Larvae of both species may reach a length of 35 mm. Soybean, sweet potato, peanut, cotton, tomato, crucifers, peas, tobacco, cocklebur, and others. Members from 28 plant families are recognized as hosts. Larval feeding on foliage is initiated on the interior lower portion of plants. As defoliation proceeds, larvae move towards the tops of plants.
Early instars feed on the lower leaf surfaces.
Older larvae consume irregular areas of leaves, characteristically leaving the larger leaf veins. About 90 percent of total defoliation occurs during the last two larval instars. Annual immigrations probably arise from Central and South America. Soybean loopers generally arrive in Georgia in June. Cabbage loopers overwinter in the pupal stage in southern states and also migrate northward.