Kyklioacalles roboris (Curtis, 1835)
This locally common western Palaearctic species occurs throughout southern and western Europe from Spain to Ukraine and Belarus, extending north to southern Norway and Sweden and the UK. Here it is very local and generally scarce throughout England and Wales, it is absent from the islands and there are very few records from the West Country and from further north than south Cumbria although adults are small, cryptic and lead concealed lives and so the species may be under recorded. The typical habitat is deciduous woodland with plenty of wood in various stages of decay but adults may also occur on isolated trees in parks etc. and in mixed hedgerows. Adults occur year-round, peaking in the spring and autumn, they are nocturnal and generally associated with dead branches and areas of dead wood on the trunks of oak, beech and chestnut but they also occur on birch, ash and hazel and on the continent have been recorded from fir trees. Little is known of the biology but it is likely that larvae develop under bark through the summer and that new-generation adults appear in the autumn, overwinter and reproduce in the spring. In general the best sampling methods are searching dead wood or beating foliage at night but they have also been taken in pitfall traps placed among leaf-litter below suitable trees, they generally occur in small numbers but may swarm in the spring and large numbers of freshly emerged adults may occur in the autumn, particularly on foliage or in pitfall traps.
Adults are small, 2.5-3.6mm and very distinctive in appearance; the body is shiny dark grey to black and variegated with black, pale creamy or white scales; the head, lateral pronotal margins and two transverse elytral bands usually with dense pale scales. Appendages dark brown, the tibial apices and femora with extensive pale scales. Head narrowly visible from above, the eyes widely separated and usually partly obscured under the pronotal margin, and with the temples forming a continuous and almost circular lateral margin. Rostrum weakly dilated at the base and apex; a little longer, shinier and less strongly punctured in the female. Pronotum transverse, straight or weakly rounded, converging in the basal two-thirds and strongly constricted subapically, in side view evenly convex on the disc and flat from the apical constriction, surface with a median longitudinal impression which is deeper at the base and often very weak or missing in the apical half, usually with several tufts of erect dark scales. Scutellum inconspicuous and usually not visible. Elytral base only slightly wider than the base of the pronotum, lateral margins rounded and widest in the apical third, striae deeply impressed, interstices variously convex, the third, fifth and seventh often strongly so and usually with tufts of raised dark scales towards the base.