Small brightly coloured wasps. The female has four visible gastral segments and the male five visible segments. The female searches for the cocooned prepupa or pupa of a tenthredinid sawfly. On finding a host cocoon the female bites a small hole in the wall. She then inserts her ovipositor and lays a single egg on the prepupa or pupa. The hole is sealed with mucilage and the larva, on hatching, feeds on the host. Nationally: 1 genus with 2 species.