The second-generation larvae also attack nuts, but the loss is less because an individual pecan nut casebearer typically requires only one nut for its development. Third-generation moths emerge during late August and September, and larvae feed in the nut shuck at the base of the nut, on the shuck surface and, to some extent, on the leaves. Most are found near the flower end of the nut, on and beneath the calyx lobes. The head is reddish-brown, and the body is sparsely covered with fine, white hairs. The larval stage lasts from 25 to 33 days.
Adult moths are slate-gray with a ridge of long, dark scales on the basal end of forewings.
Scouting and control The first generation is the most damaging. You should inspect at least 200 nut clusters. When you find that 1 percent to 3 percent of the nut clusters have been damaged, apply an insecticide. During years of heavy nut set on native trees, you can delay spraying until 5 percent of the nut clusters sustain pecan nut casebearer damage.