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.
List of largest insects
Representatives of the extinct dragonfly-like order Meganisoptera (also known as griffinflies) such as the Carboniferous "Meganeura monyi" and the Permian "Meganeuropsis permiana" are the largest insect species ever known. These creatures had a wingspan of some and an estimated body weight of over , making them about the size of a crow.