bollworm

Bollworm is a common name for the larval stage of several moths in the genus Helicoverpa, most notably Helicoverpa zea in the Americas (often called the corn earworm or cotton bollworm) and Helicoverpa armigera in the Old World (also referred to as the cotton bollworm or gram pod borer). The term is used for larvae that feed on cotton bolls and other plant reproductive parts, causing economic damage in many crops.

Bollworms have a wide geographic distribution in warm climates and can be highly migratory. They attack a broad range of crops, including cotton, corn, tomatoes, peppers, sorghum, peanuts, and various legumes. Because of their polyphagous habit, they can persist across multiple seasons and regions, contributing to substantial agricultural losses when populations are high.

Life cycle and behavior: bollworms undergo complete metamorphosis with egg, larval, pupal, and adult stages. Female moths lay clusters of eggs on leaves, flowers, or developing fruits. Larvae typically go through several instars over 1–3 weeks, feeding on reproductive structures and fruit. Pupation occurs in the soil or leaf litter, and adults emerge to reproduce. In warm regions, several generations may occur per year; in temperate areas, overwintering usually occurs as pupae or adults.

Management: bollworm control relies on integrated pest management, combining monitoring (often with pheromone traps), timely scouting, crop management, and a mix of biological, cultural, and chemical controls. Biological options include Bacillus thuringiensis toxins, nuclear polyhedrosis virus formulations, and parasitoid wasps. Crop rotation, resistant varieties, and timely harvest help reduce damage. Insecticide resistance is a concern, so rotating chemistries and following local guidelines are recommended.