Adults are migratory, and can fly long distances. The moth flies from January to April depending on the location.ĭispersal. Females live about a week during which time the lay about 800-1000 eggs. Larvae feed in the upper portion of the rice canopy on cloudy days or at night. Adults feed, mate and migrates at night and rests during the day at the base of the plant. During outbreaks many fields can be affected at the same time. Damage is often localized to one part of a field. Large angular notches can be cut away from young seedlings in a seedbed, giving an irregular appearance. They may also eat the lemma and palea of the developing grains as well as the anthers of flowers. Caterpillars can form swarms that move from one field to another, voraciously feeding on foliage.ĭuring the vegetative stage of rice, damage is evident as massive leaf removal, often including leaf veins. They feed on the leaves, leaving only the midrib uneaten. The wingspan is 35–50 mm.Ĭaterpillars are large, external feeders so they and their feeding damage are generally easily spotted. Adult moths are pale and brick-red to pale brown with a very hairy body covered with dark specks and patches. Pupa is brown, and form in surface litter or in the soil. Crowded caterpillars, such as those feeding communally, develop a much darker shade. Solitary individuals remain fairly pale in color. The head has a light and dark brown pattern. Later instars are brownish with a thin pale dorsal line, and a dark lateral line on each side. Caterpillars (larvae) move with a lopping motion. IdentificationĮggs are off-white and are laid in groups low on the leaves of the plant, often between the sheaths or on the blades. Such outbreaks, when large numbers of larvae move from field to field voraciously feeding on foliage, can occur every several years but are typically quite localized. Local impacts can occur every year, but significant damage only occurs when there are severe outbreaks. The early arrival of warm dry weather followed by rain in spring is favorable for reproduction and multiplication of army worms.

They are readily managed provided infestations are detected early enough. Considerable losses in rice seed can result from larvae cutting of the panicles. They also attack rice and maize fields and, to a lesser extent, barley and buckwheat. Armyworms can cause heavy losses to rice nurseries, with caterpillars destroying seedlings.

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