Adult behaviour of members of the Anopheles gambiae complex in the Gambia with special reference to An. melas and its chromosomal variants.

Abstract. Polytene chromosome studies on the member species of the Anopheles gambiae complex in The Gambia and sunounding areas in Senegal led to comparative observations on bionomics of sympatric populations of An. melas and. An. gambiae. Moreover, inversion polymorphisms have been .analyzed in An. melas and their possible relationships with behavioural varíations in endophily and anthropophily have been considered. An. melas shows a remarkably short dispersal from typical larval breeding places associated with mangrove swamps ald it is definilely more zoophilic and exophilic than An. gambiae. Only a very small fraction oÎ An. melas biting outdoor on animals rests indoors and consequently the human blood index is largely overestimated if based on the examination of house samples alone. Differences in the frequencies of 2Rn inversion karyotypes of An. melas were observed between parallel samples obtained from animal shelters and houses, from night catches on man outdoor and from nieht catches sn main indoor and on anirnal outdoot. Further differences were shown bv blood nied identification between human and animal fed subsamples from the same house resiing samples. Non-uniform feeding and/or resting behaviour'between carriers of alteinative 2Rn-inverìion karyotypes is postulated to explain these data.