Based on scouting observations and trap counts so far, it looks like we have finally passed the peak for western bean cutworm moth activity. Egg masses are difficult to find now in corn which tells us that the moths are no longer interested in laying eggs in that crop…unless of course there is an extremely late planted corn field in the area. Then those fields could still be at risk.
But for the most part, scouting needs to focus on the bean crop now. Do not spray fields based on moth catches or egg masses. Wait until you see pod feeding by WBC so that you are targeting the larvae that are actually doing the damage. It will result in much more effective control. There was a CropPest newsletter article that went out last week with some of my previous blog entries but also has a good picture of what early pod feeding looks like by Chris Difonzo. Click here to see the article and the photo.
Again Matador is registered for the bean crop and Matador and Decis are registered for the corn crop. No other products are registered for control of western bean cutworm at this time. We do have permission from CFIA to spray the refuge with insecticide if it reaches threshold for western bean cutworm, as long as the adjacent Bt corn field is also sprayed at the same time.