Cabbage looper

Definition

A medium-sized owlet moth (family Noctuidae), Trichoplusia ni, whose larvae are major agricultural pests of cruciferous vegetables. The common name derives from two diagnostic traits: the larva's host-plant preference for cabbage, broccoli, bok choy, and related Brassicaceae, and its characteristic looping locomotion—arching the midbody to bring the hind prolegs forward to meet the thoracic legs, then extending the anterior body in a repeating wave. Adults are nocturnal, gray-brown moths with a distinctive silvery figure-eight or Y-shaped mark on each forewing. The species is native to North America but has spread globally with commercial agriculture and is a model organism for insect physiology, viral pathogenesis, and Bacillus thuringiensis resistance studies.

Etymology

From 'cabbage' for the primary host plants (Brassicaceae) and 'looper' for the larva's looping crawling gait, arching its body into a loop when moving.

Example

In integrated pest management programs, cabbage looper populations are monitored with pheromone traps, and economic thresholds are based on larval counts per plant; heavy infestations can skeletonize cabbage leaves and contaminate broccoli and cauliflower heads with frass, rendering produce unmarketable.

Synonyms

• Trichoplusia ni

Related Terms

• Noctuidae
• looper
• Proleg
• crucifer
• Bacillus thuringiensis
• Integrated Pest Management
• pheromone trap
• Diamondback moth

Usage Notes

Strictly refers to Trichoplusia ni; the common name is sometimes misapplied to other plusiine loopers (e.g., soybean looper Chrysodeixis includens, alfalfa looper Autographa californica) that share similar larval morphology and looping locomotion. Specialists distinguish these species by adult wing patterns, larval setal arrangements, or molecular markers. The term 'looper' alone denotes the locomotory habit across multiple noctuid genera, not a monophyletic group.