By Clint Thompson
Specialty crop producers should be wary that Diamide resistance in beet armyworm exists. How widespread it is remains a question mark, says Stormy Sparks, University of Georgia Extension vegetable entomologist.
“We know it’s there, and when it’s there it’s bad. We don’t know how widespread it is,” Sparks said. “Where we’ve looked at is where we’ve had problems. When you don’t have problems, you don’t have populations to look at. You’ve got a field where they’ve treated two or three times with a diamide and you still have caterpillars, they’re going to be resistant. It’s just a question of how widespread it is and that we really don’t know.”
Sparks said resistance to Diamides, which includes Coragen, Exirel and Harvanta, is significant since beet armyworms have a broad host range. A lot of commodities would be impacted. However, other tools exist in the arsenal for producers who must manage beet armyworms every season.
“For that pest you’ve got to go to a different mode of action. There’s a lot of modes of action that are effective on beet armyworm. You can still kill them, just don’t use a Diamide for that particular pest,” Sparks said.