Beet armyworm

Spodoptera exigua

Beet armyworms are a widespread pest in California found in tomato fields every year. In some areas beet armyworm may be the most important caterpillar attacking tomato.
Eggs are laid on leaves in clusters covered with hairlike scales left by the female moth; there may be more than 100 eggs per cluster, but usually there are fewer. Newly hatched larvae feed together on foliage near the egg cluster and gradually disperse as they grow. Older larvae feed on leaves and fruit. Larvae usually are dull green with many fine, wavy, light-colored stripes down the back and a broader stripe along each side; they usually have a dark spot on the side of the thorax above the second true leg. The color varies, however, and the spot is absent in a proportion of some populations. The pupa is similar to that of the tomato fruitworm; it pupates in a depression made on or pocket just below the soil surface. The adult moth is mottled gray and brown with a wingspan of about 1 inch. The life cycle takes about a month in warm weather, and there are three to five generations a year.

Plant Protection Products