Source: Dominic Reisig, NCSU COOPERATIVE EXTENSION, 7/16/19


We have a number of effective insecticides for corn earworm in North Carolina soybeans. One of these is the insecticide chlorantraniliprole, which an active ingredient in Prevathon and Besiege. Because we are entirely reliant on this insecticide to control corn earworm (bollworm) in Bollgard II, WideStrike, and TwinLink cotton, I am encouraging growers to avoid this insecticide in soybeans to preserve it in cotton. In addition, soybean looper is resistant to this insecticide and generally shows up in the biggest numbers a few weeks after earworms. If Besiege or Prevathon is sprayed for earworm, by the time loopers show up, there are still small amounts of this insecticide left in the plant; this scenario will likely increase levels of resistance in soybean looper populations. Therefore growers should use Blackhawk, Intrepid Edge, or Steward to control corn earworms in soybeans.

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