Evaniidae is a family of parasitic wasps, generally known as the ensign wasps or hatchet wasps. There are about 400 species of ensign wasps in 20 extant genera all over the world. The ensign wasp deposits her eggs inside cockroach egg cases, where the larvae develop. Due to this behavior of ensign wasps, They're know as Cockroach Egg Parasitoid Wasps. They're also known as Cockroach Killer Wasps.