The effect of size on mate selection, fecundity and survival in Culex pipiens mosquitoes

Culex pipiens L. is a medically important mosquito due to its abundance and ability to transmit West Nile virus. Despite being the focus of many mosquito control strategies, very little is known about its mating behaviour. Several control strategies rely on knowing female mate preferences to ensure their efficacy. Therefore, the purpose of this study was to characterize mate selection based on mate quality. Because larger individuals should have more resources available to be used towards mating behaviour, it was hypothesized that larger mates (males or females) would be of higher value and preferentially mated with compared to smaller ones. By manipulating food availability, males and females were reared to be either large or small adults and were mated with either a large or small mate. Through a series of experiments, the effect of size on mate success and post-mating responses was assessed via insemination rates, blood feeding, egg laying, fertility and survival. Despite larger females living longer and being more fecund, males did not preferentially mate with larger females, nor did male size influence female survival or fecundity. Because larval rearing environment had an influence on adult morphology and fitness, it should be taken into consideration in mosquito control programmes.