In a previous post (Peanut Notes No. 179), there was a discussion about how best to control foliar-feeding insects. It is challenging to differentiate between corn earworm and tobacco budworm. You can only do so looking at the insect’s mandibles (teeth.)

Historically, pyrethroids were used with limited success. While less expensive, significant resistance to pyrethroids is found in many populations of corn earworm. Pyrethroids perform poorly on tobacco budworm. Because it is hard to distinguish between these two insects and resistance is present in corn earworm, using the more effective products that have sufficient activity against both insects is the best approach to achieve dependable control, even though there is often greater expense.

When you look at a sample from a beat cloth, you don’t know what the level of resistance to pyrethroids is for corn earworm and you don’t know the ratio of corn earworm to tobacco budworm (unless you take the time to look at the mandibles.)

The products that give broad spectrum control of these insects are also less likely to flare spider mites (compared with pyrethroids.)

Reach out to Dominic if you need to dig deeper. The question of what’s really in the beat cloth or sweep net often comes up, and the answer is not always simple.