It is a pest of cruciferous vegetables. Its damage characteristics are also called armyworm. The newly hatched larvae swarm on the back side of the host leaves, spin silk and form webs, feed on the leaf mesophyses, and leave the epidermis behind to form transparent holes. After the third age, the damage spreads, biting the leaves into holes or notches, and sometimes damaging flower buds or fruits. In severe cases, only the veins and petioles remain. Morphological characteristics: The adult body is 10-14 mm long, grey-brown, with a row of black triangular spots on the outer edge of the forewing, and a kidney-shaped spot in the center of the forewing near the front edge. There is a yellow-white longitudinal band on the abdomen. Oval, white, with white fuzz outside. The body length of the last instar larvae is about 22 mm, and the body color varies greatly, from green to dark brown; the lower line of the abdominal valve is an obvious yellow-white longitudinal band, which goes straight to the end of the abdomen and does not bend to the buttocks and feet. There is a strip above and behind each valve. White spots. Pupa yellowish brown. Life habits: 4-6 generations occur in a year. They overwinter as pupae in the soil. Adults emerge from March to April. Adults hide during the day and are active at night. They have strong phototaxis and lay eggs on the back of leaves. There are 10-250 eggs in each patch. . The larvae like to gather in crevices or depressions between leaves before they are 3-4 years old, cover them with thin threads, and bite the mesophyll inside, leaving the epidermis behind. When they grow up, they eat through the leaves and appear to be in a state of suspended animation. Occurs heavily when the climate is dry. Control measures (1) Plowing sugar beet fields in late autumn and early winter can eliminate some overwintering pupae. (2) Weeding is carried out from March to April in spring to eliminate first-instar larvae on weeds. (3) Combine with field operations to remove egg masses and kill young larvae. (4) Before the third age, spray 20% Tianda chloride suspension 1,000 times, 20% fenflurazide suspension 1,500 times, 10% fenflurazide suspension 1,500 times, and 5% Kasike dispersible Liquid 1,500 times liquid, 10% high-efficiency methacrylate emulsifiable concentrate 1,500 times liquid, 98% Badan soluble powder 1,000-1,500 times liquid, 4.5% Yunda Anzhi 1,500 times liquid, 90% Wanling soluble powder 4,000 times liquid, 5% Rugente EC 2500 times liquid, 20% methoxymethrin EC 2000 times liquid, 2.5% methamphetamine EC 2000 times liquid, 5% doxepin EC 3500 times liquid, 2.5% Bodex EC 2000 times liquid, 50% Xin Thion and phosphorus emulsifiable concentrate 1500 times liquid, etc. (5) In humid weather, spray 500-700 times of Borenicidus or Caterpillar fungus powder containing more than 10 billion spores per gram. (6) Apply beet exigua pheromone.