Updated Web Site Helps Pecan Growers Battle Pest

Pecan growers will once again be able to help make a better decision on protecting their crops from the damaging effects of a common pest.

The Pecan Kernel web site will be displaying the newest, up-to-date maps for growers to make treatment decisions on pecan nut casebearer.

The maps, first launched in 2006, give producers information about when pecan nut casebearer moths are first seen in pheromone traps and predictions when the damaging larvae (caterpillars) will first enter the pecans. This system is part of a program that was co-developed by professor of entomology Marvin Harris and Texas Cooperative Extension specialist Bill Ree.

The site regularly posts a map of the state showing the county and a decision date on when to inspect and possibly treat the pecan crop.

Predictions are based on data sent from cooperators from across the state. The cooperators also work with Extension agents and the Texas A&M University System regional research and Extension centers statewide.

Harris said cooperators sending the data can range from pecan growers and county Extension agents to public volunteers and Master Gardeners.

During the months between April and June, cooperators inspect and gather the data from special pecan nut casebearer pheromone traps in their orchards.

Once inspected, they send the collection data in spreadsheet form via E-mail to Harris or Ree. The datasets are then analyzed and consolidated for mapping purposes.

The refined datasets are added to the map, which is generated and posted regularly on the site.

"We can tell at a glance what some of the activity is when we look at the spreadsheets," Harris said.

The predicted decision date is determined by several factors, including the male moths' first appearance and weather conditions.

After mating, the first generation females lay their eggs in the pecan nutlets after pollination. Once the eggs hatch, the larvae crawl to nearby buds at the base of the pecan leaf to begin feeding.

After feeding, the larvae tunnel from the base of the compound leaves into the base of the nutlets. The larvae then move from nutlet to nutlet before pupating inside the nut. The moths usually emerge 9-14 days after pupation.

The moths can destroy a crop in some years and cause little damage in others. The key here, he said, was to predict when the first nut entry by the moths will occur.

Harris said the reason for early detection is to save time and money, as well as the environment, by using insecticides more wisely.

Pecan nut casebearer was detected early in most areas last year while other areas had later detections. Ree noted that producers who consulted the map were alert to the early onset of the moths and acted accordingly.

"I think the system is a big benefit for growers," Ree said. "It really served as a heads-up for growers last year."

Ree said that participation from growers and cooperators critical to the system.

"I feel that the more information that is given to a producer, he or she will be making a better decision," he said.

More information on pecan insect management can also be found by going to http://insects.tamu.edu/extension/publications/index.cfm and typing in the keyword “pecan.”