Cerambyx cerdo Linnaeus, 1758
Capricorn Beetle

Among the largest of the western Palaearctic longhorns and certainly the largest in northern Europe, this species is locally common throughout Europe and Asia Minor, occurring also on most of the Mediterranean islands and in north west Africa, the eastern extent of the distribution is the Black Sea (although it has been reported from Nepal) and the southern Baltic countries and to the north it occurs in some of the southern provinces of Sweden. There seems no doubt that the species has suffered and declined due to forest management over recent decades, and while it has disappeared from many former localities, it remains locally common and is sometimes abundant, it is only in warmer southern areas, and especially on some of the Mediterranean islands, that it is generally abundant. Several subspecies are described and these are mostly of doubtful validity (Sama, 2002) but some e.g. ssp. mirbeckii (Lucas, 1842), from Northern Africa and Spain, seem to be valid. The species has long been included on the British list but at most has only rarely and temporarily become established; it has been recorded from the New Forest and was almost certainly established there as emergence holes were still extant into the 21st century, beyond this it has been imported with timber from Europe and there are scattered records from timber yards etc. The usual habitat is open lowland deciduous woodland with plenty of mature oak exposed to the sun and in various stages of decay; the adults are crepuscular and nocturnal and occur over a long season; in northern Europe typically from the middle of May until the beginning of September. In good years specimens are widely recorded in parks and even domestic gardens in central Europe and while oak is the usual host the species is widely polyphagous and other recorded hosts include Cherry (various Prunus L.), elms (Ulmus L.), Ash (Fraxinus L.), beech (Fagus L.), willows (Salix L.), walnut (Juglans L.), chestnut (Castanea Mill.) and plane (Platanus L.).  Mating occurs in the summer and females oviposit among bark or damaged timber, they lay up to 30 eggs each day and will visit a series of sites to do so, often using previously infested trees. Larval development takes two or three years; during the first year they feed under bark among the phloem but after overwintering they penetrate deep into the xylem, damaging local areas and inducing leaf fall. Following a further year of development the larva excavates a gallery towards the surface and then retreats back into the xylem where it will pupate, this usually occurs during May or June and the adult is fully formed later in the summer but will remain in situ until the following year. Larvae are typical of the group; creamy or yellow with reduced legs and strongly-sclerotized mouthparts and a sclerotized pronotal shield, when fully-grown they may measure 90 mm in length and up to 20 mm across. Adults emerge from May although in warmer regions they have been recorded much earlier, they produce very distinctive large and elliptical emergence holes which typical of the genus but not species-specific. During warm spells adults will visit lights and sap runs, they are also attracted to fermenting fruit and freshly cut timber and may occur in numbers at night in any of these situations.