Oriental ensign wasp
Evania appendigaster, Family: Evaniidae
The Evaniidae, also known as the ensign wasps or hatchet wasps, are a family of parasitic wasps. They number around 20 extant genera containing over 400 described species, and are found all over the world except in the polar regions. The larvae of these solitary wasps feed on cockroaches, and develop inside the egg-cases (oothecae) of their hosts.
The female wasp lays an egg inside the roach ootheca (egg case), and the wasp larva hatches quickly and consumes the roach eggs. Technically, they are thus predators, rather than parasites or parasitoids as other parasitic wasps.
Evania appendigaster is a species of wasp in the family Evaniidae, the ensign wasps. Its native range is not known, but it likely originated in Asia. Today it occurs throughout the tropics and subtropics and in many temperate regions. It is a parasitoid wasp known for specializing on cockroaches.
This is one of the larger ensign wasps, with forewings up to about 7 millimeters long. It is black in color. The wasp may be a candidate for use as an agent of biological pest control of cockroaches.
The adult wasp lives for two or three weeks. It may spend some time on plants such as parsley and fennel.