Adults are 5-7 mm in long. Colour of moth is brown with white and creamy .Larvae is 7-8 mm in long and cream colour.
Biology and Damage
G.dealbana overwinters as larvae in the galls of big bud mites or at the bottom of buds inside coccon. The overwintering larvae move to opening buds and feed on them in mid-March. Then the larvae get inside of young twigs and make gallery along twigs. One larvae can destroy 5 twigs. Infected buds and twigs completely dry and turn to brown in colour. Pupation occur inside the twigs or dessicated leaves. Adults appear in late May and emergence continues until mid-July. Adults deposit eggs singly on the upper side of the leaves. One adult can lay up about 40 eggs. The young larvae move to underside of the leaves and feed there. After late August the larvae begin to migrate into galls of big bud mites or male catkins and feed on them. There is only one generation per year.
Altough the larvae feed on under leaves and male catkins ,this damage is not important. Serious damage can seen on twigs. Sometimes can destroy up to 80% of twigs in some local area of Turkey.
Fındık Filiz Güvesi(Turkish)