Sunius propinquus

I keyed this using Lott & Anderson. Other than initially thinking it was in a different subfamily (despite noting its resemblance to some members of Paederinae) it keyed reasonably striaghforwardly, at least for a Staph. It was collected from a pitfall trap (in propylene glycol, so no live photos) and was about 3.5mm long or a little under.

Sunius propinquus showing head (one flat view to show shape and one slightly angled to show microsculpture) and pronotum, Wendling Beck Environment Project (Norfolk, UK), 29th to 31st March 2024