This is the time of year when we become concerned about pecan nut casebearer infesting pecan nutlets. Casebearer will overwinter in a hibernaculum or cocoon and then break dormancy to begin the process that gets us to this time of year. We are now seeing the moths emerge from this process and it is these moths that will lay eggs that become the first generation pecan nut casebearer. The way we know when the moths are flying is not because we look for the moths laying eggs but that we have installed moth traps in the trees.
These traps have a pheromone inside the trap that attracts male casebearer moths. We put the traps up in the orchard about a month before we expect to see moths so that we know when the moths begin coming into the orchard. We examine the traps every 2-3 days or 3 times a week and record the number of moths captured and then remove the moths. This record of moth catches help monitor the time moths numbers are highest. Once we capture moths then 7 to 10 days later we should begin to see eggs laid on nutlets. Once eggs are laid it takes 4-5 days to hatch and 1-2 days before they enter the pecan. Scouting is very important to make this program work. This past week I had reports from several commercial growers that they had moth catches in their traps. Following the above schedule we should begin to find eggs on the pecan nutlet about May 8 or 9 and possibly nutlet entry on May 13-15. We look for either eggs or entries till we find 2 or more infested clusters of pecans out of 310, then we spray.
Commercial orchards use chlorpyrifos at 1-2 pints per acre, Confirm, spinosad, Sevin, and Bt for pecan nut casebearer control. Homeowners can use Dipel or Javelin both are organic products with bacillus thuringiensis or Entrust with spinosad which is also labeled organic. Two other products are Sevin or malathion. Follow label directions and be sure to get good coverage, moths tend to work the tree tops as well as the bottom.
Once you know when the casebearer is laying eggs mark your calendar because exactly 6 weeks later you can expect the second generation to show up. Sometimes we don’t treat for the second generation because there just aren’t enough to justify the cost but still scouting is important so that we know. (Thanks to the University of Georgia for great PNC pictures!)
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- Bob Whitney
- As an Agriculture Extension Agent for Texas AgriLife Extension Service I have had an opportunity to be involved in just about every aspect of agriculture. From the 5,000 cow dairy to the types of trees to use in a home landscape I have had a chance to learn how the different parts of an agriculture systems work together. Seedless watermelons, drip irrigation, pecan orchard management, fruit crop development, dairy nutrient management, environmental issues confronting agriculture, producer tours, field days, research projects and more have been a part of my life for over 30 years as I lived and breathed agriculture. Since 2004 I have been actively involved in consulting internationally working in Honduras, Guatemala, Egypt, Jordan, Iraq, India, and China. I have worked with missionaries and other groups dedicated to alleviating poverty among third world farmers. I lived in the Middle East in 2007-2008 working on a project for the Borlaug Institute of International Agriculture at Texas A&M University. In this project I was the Chief of Party and Team Leader for a $5.7 Million dollar effort to train Iraqi Extension agents and specialists in all aspects of agriculture.