The regulation of preimaginal populations of Aedes aegypti (L.) (Diptera: Culicidae) on the Kenya coast. II. Food as a main regulatory factor.

Abstract

Experiments were carried out in a village on the Kenya coast to investigate observed differences in pupal productivity of Aedes aegypti breeding in indoor pots. Daily addition of maize gruel, the staple food of villagers, to pots of high and low mosquito production promoted an increase of pupal numbers, although daily introduction of first-instar larvae did not significantly affect pupal production. Differences in pupal productivity were not related to differences in the numbers of eggs laid in the pots. Predation and overcrowding did not seem important in regulating the preimaginal stages. It was concluded that food, especially maize gruel accidentally introduced into the pots by villagers, was the key factor which regulated population size. As numbers of eggs are always considerable, genetic control of Ae. aegypti can be successful only when it reduces egg hatchability to a very low level. The prospects of controlling Ae. aegypti by means of health education and/or environmental management are discussed.