Grape berry moth
Insect
Grape berry moth
Paralobesia viteana (Clemens)
Tortricidae: Lepidoptera
Photos
Second generation larvae feed on the expanding berries, and feeding sites are visible as holes. Rufus Isaacs
Grape berry moth spends the winter as a pupa in leaf litter in and around vineyards. First generation adults emerge from the pupae before bloom. Male and female moths mate and then females lay circular, flat eggs directly onto the cluster around bloom. The eggs can be difficult to find because of their small size (approximately 1 mm diameter). Their shiny exterior can be used to detect them, especially with a hand lens. Eggs parasitized by wasp parasites turn black.
Larvae hatch from the eggs in 3 to 6 days, depending upon temperature, and feed on the cluster until they have developed to full size. Larvae of the first generation feed on young grape clusters and may remove sections of clusters. Then, when berries are formed, the young larvae burrow into the fruit. Webbing and larvae are visible in the small clusters during and after bloom. Damage from redbanded leafroller can be mistaken for grape berry moth at this time, so it is important to identify the larvae to determine the appropriate management strategy.