Lepturobosca virens (Linnaeus, 1758)
POLYPHAGA Emery, 1886
CHRYSOMELOIDEA Latreille, 1802
LEPTURINAE Latreille, 1802
LEPTURINI Latreille, 1802
Lepturobosca Reitter, 1913
This very local and sporadic species occurs throughout much of the Palaearctic region from the Pyrenees to the far east of Russia, China and Japan, in Europe it extends north to the Arctic Circle in Fennoscandia and south to Italy and parts of the Balkan Peninsula but the distribution is discontinuous and it is absent from some of the Baltic countries and most of the Mediterranean islands. It remains on the UK list from a few 19thCentury records from the Forest of Dean and it may also have occurred in Scotland but there are no recent records and the species is thought to be long extinct. Across most of the range it is a boreal-conifer forest species occurring to the highest extent of the tree-line and at these higher altitudes it may be locally common but it also occurs in lowland conifer forests at higher latitudes e.g. in Fennoscandia it is most frequently recorded in the far north. Across Europe it is usually associated with Scots pine (Pinus sylvestris L.) and further east with Siberian pine (P. sibirica Du Tour) but various firs (Abies Mill.) and spruces (Picea Mill.) also occasionally host the species. Adults are active over a short season from late June until early August, they are diurnal and fly well, spending much of their time visiting a wide range of flowers, mostly umbels and various compositae but also on trees and shrubs such as elderberry (Sambucus L.) or rowan (Sorbus L.) where they feed on pollen and nectar. Mating occurs through the season and females oviposit among bark or in cracks of stumps and fallen trunks, usually visiting a series of sites to do so. Larvae initially feed under healthy bark, avoiding soft or decayed areas, but soon begin to bore long and shallow galleries between the bark and xylem which may become very extensive but they do not enter the xylem, they develop over two or three years and pupate beneath the bark during May or June.
Lepturobosca virens 1
Lepturobosca virens 2
14-22 mm. Very typical of the subfamily; elongate and slender with a narrow forebody, broad elytral shoulders and long legs. Rather drab in appearance; body and legs dark grey or brown with dense creamy or greenish-grey pubescence, antennae dark with the base of segments 2-11 pale. Head broad with large and strongly curved eyes, temples short and strongly converging, surface with dense and in places rugose punctation. Antennae long and slender; reaching back to the middle of the elytra in the female and to about two-thirds from the base in the male. Pronotum quadrate or slightly elongate in the male and slightly transverse in the female, lateral margins curved and narrowed to a rounded anterior margin and broadly rounded posterior margin, surface densely punctured, transversely depressed anteriorly and medially along the disc. Elytra tapering from broad shoulders to a finely truncate apical margin, surface densely punctured and wrinkled, without striae but with various longitudinal depressions below the shoulders.
Distinguished from our other members of the subfamily by the rounded lateral margins and posterior angles of the pronotum and dorsal pubescence which is recumbent on the elytra and mostly erect on the head and pronotum.