Parabathyscia wollastoni (Janson, E.W., 1857)
POLYPHAGA Emery, 1886
STAPHYLINOIDEA Latreille, 1802
CHOLEVINAE Kirby, 1837
CHOLEVINI Kirby, 1837
PARABATHYSCIA Jeannel, 1908
This very widespread species is likely to be under-recorded due to its generally subterranean lifestyle; it occurs throughout Europe from the Mediterranean, including some of the islands, north to Holland and the UK; it is considered as very local and generally rare in northern areas but is more common in the south and is sometimes abundant in southern European mountain areas. The UK distribution appears to be restricted to South Wales and southern and central England. Adults occur year-round, they are primarily associated with subterranean organic matter e.g. they have been found among freshly harvested potatoes and other tubers and bulbs, but they have been recorded in a range of situations including decaying rhubarb and lettuce leaves, among debris in bumblebee nests, and we have found them under logs among well-decayed and damp leaf-litter in a local park, and extracted them from debris taken from Lasius niger (L.) nests in Watford town-centre gardens; in the south of the continental range they also occur among organic debris in caves. They are best searched for by sieving likely material over a tray but they are difficult to see because they roll into a ball and remain still for long periods when disturbed.
Entirely pale brown and finely pubescent, the small size and general habitus is distinctive among our fauna although it might casually be mistaken for Leptinus 1.5-1.9mm, eyeless, elongate broadly-oval and moderately convex. Head sharply-angled laterally-this outline fits tightly against the prosternum when the beetle is ‘rolled up’-and produced anteriorly, clypeus emarginate, mandibles with a single sharp apical tooth, terminal maxillary palpomere pointed and small compared with the long and apically expanded penultimate segment. Antennae inserted laterally in front of the angled expansion, long and slender with the first two segments broader and much longer than 3-6, segments 7-11 form an indistinct, loose and narrow club, segment 8 being smaller than 7 or 9. Pronotum transverse and rounded from backwardly-produced and acute posterior angles, broadest in front of the base and a little wider than the elytra,
surface evenly convex and lacking structure although usually depressed in front of the scutellum, very finely and obscurely punctured. Scutellum triangular and relatively large. Elytra elongate and smoothly curved from sloping shoulders to a continuously rounded apical margin, surface very finely and vaguely punctured and lacking striae though there is usually an incomplete sutural stria, at least in the apical half. Legs long and slender, the femora robust but only the posterior pair are visible from above, all tibiae with a pair of fine spines on the inner apical margin and a pair of larger spines on the outer margin, front and rear tibiae smooth or with only a few small setae among the pubescence, middle tibiae with about 6 long and stout spines along the external margin and a series of smaller spines towards the apex of the inner margin. Male tarsi 5-segmented, the basal protarsomeres dilated, female tarsi 5-5-4, without dilated segments.