Melanotus villosus

I make the ratio of the length of the apical 'blade' of the paramere to the whole paramere length as being 0.30 so clearly pointing to villosus.

male Melanotus villosus showing genitalia, Hoe Rough (Norfolk, UK), 23rd July 2023

I initially used Hackston to identify this and based on the relative pronotum and elytra lengths it came out as villosus. I was less clear using Duff. I think I may have been slightly confused about the relative lengths of the paramere blade as I worked out that it must in fact be Melanotus castanipes. I had another castanipes that I was examining at the same time and photographed both genitalia together. Looking back at this recently I questioned whether this one really was castanipes, as the blade looks relatively long compared to the other one (which I still think is castanipes). Re-measuring the lengths from the photo and I now make the ratio of blade to whole paramere a little over 0.28, and that puts it (if not by a long margin) in the villosus camp.

male Melanotus villosus, Bintree Wood (Norfolk, UK), 6th June 2021

Here are the two genitalia together, castanipes on the left and villosus on the right.

genitalia of male Melanotus castanipes, North Elmham Cathedral Meadows (Norfolk, UK), 2nd June 2021 (left) and male Melanotus villosus, Bintree Wood (Norfolk, UK), 6th June 2021 (right)

The small group of spines at the edge of the bursa copulatrix away from the main patch apparently make this female villosus.

female Melanotus villosus showing pronotum, face and genitalia, Wendling Beck Environment Project (Norfolk, UK), 26th May 2023

I think all of the following were before I had Duff, and so were identified using Hackston. In that case this ID would have been purely based on the relative lengths of the pronotum and elytra. Not sure how reliable that is in hindsight, but judging from the photos I think the shape of the pronotum fits villosus.

Melanotus villosus, North Elmham (Norfolk, UK), 21st June 2017

Melanotus villosus, North Elmham (Norfolk, UK), 24th July 2018

Melanotus villosus, North Elmham (Norfolk, UK), 5th August 2020

Melanotus villosus, Row Heath, West Runton (Norfolk, UK), 27th May 2017