cutworm

Cutworm is a common name for the larval stage of several species of moths in the family Noctuidae. Cutworms are typically smooth-bodied caterpillars that range in color from gray to brown or green, and they may have spots or stripes. The name derives from their habit of cutting down young plants at the soil surface as they feed at night.

They spend daylight hours concealed in soil, leaf litter, or under boards. They emerge at dusk to feed, often severing seedlings at or just below the soil line; damaged stems may wilt and topple. In crops such as corn, beans, tomatoes, and lettuce, damage is often concentrated in the first few weeks after planting.

Taxonomy and biology: The term covers larvae of many noctuid species, notably the black cutworm (Agrotis ipsilon) and variegated cutworm (Peridroma saucia). They overwinter in the pupal stage in soil in temperate regions; they pupate in late spring to early summer; adults are brown moths with muted markings that lay eggs on plants. The larvae are typically nocturnal feeders and move about to find suitable host tissues.

Management and control: Integrated pest management relies on monitoring and targeted actions. Monitor fields with pheromone or light traps for adult moths and scout seed beds for cutworm presence. Cultural controls include tillage to destroy overwintering pupae, crop rotation, weed management, and placing physical barriers around seedlings. Biological controls include Bacillus thuringiensis kurstaki, entomopathogenic nematodes, and natural enemies. Chemical controls may be used when damage is severe and a label-approved product is chosen, with timing at the larval stage for effectiveness.