Mating behaviour in the mosquito, Anopheles gambiae s.1.save

. Mating behaviour in the Anopheles gambiae complex was studied in the laboratory, using an infra‐red TV system to make observations in the ‘dark’. Maximum fertilization occurred when both sexes were at least 2 days old. In LD 12:12 most mating took place in the first hour of the dark phase. At this time, the males had erect fibrillae on the antennae and showed the maximum response to an artificial female flight tone, approaching, landing‐on and attempting to clasp the sound source. The cycle of fibrillar erection and of responsiveness to sound continued in constant dark. Males did not appear to discriminate on contact, between their own and other species. Previously mated females actively resisted copulation, but, when tethered, were unable to prevent the deposition of further internal mating plugs. Free‐flying, previously inseminated, females prevented the males from depositing internal plugs, but not from ejaculating and depositing external plugs. The differences between A.gambiae and the better known Stegomyia mosquitoes appear to be related to their different habits, A.gambiae males being less likely to encounter females of other species or inseminated females of their own species at the restricted time and place of mating.