We asked black cutworm monitoring participants to start watching traps at the beginning of April. The first moth was recorded in Ringgold County on April 3 this year. Our predictions of cutting dates (the date when black cutworm larvae are likely to be damaging corn) are based on peak flights that took place beginning April 8 in the southwestern corner of the state. Estimated peak flights for other climate divisions occurred towards the end of April and beginning of May. The map (Fig. 1) shows the predicted cutting dates for the nine Iowa climate divisions. Predictions are based on actual and historical degree day data accumulated from the dates of peak flights.
Iowa State University
Sisson, Adam J.; Jesse, Laura C.H.; and Hodgson, Erin W., "2013 Black Cutworm Scouting Advisory" (2013). Integrated Crop Management News. 84.