Sweet Corn Insect Pest Updates

Bill Hutchison, Eric Burkness and Suzanne Wold, Extension Entomology, University of Minnesota, St. Paul, Minn.

European corn borer (ECB) moth catch at all “traditional” southern Minnesota sites continue to be low, as expected this time of year, for the bivoltine strain of ECB. However, locations such as Lamberton (southwestern Minn.), where the univoltine strain is present, continue to catch moths. See Figure below. Degree-day accumulations (>50F since Jan. 1st) for much of southern Minnesota now exceed 1200, indicating the end of the first-generation flight. Third-instar larvae continue to be active in corn whorls (25% plants infested in some fields) in much of south-central and southeastern Minnesota corn.

Corn earworm (CEW) moth catch also remains very low for all pheromone trap locations (Blue Earth to Rosemount). Major influx of CEW does not occur until mid-August for most Wisconsin and southern Minnesota locations.

Armyworm infestations in corn (10-25% plants infested) appear to be most common in the southeastern area of Minnesota (Goodhue and Olmsted counties). For the most recent insect infestation data on corn, and other crops, check the weekly updates at the MDA Crop Pest survey site at: http://www.mda.state.mn.us/pestsurvey/ To use this site, select the crop of interest, then click the “check notices” button.

**For additional Minnesota ECB Flight Summaries, see the BugWeb site “Map” and click on the location of your choice, at: www.mnipm.umn.edu/Bugweb.

Co-Editors: Bill Hutchison, Department of Entomology, University of Minnesota, hutch002@tc.umn.edu
Jeanne Ciborowski, IPM Program, Minnesota Department of Agriculture, jeanne.ciborowski@state.mn.us
Cindy Tong, Department of Horticulture, University of Minnesota, ctong@extension.umn.edu
Production Editor: Suzanne Wold, Research Specialist, University of Minnesota, woldx018@tc.umn.edu

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Last Revised July 19, 2000.
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