Armyworms continue to invade pastures and crops in Oklahoma, with OSU Extension Entomologist Dr. Tom Royer calling it a "huge year for fall armyworm in pastures, sorghum, and now wheat and canola." Royer wrote in an Extension release last week that "Fall armyworms have been very active this summer and fall. As wheat planting progresses, producers need to check fields regularly after seedling emergence. Scout for fall armyworms by examining plants in several (5 or more) locations in the field. Fall armyworms are most active in the morning or late afternoon.
"Look for “window paned” leaves and count all sizes of larvae. Examine plants along the field margin as well as in the interior, because they sometimes move in from road ditches and weedy areas. The suggested treatment threshold is 2 - 3 larvae per linear foot of row in wheat with active feeding. We won’t get relief from fall armyworms until we get a killing frost, so keep vigilant!"
Royer, in a Wednesday evening email- added to those comments by saying armyworms have been found in newly planted canola- so scout those fields as well and if you find one caterpiller per foot row in canola- that's the the threshold to use as justification to spray.