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.
Mydas fly
The Mydidae (sometimes misspelled as Mydaidae), or Mydas flies, are a cosmopolitan family of flies. It is a small family, with about 471 species described. They are generally large in size, including the largest known fly, "Gauromydas heros" (syn. "Mydas heros"). Many of the species, in addition to their large size, are mimics of stinging hymenopterans, especially wasps. Most mydids are found in arid and semiarid regions of the world, but they are also found in other habitats.