Pay Attention: Pecan Nut Casebearer a Concern for Southeast Producers

Clint ThompsonGeorgia, Pecan

By Clint Thompson

The time is now for Southeast pecan producers to pay attention to pecan nut casebearer, a pest that can devastate pecan trees if left unchecked.

Photos courtesy of UGA Pecan Blog/Adult PNC moth (left), eggs: whitish when fresh and then turn orange/pink before hatching (middle), nut damage as indicated by webbing and black granules as result of feeding.

Apurba Barman, University of Georgia (UGA) Extension pecan entomologist, noted in the UGA Pecan Blog that the tiny nutlets on the trees’ terminal branches are exposed to feeding by the casebearer caterpillars.

“The adult moths of this species emerge out of their overwintering stage in the spring and are often active in pecan orchards from mid-April onwards,” Barman wrote. “The first generation of the moths is more serious, as the females lay eggs on small nutlets, and the caterpillars coming out of these eggs can feed on multiple nutlets in a cluster.”

Growers should remember that once caterpillars enter the nutlets, insecticide applications become ineffective. Producers must be timely with their pesticides, as there is a short window between the caterpillar’s emergence from egg to nut entry. An insecticide chemistry that has longer residual activity must be applied at the time when the majority of the eggs are present on the nutlets and ready to hatch.

“It’s important that we make an insecticide application in a timeframe where you have some residual insecticides around that area and the caterpillars come in contact with the insecticide. Once they’re inside, they’re not going to come in contact with the insecticide,” Barman said. “That timeframe is very critical when we’re going to make that application. If you’re late by one week or a few days, you’re going to miss that window.”

UGA Pecan Blog