The Midwest is alive with WBC moths. Moths have been captured this year much earlier and in higher numbers in Michigan, Ohio, Ontario and Pennsylvania. Current Trap Catch Maps are available at:
This increases our risk of having eggs laid in corn, since corn was planted so early this year and is in the ideal stage that the moths are attracted to. Moths like to lay their eggs in corn before it tassels.
Scouting for eggs should start in early July. Eggs are laid on the upper surfaces of leaves and are usually on new vertical leaves near the whorl. There are typically 20-200 eggs per mass and are pearl white when first laid. Their colour then ages to a tan and then purple just before they hatch, which is usually in about 6-7 days.
Scout 20 plants in 5 areas of the field. If 5% of the plants you scout have egg masses on them, spray is necessary. But call or email me first. WE WANT YOUR WBC EGGS! Jocelyn Smith at UGRC will be conducting trials this year and we need WBC eggs to be able to do the research. We would be happy to come and take the eggs away for you.