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Posted 16 May 2010. PMN Crop News.


Source: University of Illinois Press Release.

Urbana-Champaign, Illinois (April 22, 2010)--Although the numbers are very small, black cutworm moths have been caught in pheromone traps across northern Illinois. University of Illinois Extension staff and cooperators will monitor these traps until June 1.


Storm fronts carry adult black cutworm moths to Illinois. Moths "drop out" of these storm fronts and seek attractive egg laying sites, especially common chickweed and other winter annuals.

If and when 9 or more moths are caught in a trap over a one- or two-day period, this is referred to as an "intense capture" and we begin accumulating heat units or degree-days to predict date of cutting of corn by the larvae. Black cutworm larvae are expected to begin cutting corn with the accumulation of approximately 300 degree-days, base 50 degrees F, after an intense capture.

Cutting dates for your area can be predicted by using the Degree-Day Calculator at the University of Illinois IPM website and Illinois State Water Survey WARM website

If tillage or herbicides eliminate weeds one to two weeks before planting, black cutworms that had been present probably starve to death. The presence of weeds only a few days before planting increases the likelihood of cutworm damage if larvae are present in the field.

With the amount of tillage that has already occurred this spring, the limited number of storm fronts, and the amount of corn that has been planted, hopefully black cutworm will be a non-issue pest this year. Updates on black cutworm will be provided in The Bulletin, a newsletter issued by the University of Illinois at this website

Further information on black cutworm is available at this University of Illinois website:, or at your local University of Illinois Extension office. In Ogle County call (815) 732-2191.

Jim Morrison