Cabbage Looper
Trichoplusia ni (Hubner), Noctuidae, LEPIDOPTERA


DESCRIPTION

Adult - The cabbage looper moth has a wingspan of about 38 mm. Near the center of each brownish-gray forewing is a silver figure-eight design; the lighter colored hind wings have dark margins.

Egg - The round, greenish-white egg is slightly smaller than a pinhead.

Larva - This green larva has three pairs of prolegs and several white stripes which run the length of the body. When fully grown, the caterpillar is less noticeably striped and measures 30 mm long. It moves in a characteristic "looping" motion.

Pupa - The green or brown pupa is approximately 19 mm long and encased in a loosely woven cocoon.


BIOLOGY

Distribution - Native to North America, the cabbage looper is common from southern Canada into Mexico. In the U.S., this caterpillar is primarily a problem in the South.

Host Plants - The cabbage looper infests a large range of plants. Some cultivated hosts include: cabbage and related plants, cotton, potato, spinach, lettuce, celery, parsley, tomato, and soybean. Collards and cotton are preferred over broccoli, cauliflower, or cabbage for oviposition.

Damage - Cabbage looper feeding injury closely resembles that of the imported cabbageworm. The young caterpillars feed on the undersides of leaves. As the larvae mature, they move to more protected areas deeper within cabbage heads. These larger larvae feed between leaf veins as they progress from the outer to the inner leaves.

Life History - Cabbage loopers overwinter as pupae in Florida and adjacent states. The inconspicuous night-flying moths emerge in spring, and females soon begin depositing 275 to 350 eggs, singly, on the upper surface of leaves. Several days later, young loopers hatch from the eggs and begin feeding. The caterpillars consume foliage voraciously for 2 to 4 weeks before spinning cocoons on the host plant foliage and pupating. Within 2 weeks the next generation of moths emerge. There are three or more generations each year in North Carolina.


CONTROL

The use of resistant cabbage varieties such as Mammoth Red Rock, Chieftan Savoy, and Savoy Perfection Drumhead helps reduce cabbage looper damage. On most crucifers, however, chemical control of this pest becomes necessary.

Insecticides for control of the cabbage looper are most effective on young and exposed larvae. A 7-day spray schedule is usually recommended for caterpillar control on crucifers. For recommended chemicals and rates, consult the current North Carolina Agricultural Chemicals Manual.

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