Korynetes caeruleus (De Geer, 1775)

This is a widespread native Palaearctic species occurring throughout Europe and Mediterranean North Africa to the south of Fennoscandia and extending east through Siberia to China and Japan; in the wild it is saproxylic but it is also a pest of various stored products and so through transportation has been recorded under artificial conditions more or less worldwide. In Europe it is a mostly lowland species which varies widely in abundance; it is generally common in the south but rather patchy further north e.g. it is common in Denmark but generally rare on Poland and in the UK is a local insect of southern and eastern England and, apart from the Severn Valley and a few coastal records from Wales, is absent from the west. Adults appear in the wild from April and may persist until September, the typical habitat is dry deciduous or coniferous woodland, wooded borders and parkland and they are usually associated with decaying timber infested with scolytids or ptinids etc. although early in the season they may also occur on various flowers during warm sunny spells. Mating occurs in spring and early summer on trunks and branches, often on areas devoid of bark and close to the entrance burrows of other beetles, and soon after the female will visit several burrows and lay a few eggs either on the surface or just inside, and then she will die. Larvae develop within these burrows feeding upon the early stages of other species and eventually pupating within a chamber near the surface. Adults may eclose in the autumn and remain in place until the spring or, in cooler northern latitudes, eclose in the spring after the larvae have continued feeding into the autumn and pupated later in the year. The presence of Korynetes usually indicates a severe infestation of wood-boring beetles and so adults may be attracted to infested timbers in buildings during the summer and oviposit indoors, they may also be attracted to various commodities and under these circumstances they may become continuously breeding, with adults and larvae present through the year. Species of beetle recorded as prey under artificial conditions include Dermestes frischii Kugelann, 1792, Xestobium rufovillosum (DeGeer, 1774) and Niptus hololeucus (Faldermann, 1836), and adults have been reared from larvae developing on old bones, grain, stored meat and wheat, both in domestic situations and commercial bone-meal works, glue-factories, grain warehouses and timber-storage facilities.