Please refer also to the following links for details on this group:
Evanioidea = Link 1
Evanioidea. --In this Superfamily the abdomen is attached high above the hind coxae , the antennae are filiform and have 13 or 14 segments. The trochanters have two segments, and the front wing venation is usually complete and there is a costal cell. Some (Gasteruptlidae and Aulacidae) superficially resemble ichneumons. All are parasitoids of other insects.
This is a small Hymenopteran superfamily that includes three families, two of which, Aulacidae & Gasteruptiidae, are more closely related to one another than they are to the remaining family, Evaniidae. However, there is an extensive fossil record that tends to fill in the gaps between the lineages. They have the common trait of the metasoma being attached very high above the hind coxae on the propodeum.
It is a scarcely-known group as a whole, with about 1110 known species, and many species await description. While each of the three families differs in biology, within each family they are nevertheless uniform in appearance and biology.