Biology

The adult chafer appears around May and is on the wing until August. Females lay their eggs on rotting wood on the trunks of old trees, in the UK usually fruit trees. They show a preference for 'stone and pome' types, that is cherry and plum, and apple and pear. However, it also occurs on oak trees in the New Forest, and in Europe it is associated with ancient oaks. The grubs grow to a length of 30 mm and take two years to grow to the stage where they pupate.