corn earworm

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Helicoverpa zea

FAMILY

Noctuidae

TAXONOMY

Phalaena zea Boddie, 1850, North America.

OTHER COMMON NAMES

English: Tomato fruitworm, sorghum headworm, vetchworm, cotton bollworm; Spanish: Gusano cogollero, tomatero, bellotero, gusano del fruto.

PHYSICAL CHARACTERISTICS

Adults are medium-sized and sandy-colored, with a wingspan of 1.50 in (37.5 mm). Forewings have faint, irregular markings on the apical half; the hind wings are a dull translucent white with a narrow dark apical band. Full-grown larvae (1.28–1.60 in, or 32–40 mm) are variously colored red, pink, or green with irregular longitudinal dark stripes. Body has spinules.

DISTRIBUTION

Southern Canada to Argentina.

HABITAT

Adults are found on flowers at dusk and can be attracted to lights; larvae are found on ears of corn, tomatoes, and other crops.

BEHAVIOR

Adults fly mainly at dusk. Hatched larvae tunnel into fruit often associated with frass (insect excrement) but can be found on flowers, leaves, and seedlings.

FEEDING ECOLOGY AND DIET

Larvae are serious pests of corn, tomatoes, and cotton. Occasional hosts include bean, broccoli, cabbage, chrysanthemum, eggplant, head cabbage, lettuce, okra, pepper, and more than 100 other plants.

REPRODUCTIVE BIOLOGY

Females can lay eggs on corn silks, on terminal leaflets of tomatoes, and on the crowns of seedlings of lettuce. Larvae pupate about 2–6 in (5–15 cm) beneath the soil and overwinter.

CONSERVATION STATUS

Not threatened.

SIGNIFICANCE TO HUMANS

A major pest of several important food crops, necessitating various forms of integrated pest management, especially in the warmer parts of its range.

Infestation of the ears of cattle by rhabditis bovis, often complicated by blowfly infestation.