Granulate Cutworm
Feltia subterranea (Fabricius), Noctuidae, LEPIDOPTERA


DESCRIPTION

Adult - Both the thorax and forewings of the granulate cutworm moth are yellowish-brown. The thoracic collar is dark with a distinct black line, and the abdomen is gray. The hind wings are pure white, though the veins and a slight border may be smoky gray- brown with a blackish tinge. The wings span from 38.0 to 44.5 mm.

Egg - The egg is almost hemispherical with the lower surface smooth and flat or slightly convex. When first laid, the egg is yellowish-white, but it becomes darker before hatching. The egg is 0.63 to 0.75 mm across.

Larva - The head of this caterpillar is pale brown; the body is dark brown to gray with pale longitudinal stripes. The skin surface is covered with small, black, conical granules which can be seen with a 10X hand lens. The six larval stages range from 2 to 38 mm in length.

Pupa - The pupa is about 16 to 20 mm long.


BIOLOGY

Distribution - Though it occurs from Massachusetts and New York to California, the granulate cutworm probably does not breed regularly in its northern limit. It is abundant in the southern United States and occurs as far south as the Bahama Islands, Cuba, Puerto Rico, Central America and South America.

Host Plants - Granulate cutworms have been observed feeding on over 61 hosts of economic importance. In addition to corn, these worms also feed on the foliage of young cotton seedlings, threaten tobacco plant beds in North Carolina, and apparently are becoming a primary pest of peanuts in Georgia. Other hosts include alfalfa, bean, beet, Brussels sprouts, cabbage, cauliflower, clover, dandelion, eggplant, grass, pepper, pea, plantain, potato, sweet potato, tomato, turnip, and wheat.

Damage - The granulate cutworm causes its most serious damage by cutting off small plants near the ground. If the plant is too large to be severed at ground level, the larva climbs the plant and feeds on the foliage.

Life History - No life history study has been made in North Carolina, though rather extensive research has been conducted in Louisiana. In North Carolina, granulate cutworms are believed to overwinter as larvae or pupae. In the spring, moths emerge and lay eggs. Each female deposits an average of 325 eggs which hatch 3 to 5 days later. The larvae develop through six instars in about 4 weeks during July and August and in 5 to 7 weeks during August and September. These caterpillars feed at night, retreating during the day into the soil or under trash near the plants upon which they fed the previous night. Mature larvae burrow 5 to 15 cm below the soil surface and pupate. The pupal stage lasts 2 weeks (or slightly longer) in July, August, and the first part of September. Larvae which pupate after mid-September overwinter in the pupal stage. There are five to six generations per year in Louisiana and probably two to three in North Carolina.


CONTROL

Crop rotation is a commonly used method for controlling this pest on a large scale. Chemical controls include poison baits or directed insecticides when needed, and pre-plant insecticides in areas with a high cutworm incidence. Treatment should begin when 5 percent or more of the optimum stand of seedlings has been cut. For specific control information, consult the current North Carolina Agricultural Chemicals Manual.