Inchworm

Inchworm is a common name for the larval stage of moths in the family Geometridae, within the order Lepidoptera. The term inchworm, and the related name geometer moth, refer to the larva’s distinctive method of locomotion: they clasp with their front legs, extend the body forward, and then bring the hind end forward in a looping motion, creating a short “inch” of movement.

Geometer larvae are typically slender caterpillars that range in color from green to brown or mottled patterns to resemble leaves. They usually have three true legs near the head and either two or no complete pairs of prolegs along the abdomen, especially lacking in the middle segments. This arrangement produces the characteristic looping gait.

Inchworms are widespread and feed on a wide variety of plants, including trees, shrubs, garden ornamentals, and crops. Some species can become pests, causing defoliation or cosmetic damage. They are mostly nocturnal, feeding at night and hiding during the day. Adults are moths with slender bodies and various wing patterns, often held flat or tent-like when at rest.

Life cycle and management: Geometer moths undergo complete metamorphosis, with egg, larval (inchworm), pupal, and adult stages. Eggs are laid on host plants; larvae pupate in leaf litter or soil. Management in gardens and fields may involve removing webbing or caterpillars by hand, conserving natural enemies, and, when appropriate, applying targeted biological controls such as Bacillus thuringiensis preparations.