Tachyporus hypnorum

(In an earlier version of this page I had failed to save the page before uploading it (and failed to upload it after saving it) which meant that it showed several images incorrectly captioned and the text didn't make sense. Apologies for any confusion.

The difficulty in seeing the elytral microsculpture has caused me a few issues with this species. In this case I could, just, see a vague hint of microsculpture on the elytra. It was far from clear and difficult to see at all, but maybe enough to qualify? Anywway, the other characters all seemed good for hypnorum, so I'm pretty confident it is.

Tachyporus hypnorum showing elytra and maxillary palps, Ling Plantation, North Elmham (Norfolk, UK), 6th April 2024

Now armed with Duff I'm less concerned about not being able to clearly make out the microsculpture - Duff suggests this requires 100x magnification and indirect lighting (I could just about make it out on this one using the compound microscope, at least near the apex). This one seems to tick all the boxes for hypnorum except I struggled to see some of the setae. Of these the one I really wanted to see was the humeral seta but I could not positively identify it on either elytron. The specimen had been in a pot for over 4 years and it was at least the second time I'd examined it, so it's entirely plausible that some of the setae could have come off - I could see what might have been a pore on both sides but I wasn't entirely convinced. None of my references provide diagrams for the genitalia for this species so I'm not sure if the aedeagus helps confirm or not. The forebody length (head to apex of elytra) was 2.0mm and the elytra was 0.99mm long. The internal sac sclerite (at least I assume that's what it was) was very short at 0.024mm long. The beetle had come to light.

male Tachyporus hypnorum showing maxillary palp, elytra (both, one at 2 focuses) and aedeagus, North Elmham (Norfolk, UK), 6th June 2020

This one seemed to be relatively straightforward. I was able to see most of the elytral setae and these were correct for hypnorum, and the elytral microsculpture was just visible under high magnification with the compound microscope. It was interesting to compare the elytra with a Tachyporus pulsillus that I'd just examined.

female Tachyporus hypnorum showing maxillary palps, elytral lateral setae, elytra and abdominal tergites, North Elmham Cathedral Meadows (Norfolk, UK), 12th April 2022

Here are the elytra on the right compared next to a Tachyporus pusillus on the left.

elytra of female Tachyporus pusillus, North Elmham (Norfolk, UK), 3rd March 2022 (left) and female Tachyporus hypnorum, North Elmham Cathedral Meadows, 12th April 2022