Mosquito
Mosquitoes of the genus "Toxorhynchites" never drink blood. This genus includes the largest extant mosquitoes, the larvae of which prey on the larvae of other mosquitoes. These mosquito eaters have been used in the past as mosquito control agents, with varying success.
Coscinocera
The genus contains "Coscinocera hercules", the largest moth in Australia, and the insect with the largest wing surface area.