Cutworms are the larvae of drab brown “miller moths” (family Noctuidae), also called dart moths or owlet moths. The adults are not active in daytime, but may fly up from foliage if disturbed. Only the caterpillar stages feed on plant tissues. “Climbing cutworms”, such as the army cutworm and the dingy cutworm, feed on above-ground portions of the plants (tender leaves, flowers and buds). Climbing cutworms usually feed at night, resting under soil or debris during the day. There is one generation per year.
Army cutworm moths place their eggs on or just below the soil in late summer; the eggs hatch in the fall, and the larvae overwinter in the soil. When a feeding area is exhausted, larvae sometimes move as a group to find new feeding areas. The adult moths emerge from soil cocoons in May and early June, subsequently migrating to higher elevations for the summer, and returning in the fall to lay eggs. Host plants are diverse, but army cutworms are mainly a problem in small grains, sugarbeet, and alfalfa.
Dingy cutworm moths insert their eggs in the flower heads of composites such as ragweed or goldenrod, in the fall. This species overwinters in the larval stage, and is a pest of many plants including small grains, corn, and alfalfa.
Pale western cutworm moths place their eggs in loose soil in the fall; the eggs hatch in late winter. This is a non-climbing species that spends its entire larval life in contact with soil. It feeds by severing plants below the soil line. PWC is a pest of small grains, corn, alfalfa, and a wide variety of other crops.
