Lordithon lunulatus (Linnaeus, 1760)

A generally common and often abundant species throughout most of the temperate Palaearctic region, in Europe occurring from lowland to subalpine zones from Spain to the Black Sea and north to the UK and above the Arctic Circle in Scandinavia, it is absent from some of the warmer Mediterranean regions and North Africa generally but does occur on some of the islands.  In the UK it is generally common across England and Wales, including Anglesey and the Isle of Wight, and much more local and scarce further north to Orkney and in Northern Ireland. Adults occur year-round, they overwinter in litter or moss etc. and may become active during mild spells, they otherwise occur from April until October, peaking in abundance from June until August. Typical habitats are open woodland and wooded parkland where they are associated with decaying fungi, usually terrestrial sporocarps and those developing in abundance on fallen timber; much less  on arboreal fungi. The state of decay is more important than the species of fungus involved as adults (and probably larvae as well) are predatory and hunt springtails and mycetophagous diptera larvae etc., they will soon arrive at damaged fungus during the summer but usually only in small numbers. Little is known of the biology but breeding is likely to occur in the spring and early summer, and these adults are likely to die off before the new generation emerges. Adults are infrequently observed, they are nocturnal and live among decaying fungal material or in the ground beneath, they may be found by pitfall trapping or sieving likely material and they have been recorded in flight-interception traps but in general they seem to prefer wet, or at least damp, host material, maybe because they are attracted to the volatiles, which is not the most pleasant stuff to investigate, on the other hand they usually occur among large numbers of other beetles and so taking samples is a rewarding way to find the species. On warm summer nights adults will very occasionally be found running on pathways or on logs and this may be a prelude to dispersal, conversely they may become established over a long period at a single site; in a local Watford woodland they were active every month among a very large decaying mass of Laetiporus growing on shaded Prunus avium logs over several years.