Status of European Corn Borers

June 23, 2000
Dave Mowers with Mowers Soil Testing Plus in Toulon, Illinois, told me on June 20 that he has never seen so few first-generation European corn borers. And in Dave's area of the world in northwestern Illinois, economic infestations of European corn borer occur with some frequency. Dave Feltes, IPM Educator at the Quad Cities Extension Center, also reports finding very few signs of European corn borer activity. On the other hand, Alan Mosler, Monty Webb, and Terry Catlin with Twin County Service Company (serving Franklin, Jackson, Perry, Saline, and Williamson counties) reported finding as much as 70% of the plants in some fields exhibiting pinholes and other whorl-feeding injury caused by both European and southwestern corn borer larvae. It is ironic that the amount of injury being caused by corn borers in southeastern counties this year is greater than the amount of injury being caused in northwestern Illinois. It is usually the other way around, although the presence of southwestern corn borers in southern Illinois changes things a bit.

We didn't expect much of a first generation of European corn borers this year, based on the low densities of overwintering larvae we observed last fall. And although the early planting of corn this year would have encouraged good survival of corn borer larvae, the heavy rains that have fallen in some areas for the past couple of weeks likely resulted in significant mortality of both young larvae and adults. As it stands right now, we probably will not experience many problems with first-generation European corn borers this year. Nevertheless, when adults that will lay eggs for the second generation begin emerging in July, we'll keep you apprised. And people in southern Illinois will want to keep their eyes on the second generation of southwestern corn borers, too.--Kevin Steffey

Author: Kevin Steffey