Several species of cutworms attack plants in the vegetable garden. Surface-feeding cutworms are common pests of young vegetables planted early in the season. A single surface-feeding cutworm can sever the stems of many young plants in 1 night. It eats through the stems just above ground level. Tomatoes, peppers, peas, beans, and members of the cabbage family are particularly susceptible. Some cutworms can climb up the stem or trunk of grapes, blueberries, brambles, tomatoes, and other garden crops to feed on young leaves, buds, and fruit. Cutworms hide in the soil during the day and feed only at night. Adult cutworms are dark, night-flying moths with bands or stripes on their forewings.
Apply an insecticide containing chlorpyrifos or diazinon, or a bait containing carbaryl around the base of undamaged plants where cutworm damage has been observed. Make sure your plant is listed on the product label. Since cutworms are difficult to control, it may be necessary to repeat the application at weekly intervals. Before transplanting new plants into the area, apply a preventive treatment of the biological insecticide Bacillus thuringiensis (Bt), or an insecticide containing chlorpyrifos or diazinon and work it into the soil. Cultivate the soil thoroughly in late summer and fall to expose and destroy eggs, larvae, and pupae. Further reduce damage with a cutworm collar around the stem of each plant. These collars can be made of any stiff material, such as cottage cheese or milk cartons with the bottom removed, tin cans, or aluminum foil. They should be at least 2 inches high, and pressed firmly into the soil. To reduce injury from climbing cutworms, inspect your plants at night with a flashlight and pick off and destroy any cutworms you find. (For more information on cutworms, see Cutworms.)
