''Metopius'' is a cosmopolitan genus of

parasitoid In evolutionary ecology, a parasitoid is an organism that lives in close association with its host (biology), host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionarily stable str ...

ichneumon wasp The Ichneumonidae, also known as the ichneumon wasps, Darwin wasps, or ichneumonids, are a family of parasitoid wasps of the insect order Hymenoptera. They are one of the most diverse groups within the Hymenoptera with roughly 25,000 species cur ...

s in the subfamily

Metopiinae The Metopiinae are a worldwide subfamily of the parasitic wasp family Ichneumonidae. Metopiinae are koinobiont endoparasitoids of Lepidoptera. There are 26 extant genera. A bulging shield-like face is diagnostic for members of this subfamily, but ...

. They lay eggs inside caterpillars of

Lepidoptera Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...

that are found in leaf rolls, and the adult wasps later emerge from the

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...

. They are black and yellow striped and reach over in length. Their coloring may be mimicking

potter wasp Potter wasps (or mason wasps), the Eumeninae, are a cosmopolitan wasp group presently treated as a subfamily of Vespidae, but sometimes recognized in the past as a separate family, Eumenidae. Recognition Most eumenine species are black or brown, ...

s. ''Metopius'' spp. make a buzzing noise when captured.

References

Ichneumonidae {{Ichneumonidae-stub