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.
Reesimermis nielseni
"Reesimermis nielseni" is a parasite of the larvae of mosquitoes. It is known to infect 22 different species of mosquito in the wild and another 33 species in the laboratory.