The Diapriidae are a family of insects belonging to the order Hymenoptera. These tiny wasps have an average length of 2-4 mm and never exceed 8 mm. They are typically parasitoids on the larvae and pupae of a wide range of insects, especially flies; a few are hyperparasitoids (e.g., Ismarus, which parasitizes Dryinidae, which are themselves parasites of leafhoppers). The about 2,300 described species in 150 genera are divided into four subfamilies, and the group has a global distribution.