Variegated Cutworm
Peridroma saucia (Hubner), Noctuidae, LEPIDOPTERA


DESCRIPTION

Adult - The forewings of this moth are basically yellow or brown with pale mottled designs, while the hind wings are white with brown veins and margins. The wingspan varies from 3.8 to 5.0 cm.

Egg - The spherical, white or pale yellow eggs are ribbed and slighted less than 1 mm in diameter. They are laid in irregular, elongate patches and turn brown before hatching.

Larva - The smooth-skinned larva is pale gray or light brown mottled with dark brown. The first four abdominal segments (at least) bear two yellow or orange dots while the eighth segment is marked with both a black spot and a yellow spot. The mature larva may be as long as 40 mm and curls into a C-shaped ball when disturbed.

Pupa - The reddish-brown pupa is 15 to 20 mm long.


BIOLOGY

Distribution - The range of the variegated cutworm spans most of North America including Canada and Alaska and extends into South America. It is also found in Europe and the Mediterranean area. Although it is of most importance in the Pacific Northwest and some northeastern states, this cutworm is an occasional pest in North Carolina, especially in areas with sandy or sandy loam soils.

Host Plants - The variegated cutworm feeds on a variety of garden crops, trees, vines, grasses, field crops, ornamentals, and greenhouse plants. Of the forage crops, it prefers alfalfa and sweet clover.

Damage - Beginning in early spring and continuing throughout the summer, variegated cutworms climb host plants and devour foliage, buds, and fruit. Damaging infestations, however, are sporadic. Because the variegated cutworm is one of the few cutworm species that climbs the plant to feed, its presence is usually more striking than that of subterranean cutworms. Late larval instars, however, do burrow in the soil and cut off plants at or near the soil surface.

Life History - Variegated cutworms overwinter as pupae with a high percent mortality occurring during this life stage. Female moths emerging from surviving pupae compensate by laying over 2000 eggs during their short life span. Clusters of 60 or more eggs are deposited on stems or leaves of ow-growing plants as well as on fences and buildings. During the summer, eggs usually hatch in 5 days. The active larvae feed at night and on cloudy days for about 3 1/2 weeks before burrowing into the soil to pupate. The non- overwintering pupal stage lasts 2 weeks to a month before second generation moths emerge. Requiring 48 days to complete a life cycle, variegated cutworms produce two to four generations each year depending on weather conditions and latitude.


CONTROL

Cultural controls are difficult to employ for pasture crops since plowing and rotation are not easily accommodated. In forages, however, deep tillage late in the fall destroys many overwintering pupae. Since certain insecticides pose residue problems, consult current North Carolina State Agricultural Extension Service recommendations for specific information on insecticides, rates, formulations, and waiting periods.