Managing armyworm pressure
Infestations of armyworms in corn fields across Indiana are sporadic this year. Purdue Extension entomologist Christian Krupke tells Brownfield as the armyworms get larger, farmers will begin to see total defoliation of the corn plant.
By then, he says, it is too late. “The time to get them is early,” he says. “When you see notches in the leaves and the plants start to look ragged. So this is one of those pests that you have to walk in the field to see the damage.”
Krupke tells Brownfield there are some fields that are more at risk than others. “The most at risk fields are ones that had a grassy cover-crop or a lot of grassy weeds,” he says. “Annual rye grass is a popular cover crop in Indiana – but it also attracts female army worms that are looking for a place to lay eggs.”
He says the best way to control armyworms is by scouting fields early and if needed, applying a foliar pyrethroid.