sometimes two chasing one, and contending with great eagerness, regardless of the innumerable dangers that surround them, who shall win the prize.
The workers, who are continually prowling about in their covered ways, occasionally meet with one of these pairs, and, being impelled by their instinct, pay them homage, and they are elected as it were to be king and queen, or rather father and mother, of a new colony[42]: all that are not so fortunate, inevitably perish; and, considering the infinite host of their enemies, probably in the course of the following day. The workers, as soon as this election takes place, begin to inclose their new rulers in a small chamber of clay, before described[43], suited to their size, the entrances to which are only large enough to admit themselves and the neuters, but much too small for the royal pair to pass through;—so that their state of royalty is a state of confinement, and so continues during the remainder of their existence. The impregnation of the female is supposed to take place after this confinement, and she soon begins to furnish the infant colony with new inhabitants. The care of feeding her and her male companion devolves upon the industrious larvæ, who supply them both with every thing that they want. As she increases in dimensions, they keep enlarging the cell in which she is detained. When the business of oviposition commences, they take the eggs from the female, and deposit them in the nurseries[44]. Her abdomen now begins gradually to extend, till in process of time it is enlarged to 1500 or 2000 times the size of the rest of her body, and her bulk equals that of 20,000 or 30,000 workers. This part, often more than three inches in length, is now a vast matrix of eggs, which make long circumvolutions through numberless slender serpentine vessels:—it is also remarkable for its peristaltic motion, (in this resembling the female ant[45],) which, like the undulations of water, produces a perpetual and successive rise and fall over the whole surface of the abdomen, and occasions a constant extrusion of the eggs, amounting sometimes in old females to sixty in a minute, or eighty thousand and upwards in twenty-four hours[46]. As these females live two years in their perfect state, how astonishing must be the number produced in that time!
This incessant extrusion of eggs must call for the attention of a large number of the workers in the royal chamber (and indeed it is always full of them), to take them as they come forth and carry them to the nurseries; in which, when hatched, they are provided with food, and receive every necessary attention till they are able to shift for themselves.—One remarkable circumstance attends these nurseries—they are always covered with a kind of mould, amongst which arise numerous globules about the size of a small pin's head. This is probably a species of Mucor; and by Mr. König, who found them also in nests of an East-Indian species of Termes, is conjectured to be the food of the larvæ.