Damage Characteristics of Cutworms and Integrated Field Control Methods

Cutworm is the collective name for the larvae of various pest species in the Noctuidae family. It gets its name because the larvae often bite through the roots and stems of crop seedlings at night, and farmers also commonly call it soil silkworm or root-cutting worm. It is a typical underground pest, hiding in the shallow soil layer during the day and crawling out at night to move about and feed, so its damage is highly concealed.

The species commonly seen in production include the black cutworm, the yellow cutworm, and the large cutworm, among which the black cutworm is the most widely distributed and the most common. Cutworms have very diverse feeding habits, and the seedlings of corn, cotton, vegetables, and various nursery stock can all be damaged. The larvae are mostly active at night and often bite through seedlings close to the ground, causing missing plants and broken rows; in severe cases, an entire seedbed may be destroyed.

Cutworm control should be based on agricultural measures. Before sowing, deep-plow and sun-dry the soil and clear weeds in and around the field to destroy the environment where adults lay eggs and larvae hide. During the adult emergence period, sugar-vinegar liquid traps or insect-killing lamps can be set up to trap and kill them, reducing the field pest source. For larvae that have already entered the damaging stage, you can open the surface soil near the damaged seedlings in the early morning and catch them by hand, or use roasted wheat bran or fresh vegetable leaves mixed with pesticide to make poisoned bait and scatter it among the seedlings in the evening to trap and kill them. When pest density is relatively high, combine this with pesticide root drenching or ground spraying.

It should be noted that young larvae mostly gnaw on tender leaves and growing points, and only after the third instar do they burrow into the soil to bite the roots and stems. Therefore, control should begin early when notches appear on seedling leaves. If you wait until plants fall over in patches, the loss has often already occurred. By combining field cleaning and land preparation, adult trapping and killing, and pesticide control, and by persisting in early inspection and early treatment, cutworm damage can be controlled fairly well.