toggle menu

Cutworm Sod Webworm

Cutworms can devastate your lawn.

Cutworms are large, plump, dull colored grayish, green and brown larvae, that viciously chew on grass plants. They live on the soil surface or in the thatch layer. During the day they burrow into vertical holes to hide. When nightfall arrives they emerge from their burrowed hole and feed at the rim of the hole. Stems, leaves and roots of grass plants may be injured leaving yellowish/ brown dead patches with a hollow hole in the middle of the circle. Weed Man clients beware! The damage looks quite similar to symptoms of dryness and many homeowners mistakenly assume that the lawn requires only water to restore the lush green appearance.

Cutworms are

Other symptoms to watch for include birds - starlings have a keen ability to locate cutworm larvae. When these birds return frequently to an area cutworm larva may be present.

Life Cycle

To control an insect population we must understand its habits and life cycle. The adult cutworm appears in the spring as a grayish/brown moth with a 1 – 1 ½ ” (2 ½ cm – 4 cm) wing span. Adult cutworms do not damage lawns. They lay their eggs in the spring during the night leaving them on grass blades. Larvae emerge and begin feeding as early as June with damage appearing in June/July. Cutworms actually feed at night on grass blades that they chew off close to the base of the plant. Dead patches of grass begin to appear and may be pulled away easily by hand.

Sod Webworm (Parapediasia)
Sod Webworm can injure your lawn severely.The immature larvae stage of the Sod Webworm is as long as 3/4 of an inch and are dirty white or tan colored and frequently have rows of dark spots along their back. Pictured below the larvae is the adult moth that does not harm the lawn.

The immature larvae stage of the Sod Webworm is as long as ½" and are dirty white or tan colored and frequently have rows of dark spots along their back. Pictured below the larvae is the adult moth that does not harm the lawn. Sod Webworm adults are small tan moths, ¼ - ¾" (½ - 2 cm) long. The adults are frequently seen darting across the lawn, especially when disturbed. The adult moths do not harm the lawn. The immature or larvae stage of the Sod Webworm are as long as ¼ “ (2 cm) and are dirty white or tan colored and frequently have rows of dark spots along their back. As with cutworm damage, the symptoms of damage appear similar to that of dryness. As larvae, they construct tunnels or burrows through the thatch layer, sometimes extending into the soil. The name Webworm is derived from the insect's habit of lining its tunnel with silk-like material that they produce.

Life Cycle

The adults emerge from the lawn in May or June flying mainly during the evening hours laying eggs randomly throughout the lawn. The larvae emerge from the egg and begin feeding immediately. Damage is caused by larvae chewing off grass stems and leaves while feeding during the summer and into early fall. The dead patches of grass pull away easily in clumps revealing masses of silk with the green excrement pellets left by larvae. Severe damage may result in September if the population throughout the summer builds up.

Control for Cutworm and Sod Webworm
Your Weed Man is a trained specialist and is capable of identifying the damaging insect. He can recognize the difference between a simple drought problem and a serious insect infestation. Your Weed Man uses materials that are applied carefully and precisely at the correct times to be most effective in controlling these serious lawn pests. Your Weed Man needs YOUR HELP. Call and he will inspect your property FREE OF CHARGE! If you do have these insects, he can protect your investment in your property by promptly treating the problem. If your brown patches are due to lack of water, he can advise you on correct watering procedures.