Cercyon quisquilius

I used Duff to identify this first and it keyed straight to quisquilius. I double-checked the ID by using Hackston and this was useful as it contributed a couple of additional confirmatory characters but also had a problem as I do not consider that the raised area on the metasternum is sharply bordered on the front margin, as required at couplet 6. However the other main character at this couplet suggested I should continue as if it was (i.e. the palps were pale except for the terminal segment). Just in case, I followed the alternative route too, and that soon led to a dead-end.

As you can see in the photos, this beetle had a mite crawling over it.

Cercyon quisquilius showing pronotum side, elytal base, prosternum, mesosternum and metasternum, Wendling Beck Environment Project (Norfolk, UK), 8th September 2023