What is in this article?:
- Pecan states all reporting casebearers
- Cost-effective control
- The decision window has passed for growers in the 14 pecan-producing states to spray for the first wave of pecan nut casebearer (PNC) moths this year.
Controlling the moths is a fairly simple and cost-effective process. Most producers use Intrepid, a growth regulating chemical that does not damage beneficial insects. Intrepid lasts up to twice as long as other chemicals and also prevents infestation from other caterpillars that emerge later in the summer.
While most pecan growers are eager to control the casebearer, some use the moth to their advantage. The moth can aid producers during particularly heavy production years by thinning out the nuts, thus promoting healthy crops the following season. This year is shaping up to be one of those heavy production years with several trees showing extremely large crops.
Most casebearer eggs are found at the tip of the nutlet, either on the top (stigma) or hidden just under the tiny leaves (sepals) at the tip of the nutlet. You need a good hand lens to identify casebearer eggs and determine their development (hatched, white or pink). Also, look for bud feeding just below the nut cluster to detect the presence of newly hatched larvae.
In commercial operations, AgriLife Extension recommends many insecticides that are labeled for controlling pecan nut casebearer on pecan. Base your insecticide choice on applicator safety, grazing restrictions if livestock are present and potential impact of the insecticide on beneficial insects and other pests.
Thorough spray coverage, accurate timing to treat hatching larvae, using recommended insecticide rates, and proper sprayer calibration are critical for achieving good control of the pecan nut casebearer.
The use of pyrethroid (e.g., Asana, Ammo, Warrior) or carbaryl (e.g., Sevin) insecticides has sometimes been followed by outbreaks of aphids or spider mites in pecans. For this reason, using these insecticides for the pecan nut casebearer is discouraged, especially if the orchard has a history of aphid or mite problems. If you use pyrethroid insecticides, apply them no more than once per season.
Insecticide labels can change from year to year, so it is the user’s responsibility to follow current label directions for worker safety, grazing restrictions and application rates for target pests. Commercial growers should refer to E-125, “Managing Insect and Mite Pests of Commercial Pecan in Texas,” available at http://tcebookstore.org.