To receive weekly email notification when the latest issue of the Bulletin is online, click on this link and fill out the form.

Heads Up for Stalk Borers

May 17, 2002
It's probably a bit early for farmers in northern Illinois (where quite a bit of corn has been planted) to be concerned about stalk borers, but degree-day accumulations can provide a "heads up." Figure 2 shows actual degree-day accumulations (base 41 deg F, the minimum developmental temperature for stalk borers), from January 1 through May 13, 2002. Stalk borers first begin to move into corn when about 1,100 heat units have accumulated from January 1; 50% movement occurs when about 1,400 to 1,700 heat units have accumulated. We recommend scouting when 1,300 to 1,400 heat units have accumulated, and a decision to treat with an insecticide should be made between 1,400 and 1,700 heat units. The map in Figure 2 suggests that farmers in southern counties (where very little corn has been planted) should watch for stalk borers; however, farmers in central and northern Illinois probably won't see stalk borers right away. When (if) temperatures become more late spring-like, development of stalk borers will accelerate. I'll provide a more detailed article about stalk borers in next week's issue of the Bulletin.--Kevin Steffey

Author: Kevin Steffey

The Pest Management and Crop Development Bulletin
Executive Editor: Kevin Steffey, Extension Entomologist

Subscription information: Phone (217) 244-5166 or email
Comments or questions regarding this web site: