Corn earworm

Definition

A common name applied to two closely related noctuid moth species whose larvae are major agricultural pests of corn, cotton, tomato, and other crops. In the Americas the term refers primarily to Helicoverpa zea (also called cotton bollworm and tomato fruitworm), while in Europe, Asia, Africa, and Australia it denotes Helicoverpa armigera (Old World bollworm, African bollworm). The larvae feed on developing kernels, fruits, and flower buds, causing direct damage and secondary infection by pathogens. Despite their morphological similarity and overlapping host ranges, the two species differ in geographic distribution, pheromone blends, and pesticide resistance profiles, with H. armigera showing greater invasive potential.

Etymology

From the larval habit of feeding on the silks and kernels of maturing corn ears.

Example

In integrated pest management programs, pheromone traps are deployed to monitor corn earworm flight and time insecticide applications before eggs hatch on sweet corn silks.

Synonyms

• cotton bollworm
• tomato fruitworm
• sorghum headworm
• vetchworm

Related Terms

• Helicoverpa
• Noctuidae
• bollworm
• fruitworm
• earworm
• Helicoverpa armigera
• Helicoverpa zea
• larval host plant
• pheromone monitoring
• Bt corn
• Pesticide resistance management

Usage Notes

The name is ambiguous without geographic context; specialists typically specify Helicoverpa zea or H. armigera to avoid confusion. In North American agricultural literature, 'corn earworm' is understood to mean H. zea unless otherwise stated. The larval stage is the damaging phase; adults are nectar-feeding moths that disperse widely. The species are partially reproductively isolated where their ranges overlap, though hybridization has been documented. Resistance to pyrethroids and Bt toxins has driven shifts in management strategies for both species.