The genus can be recognized at once by the felty setose and flattened mesosternum of females and the distinctive shape of the first metasomal tergite. 
Antennal segments 30. Female mesosternum, propodeum and metasoma dark, forewing pterostigma infuscate. Length of first metasomal tergite 1.4 times its apical width, longitudinally rugose. Ovipositor gradually curved and comparatively slender. 

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.

Parasite of adult Curculionidae (Brachyderinae) on herbs (e.g. Sitona humeralis Stephens on Medicago species).

Widespread, under-recorded.

Unknown. 

van Achterberg, C. (1992). Revision of the European species of the genus Pygostolus Haliday (Hymenoptera: Braconidae: Euphorinae), with a key to the Holarctic species. Zoologische mededelingen, 66(24), 349-358.