Leptopilina is a genus of parasitoid wasp in the family Figitidae. The genus is best known for the three Drosophila parasitoids Leptopilina boulardi, Leptopilina heterotoma and Leptopilina clavipes, used to study host-parasite immune interactions. The venom released by L. heterotoma during oviposition contains virus-like particles that delay host larval development and suppress the host cellular immune response.