Widespread in central and northern Europe; absent in many Mediterranean regions but extending north into the UK and the Baltic countries where it reaches into southern provinces of Norway and Sweden, to the east it extends sporadically into European Russia. The species is very local and generally scarce throughout this range, although it is probably more common in cooler northern regions. In the UK it is very local and scarce in Southern and Central England and Wales; it was formerly more widespread, extending into Southern Scotland, but it is thought to have declined over recent decades. Associated with a range of broadleaf trees, especially alders (Alnus Mill.) and poplars (Populus L.), and much less frequently with conifers, especially pines, and usually in damp or wet situations such as river or lake margins or carr. Adults also occasionally occur among plant debris, compost and decaying sporocarps. Adults are present year-round; they overwinter under bark or among moss or litter near to suitable trees, and are active from March until September or October, peaking in abundance during May and June, and again in September. They are nocturnal and they fly on warm evenings to visit sap and insect-infested wood where the larvae are thought to develop in beetle galleries etc. It is likely that both adults and larvae are detritivores or mould feeders, but adults have been recorded from a range of beetle galleries including those made by larvae of Elateroides dermestoides, and the bark beetles, Xyleborus dispar (Fabricius, 1792) and Taphrorychus bicolor (Herbst, 1794), suggesting that either or both may also be predatory. Although very local and rare the species is sometimes abundant where it occurs. Adults may be found under damp or even wet bark or at sap during spring and early summer, otherwise they may occur in suitable extraction samples or among flood-refuse.