1-2mm black parasitic wasp. Frons with characteristic parallel arched ridges.

Unless identified by a known expert, a photo (or photos) should be submitted with the record showing the key features and/or these should be described in the comments box, noting the key used.

All year.

Egg parasitoid of Shieldbugs, including Red-legged Shield Bug (Pentatoma rufipes), Green Shield Bug (Palomena prasina) and Brown Marmorated Stink Bug (Halyomorpha halys). Distribution spans the Palearctic region, including the UK.

Probably common but rarely recorded. 

Unknown.

Talamas, E.J., Johnson, N.F., & Buffington, M. (2015) Key to Nearctic species of Trissolcus Ashmead (Hymenoptera, Scelionidae), natural enemies of native and invasive stink bugs (Hemiptera, Pentatomidae). Journal of Hymenoptera Research, 43, 45-110.