Sod Webworms

Sod webworms are the larval, or caterpillar, stage of a small night-flying moth. The moth is about 3/4 inch long, cigar- shaped, and gray. It has two noticeable finger-like projections on the front of the head. You may see it during the day while mowing or walking across the lawn. The moth flies short distances in a zig-zag pattern before settling quickly back into the grass.

The webworm larvae generally feed at night and prefer areas that receive plenty of direct sunlight during the day. Problems seldom develop in shaded areas. During the day the larvae may be found in small silken tunnels in grass thatch. They feed on grass blades next to these tunnels by clipping them off at the thatch line. Injury appears as small hand-sized brown patches. This insect attacks bermudagrass and zoysiagrass.