Arthaldeus pascuellus

Apparently a common grassland species.

This one came to light at the edge of wet woodland. The pattern of the vertex suggested Arthaldeus and the absence of a strong pale line through the frons pointed to pascuellus, but to be sure I hadn't overlooked something I checked the genitalia (probably quicker than painstakingly taking it all the way through the keys). Although the subgenital plates are visible before clearing I could not make out the tiny tooth at their tips when examining the undissected insect under 63x magnification. Once cleared these became much easier to see.

male Arthaldeus pascuellus showing close-up of vertex, frons, subgenital plates (before and after clearing), sternal apodemes, pygofer and aedeagus (side and flat views), Wendling Beck Environment Project (Norfolk, UK), 18th August 2024

This one was swept from grass. This time I relied on the vertex and frons pattern for the ID.

Arthaldeus pascuellus showing frons, North Elmham Cathedral Meadows (Norfolk, UK), 23rd June 2021