Cabbage Looper, Trichoplusia ni
(Lepidoptera: Noctuidae)

The cabbage looper is found throughout the United States wherever crucifers are grown, although it has a wide host range. The cabbage looper does not enter diapause and is only able to overwinter in the southernmost United States. The number of generations completed each year varies from two to seven. Generations may overlap. Cabbage looper eggs are yellowish-white or greenish and bear longitudinal ridges. The young larvae are initially white but become pale green as they feed on foliage. Larvae crawl by arching their back to form a loop and then projecting the front portion of the body forward. The larva has several narrow white stripes on the back and in some cases may be entirely green. A white cocoon is formed on the underside of foliage or in plant debris. The pupa inside the cocoon is brown or black. The forewings of the adult are gray-brown and the hind wings are light brown at the base with the distal portions dark brown.

Vegetable crops that are commonly attacked by the cabbage looper include broccoli, cabbage, cauliflower, collards, mustard, radish, turnip, watercress, beet, cantaloupe, celery, cucumber, lima beans, lettuce, parsnip, pea, pepper, potato, snap bean, spinach, squash, sweet potato, and watermelon. Larvae feed on the underside of the leaves and may cause a netted appearance or may chew large holes in the leaf depending on the age of the larvae. There are several natural enemies that attack the cabbage looper and a nuclear polyhedrosis virus help keep populations at low levels. Many sampling strategies are developed for cabbage looper, including blacklight traps and pheromone traps. Insecticides may be used but resistance has become a problem with many of the chemicals used. Bacillus thuringiensis is a common biological control agent used to suppress cabbage looper populations. Cultural control practices include row covers, crop rotation, destruction of crop residues and alternate hosts, and the use of resistant varieties.

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Cabbage looper, Trichoplusia ni, adult.
(Photographer: J. Capinera, University of Florida)

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Cabbage looper, Trichoplusia ni, young larva.
(Photographer: J. Capinera, University of Florida)

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Cabbage looper, Trichoplusia ni, pupa.
(Photographer: J. Castner, University of Florida)

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Cabbage looper, Trichoplusia ni, mature larva.
(Photographer: J. Castner, University of Florida)

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