Length ~2mm. The antennae arise from a prominent raised ledge or "shelf" high on the face above the clypeus, a defining structural feature of Diapriidae. Extremely reduced wing venation lacking a closed cell, featuring a short marginal vein near the basal front edge of the forewing. The wing margins are heavily fringed with fine hairs (cilia). As indicated by the specific name crassifemur ("thick thigh"), the legs feature distinctly swollen or incrassate femora compared to related species in the genus. 

Unless identified by a recognised expert, a photo is required and the specimen should be examined with a microscope. In the comments box, state the key or ID method used and describe the size and identifying characters.

Koinobiont pupal endoparasitoids of Diptera.

Unknown.

Unknown.

G.E.J. Nixon (1957) Diapriidae (Diapriinae). Hymenoptera, Proctotrupoidea. RES Handbooks for the Identification of British Insects Vol 8, Part 3dii.