The vine moth (Eupoecilia ambiguella), is an important pest of grapevine. Other hosts include Hedera and currants. It is widely distributed in central and southern Europe.
Life cycle and appearance of Vine moth
The adults have a wingspan of 12-15 mm and whitish ochreous forewings marked with yellowish ochre and a dark, brownish to black band across the middle of the forewings. The hindwings are grey. The eggs are 0.8 x 0.6 mm and greyish brown when laid. Later they become speckled with orange. The larvae are up to 12 mm long; body pinkish brown or yellowish brown to olive green and a brown or black head. The pupae are 5-8 mm long and reddish brown.
In central Europe, there are usually two generations per year and in southern Europe there are three. Adults appear from mid April to May. The eggs are laid on unopened flower buds and hatch after 1-2 weeks. The larvae start feeding and spin several buds together as shelters. These shelters become larger and more dense as larval development progresses. Larval development takes 3-4 weeks. The larvae then pupate in their shelters or in folded leaves. Adults of the nest generations appear after about 10 days. The larvae of the last generation overwinter in cocoons hidden in or beneath bark of older vine stems or in cracks of posts.
The larvae destroy flower buds and also cause the death of open flowers and young fruitlets. Later in the season they destroy developing or maturing grapes. Fungal pathogens often invade the damaged tissue, which can lead to further losses. The silken larval habitations and sticky exudations from damaged fruits contaminate grape bunches.