Genetic structure of the East African domestic populations of Aedes aegypti

Abstract

THE yellow fever mosquito, Aedes aegypti, is a complex species. Morphological, physiological, and behavioural variation is extensive and complex^1–4. In the Rabai area near Mombasa, Kenya, three forms of A. aegypti can be distinguished⁵. A light coloured population breeds exclusively in water jars stored inside houses; this is referred to as the domestic form. In disturbed areas adjacent to villages (such as farmland), a form of varying darkness is found breeding in discarded containers or footholds cut in coconut palms; this is the peridomestic form. In tropical forests, an exclusively dark form is found breeding in tree-holes or occasionally rock-holes; this is the feral form. These forms are behaviourally distinct from one another⁵; and, even though they can be found in close proximity to each other, they are often also genetically distinct⁶ (W.J.T., L. E. Munstermann and J.R.P. in preparation). We present here a population genetic analysis of the domestic populations of A. aegypti in villages in the Rabai area. We conclude that the mosquito population in each village is a panmictic unit with no significant genetic substructuring ; that significant genetic differences exist between villages less than 2 km apart ; and that gene frequencies are temporally stable.