Scaphisoma assimile Erichson, 1845
Although widespread in Europe, extending to Ukraine, Russia and southern Scandinavia, it is sporadic and generally rare throughout its range and this applies to the UK where it may only have occurred historically as an occasional introduction or may have been established and is now possibly, or even probably, extinct. It was mentioned in Fowler (Vol. 3, 1889) and there are several documented nineteenth century records but Joy does not include it in his handbook and there are only very few twentieth century records; from Hampshire and Berkshire, and the most recent in 1974 from Kent (Philp, E. 1990 Ent Rec J Var. 102:116.). On the continent it is associated with wood decay fungi in deciduous woodland etc. and the adults have been recorded from fruiting bodies of Rigidiporus latemarginatus (Duries & Mont.), the 1974 UK record was from decaying plant litter.
At 1.7-2.0mm the present species is similar in size to our other Scaphisoma species; from S. agaricinum it is readily distinguished by the sutural stria of the elytra which extends onto the basal margin, and from S. boleti by the black elytra and more dense dorsal punctation but there are also some comparative differences which become obvious when they are placed side by side; S. assimile is broader with a longer pronotum and less strongly tapering elytra. When mature the adults are entirely black with the elytral apex very narrowly pale and the appendages brown.