Estudo dos factores que influenciam o acasalamento em mosquitos do gênero Anopheles

Abstract

The importance of the genus Anopheles lies in the fact that it contains the vectors of malaria, filariasis and some arboviroses. The increasing resistance of anophelines to insecticides requires the search for alternative forms of control. Methods under study include the use of sterile male and transgenic mosquitoes. However, the use of these methods requires an understanding of anopheline behaviour including mating behaviour. In this study we studied the factors influencing the mating of An. gambiae s.l. and An. junestus s.l. in Massavasse (Gaza) and Furvela (Inhambane). Mosquito swarms were observed at twilight time. Swarming mosquitoes were collected using an entomological net and separated by morphological characters into An. gambiae s.l. and An. Junestus s.l. using the key of Gillies & Coetze, (1987). The locations where the swarms occurred were described schematically, showing the distances between them and houses, plants, and other details considered relevant. Mosquitoes contained in a cage were observed for 72h consecutively in order to understand the variation of their flight activity rhythm. The wing size of mosquitoes collected in swarms, leaving or resting in houses was measured. The mean wing lengths of these three groups were compared using ANOVA to test the hypothesis that swarm formation is related to male size. An. gambiae s.l. and An. Junestus s.l. are sympatric in both Furvela and Massavasse. Swarms were observed only at sunset where higher flight activity was also observed. Swarms of these species occur in the same places and at the same times, however no marker associated with swarm formation was observed. In Massavasse the formation of An. pharoensis swarms was conditioned to the existence of white markers. No significant differences were observed in the mean wing lengths of males of An. gambiae s.l. collected in swarms, leaving or resting inside the dwellings (F =0.2485 ; DF = 2 ; P = 0.7807 ). The same was observed in relation to An. Junestus (F =0.3142 ; df=2 ; P = 0.7315 ), rejecting the hypothesis of swarming as a function of male size