5 Insects To Look For In Your Fields And How To Manage
Farming would be a lot easier and less risky if each year came with its own instructions. Although there may be no instruction manual, a solid game plan is needed to weather whatever surprises the growing season may bring.
Controlling damaging insect populations in Mississippi soybean fields poses a problem for farmers each year. The decision to treat is often based on thresholds, which is the point at which steps should be taken to prevent insect infestations from causing an economic loss.
According to Don Cook, Ph.D., Mississippi State University (MSU) entomologist at the Delta Research and Extension Center in Stoneville, insect pests caused more than $40 million in crop-yield losses in Mississippi in 2015.
Entomologists develop thresholds to help farmers determine when control treatments will bring an economic benefit.
“For insect pests, determining bushels per acre lost for every pest can be almost impossible,” says Angus Catchot, Ph.D., MSU Extension entomology professor. “However, in nearly every situation, yield will be protected by applying appropriate insecticides targeted at the pest of interest when economic thresholds are reached.”
Thresholds are valuable tools for insect control that allow farmers to make better management decisions, reduce negative environmental impact and reduce unnecessary input costs.
Be on the lookout for these insects and others that may be in your fields this summer, and manage your crops according to the MSU-recommended thresholds for treatment.
Much greater detail on these insects can be found in the MSU 2016 Insect Control Guide for Agronomic Crops. Visit the Mississippi Soybean Promotion Board (MSPB) website, mssoy.org, for an online version of the guide. MSPB invests soy checkoff funds in research that addresses production problems faced by Mississippi soybean farmers. Many of these threshold recommendations were developed with the help of checkoff funding.
Bean Leaf Beetle - Before bloom, apply insecticide if beetles are present and defoliation reaches 35 percent. After bloom, apply if defoliation reaches 20 percent. Or apply if 50 percent of plants have beetles feeding on one or more pods.
Green Cloverworm/Velvetbean Caterpillar - Before R1, or when the plant has one flower open on any node on the main stem, treat at 35 percent defoliation. After R1, treat when you find nine worms per 25 sweeps.
Corn Earworm – Before R1, treat at 35 percent defoliation. After R1, treat when you find nine worms per 25 sweep.
Soybean Looper - Before R1, treat at 35 percent defoliation. After R1, treat at 20 percent defoliation.
Stink Bugs – Before R6, or when a green seed is filling a pod cavity, apply insecticide when you find nine bugs per 25 sweeps. After R6, for the next 7-10 days, double the thresholds to prevent damage to seed.