Prey Consumption Patterns of the Predatory Mosquito, Toxorhynchites towadensis, in relation to Prey Abundance, Prey Age Structure, and Patch Size

Prey consumption patterns of the predatory mosquito, Toxorhynchites towadensis, were investigated in relation to prey abundance, prey age structure and patch size over the course of predator development in the laboratory. The pattern of prey consumption of T. towadensis larvae was different for different prey instars. Cumulative consumption of second instar prey increased convexly toward an upper asymptote. However, sigmoidal association was observed with fourth instar prey. A similar tendency of prey consumption also appeared in the containers containing both instars. Though younger predatory larvae consumed more second instar prey than fourth instar prey, older predatory larvae preferred fourth instar prey. These results suggest switching by predator between second prey instar and fourth one. The number of days predators took to consume all prey individuals provided decreased concavely toward a lower asymptote as total dry weight of prey increased, indicating that the time to consume all prey decreased as amount of prey increased. On the other hand, neither effects of patch size nor prey abundance on prey consumption were observed.