Black Cutworm Problems Scattered Across the State

Published: May 17, 2010

The potential for black cutworm problems continues in fields where emerging and seedling corn plants are present. Although widespread problems with this pest have not occurred this year, some fields across the northern and central regions of the state have required rescue applications of insecticides. The potential risk from this pest depends on where the migrating moths laid their eggs, on the number of larvae produced from the eggs, and the growth stage of the corn seedlings when larger black cutworm larvae are present. Corn plants are typically susceptible to "cutting" damage through the 4th leaf growth stage. Although most corn fields in the state will not experience black cutworm problems this year, some fields will become infested with economic populations of larvae. Corn just emerging at this time is most at risk as large larvae may be present in fields. Other fields with black cutworm infestations may have larvae of differing sizes. This indicates that larvae may cause damage for an extended period of time in contrast to a limited period of damage when all larvae are in the same growth stage. Although wet conditions may limit scouting activities for this pest, it is recommended that corn fields be scouted at least weekly from seedling emergence through the 4-leaf stage of growth.