Anotylus inustus (Gravenhorst, 1802)
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POLYPHAGA Emery, 1886
STAPHYLINOIDEA Latreille, 1802
OXYTELINI Fleming, 1821
Anotylus Thomson, C.G., 1859
Widespread and locally common across southern parts of the Palaearctic region, this species is known from North Africa and Asia Minor to the far east of Russia, China and Japan. In Europe it has a mostly southern and central distribution, from Portugal to Italy and Greece in the south and common on most of the Mediterranean islands, and north to the UK, Denmark, Faroe, and some southern provinces of Sweden but otherwise absent from Fennoscandia. Throughout most of the European range it occurs in lowlands and lower mountain valleys, usually on open sites exposed to the sun, but going north it becomes more sporadic and local, often being common only on cattle pasture. In the UK it is generally common and often abundant across Central and South eastern England and lowland areas of Wales but much more local and scarce in the West Country, further north to the Scottish Highlands and in Ireland. Adults are present year-round, they overwinter among decaying litter, compost or in organic-rich soil and are active over a long season, from March until October or November depending on the season, and they peak in abundance during May and June and again in the autumn. Typical habitats are open and rather dry sites on light sandy or chalky soils with patchy vegetation and plenty of exposed substrate; they are often abundant on dung pasture but might be encountered among decaying organic matter in most fairly dry situations. Adults fly well and often swarm in warm weather, particularly in the evening, they are quick to colonize new sites and they often occur at disturbed sites in urban situations. Little is known of the biology but adults, and very probably larvae, are predatory, they are often abundant in dung and so it is likely that larvae develop rapidly in the summer to produce the autumn peak in adult numbers. Adults are readily sampled at dung during the warmer months but they may occur among decaying organic material generally or in extraction samples at any time, they are frequent in suitably placed flight-interception traps and have been recorded from decaying fungi and at sap. Ariel sweeping on dung pasture or woodland margins may produce large numbers of adults but they will need to be taken for critical examination as several closely similar and abundant species often occur together.
3-4 mm. Robust, parallel-sided and discontinuous in outline, body entirely shiny black or with elytra dark brown, especially towards the apex, antennae black, legs brown, usually with the tibiae and tarsi paler. Head smooth but sometimes with a small patch of cellular microsculpture inside the antennal insertions, otherwise rather coarsely punctured, these often within longitudinal striations towards the base, eyes small and weakly convex, temples smoothly rounded to a wide neck. Clypeus truncate, with very fine punctures but lacking microsculpture. Antennae inserted laterally outside the base of the mandibles, basal segment long and evenly expanded from the base, and segments 5—11 transverse and much broader than segments 2-4. Pronotum transverse, broadest about the middle and smoothly curved to obtuse or almost rounded angles, lateral margins smooth, surface with a more or less complete median longitudinal impression and another partial impression either side from the apical margin, lateral third or so distinctly depressed , entire surface strongly and closely punctured and with partial longitudinal striations. Scutellum cordate with a median longitudinal keel. Elytra transverse and slightly dilated from rounded shoulders to truncate apical margins, sutural margin with a doubled raised border, surface evenly and rather strongly punctured and with variable longitudinal striations and fine pale pubescence. Abdomen parallel-sided or weakly dilated, strongly bordered with segments broadened from the base, all tergites evenly punctured and pubescent and with extremely fine microsculpture. Femora unarmed. Tibiae only weakly expanded from the base, front tibiae excavate externally before the apex, front and middle tibiae with numerous external spines, hind tibiae with spines towards the apex. Tarsi 3-segmented; two basal segments small and broad, terminal segment long and slender. Claws smooth with a small tooth at the base. Males may usually be distinguished by their wider or more developed head but this is very variable, in doubtful cases the apex of the seventh sternite should be examined; in females it is simple while in males it has a small pubescent tubercle either side of the middle.