Osphya bipunctata (Fabricius, 1775)
POLYPHAGA Emery, 1886
TENEBRIONOIDEA Latreille, 1802
OSPHYINAE Mulsant, 1856
Osphya Illiger, 1810
This is a very local and generally rare species across most of Europe, being locally common only in some warmer southern regions; it occurs from Spain to Asia Minor in the south and extends north into the UK and southernmost provinces of Fennoscandia, it is widespread in western Russia and has been recorded from the eastern Palaearctic region although this distribution may not be continuous, in the UK it is very local across the south midlands with scattered records from East Anglia, Somerset and Kent. Adults occur between April and July, peaking in abundance during May but they tend to be solitary and very rarely occur in numbers, they fly well and visit flowers of various trees and shrubs to feed on pollen including hawthorn (Crataegus monogyna Jacq.), from which it is most frequently recorded, maple (Acer campestre L.) and various viburnums (Viburnum L.) and they also visit umbels and other flowers. Typical habitats are open sunny grassland or scrub with plenty of herbaceous vegetation, often on hillsides, along hedgerows and wooded borders and, on the continent, on coastal dunes. Little is known of the biology but larvae have been reared from decaying hawthorn wood on the continent and they are thought to develop in a range of dead and decaying broadleaf trees.
Both sexes vary greatly in size, from 5 to 11 mm, soft-bodied, flattened and elongate, suggestive of a cantharid but readily distinguished by the tarsal formula, the colour is very variable but never metallic, head usually dark with pale anterior margin, pronotum pale brown, often with darker discal spots, or dark grey, often with pale margins, the elytra is usually unicoloured brown or dark grey but rare bicoloured forms occur that have dark streaks on pale elytra, legs variable from completely pale brown to dark grey but most specimens bicoloured femora and various dark markings on extensively pale tibiae, and the tarsi are usually extensively darkened. Dorsal punctation fine and dense, a little coarser on the elytra, pubescence short, dense, pale grey and recumbent. Head transverse from above with emarginate, convex and protruding eyes. Maxillary palps long and robust in both sexes, the penultimate segment short and strongly broadened from the base and the terminal segment long and narrowly securiform, antennae 11-segmented, filiform with the basal segment
Osphya bipunctata 1
broad and the second segment much shorter than the others. Pronotum transverse, broadest about the middle and narrowed to widely rounded posterior angles and continuously rounded apical margin, lateral margins explanate and strongly bordered, basal margin strongly bordered laterally, only indistinctly so medially, surface flattened and with indistinct basal fovea. Elytra almost parallel-sided, with rounded shoulders and a continuous apical margin, without striae, the punctures moderately strong and often forming indistinct transverse or oblique series. Legs long and robust; in the female slender throughout, in males the front and middle legs are normally developed but the hind legs vary considerably, they may be similar to those of the female (usually smaller specimens) or the femora may be greatly enlarged and possess a ventral tooth, and the tibiae may be thickened and bent at the base and produced into a long inward spur at the apex (usually larger specimens.) Tarsi 5-5-4 with the basal segment elongate, most notably on the hind tarsi, and the penultimate segment broadly bilobed. UK specimens are generally less variable then those on the continent; males are dark grey with pale pronotal margins while females are brown with the head, two small spots on the pronotum and the elytral apices black, but they can always be distinguished by the form of the fifth abdominal tergite which is smoothly curved apically in the female.