07/08/08 Some farmers urged to scout for wheat head army worm

Washington Ag July 8, 2008 Washington State University Extension reports that for the second year in a row wheat and barley in the Reardan/ Davenport area is subject to infestation by the alleged wheat head army worm. Extension's Dianna Roberts says alleged because a positive identification of the insect has not been made, but that hasn't stopped it from causing damage and yield loss. She says is important for growers in that area to check their fields immediately. Growers should look for white patches at the base of the flag leaf where the chlorophyll layer has been stripped off. Then check the head of the grain even if it is still in the boot. The pest is a looper caterpillar that ranges from 3 to 25 mm in length with small ones being light gray or cream colored and large ones are green with yellow stripes down the side. Roberts says telltale damage is a small hole bored in the base of each floret. She says farmers in the Davenport area are seeing from three up to seven affected heads out a random sample of ten. While there are no insecticides labeled specifically for wheat head army worm Roberts says chemicals registered for wheat may be used. One product is Warrior but it has a pre-harvest interval of 30 days. Another product, Mustang Max has a 14 day pre-harvest interval. Application is most effective early in the morning. I'm Bob Hoff.