Stephanidae

The Stephanidae, sometimes called crown wasps, are a family of parasitoid wasps. They are the only living members of the superfamily Stephanoidea. Stephanidae has about 365 living species. The family is considered cosmopolitan in distribution, with the highest species concentrations in subtropical and moderate climate zones. Stephanidae also contain four extinct genera described from both compression fossils and inclusions in amber.

==Description== Stephanids are noted for their ocellar corona, a semicircular to circular set of projections around the middle ocellus, forming a "crown" on the head. Only stephanids and the similarly old Hymenoptera family Orussidae have ocellar coronae, and it is uncertain if they developed the structure separately or if a common ancestor of both developed it and it was then lost in all but the two families. Weakly developed grooves starting at the base of the antennae and extending past the eyes to the back of the head capsule are present. This feature is seen more developed in hymenopteran families in which the adults emerge from pupal chambers in wood. All genera of Stephanidae have a pronotum that is modified to some extent. They bear highly modified hind legs, with a swollen hind femur that has large teeth on the underside, and the tibiae have a tip end that widens distinctly. The largest species, reaching up to in length, are found in the genus Megischus.