Atomaria atricapilla Stephens, 1830

This mostly Western Palaearctic species is generally common throughout Europe and Asia Minor and extends east into Siberia, also known from many of the Mediterranean islands, North Africa and Iceland; in Europe it is reaches north to the UK, Denmark and the Baltic countries; in Norway and Sweden reaching the Arctic Circle but in Finland it is very rare and known only from the extreme south. In the UK it is generally common throughout England and Wales, including all the islands, much less so further north to the Western Isles, Orkney and Shetland and in Ireland it is widespread but mostly coastal in the south and east. The species is usually associated with decaying vegetation in a wide range of habitats including damp grassland and arable land, but it is sometimes common among compost or grass cuttings in gardens or in hay or straw in stables and farms etc., and in Europe it is often common among vegetation on dry slopes and woodland margins in mountain valleys etc. Adults occur year-round; they overwinter among tussocks or damp litter and are active from March until November or December, peaking in abundance from May until July. They fly well and often visit umbel flowers etc. in numbers during warm weather but otherwise remain hidden among litter etc., although in the autumn they sometimes occur in large numbers among pungent decaying terrestrial fungi in damp situations and here they tend to be active through the night. The biology is not known but larvae probably develop among decaying vegetable matter and are mycophagous or saprophagous. Adults can be sampled by sieving or taking likely samples for extraction, but they sometimes occur when sweeping long vegetation or in flight-interception traps.