Stictoleptura rubra (Linnaeus, 1758)
POLYPHAGA Emery, 1886
CHRYSOMELOIDEA Latreille, 1802
LEPTURINAE Latreille, 1802
LEPTURINI Latreille, 1802
Stictoleptura Casey, 1924
Often included in older works under the genus Corymbia Gozis, 1886, the common name refers to the colour of the female. This local but widespread species occurs throughout Europe from Portugal to Greece and north to the UK and central provinces of Finland, it is present through central Russia and extends to China, Japan and South Korea, and the subspecies S. r. numidica (Peyerhimoff, 1917) is endemic to Algeria. In the UK it is presumed to be a naturalized immigrant, it is locally common in East Anglia and has spread over the twentieth century into other parts of south and central England and Wales, probably due to the widespread commercial pine plantations. Adults occur in conifer and mixed woodland, they are active from June until September and may be seen on warm summer days when they fly and visit flowers to feed on nectar and pollen, the usual hosts are pine (Pinus L.) and spruce (Picea Mill.) but other conifer such as firs (Abies Mill.) and larches (Larix Mill.) are attacked and they occasionally use deciduous trees such as oaks (Quercus L.) and Beech (Fagus sylvatica L.). Mating occurs through the season, either on flowers or on trunks, and females oviposit into bark or in cracks on denuded wood, mostly on standing trunks and stumps but also on fallen timber and logs. Larvae develop over two or three years, they feed deep into the sapwood (xylem), producing longitudinal galleries, avoiding decaying areas, and pupate during May and June in a cell beneath the bark or near the surface of the xylem. Here first adults usually appear from the middle of June but in warmer southern continental areas they occur over a much longer season and may be active from May.
Stictoleptura rubra 1
Stictoleptura rubra 2
Stictoleptura rubra 3
10-20 mm, both sexes vary quite widely in size but females are generally larger and broader than males, in both cases they are distinctive among our UK fauna by colouration and general habitus, see below. Females are entirely reddish-brown with a darker head and scutellum while males have a black forebody and pale brown or yellowish elytra, the antennae are black in both sexes and the legs are brown with the femora and tarsi variously darkened. Head large with fine dense punctures and a variable flat depression to the vertex, temples long and sharply angled and eyes only shallowly emarginate about the eyes. Antennae robust and weakly serrate, in the male reaching to the apical quarter of the elytra, in the female reaching to the middle. Pronotum slightly elongate in the male and quadrate in the female, densely and moderately strongly punctured and with short silvery or yellow pubescence, surface with well-developed sub-basal and sub-apical transverse grooves, a variable impression laterally near the base and a weak longitudinal impression that is often indistinct or only obvious towards the base. Elytra broadest at rounded shoulders and narrowed to a sharp tooth outside an incurved apical margin, surface densely punctured throughout, these becoming weaker towards the apex, without striae but with a variable longitudinal impression inside the shoulders and sometimes with one or two weak longitudinal ridges. The sexes are easily distinguished by colour but the female is variable and sometimes has black spots on the pronotum and rarely the elytra may be yellow.
Paracorymbia fulva (De Geer, 1775) is superficially similar to males of the present species but is on average smaller and may be distinguished by its filiform antennae and long, outstanding pubescence to the pronotal disc.