Chloroperla tripunctata

Apparently a very common species in the west and north of Britain, but absent here in East Anglia.

I'd kept this specimen back until the new Stoneflies book was published (2022) and this was the first stonefly I put through the keys there. It keyed very easily, although the epiproct wasn't visible on the dried specimen until I'd macerated the abdomen in potassium hydroxide solution.

male Chloroperla tripunctatashowing wings and abdomen tip (showing ectoprot), Keswick (Cumbria, UK), 12th June 2021