Xantholinus linearis

I was pretty happy this was linearis without dissecting it, but always good to confirm it with an aedeagus, even if I did somehow manage to rupture the aedeagus when breaking the tip of the abdomen off.

Xantholinus linearis showing pronotum (from above and side) and aedeagus (two views), North Elmham (Norfolk, UK), 9th August 2023

These were in pitfall traps (in propylene glycol, so no live photos). I'm not aware of identification characters in the female genitalia but this first one had a large sclerotised area that was not present on female Xantholinus longiventris that I've examined.

female Xantholinus linearis showing pronotum and genitalia, Wendling Beck Environment Project (Norfolk, UK), 29th to 31st March 2024

Xantholinus linearis showing pronotum, Wendling Beck Environment Project (Norfolk, UK), 29th to 31st March 2024

This was one of my first Xantholinus and I used Mike Hackston's keys to identify it, found in a pitfall trap (pretty much covered in mud and barely alive). At first the elytra didn't seem very shiny and I nearly put it down as linearis, but subsequently decided it was gallicus. There was a very slight hint of linearity in the punctures at the edges - but was this enough to qualify as, "the punctures not so scattered and somewhat organised into lines" (as Hackston has for linearis)? I wasn't sure, so checked the genitalia, and the aedeagus had "two larger bent teeth well separated from the rows of smaller teeth towards the base" which according to Hackston makes it gallicus. Hackston only has a diagram for linearis (not gallicus) but in hindsight that diagram isn't very helpful as it doesn't show the teeth. I looked back at the elytra and concluded that there was a bit of a shine, and I couldn't see the microsculpture (also correct for gallicus) - although looking back at my photos I wonder if I was examining them detached and backlit which maybe isn't the best way to see the microsculpture. I also found an extremely high quality image of linearis which showed the elytral punctures to be more clearly organised into lines than on mine, which made me feel more comfortable that gallicus was the correct ID. To be honest I think that was a reasonable conclusion given Hackston's description of teh genitalia, but having now had some linearis and access to both Lott & Anderson and Duff, I think it was wrong. I think the aedeagus is in fact a much better match for linearis and wrong for gallicus.

Xantholinus linearis showing head (with close-ups of front from above and below), pronotum, elytra (with close-up showing of centre of one) and aedeagus (second photo just showing the inner sac), Wendling Beck Environment Project (Norfolk, UK), 2nd to 12th November 2022