Dolichosoma lineare (Rossi, 1794)
POLYPHAGA Emery, 1886
CLEROIDEA Latreille, 1802
DASYTINAE Laporte, 1840
Dolichosoma Stephens, 1830
This is a mostly western and northern European species; it is locally common in lowland to about 1500m from France to western Poland and around the northern Baltic coasts, but otherwise very local and scarce, extending sporadically south to the northern shores of the Black sea and east into central Siberia. In the UK it is restricted to coastal grassland, saltmarshes and tidal estuaries and creeks in south-eastern England from Kent to Lincolnshire; it has suffered a decline over recent decades and is currently threatened in many places by loss of habitat through the construction of sea defences, changes in agricultural practices and overgrazing by cattle. Adults are active over a short season from the end of May until the end of July or early August, they are diurnal and occur among low vegetation, often on banks exposed to the sun and often in numbers, they sometimes visit a range of flowers and are often found on developing ovaries after the petals have fallen. In Europe the usual habitat is open woodland or grassland on sandy or chalky soils and though very local adults tend to occur in large or very large numbers and may be found swarming on flowers including those of sea thrift (Armeria maritima (Mill.), hawkweeds (Heiracium L.), knapweeds (Centaurea L.) and various thistles (Cirsium Mill.) Little is known of the life-history but gravid females have been recorded in June and July and both adults and larvae have been found among decayed wood and under bark of standing deciduous and coniferous trees and fallen timber, adults have been observed feeding on pollen and larvae are known to be predatory.
5.5-6.5mm. The general appearance is absolutely distinctive among our UK fauna and should not be confused with any other species, it may superficially resemble an oedemerid or a longhorn but the tarsi are quite different. Entirely black with a green or, rarely, blue metallic lustre, the dorsal surface has dense short grey pubescence which is quite distinctive in the field. Head quadrate and widest across large convex eyes which are longer than the straight, converging temples, vertex only weakly convex, clypeus with a slightly raised V-shaped ridge between the eyes. Antennae inserted laterally in front of the eyes, the insertions visible from above, 11-segmented and weakly serrate distally. Pronotum elongate and slightly narrower than the head across the eyes, lateral margins straight and parallel, anterior angles rounded and posterior angles perpendicular, surface flat or weakly uneven and with a variable longitudinal median impression. Scutellum transverse and truncate. Elytra very elongate with rounded shoulders and slightly sinuate lateral margins, apical margins separately pointed, surface densely punctured and finely rugose, without distinct striae but often with variously formed longitudinal costae. Legs long and slender femora and tibiae smooth, middle and hind tibiae with stiff setae along the inner margin and fine terminal spurs. Tarsi 5-segmented, claws smooth and without a basal tooth. The sexes differ only slightly but the female elytra are distinctly more dilated towards the apex when compared to those of the male.
Dolichosoma lineare 1
Dolichosoma lineare 2