There are two species of rootworm in Georgia peanut fields, the southern corn rootworm and the banded cucumber beetle. The immature or larval stage of both species feed on developing peanut pods and require moist soil conditions for survival. Rootworm infestations are typically found in fields with center pivot irrigation and heavier soil texture.
With the abundance of rainfall in much of Georgia this season, we will almost certainly find rootworm injury in fields that are not typically infested with this pest. Growers with a history of rootworm injury have been scouting and/or treating fields for several weeks, but it is important that we take time to check fields that we might not normally consider high risk. We are seeing very high rootworm populations in our research trials in Plains, GA; two weeks ago, over 60% of the pods sampled from untreated plots had been injured by rootworm.
Granular chlorpyrifos is currently the best option we have for managing rootworms. Fields where chlorpyrifos is applied will be at increased risk from foliage feeding caterpillars and spider mites, but that is the price we have to pay if rootworms are present.
This short video provides additional information about scouting for and identifying rootworm and rootworm injury in peanut.
If you have questions about rootworm or other insect management concerns in peanut, contact your local UGA County Extension agent.