Mark Carlton, extension crop specialist, and I found a field in Marion County on May 16 that had variegated cutworms feeding on young corn plants. The variegated cutworms were feeding on the leaves, chewing both circular holes and eating along the leaf margin. We did not find any variegated cutworms actually cutting corn plants or in the soil near cut plants, although the field did have black cutworms 1.5 inches in length and wireworms that were causing stand loss.
This is the first time that I have seen variegated cutworm attack corn and I would consider the behavior very rare. Variegated cutworms are fairly common in alfalfa. They also were abundant on common milkweed in this particular field.
Variegated cutworms can be identified by the very small yellow spots along the top of each body segment and the dark triangular spot near the tail end of the larva. The yellow spots may be hard to see or nonexistent near the end of the cutworm if it is an early instar. The variegated cutworm also might be confused with the armyworm because both species have black stripes on their prolegs.
|Variegated cutworm feeding on corn.|
Leaf feeding by variegated cutworms will not cause economic damage. Chemical control of variegated cutworms is probably unnecessary in corn.
This article originally appeared on pages 90-91 of the IC-486(11) -- May 28, 2001 issue.