Last Warning of the Season for Stalk Borer Movement into Northern Illinois Cornfields

June 9, 2000
Stalk borers are completing their movement into cornfields. If you haven't already checked your cornfields for stalk borers this season, you're too late for southern and central Illinois. Producers in extreme northern Illinois are quickly running out of time as well. Figure 3 indicates that for the southern two-thirds of the state, approximately 50% of the stalk borer movement into corn had already taken place by May 29. As we've mentioned in several previous issues of the Bulletin, stalk borers first begin to move into cornfields when 1,100 heat units (base 41°F, from January 1 to May 29) have accumulated. Fifty percent movement occurs when approximately 1,400 to 1,700 heat units have been reached. For background information on this insect pest, please consult issue no. 7, no. 8, and no. 9 of the Bulletin.--Mike Gray

Author: Mike Gray