Corn Earworm Pest Alert - Southern Minnesota

Bill Hutchison, MN Extension IPM Program, & Dept. of Entomology, University of Minnesota, St. Paul, MN 

August 24, 2017

During the past 7-10 days several Corn Earworm (CEW) pheromone trap volunteers have confirmed significant increases in moth flights, with counts ranging from 50/night at Owatonna and Rosemount, to >175/night at Blue Earth. Although the CEW catch has been low, so far at Lamberton, sweet corn in the Sleepy Eye area could also be at risk. Current CEW moth flight numbers for all MN locations, can be viewed on the CEW Moth Page on VegEdge

This VegEdge page also includes more information on CEW action thresholds for sweet corn and snap beans. Given the thresholds for sweet corn are >5 moths/night for two consecutive nights, the current CEW pressure is substantial, and sweet corn that is at peak to late-silk will now be attractive for egg-lay. Protective insecticide applications are needed to minimize the risk of kernel feeding and quality losses. Until new solutions are available, we continue to recommend the maximum rate/acre for the pyrethroids (e.g., Warrior, Mustang Maxx, Bifenthrin), with sprays applied on a 6-7 day schedule, depending on moth pressure and ambient temperatures.  

CEW moths

Corn earworm moths