Ilybius quadriguttatus

I initially used Mike Hackston's key to identify this. The elytral microsculpture was only obviously elongated close to the suture in the basal region but the other characters checked out fairly straightforwardly. I double-checked with Duff, not least because I wasn't comfortable with size being the only character used to eliminate ater - but this was pretty much the case in Duff too (he also separates them on how matt or shining the upperside is but I find that quite subjective in the absence of reference material to compare with). This one was 11.5mm long.

Ilybius quadriguttatus showing keel on last segment of abdomen, elytral microsculpture (near middle of elyra and base around suture) and outer front claw, Wendling Beck Environment Project (Norfolk, UK), 11th June 2023

I initially used Mike Hackston's key to identify this. The elytral microsculpture was only obviously elongated close to the suture in the basal region but the other characters checked out fairly straightforwardly. I double-checked with Duff, not least because I wasn't comfortable with size being the only character used to eliminate ater - but this was pretty much the case in Duff too (he also separates them on how matt or shining the upperside is but I find that quite subjective in the absence of reference material to compare with). This one was 11.5mm long.

Ilybius quadriguttatus showing keel on last segment of abdomen, elytral microsculpture (near middle of elyra and base around suture) and outer front claw, Wendling Beck Environment Project (Norfolk, UK), 11th June 2023