Polyphylla fullo (Linnaeus, 1758)
This is the largest of the European species of Melolonthinae and the only member of the genus to occur in Central Europe; it is otherwise widespread, reaching north to the south of Sweden and south to North Africa, it is widespread but sporadic east to the Caucasus and Ukraine and sporadic further south and east e.g. it is absent from Greece (although similar species have been mistaken for it) but occurs in Turkey and the Middle East. It is thought to be long-extinct in the UK; several specimens were found on the Kent coast (mostly on sand dunes around Sandwich and Deal) in the early nineteenth century but it has not been recorded since and the few modern records are almost certainly from human importations, but further records are possible as the species occurs along the northern continental coast and is a strong flier. It is generally rare across much of its central and northern range, becoming locally common or abundant only in the south, although large populations occasionally occur on northern coastal dunes and dune slacks; it seems to have suffered a recent and general decline and is protected in some areas. Adults occur between June and August with only occasional specimens appearing into late summer or autumn, typical habitats include well-vegetated and open wooded areas, wooded parkland and dunes, they emerge en-masse and feed on the foliage of various trees but especially pines and may be damaging to young trees when large populations occur. They are crepuscular and nocturnal although being large and conspicuous will often found on trunks or low branches during the day, they swarm around host trees and shrubs and mating occurs among the foliage. Females oviposit in light sandy soils; usually near the base of herbaceous plants or among perennial grasses, and each will produce between 25 and 40 eggs which will hatch within about 4 weeks. Larvae develop over 3 or 4 years; they feed on herbaceous roots during their first summer and move deeper into the soil to overwinter, in the second and third years they begin to chew through the roots of trees and shrubs and can cause severe damage to or even kill saplings and small trees; in warmer areas they are a serious pest of vines, fruits and and root-crops such as potatoes and in recent years have caused serious damage to ornamental grass in parks and gardens. Pupation occurs in a subterranean cell during May and June and adults eclose after 3 weeks, they remain in the soil for a few days to harden and emerge in the evening. Both sexes fly well and stridulate loudly when handled.
Adults are very distinctive and should not be confused with any other species (although similar species occur in the south of the range); they are large, 30-40mm, and dark chestnut brown mottled with patches of pale pubescence. Males are distinguished by the curved and very long antennal lamellae (for which the species is named, Polyphylla = many leaves) and the form of the front tibiae which lack the large fossorial teeth present in the female.