Ovipositional Behavior of <i>Anopheles gambiae</i> Mosquitoes

ABSTRACT

Mosquito eggs laid within two hours are necessary for transgenic (injection) studies, because mosquito eggs become hard after that period. Thus, in order to have eggs available within this two-hour window, it is important for transgenic studies to understand the ovipositional behavior of <i>Anopheles gambiae s.s.</i>. In the present study, the ovipositional behavior of <i>An. gambiae s.s.</i> (Kisumu) was investigated in several different conditions age of mosquitoes, time post blood meal to access oviposition substrate, and light conditions. Two groups of mosquitoes, 3–5 day old and 9–11 day old mosquitoes were blood-fed. For those mosquito groups, an oviposition dish was set either at 48 hours or 72 hours after the blood meal either in a light condition or in an artificial dark condition. The number of laid eggs was compared among different conditions. The 3–5 day old mosquitoes apparently produced a higher number of eggs than 9–11 day old ones, while there was no significant difference between the 2 groups. The number of laid eggs per one surviving blood-fed mosquito in the dark condition was significantly higher than that in the light condition (<i>p</i> = 0.03). Providing an oviposition dish at 72 hours after blood meal resulted in a significantly higher number of laid eggs per one surviving blood-fed mosquito compared to providing an oviposition dish at 48 hours after blood meal (<i>p</i> = 0.03). In conclusion, the optimal condition to have readily available egg supply in the present study for transgenic analysis was as follows 3–5 days old mosquitoes with an oviposition dish placed at 72 hours after the blood meal in a dark environment.