Fig. 231.—Some of the forms of Termes lucifugus. 1, Young larva; 2, adult worker; 3, soldier; 4, young complementary queen; 5, older substitution queen; 6, perfect winged Insect. (After Grassi.)
The period of development apparently occupies from eighteen to twenty-three months. At intervals swarms of a great number of winged individuals leave the nest, and are usually promptly eaten up by various animals. After swarming, the wings are thrown off, and sometimes two specimens or three may be seen running off together; this has been supposed to be preliminary to pairing, but Grassi says this is not the case, but that the object is to obtain their favourite food, as we shall mention subsequently.
Although these are the usual habits of Termes lucifugus at present in Sicily, it must not be concluded that they are invariable; we have in fact evidence to the contrary. Grassi has himself been able to procure in confinement a colony—or rather the commencement of one—accompanied by a true royal pair; while Perris has recorded[[291]] that in the Landes he frequently found a royal pair of T. lucifugus under chips; they were accompanied in nearly every case by a few eggs. And Professor Perez has recently placed a winged pair of this species in a box with some wood, with the result that after some months a young colony has been founded. It appears probable therefore that this species at times establishes new colonies by means of royal pairs derived from winged individuals, but after their establishment maintains such colonies as long as possible by means of complementary queens. It is far from improbable that distinctions as to the use of true and complementary royalties may be to some extent due to climatic conditions. In some localities T. lucifugus has multiplied to such an extent as to be very injurious, while in others where it is found it has never been known to do so.
The Termitidae of Africa are the most remarkable that have yet been discovered, and it is probably on that continent that the results of the Termitid economy have reached their climax. Our knowledge of the Termites of tropical Africa is chiefly due to Smeathman, who has described the habits of several species, among them T. bellicosus. It is more than a century since Smeathman travelled in Africa and read an account of the Termites to the Royal Society.[[292]] His information was the first of any importance about Termitidae that was given to the world; it is, as may be well understood, deficient in many details, but is nevertheless of great value. Though his statements have been doubted they are truthful, and have been confirmed by Savage.[[293]]
Fig. 232.—Royal cell of Termes bellicosus, partially broken open to show the queen and her attendants. (After Smeathman.) B, Antenna of the queen; b, b, line of entrances to the cell; A, A, an entrance, in this line, closed by the Termites. × ⅞.
T. bellicosus forms buildings comparable to human dwellings; some of them being twenty feet in height and of great solidity. In some parts of West Africa these nests were, in Smeathman's time, so numerous that they had the appearance of villages. Each nest was the centre of a community of countless numbers of individuals; subterranean passages extended from them in various directions. The variety of forms in one of these communities has not been well ascertained, but it would seem that the division of labour is carried to a great extent. The soldiers are fifteen times the size of the workers. The community is dependent on one royal couple. It is the opinion of the natives that if that couple perish so also does the community; and if this be correct we may conclude that this species has not a perfect system of replacing royal couples. The queen attains an almost incredible size and fertility. Smeathman noticed the great and gradual growth of the abdomen, and says it enlarges "to such an enormous size that an old queen will have it increased so as to be fifteen hundred or two thousand times the bulk of the rest of her body, and twenty or thirty thousand times the bulk of a labourer, as I have found by carefully weighing and computing the different states." He also describes the rate at which the eggs are produced, saying that there is a constant peristaltic movement[[294]] of the abdomen, "so that one part or other alternately is rising and sinking in perpetual succession, and the matrix seems never at rest, but is always protruding eggs to the amount (as I have frequently counted in old queens) of sixty in a minute, or eighty thousand and upward in one day of twenty-four hours."
This observer, after giving an account of the great swarms of perfect winged Insects that are produced by this species, and after describing the avidity with which they are devoured by the Hymenopterous ants and other creatures, adds: "I have discoursed with several gentlemen upon the taste of the white ants; and on comparing notes we have always agreed that they are most delicious and delicate eating. One gentleman compared them to sugared marrow, another to sugared cream and a paste of sweet almonds."
From the preceding brief sketch of some Termitidae we may gather the chief points of importance in which they differ from other Insects, viz. (1) the existence in the community of individuals—workers and soldiers—which do not resemble their parents; (2) the limitation of the reproductive power to a single pair, or to a small number of individuals in each community, and the prolongation of the terminal period of life. There are other social Insects besides Termitidae: indeed, the majority of social Insects—ants, bees, and wasps—belong to the Order Hymenoptera, and it is interesting to note that analogous phenomena occur in them, but nevertheless with such great differences that the social life of Termites must be considered as totally distinct from that of the true ants and other social Hymenoptera.
Development.—Social Insects are very different to others not only in the fact of their living in society, but in respect of peculiarities in the mode of reproduction, and in the variety of habits displayed by members of a community. The greatest confusion has arisen in reference to Termitidae in consequence of the phenomena of their lives having been assumed to be similar to those of Hymenoptera; but the two cases are very different, Hymenoptera passing the early parts of their lives as helpless maggots, and then undergoing a sudden metamorphosis to a totally changed condition of structure, intelligence, and instinct.