Aleochara curtula (Goeze, 1777)

This generally common species occurs from lowland to alpine altitudes throughout Europe with the exception of the most northern provinces of Fennoscandia, further afield it is among the most widespread members of the genus, occurring across the Palaearctic region east to Japan and south into the Oriental region and tropical Africa, it has also become established in north America since the early twentieth century and has been widely recorded in South America. Here it occurs throughout the British Isles; it is locally common throughout south and central England and rather more local and scarce in the West Country and further north to the Scottish Highlands and Outer Hebrides. Adults occur year-round and are active from early spring until the autumn, they are typically attracted to freshly decaying carrion but may also be found at dung or strongly smelling decaying vegetation e.g. we found them in numbers among foul-smelling decaying seaweed in North Somerset and they may be abundant in decaying terrestrial fungi in the autumn, but through the spring and summer they will quickly be attracted in numbers to carrion. They run quickly about the host material predating insect larvae etc. and when disturbed will either take flight or vanish into adjacent vegetation or crevices in the ground so that to sample them the best way is to sieve a sample or throw it onto a tray. Mating occurs throughout the season and eggs are laid into the host material. Larval are solitary parasites of cyclorrhaphous diptera, they develop rapidly and pass through two distinct stages; first instars are campodeiform and very active, they search through host material until they find a suitable dipteran pupa, here they are guided by volatiles from the pupal spiracles, they then chew their way into the pupa and feed on the contents, the following two instars are eruciform and will continue feeding in situ until they pupate. Each pupa will host only a single larva and so competition is intense among late arriving larvae and after a certain time the host material becomes unattractive to adult beetles, because of this there is also a wide variation in adult size as pupae of various sizes and of several host species can be utilized. Adults may be obtained in numbers using carrion-baited traps, freshly-decaying fish placed among leaf litter in just about any situation will usually attract many specimens, on a warm day they may even be seen flying in and vanishing beneath the sample, in warm weather they will also appear occasionally when sweeping among vegetation or above dung pasture.