Oviposition by Anopheles melas and Its Effect on Egg Survival during the Dry Season in the Gambia, West Africa

Abstract

Anopheles melas Theobald oviposits after dark in the first half of the night, on damp mud under Avicennia mangrove during neaptides in the Gambia. During oviposition the abdomen is usually slanted, with the eighth segment held vertical to the substrate. Eggs appear rhythmically every 10–12 sec, in 2 distinct movements of extrusion and ejection; 8–10 sec elapse between these 2 movements, during which the egg is inseminated. Eggs are laid on clamp substrate rather than surface waters, in 3 characteristic patterns, of which egg clumps produced by stationary females afford the least chance of egg survival under the desiccating conditions of the dry season.