Caterpillars That Eat Crops

Corn

• The widespread caterpillar pest Heliothis zea, or the corn earworm, got its name from its devastating effect on corn crops. These caterpillars do not feed on the foliage, but on the young corn silk. After they finish consuming the cornsilk, they begin to eat the corn kernels as well. Damaged corn, once husked, will be full of damaged kernels and caterpillar fecal trails. This caterpillar also damages tobacco, cotton and tomato crops, rapidly defoliating infested plants.

Brassicas

• The larvae of the cabbageworm, Artogeia rapae, are light green with a thin yellow stripe down the center of their backs and two broken yellow stripes down each side. Although seemingly sluggish, they grow quickly in size. Despite their name, they frequently attack cauliflower, turnip, broccoli, mustard and canola crops. The adult is a black-spotted butterfly that is frequently seen flying in and around crop fields.

Soy

• Anticarsia gemmatalis, or the velvet bean caterpillar, is an indigenous North American pest. Until commercial soybean crops were introduced, this caterpillar lived mostly on native velvet bean plants. The adult lays its eggs directly on soy leaves. These eggs hatch in less than a week, devouring the foliage of the soybean plant. This species does not usually attack soy crops until late summer.

Potato

• Although the turnip moth caterpillar, Agrotis segetum, does eat foliage when mature, the immature caterpillar eats only roots and tubers. During this stage of the pest's life, it is known as the potato cutworm. The potato cutworm can cause serious damage to a potato crop by burrowing into potato tubers, destroying their commercial viability. The cutworm also eats new young shoots, causing plants to die back. The silver Y moth, Autographa gamma, while not as serious a pest as the potato cutworm, can decrease potato crop yields by feeding on foliage.