University of Illinois

No. 3/April 11, 1997

Black Cutworm Migration Continues to Blanket Illinois

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Black cutworm moths continued to make their migratory trek throughout Illinois during the monitoring period of March 29 to April 4. Similar to the last 2 weeks of March, moths were captured in cooperators' pheromone traps as far south as Alexander County, northward to Ogle County. Captures also were common in western areas of the state (Adams, Hancock, and Pike counties); eastward to DeWitt, Iroquois, Piatt, and Vermilion counties. Intense captures of moths (nine or more moths caught over a 1- to 2-day period) were not common; however, a cooperator in Monroe County reported an intense capture on April 1. Based upon this intense capture, Bob Scott, Illinois State Water Survey, is projecting that cutting of susceptible cornplants (1- to 4-leaf stage) could begin as early as May 3 for Monroe County. Intense captures of moths in March for Alexander and Randolph counties suggest that cutting could begin even earlier, by April 29. Scouting efforts should be concentrated in fields that had infestations of winter annual weeds.

The first 3 weeks of our black cutworm monitoring efforts have revealed a strong northward push of moths. As mentioned previously, this suggests that vigilant monitoring efforts are required during the seedling stage of corn plant development. We will continue to keep you updated throughout the spring regarding any changes in the migration of this potentially significant insect pest of corn.

Mike Gray, Extension Entomology, (217)333-6652