Problems with soybean insect pests still remain widely scattered. However, there are some signs of things to come.
- Stink bugs are being found near or above treatment levels in some of our earliest maturing fields. Expect the number of infested fields to increase as more and more soybean fields start approaching R5. Thus far, populations have been almost exclusively composed of green stink bugs. This species is easy to control with most synthetic pyrethroids (e.g, Baythroid XL, Brigade, Declare, Karate, Mustang Max, etc.). Treat when 36 stink bugs or more found per 100 sweeps.
- Corn earworms have not been reported and treatment levels in any soybean fields, and I don’t expect widespread problems this year. But there have been reports of treatment level populations across the river in Arkansas and from the Bootheel, so we need to remain alert. As with stink bugs, treatment is recommended when 36 or more larvae are found per 100 sweeps.
- Soybean loopers … will we have a problem this year? Soybean loopers reach our state about every 3-4 years, typically beginning sometime in mid August. Whether they reach Tennessee can often be predicted by the action further south (as this pest migrates from the south). Treatment level populations of loopers are currently being reported in Louisiana and southern Mississippi. This is a pretty early start for them and may indicate problems down the road for Tennessee. My best advice is to avoid unecessary sprays of insecticides; the pyrethroid insecticides are notorious for wiping out beneficial insects and creating problems with soybean loopers.