Images:
A large family of small to medium (1-8mm) beetles, Nitulidae has 91 British representatives and are perhaps most familiar as tiny black beetles which flock to anything bright yellow on sunny summer days. There are five subfamilies in Britain.
Meligethinae are small shining black beetles which feed as both larvae and adults on buds and flowers. A wide range of plant families are attacked but each beetle species is highly host-specific, feeding almost entirely on a single plant species. Two exceptions to this are Meligethes aenus (Fabricius) and M. viridescens (Fabricius), which feed on a wide range of Brassicaceae flowers and consequently have become pest species on oilseed rape and several other Brassica crops.
Carpophilinae consists of two genera, Carpophilus and Epuraea. Carpophilus species are largely found in association with fungi, particularly on mouldy fruit, and consequently several species occur synanthropically and are known as stored-product pests. Epuraea are less well known but appear to have diverse life-histories: several are found in association with wood-boring beetles, particularly Scolytinae spp. in conifers, while others develop in subterranean nests (particularly of bumblebees) and others are associated with fungi. Adults are frequently encountered on flowers and at sap runs.
Nitidulinae are another ecologically-diverse but largely unknown group. Several species (particularly Nitidula and Omosita spp.) are associated with dried carrion and bones and many of the remainder are found chiefly in fungi. Saronia grisea (L.) and S. punctatissima (Illiger) can be found mainly on sap runs, and in fermenting vegetable matter and the galleries of larvae of the goat moth, Cossus cossus (L.). Amphotis marginata (Fabricius) is strongly myrmecophilous in the nests of Lasius fuliginosus Latreille.
Cryptarchinae are most often found on sap runs, although specimens are sometimes found in the galleries of wood-boring beetles, beneath bark, or further afield. Little is known of their ecology.
Cybocephalinae consists of just one species in Britain, the 1-1.5mm Cybocephalus fodori Endrödy-Younga. This is a predator of scale insects (Coccoidea: Diaspididae) which has been found on birch trees on Putney Heath, London.