University of Illinois

No. 1/March 21, 1997

Black Cutworm Monitoring Program in Place

The 1997 black cutworm monitoring program is under way. Earlier this week, we sent pheromone trapping kits to 100 cooperators statewide. Within a week, participants will begin sending us postcards indicat ing whether or not any captures have occurred. As the spring progresses, we will report intense captures of black cutworm moths (nine or more moths caught over a 1- to 2-day period) when they occur. More importantly, we will offer projections about when c utting likely will take place for a given area of the state. After 300 heat units (base 50oF) have accumulated beyond an intense capture, black cutworm larvae have the potential to begin cutting plants. For black cutworms to begin cutting, they must have reached the fourth larval instar. Corn fields most susceptible to cutting and economic losses are those with plants at the 4-leaf stage of development or smaller. As the spring progresses, we intend to keep you up-to-date regarding this potentially import ant insect pest of corn. Recall that most cornfields do not require an insecticide treatment for black cutworms. Paying attention to reports of intense captures, heat-unit accumulations, growth stages of plants and cutworms, and applying a rescue treatmen t when needed represents the best management approach for this insect.

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