Roseville, Vernon St., 38.7227, -121.2993, Elevation = 50m (164'), Placer County, California, USA
September 3, 2019
Size: 2.6 mm
Taken from a Lingren Funnel Trap.
Posted to verify genus & species.
Looks very much like Teretrius orbus, with the impressed humeral striae, but this range is wrong for that species and no others in BG have that character that I can find.
Characters important from Arnett
(1).
Head
--
Frons evenly convex.
-- Labrum plurisetose, seen in above photo sticking out under clypeus.
-- Antennal club
not concealed by extension of prosternal lobe.
-- Antennal funicle in repose curving outward seen in above photo.
Thorax
-- Mesepimeron visible from above, seen in dorsal and side views.
--
Pronotal disk without longitudinal or transverse grooves.
Body
-- Elytra with impressed humeral striae, seen best in
side view.
--
Pygidium evenly convex.
-- Elytra striae obsolete.
-- Form cylindrical and parallel-sided.