Originally published April 2, 2012
All, I have been seeing more instances of true armyworms infesting wheat in the North Louisiana. These include wheat plots at St. Joe and Winnsboro at various stages of growth. Our threshold for armyworms is 5 worms per square foot with foliage loss occurring. If armyworms reach the flag leaf and the wheat has not headed an application should be made. I have also encountered varying levels of stink bugs (primarily rice stink bug) in wheat. Populations of stink bugs have to be high for damage to occur and our threshold is 10% infested wheat heads in the milk stage and 25% infested heads in the soft dough stage. Stink bug numbers will usually be higher around the edges of a field with numbers falling off as you walk further toward the middle. This means you may reach threshold around the edges of a field, but may also be well below threshold 100 feet in. Applications of pyrethroids can control both of these pests.
Rice stink bug photo courtesy of Gus Lorenz
Armyworm larvae on wheat heads photo courtesy of Robert Bellm, University of Illinois Extension
The LSU AgCenter and the LSU College of Agriculture