Lithocharis nigriceps

I assume it will get easier with more experience but at the moment I still find the decision as to whether the antennal insertion points are on the upper or side surface of the head the first stumbling block when identifying rove beetles. In this case, with the benefit of hindsight I can see why it was the side, but this was less clear than on another pair of beetles I was examining at the same time, so in some doubt I keyed it both ways. If I took it to be upper then they keyed to subfamily Staphylininae but reached a dead-end when attempting to key it as such. If I took it to be side then they keyed to subfamily Paderinae and then to Lithocharis nigriceps, and as that's a species that does look like my sepcimens so I assume this is correct.

Once at Lithocharis the species was identified as nigriceps based on the temples being clearly longer than the eyes and the pronotum having a narrow unpunctured line down the middle (at least in the rear half, less clear towards the front). The third character separating nigriceps from ochracea relates to the eighth sternite of the males. The eighth sternite was withdrawn into the seventh so, unsure if they were males or females, I dissected them. Both had what I take to be spermatheca and no sign of any male genitalia, so I assume they are both females. The specimens were about 3.0 to 3.2 mm long (but the specimens were dried so the abdomen may have been longer in life).

female Lithocharis nigriceps showing close-ups of head, maxillary palps, pronotum (2 views), hind tarsi, front tarsi, tip of abdomen from below and spermatheca, Wendling Beck Environment Project (Norfolk, UK), 6th September 2023

second female Lithocharis nigriceps showing close-ups of head, maxillary palps, pronotum (2 views), hind tarsi, front tarsi, tip of abdomen from below and spermatheca, Wendling Beck Environment Project (Norfolk, UK), 6th September 2023

I caught four more of these two nights later at another site within the same project area. This time one was a male, enabling the identification to be checked against an additional character. The 8th sternite was visible without dissecting the insect but wasn't very east to see, so I cleared the abdomen for a better look. It was also useful to see the long black hairs and short dense black hairs lining the apex of what I think must be the 7th sternite, a feature that will probably serve to enable the insects to be sexed without dissecting them.

male Lithocharis nigriceps showing close-ups of head, pronotum, tip of abdomen from below (2 focuses) and aedeagus and 8th sternite, Wendling Beck Environment Project (Norfolk, UK), 8th September 2023

Here are the females.

female Lithocharis nigriceps showing close-ups of head, pronotum amd spermatheca, Wendling Beck Environment Project (Norfolk, UK), 8th September 2023

second female Lithocharis nigriceps showing close-ups of head, pronotum amd spermatheca, Wendling Beck Environment Project (Norfolk, UK), 8th September 2023

third female Lithocharis nigriceps, Wendling Beck Environment Project (Norfolk, UK), 8th September 2023