1. Education

Bronzed Cutworm and Other Cutworms

Nephelodes minians


Cutworms are so named for their annoying habit of cutting down seedlings, usually right at or near the soil surface.
Bronzed cutworm.

Bronzed cutworm.

Whitney Cranshaw, Colorado State University, Bugwood.org

Description: Cutworms are the caterpillars of various moths in the family Noctuidae. They vary in color and markings according to species, but a common behavior of cutworms is their tendency to curl into a letter C shape when disturbed. The adult moths are medium-sized, somewhat drab night fliers. The moths pollinate flowers, and don't do any direct harm to garden crops.

Life cycle: Cutworms generally overwinter as larvae, so they're ready to feed as soon as temperatures warm and the first garden plants are installed. By late spring, the caterpillars have tunneled into the soil to pupate. Adult moths emerge in summer, when they mate and lay eggs. A singe female may lay hundreds of eggs, often on weeds in the garden. The new generation of larvae feed until temperatures drop low enough to send them into hibernation for winter.

Crops damaged: Tomatoes, peppers, eggplant, potatoes, corn, peas, beans, celery, carrots, lettuce, and many other common garden crops. Different cutworm species prefer different host plants.

Signs and symptoms: Young garden plants severed at or near the soil surface, usually overnight. Most cutworm problems occur in spring when plants are tender and small. Some cutworms feed on foliage, buds, or fruit, and others feed on the roots.

Control measures:

  • Turn and till your garden soil before planting in the spring to disturb overwintering cutworms.
  • Look for signs of cutworm activity late in the day or in the early evening, when the caterpillars are most active. Damaged or severed stems or the presence of frass may indicate a cutworm problem.
  • If you find evidence of cutworms, try to find them in the soil around the affected plant. Collect and destroy any cutworms you find hiding in the soil.
  • Install collars around seedlings to act as a barrier to cutworms. Push one end into the soil a few inches, and allow the other end to extend above the soil surface. Cardboard toilet paper rolls can work well for this.
  • Plant a perimeter of sunflowers around your garden to act as a trap crop for cutworms. Monitor the sunflowers for cutworms and destroy them as you find them.
  • Remove any plant debris and pull weeds to minimize places for small cutworms to shelter.
  • At season's end, turn and till your garden soil again.

  1. About.com
  2. Education
  3. Insects

©2014 About.com. All rights reserved.