The Caste System of the Termite

The oldest civilization on earth is that of the termites. The super-organization which these blind white creatures of the dark have achieved precedes by thousands of millenia those of the ants and the bees. Termites have a far longer history on earth, being considered modifications of the ancient cockroaches who were among the first insects to leave any traces of their existence on land. Cockroaches swarmed in the club moss forests at least 250,000,000 years ago. The termite order is at least 30 million years old; some of its most primitive forms still are alive.

In most of the approximately 2,000 species of termites which have been identified all over the world there are five castes, apparently determined from birth although not so rigidly as among ants. First are the winged males and females with large brains and eyes and hard, dark shells. These depart in great swarms from the ancestral nest once or twice a year, usually in spring and fall. They are feeble flyers and depend chiefly on transportation by air currents. The majority are eaten by birds. The few surviving pairs from such a flight excavate cells in the earth or in wood and start new colonies. There is at least one king and one queen in each cell. Sometimes there are two or more pair. They remain partners for life. Both are imprisoned within the cell. Before entering it they slough off their wings, which henceforth would be worthless.

The termite queen becomes an inert, egg-laying machine, sometimes the size of a small potato. In some species she lays an average of sixty eggs a minute, or 80,000 a day. She may live as long as ten years. Thus each queen ideally produces about a half billion new individuals. Her bulk increases as much as 50-fold in adult life—about the most phenomenal growth in nature.

The second termite caste, for which there is no parallel among the ants, consists of both males and females with only rudiments of wings, less fully developed reproductive organs, and somewhat smaller eyes and brains. They presumably serve only as an auxiliary royalty, functioning in case the true rulers die. Apparently by some subtle alchemy known only to termites they can be transformed into fully functioning sexual individuals if an emergency arises.

A third caste is made up of smaller insects with extremely minute eyes and brains and barely discernible reproductive organs. Below them come the entirely unpigmented, soft-bodied workers with still smaller eyes and brains—usually, in fact, with no eyes at all. These still are potentially males and females, in distinction to any society where all workers and soldiers are female. Lowest in the scale are the big-headed, blind soldiers, also of both sexes, with barely a trace of brain.

Relative numbers in these castes differ from species to species. An analysis of an Australian termite colony accounted for 1,560,500 workers, 200,000 soldiers, and 44,000 potentially reproductive individuals.