Epuraea aestiva

This is a difficult genus to identify, but aestiva is apparently the commonest member.

This individual was the first aestiva that I have identified but I don't think I would have been able to name it confidently without having examined its genitalia. I used both the Hackston and Duff keys and neither clearly led me to a convincing conclusion before checking the genitalia. Duff did lead me to aestiva, but there was at least one contrary indication, namely the presence of a median longitudinal impression extending for most (not all) the length of the metasternum. The punctures on the pronotum were really hard to see, but appeared to be intermediate between aestiva and melina as illustrated in Duff.

male Epuraea aestiva showing its pronotum, metasternum and its aedeagus (side, flat, close-up of apex), North Elmham Cathedral Meadows (Norfolk, UK), 27th May 2021

The next one (I didn't process them in order) wasn't much easier. I tentatively arrived at aestiva using both keys but it wasn't entirely straightforward. The mid coxae were slightly more separated, intermediate between the figures accompanying couplet 7 in Duff (but the gap between the hind coxae matched the illustration for aestiva better). Unlike the previous individual the pronotum puncturing was clearly dense. Like the other one, this showed a clear median longitudinal impression extending for most of the length of the metasternum. Am I misinterpreting this feature, have I gone wrong some other way, or has Duff got it wrong? I can't see how else to interpret it!? This one was a female so I couldn't check its genitalia, but I'm reasonably confident the ID is correct (though always happy to hear from anyone if you think it might not be).

female Epuraea aestiva showing its metasternum and pronotum, North Elmham Cathedral Meadows (Norfolk, UK), 7th May 2021

This one pre-dated the last two but was processed later. The ID was relatively straightforward now. I'm not sure if the line down the middle of the metasternum is really impressed, or if it isn't just a visible line beneath the surface. Anyhow, I guess I need to find a melina to see what the difference is.

female Epuraea aestiva showing its pronotum, metasternum and 3 views of the aedeagus (median lobe beside tegmen), North Elmham Cathedral Meadows (Norfolk, UK), 2nd May 2020

I netted this one in flight. I keyed it using Duff and got to aestiva before checking the genitalia matched.

male Epuraea aestiva showing its hind tarsal claw, mid coxae, metasternum and aedeagus, Wendling Beck Project (Norfolk, UK), 19th April 2025

This one, taken the same day, was found by sweeping. Although not shown here the aedeagus was checked.

second male Epuraea aestiva showing metasternum, Wendling Beck Project (Norfolk, UK), 19th April 2025

This was 2.8mm long but somehow I managed to see it in flight and get a net round it. One of the recurring problems I have with beetle identification is interpreting tarsal claw shape. Apart from the difficulty in seeing it at all in some cases, the challenge is often interpreting how much of a basal swelling is acceptable for a claw described as simple, and how much is needed for it to be described as appendiculate or toothed. In this case there was a small basal swelling but I suspected it wasn't sufficient to describe it as toothed, and therefore it could not be melanocephala. I had previously identified melanocephala and comparing the current specimen with photos of that one's claw, the swelling on this one was clearly smaller than on that. So taking it to be simple it keyed straightforwardly to aestiva.

As it was a male, it made sense to confirm with reference to the genitalia. Slightly annoyingly, of all the Epuraea, the genitalia of melanocephala seem to be one of the most similar to that of aestiva, and in my specimen the two sides of the tegmen were much more widely separated than Duff illustrates for aestiva. However the inner edges of the two sides are convex as shown for aestiva (but not melanocephala) and the median lobe seems to clinch it. The photos at the Beetles of Europe website, coleonet.de, only show side views of the tegmen for each of these species, but the photos there of the median lobe make the differences in that even clearer so I'm happy this is aestiva not melanocephala.

Once again this specimen showed a dark line down the centre of the mesosternum which would be easy to interpret as a median longitudinal impression. However it's not clear to me that this is actually an impression, so presumably this would be more clearly impressed should I ever find Epuraea melina?

male Epuraea aestiva showing head, antenna, apex of sternites (and elytra), mid tibia, fore tarsus, pronotum, fore and mid tarsal claws, metasternum (2 views), pronotal punctures, aedeagus (median lobe and tegmen unseparated), tegmen (2 flat views and one from side) and median lobe, North Elmham (Norfolk, UK), 31st March 2026