A new insect

Another first : we were staying at my parent's vacationhouse
in the forest and we met lots of these beetles, may bugs -
melolontha melolontha (meikever / oldenborre). They were
literary swarming the place.

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 preferred food for adults is oak
leaves, but they will also feed on conifer needles. The larvae,
known as white grubs hatch after four to six weeks. They feed
on plant roots and 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 may bug in six weeks. They overwinter
in the earth at depths between 20 and 100 cm. They work
their way to the surface only in spring. Because of their long
development time as larvae, may bugs appear in a cycle of
every three or four years; the years vary from region to region.
There is a larger cycle of around 30 years superimposed, in
which they occur in unusually high number.