Melolontha hippocastani

The cockchafer, colloquially called May bug or doodlebug, is a European beetle of the genus Melolontha, in the family Scarabaeidae. Once abundant throughout Europe and a major pest in the periodical years of 'mass flight', it had been nearly eradicated in the middle of the 20th century through extensive use of pesticides and has even been locally exterminated in many regions. However, since an increase in regulation of pest control beginning in the 1980s, its numbers have started to grow again. There are three species of European cockchafers: Adults of the common cockchafer reach sizes of 25–30 mm; the forest cockchafer is a little smaller (20–25 mm). The two species can best be distinguished by the form of their tail end: it is long and slender in the common cockchafer, but shorter and knob-shaped at the end in the forest cockchafer. Both have a brown colour. Male cockchafers have seven 'leaves' on their antennae, whereas the females have only six. The species M. pectoralis looks similar, but its pygidium is rounded. The cockchafer should not be confused with the similar European chafer (Rhizotrogus majalis), which has a completely different life cycle, nor with the June beetles (Phyllophaga spp.), which are native to North America, nor with the summer chafer (or 'European June bug', Amphimallon solstitiale), which emerges in June and has a two-year life cycle. (All of these are Scarabaeidae, have white grubs, and are turf pests.) Adults appear at the end of April or in May and live for about five to seven weeks. After about two weeks, the female begins laying eggs, which she buries about 10 to 20 cm deep in the earth. She may do this several times until she has laid between 60 and 80 eggs. The common cockchafer lays its eggs in fields, whereas the Forest Cockchafer stays in the vicinity of the trees. The preferred food for adults is oak leaves, but they will also feed on conifer needles. The larvae, known as 'white grubs' or 'chafer grubs', hatch after four to six weeks. They feed on plant roots, for instance potato roots. The grubs develop in the earth for three to four years, in colder climates even five years, and grow continually to a size of about 4–5 cm, before they pupate in early autumn and develop into an adult cockchafer in six weeks.