The first report of spraying for armyworm in sweet corn in Essex County came in today. We are not sure how heavy of infestation to expect in other fields but wheat and newly emerging corn fields should be scouted in Essex, Chatham-Kent, Lambton, Elgin and Middlesex counties asap. Armyworm reports from Essex tend to give us a few days heads-up to catch any infestations in the neighbouring counties. But other counties in southwestern Ontario should be scouted in the next 7 days to 10 days to determine if armyworm is present there.
A CropPest Newsletter article will go out later this week with details on scouting and management strategies. You can also find information in the Agronomy Guide for Field Crops and past CropPest articles (links provided below)