Nephanes titan (Newman, 1834)

Among the smallest of our UK beetles, and outdone in this respect only by Baranowskiella ehnstromi, this ironically-named species is widespread across Central and Northern Europe from the Pyrenees to Italy and Ukraine in the south and north to the UK and into central Fennoscandia. The species is known from Western Russia and is present on most of the Mediterranean islands as well as the Azores and Canary Islands; it is widespread in North Africa and has recently been discovered among specimens collected from the Ivory Coast (Darby, 2020). The species was first described from North America in 1971 from adults and larvae collected in Illinois between 1967 and 1974, and since then it has been found to be widespread and common but whether it is native to that region or an established Old World introduction is not known. This is among the smallest of the world’s non-parasitic insects but despite this it has been the subject of much research; it has a tiny brain and a limited neuronal system but has been found to display cognitive learning behaviour (Polilov et al, 2019). In the UK it is widespread though very local throughout England and Wales, with the possible exception of the West Country, and is known Ireland and from Man but is seemingly absent from the other islands. Adults occur year round, they are active in suitable habitats through the year and peak in abundance from July until the autumn, the phenology might suggest a univoltine development but under suitable conditions the species is more likely to be continuously brooded. The typical habitat is among decaying vegetation but both adults and larvae are more usually associated with dung, manure heaps, and neglected decaying straw and hay, and in such situations both stages may be abundant through the milder months. Little is known of the biology but, typical of the family, females probably mature a single relatively large egg at a time, and larvae, which are definitely not predatory and probably feed on fungal spores, take about three weeks to fully develop. Adults may be sampled by extraction, and here they usually occur in numbers, but they fly well and sometimes swarm about manure or compost, and at least in northern Europe, sometimes over dung pasture or open grassland.