Description:
Cutworms and armyworms are the caterpillars of several species of night-flying moths. Cut-worms are plump, smooth and often, greasy-looking. Typically, cutworms curl up tightly when disturbed. They have greenish, brownish, grayish, or striped bodies, up to 1 3/4 inches long. Although about the same size, the armyworms differ in appearance. True armyworms are plump, sparsely-haired, generally green to brown larvae, with dark stripes running down the sides and back. These caterpillars feed on the aboveground plant parts of many grasses and is a pest of many garden and field crops.

Life History: Cutworm larvae may be noticed early in the growing season or not until later in the summer when subsequent generation begin feeding. Adult cutworm and true armyworm moths first appear between April and July. Females lay about 500 eggs on the lower leaves of grasses over a 2- to 3-week period. The caterpillars usually remain hidden during the day and feed at night. A second or third generation of cutworms may emerge in the summer and early fall. Cutworm larvae stop feeding and seek concealed areas to spend the winter during mid-fall. In contrast, many of the armyworms are not successful in over-wintering in Kansas.

Damage:
Cutworms feed on grass blades and cut plants off near the soil surface. Grasses appear ragged and may turn brown from the feeding of any of these larvae. Damage is more likely to occur if the lawn borders cropland or large untended fields. Armyworms, in particular, seem to be attracted to areas of lush vegetation. Inspect lawns more frequently when vegetation in these nearby ‘source zones’ is destroyed, forcing the caterpillars to seek out new food. If cutworms are suspected, check the damaged areas a couple of hours after dark. Depending on the species involved, larvae may be feeding up on the plant foliage or down near the crown of the plant. Damage near the crown should be considered much more serious than simple foliar feeding.

References:
1. Kansas State University Entomology Pub "Lawn and Turf Insect Management Part II. Webworm, Cutworm,  Armyworm, Chinch Bug, and Ant.  Entomology 490

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