Leiosoma troglodytes (Rye, 1873)
This rare and very local species is known from only a few sites in southern England from South Hampshire to Kent and possibly (unconfirmed) Surrey, it was formerly known from Ireland (Galway and Antrim) but has not been recorded in recent decades, beyond this it is known from only a few sites in northern France. The biology is very poorly understood; adults have been recorded during January and August in France, and in April, May and October in the UK, suggesting a life-cycle typical of the genus with larvae developing during spring and summer and adults overwintering. Habitats include damp grassland, especially on chalky soils; open woodland and wetland margins and adults are associated with various Ranunculaceae including buttercups (Ranunculus L.) and Wood Anemone (Anemone nemorosa (L.) Holub), which are also likely to be larval hosts.
1.8-2.4 mm. Very similar to our other members of the genus in habitus and colour but on average smaller and broader, the pronotum is duller and the elytral striae are more strongly and closely punctured, beyond this it is readily recognized by the metepisterna which lack the dense pale scales seen in our other species. Males may be distinguished by the antennal insertions being closer (about the width of the rostrum) to the apex of a slightly shorter and broader rostrum, in female the rostrum is a little longer and narrower and the antennal insertions are distinctly more removed from the apex.
© Mark Gurney