Abstract: This paper deals with polyethism in the Formosan subterranean termite, Coptotermes formosanus Shiraki. Experiments showed that the aged workers carried out most tasks in the colony and played important roles in the maintenance of the society. Also the castes were an important factor influencing the division of labour. In nutrient trophallaxis, the soldier was a very important caste enjoying the special right to get the food from workers; nymphs had no foraging ability and also lived on food from the workers.

Key words: Coptotermes formosanus Shiraki, polyethism, trophallaxis, age, caste