Cryptocephalus labiatus (Linnaeus, 1761)
This species is generally common throughout the Palaearctic region from Europe to the far east of Russia in the north and from Spain to Turkey and through Asia Minor in the south; it occurs throughout Europe to the far north of Fennoscandia and is also present on Iceland. In the UK it is locally common throughout England and Wales although with the general exception of the West Country, much less so through Scotland to the northern Highlands and it is also known from south west Ireland (Killarney). The usual habitat is broadleaf woodland and wooded parkland but adults often occur on moorland and heaths etc. where birches are common. Adults are active from May until September and peak in abundance during June although specimens have been recorded throughout the year. Larval hosts include a range of broadleaf trees, but especially Birch (Betula L.), Hazel (Corylus L.) and various willows (Salix L.) while adults feed on a wide range of trees, shrubs and herbaceous plants. Mating occurs in the spring and egg cases are produced over several months, these are attached to host foliage and larvae emerge after about three weeks. Larval development is rapid but they usually aestivate during the summer and resume feeding in September; final instars may pupate late in the year but the majority of larvae, including first and second instars, will attach themselves to twigs and overwinter to resume feeding the following spring. Fully-grown larvae pupate from February but earlier instars will become active later and resume feeding and pupate later in the spring or early summer, thus new-generation adults occur from early April until June. Adults may be swept from trees and shrubs throughout the spring and summer but they just as often occur on herbaceous foliage, they also fly in warm weather and often appear in flight-interception traps.
Cryptocephalus labiatus 1
Cryptocephalus labiatus 2
2-3mm. Broad and convex; body glabrous and shiny black but for the front of the head which is yellowish, antennae dark with up to five basal segments yellow, legs pale but always with at least the femora and tarsi partly dark. Head hypognathous and mostly hidden from above. Pronotum transverse and strongly convex, broadest at acute posterior angles and narrowed to a rounded anterior margin (from above), lateral borders narrow throughout and from above only visible about the base, surface extremely finely punctured and the base strongly bisinuate. Scutellum large, triangular and smooth, as the pronotum. Elytra almost continuous in outline with the pronotum, parallel-sided but slightly constricted about the middle and continuously rounded apically, sub-humeral calli usually well-developed, striae strongly punctured from the base, becoming weaker towards the apex, the lateral striae often more strongly impressed, interstices flat and extremely finely punctured. Superficially similar to C. querceti Suffrian, 1848 but always with the legs at least partly darkened.