Grape leaffolder—Desmia funeralis
Moths of the grape leaffolder are almost black, with two white spots on the forewings and two white stripes across the abdomen. Larvae are translucent but appear greenish because ingested leaf tissue shows through the body wall. Small black spots, located above the second pair of legs, are present on later instar larvae.
Grape leaffolders have three generations a year (about April - May, June 15 - July 15, and August). After overwintering as pupae, moths emerge in April or May and lay flat, elliptical eggs singly on either the upper or lower surface of the leaf. Many are deposited against the leaf veins on the underside of the leaf. After hatching, larvae feed between two webbed leaves for about 2 weeks. Then each pale green larva rolls a leaf edge and feeds from the inside on the leaf edge. Larvae turn darker green as a result of this leaf feeding. If disturbed, larvae wriggle vigorously and drop to the ground without a silken thread. Mature larvae construct a separate leaf envelope on the edge of a leaf in which they pupate.
Leaffolders construct leaf rolls and feed on leaves. They may also eat berries late in the summer if worm populations are large and foliage sparse.
Remove suckers and thin leaves during the growing season to help remove leaffolder eggs. Handpick rolled leaves. Several parasites, including the larval parasite Bracon cushmani, and many generalist predators attack grape leaffolders and may keep them under fairly good control. Applications of Bacillus thuringiensis or spinosad are also effective.
Grape leaffolder larva
Grape leaffolder adult