Selandria serva

This species is very similar to the much rarer Selandria melanosterna but at 7mm long this individual was too small to consider that larger species.

male Selandria serva showing its wings (top lit and backlit) and aedeagus, Dillington Carr (Norfolk, UK), 14th May 2022

With a total length (front of head minus antennae to tip of wings) of 8.9mm this individual was larger than the stated size range for serva, so melanosterna needed to be checked for more carefully - and also the similar genus Brachythops although that's also meant to be smaller. The third segment of the antenna was much shorter than the apical three segments so that ruled out melanosterna, and the first segment of the tarsus was only marginally shorter than the second to fourth segments, ruling out Brachythops. I don't know if the aedeagus is helpful for ID with these, but it looked reassuringly similar to the individual above.

male Selandria serva showing its wings, hind tarsus and aedeagus, Elmham railway (Norfolk, UK), 3rd June 2022