Louisiana producers crack down on pecan pest

While the pecan harvesting season is still months away, LSU AgCenter pecan specialists remind producers to stay alert for the pest known as the pecan nut casebearer.

Michael Hall, an associate professor at the LSU AgCenter's Pecan Research-Extension Station in Shreveport, La., said monitoring this pest has been made easier with pheromone traps designed to attract the pecan nut casebearer.

“Place the traps at a convenient height and throughout the orchard,” Hall said. “In orchards of 50 acres or less, use three to five traps. In orchards greater than 50 acres, use at least five traps.”

Traps should be checked three times a week, Hall said.

According to Bill Ree, a colleague of Hall's at Texas A&M University, the pests begin laying eggs seven to 10 days after the initial catch is noticed, and their entry into the nuts starts about 12 to 16 days after the initial catch. Hall said it also is important to monitor nut clusters for signs of eggs.

The traps can be bought individually, as multiple trap kits and in bulk, Hall said. The traps that most effectively monitor the pecan nut casebearer insect are the wing trap, the intercept trap and the delta trap, according to Hall.

The pecan nut casebearer is about one-third inch long, is silver-gray in color and has a ridge of scales that appears as a band across the wings about one-third of the way down from the head.

Among the Louisiana sources Hall noted for pheromone and traps are Papa Pecan Co. at 830-379-7442; Pecan Producers Inc. at 800-527-1825; and Gemplers at 800-382-8473.

In addition to calling those companies, Hall suggested producers check with their local co-ops or pesticide suppliers for the pheromone and/or traps.

For control of first generation pecan nut casebearers, Hall suggested using Confirm 2F (8 to 12 fluid ounces per acre) plus a non-ionic surfactant. Even though Confirm is a little more expensive, Hall said it is a growth regulator that is specific to insects such as the pecan nut casebearer and hickory shuckworm. It has no adverse effects on beneficial insects and is safe to apply, he said.

If hickory nut curculio or pecan weevil do not occur in an orchard, consideration should be given to using Confirm for control of both pecan nut casebearer and hickory shuckworm, Hall said. Other suggested materials to use include Lorsban 4E (1.5 to 2 pints per acre) and Imidan 70W (1 to 1.5 pounds per acre).

Hall said growers should be sure to adjust the pH of the water used for spraying to 5.5 to 6.5, since the activity of the insecticide decreases dramatically when the pH of the water is above 7.0.

In addition, Hall cautioned to remember that coverage is critical. “Nuts occur on the inside and outside of the tree canopy,” he said, adding, “Take the time to thoroughly spray the tree. Poor coverage means poor control.”

Randy Sanderlin of the LSU AgCenter also reminds everyone that now is the time to be making the first fungicide application to pecan trees. Contact Sanderlin at the LSU AgCenter Pecan Research-Extension Station if there are any questions regarding fungicides and rates.

In 2000, the Louisiana pecan crop was about 10.6 million pounds from identified orchards and native groves — a decrease of 27 percent from 1999 due, in large part, to reduced production caused by the prolonged drought. The gross farm value was estimated at more than $9.1 million from the 26,303 acres on which pecans are produced in Louisiana.

In addition, many of the native acres of pecans and homeowner trees are not identified in those totals because they are widely scattered and on unmanaged land, experts say. These trees are harvested at two- to five-year intervals by the owners and are expected to add 3 million pounds to pecan sales in Louisiana this year.

The pecan harvest season in Louisiana starts in October.

A. Denise Coolman writes for the LSU AgCenter.

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