Field Corn XI-17

Variegated Cutworm

Frank B. Peairs

Cutworm Adult	Cutworm Larva

Identification (and life cycle/seasonal history)

The adult variegated cutworm is a large moth with a wingspread of 45 millimeters (1¾ inches).  The forewings of the moths have a light tan color and black markings.  Two pale eyelike marks, separated by a black bar, appear in the upper middle of the front wings.  The hind wings are silvery white.  Larvae are ash-gray to dark brown in color with a distinct row of pale yellow spots along the back.  Most have a broad orange stripe along each side of the body and frequently a dark W-shaped mark on the tip of the abdomen.  Fully developed larvae are 38 to 45 millimeters (1½ to1¾ inches) long.

Moths emerge from overwintering pupae in the early spring.  The adult females lay eggs in clusters of 40 to 70 on the stems of dead twigs, plant stems, and leaves.  Depending on area temperatures, most eggs hatch within four to nine days.  Larvae may feed and grow for 33 to 40 days until fully grown.  Mature larvae enter the soil, form a cell and pupate.

Plant Response and Damage

The variegated cutworm is seldom a serious pest of corn.  Unlike other cutworms, these cutworms climb the plant and feed on leaves, usually feeding at night.  They may also feed on the tips and silks of developing corn ears.  Often, defoliated or cut plants will be the only indication of their presence.  The larvae may be found during the day hidden among surface litter, in loose soil, or under objects.

Categories: Field corn, Insects, Variegated cutworm

Date: 04/16/2004