Entries » Illinois European Corn Borer Monitoring 2012

Counties with European corn borer moth traps (click on a highlighted county to see trap captures)

Map Embed Code

NameIllinois European Corn Borer Monitoring 2012

European corn borer overwinters as mature larvae. Larvae pupate and emerge as adults in late spring. Females lay eggs for the first-generation in cornfields or on secondary grass hosts.Young larvae move to and, depending on the growth stage of the corn plant, feed in the whorl, ear, or leaf collar. As borers mature to the 3rd or 4thinstar, they begin to bore into the stalk and midribs or leaves where they develop and pupate. They emerge as moths in a week to ten days after pupation. Moths begin to lay eggs fora second generation in cornfields that are tasseling and on late-planted corn.  The second generation larvae pass through the same stages as the first generation. A third generation may occur in the southern third of Illinois.

Corn borer larvae feed on all parts of the corn plant except the roots. First-generation larvae are found feeding on the leaves of corn in mid-to-late whorl stages. They chew small holes in the leaves creating a "buckshot" effect. As corn borers mature they leave the whorl and begin tunneling in leaf midribs and sheaths. After reaching approximately 1/2 inch in length (third instar) borers tunnel into the stalk, and feed until full grown. The second generation is present on corn after tassels have emerged. They feed on pollen in leaf axils or on leaves. As they get larger, they feed on leaf sheaths, collars, and midribs until they eventually enter the stalk. Second generation corn borers also may enter the ear or earshank.