Tenthredo crassa can be found in most of Europe.
These sawflies inhabit meadows, edges of forests, hills and mountainous areas, at an elevation up to 1,500 metres above sea level.
Tenthredo crassa has a black head, thorax and abdomen, with black femurs, yellowish tibiae and tarsi. 
The antennae are black, with three white final segments (clearly shown on the photos).

Berggasthaus Sucka area, Triesenberg, Liechtenstein, 7 August 2020