Eurynebria complanata (Linnaeus, 1767)
This very local and generally rare coastal species is now classified as endangered following a severe decline over recent decades; it was formerly widespread in Kent and the West Country and Wales bordering the Severn but is now more or less restricted to a few sites in South Wales and there are also populations in southeast Ireland. Further afield it is native to south and west Europe, including various Mediterranean islands, where it has also suffered a decline although, as in the UK, it is often common where it occurs. This decline has been partly, alongside the general abuse visited upon our beaches by tourism, attributed to the use of mechanical devices to clean beaches of debris; adult beetles are nocturnal and spend the day sheltering under wood and other debris, generally within 3-15metres of dunes or cliffs. The typical habitat is sandy beaches beyond dune systems and it is thought the larvae cannot develop on shingle, by night the adults are active around the strand-line; they are predatory upon various amphipods e.g. Talitus saltator (Montagu, 1808) or Talorchestia brito Gonςlaves, S.C., 2003 but will also take diptera larvae etc. In the UK adults are active from April or May until late in the year, peaking during June and again in August and September, mating occurs in late summer and autumn and is followed by oviposition. Eggs are laid singly in the sand and the resulting larvae develop through the winter. Pupation occurs in the sand from March to produce new-generation adults from April or May although many, or even most, will overwinter as pupae or even adults from the previous autumn. Overwintering adults are thought to move away from beaches into dune systems in the autumn.
Adults are very easily recognized by their large size, 16-23mm, and sandy-brown colouration, especially as they are restricted to shoreline habitats. Entire beetle pale to dark sandy-brown with the elytra variously patterned with black, often with numerous longitudinal lines which are confluent and produce two transverse areas but sometimes sparse and reduced to obscure transverse bands behind the middle. Head transverse with large convex eyes and smooth, only weakly convex. Antennae and palps long and slender, the terminal maxillary palpomere truncate. Pronotum widely transverse, rounded laterally and strongly sinuate before sharp posterior angles. Elytra long and evenly curved laterally from weakly-developed shoulders to continuously rounded apices, with well-impressed but only very finely punctured striae and weakly convex, almost flat, interstices. Legs long and slender; pro-tibiae without an internal antenna-cleaning notch.