Scout for corn borer in non-Bt fields
Corn borer pressure could be mounting in non-Bt fields.
University of Minnesota Extension integrated pest management specialist Bruce Potter says scouting should begin with the earliest-planted corn.
“You can look for shot-holing in the whorls. And if you do find shot-hole plants, look for larvae and calculate an economic threshold.”
If threshold levels are met, he tells Brownfield insecticides are usually effective.
“As long as you get the timing down correctly. Foliar insecticides work fairly well (because) the corn borer larvae are still in whorl, so it’s easy to get at them with an insecticide.”
Potter says later generations of corn borer are tougher to treat because the canopy is above the ear leaf where the larvae are typically found.