Effects of adult body size on fecundity and the pre-gravid rate of Anopheles gambiae females in Tanzania.
The influence of adult body size on the pre-gravid state and fecundity was studied in Anopheles gambiae Giles females hand-caught inside houses and virgin females collected as pupae in Tanzania. Blood-fed mosquitoes were kept for 2-3 days before dissection and examination for insemination and ovarian condition. Those females which did not develop eggs were classified as pre-gravid. The number of mature eggs in those mosquitoes which became gravid was counted. Virgin females were fed and kept for egg maturation in the laboratory. Wing-length of females was measured as an index of mosquito size. The overall pre-gravid rate in the resting An.gambiae population was found to be 21% and, of these, 66% had been inseminated. In the virgin females the pre-gravid rate was 92.6%. The mean wing-length of wild females which became gravid was significantly larger than those which remained pre-gravid. There was a positive correlation between fecundity and wing-length. Smaller females tended to require two or three bloodmeals to facilitate completion of the first gonotrophic cycle. The critical size permitting oviposition from the first blood-meal was a wing-length of 3 mm.
Lyimo
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Ifakara Centre, Tanzania.
Takken
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D000818:Animals; D000852:Anopheles / Q000033:anatomy & histology* / Q000502:physiology*; D001824:Body Constitution; D005247:Feeding Behavior; D005260:Female; D005298:Fertility; D011891:Rain; D013636:Tanzania; D014921:Wings, Animal / Q000033:anatomy & histology