Insect pests can cause costly problems in the pecan orchard. There are times to spray for these menaces, and you can use insect traps to help you determine when. Insect traps are another tool in your integrated pest management plan, which you design to balance the economic and environmental considerations of your operation. Traps, if properly used, can be an effective way to monitor pest populations and determine if an economical threshold for spraying has been met. Here are some tips to consider when setting traps for pecan nut casebearer, hickory shuckworm and pecan weevil.
Lures can be temporarily stored in unopened, factory-sealed packages in a cool, dry place. If you are going to carryover for multiyear use, it is recommended to put lures in the freezer. Sticky inserts should be kept in cool temperatures to prevent melting of adhesive.
Pecan nut casebearer traps should be distributed no more than 100 yards apart in the orchard.
Orchards less than 50 acres should have at least three traps dispersed throughout the orchard. Orchards larger than 50 acres should have at least five traps. Traps should be more than 100 yards apart. Geographic features such as bottoms or unmanaged natives might require more traps. Hang traps from branches that have terminals with nutlets. Place in an accessible location around 6 to 8 feet above the ground. The lure is a rubber septa which has been saturated in pheromone; it should be placed on its side in the middle of the sticky insert sheet that is placed inside the trap. The lure should be replaced every four weeks; when removing the old lure, discard it outside the orchard. If the sticky material has become hard and non-sticky, replace the adhesive sheet with a new lure.
You will see lures for hickory shuckworm that can be placed in the same traps as the pecan nut casebearer. Research has not shown the lure to be effective in trapping the hickory shuckworm, so I currently do not recommend using the pheromone traps for the hickory shuckworm.
Wire cone traps, pyramid traps and circle traps are used in the orchard for weevils. Wire cone traps and pyramid traps are on the orchard floor, which can complicate other activates in orchard floor management. I recommend the circle trap because it is installed in the tree and does not affect orchard floor management. Commercial cones can be purchased, or you can build your own from plans at http://bit.ly/weevil-pecan .
When installing the circle trap on a tree, place the traps on the north, west or northwest part of the tree. If your orchard is part of an integrated operation and you have cattle in the orchard, you will want to make sure your traps are high enough in the tree to avoid curious cattle. The trap can be secured to the tree by multiple options. I would recommend some type of twine, rope or even bailing wire. You can staple it to the tree but removal of the trap would cause damage to the trap. On the bottom of the trap, you should smooth the bark underneath to create a smooth connection for the trap and the tree. This will deter weevils from climbing under the trap into a crevice created by the rough bark.