Psammotettix confinis

This was a tricky ID... Firstly the RES key sent me down the wrong route because it says confinis should be, "Macropterous, with fore wings considerably longer than abdomen". On this leafhopper you can clearly see the abdomen tip protruding slightly beneath the tips of the forewings so I opted for the option, "Brachypterous, with fore wings not or hardly longer than abdomen". This seemed clear enough so I didn't finish reading (rookie error), otherwise I might have noticed that my leafhopper had a well-developed appendix which goes with the longer-winged option. After keying it to a montane species from Scotland (frigidus) I figured I'd gone wrong, and noticed that some photos of supposedly long-winged species (e.g. of sabulicola in the German photo guide) showed the abdomen visible beyond the wing tips.

That wasn't the end of the problems as the key fails to give any clear diagnostic differences for some females. The best fit seemed to be confinis, but although some of the "usual" features of nodosus weren't present, there was nothing in the description of nodosus that completely ruled that out. It seemed to be a better match for typical confinis than typical nodosus, and the presence of four dark dashes on the front of the vertex was mentioned for confinis but not nodosus, supporting this ID, but the key doesn't say these aren't possible in nodosus.

The photo of confinis in the German photo guide was closer than the photo of nodosus, but given the variability of both species (inferred from the RES key) this didn't really confirm the ID. However the Biedermann and Niedringhaus key does reassure me that the ID as confinis is correct. It says nodosus should have a more-or-less acutely angled vertex, as long as the pronotum and flat in side view. When I was going down the short-winged rabbit hole I'd ruled albomarginatus out based on the vertex not being acutely angled or flat in side view, so I knew that wasn't right, and the vertex is definitely shorter than the pronotum. B&N doesn't say about the vertex angle/flatness for confinis, but it does say that the vertex is slightly shorter than the pronotum, as it is on mine.

female Psammotettix confinis, Wendling Beck Environment Project (Norfolk, UK), 22nd October 2022

I have one previous record of this species which was keyed using the RES key. This one was a male, but not confirmed with reference to the genitalia. I must have messed up the dissection because the bit I extracted thinking it was the aedeagus did not resemble any Psammotettix aedeagus (or any other aedeagus so far as I could find). Rather too late (having lost the rest of the abdomen tip) I concluded that I had extracted the wrong body part!

Psammotettix confinis, North Elmham Cathedral Meadow (Norfolk, UK), 8th September 2020

Eventually I found a couple more males (along with another female). The two males were 3.3mm long.

male Psammotettix confinis showing aedeagus (from rear, in abdomen and isolated, and from side), Wendling Beck Environment Project (Norfolk, UK), 15th September 2023

This is the other male.

male Psammotettix confinis showing aedeagus, Wendling Beck Environment Project (Norfolk, UK), 15th September 2023

The female was a bit larger at just over 3.5mm. I think it's safe to call it confinis based on the shape of the vertex and the presence of two males.

female Psammotettix confinis, Wendling Beck Environment Project (Norfolk, UK), 15th September 2023

When I originally looked at this female I didn't feel comfortable naming it. Both the RES and Hackston keys lead to cephalotes/confinis/nodosus but beyond that it was tricky. Most cephalotes are quite different in appearance, being green and lacking dark marks, but both keys refer to a brown form which has dark marks. I am unable to find any pictures of this form. The maximum length given for cephalotes (3.7mm) is slightly smaller than this specimen (3.9mm). Therefore I don't think it's cephalotes, but the size difference is slight and in the absence of more clarity over the appearance of the brown form I am not completely certain how to eliminate this possibility.

Theoretically the weakness of the dark markings in the wings (almost absent except near the apex) should eliminate confinis and nodosus - but I susepcted that it may be in range for weakly-marked specimens of these species - and indeed the female confinis above was even plainer than this. Hackston gives the top end of confinis size as 3.7mm so if it is one of those I figured that the size should theoretically make it nodosus. However, I didn't think it was safe to identify it as nodosus on that basis, and indeed I now see that Biedermann and Niedringhaus allow for confinis to be up to 4.0mm (I missed that first time around).

Psammotettix helvolus is not included in the RES key and although mentioned, it is not keyed out in the Hackston key either. I'm not sure what it's UK status is - the NBN Atlas shows six records in and around London, the nearest to here being in Hertfordshire - but this is not generally a good up-to-date source of leafhopper distribution data (albeit perhaps the best available) so this species needs to be considered. It is covered by the German books and does look rather similar, being plainer than confinis and nodosus with just weak dark markings adjacent to the apical veins, but the photos in the German book (both male) don't show significantly whiter dorsal ends to the veins in the clavus as this does. So I suspect it isn't helvolus but there isn't enough information in the keys or books to rule this out.

When I first examined this I forgot about the difference in vertex shape alluded to in Biedermann and Niedringhaus so felt that it was not possible to name it for certain, and noted that the size perhaps made it more likely to be nodosus. Looking back at it now, given that I now know it's not too big for confinis and the vertex shape fits confinis, as well as the fact that I've now identified several confinis from different sites within the project area, I think it's probably safe to assume this is confinis too.

female Psammotettix confinis, Wendling Beck Environment Project (Norfolk, UK), 20th July 2023