CUTWORM

MEET THE PEST

Cutworms are familiar pests to people who have experienced damage to their lawns, and to the stems of crops and seedlings in May and June. Cutworms feed at night. Plants are often cut off completely at or just below the soil surface giving the appearance of a freshly mowed area. Some cutworm species climb and will feed on the leaves of plants. Damage is inflicted by the larval stage, which is a one to two inch (2 2 to 5 cm) caterpillar. Its grey to brown body has white stripes down each side, and is soft, plump and hairless. A disturbed cutworm will curl up.

LIFE CYCLE

The life cycle of the cutworm consists of egg, larva, pupa and adult. One generation is produced each year. Eggs overwinter on the tip of grass blades or on the top layer of soil. When spring arrives, larvae emerge from the eggs and experience six growth stages or instars before they pupate in early July. The pupal stage is a resting period while the cutworm changes from larva to adult. The adult, a brown moth with a wingspan of 1 1/2 inches (3 4/5 cm), emerges and lays eggs which overwinter.

CONTROL

Monitoring

To determine if cutworms are present, look for signs of freshly cut crops and plants. Take a flashlight at night to search the bottom of the plant and the top layer of soil for cutworms. Handpick the cutworms you find and squash them or drown them in a bucket of soapy water.

Physical

Since eggs are laid during the fall by adults, removing weeds and mowing the grass close to the ground will aid in prevention of cutworm infestation.

A protective collar made of plastic or sturdy cardboard such as plastic drink bottles or milk cartons as well as toilet paper rolls are very helpful in protecting plants. Place the collar around the plant and push into the soil to prevent the cutworm from attacking the stem.

A trap can be made by placing a sticky substance such as molasses around the base of each plant. When the cutworm emerges to feed, it will come in contact with the molasses, get stuck, harden and die. Rain will wash away the molasses, thus, re-treat as often as necessary.

Another option is to sprinkle crushed egg shells around the plant base. Crawling over the shells, will cause the cutworm to dehydrate and die.

Biological

Birds such as bluejays, sparrows, blackbirds and wrens feed on cutworms. By attracting these winged friends, natural control of the pest is possible. Place bird feeders close to infested areas. Skunks also dig and feed on cutworms. Beneficial nematodes also eat cutworms and other insects which are found in soil. Products containing these nematodes can be purchased at garden centers. Some parasitic wasps deposit eggs in the body of the cutworm which pupate on its back, killing the cutworm.

Chemical

If physical and biological control measures are not effective, use a pesticide which will have a minimal impact on both you and the environment. Diatomaceous earth is an insecticidal dust which acts as an abrasive. It cuts the outer layer of the cutworm's body causing it to dehydrate and then die. The dust should be sprinkled around the base of the plant so that the cutworm must cross it to access the plant.

If the above measures are not effective, consult with an expert at a garden center for additional pesticides available. Before using pesticides, consult the Backyard Bug Brigade Brochure which contains information on safe pest control.

Always use a registered domestic class pest control product labelled for cutworm control and carefully follow the label directions.