Peritrechus geniculatus

This was found by suction on an ex-arable lowland meadows. Separation from Peritrechus nubilus seems to revolve around the thickness of the third antennal segment and the shape of the pronotum. The third segment should be as thick or thicker than the first segment on this species, thinner on nubilus. In fact I made it very slightly thinner on this one (0.12mm vs. 0.13mm) but I think these are close enough to be considered about the same. Comparing with photos of both species (including my own of nubilus) it seems to fit geniculatus best on both antennal width and pronotum shape. Both species are supposed to be common.

Peritrechus geniculatus showing front femoral spines, Wendling Beck Environment Project (Norfolk, UK), 25th August 2025