Sod Webworm

Average size: .66"

The larvae stage of the sod web worm can cause damage to turf throughout the growing season, though most of the damage occurs during the hot dry months of July and August. Visually, the damage appears to have the same symptoms of heat stress or drought stress on the turf. The adult moth stage does not damage grass.

Sod webworm damage will first exhibit areas of turf thinning and turning tan. The sod webworm lives in tunnels in layers of thatch or in the soil near the surface, these tunnels will have a silken webs that holds soil particals and debris together. At night, the sod webworm will emerge to feed on blades of grass near the surface of the soil or thatch line. Most damaged areas will be about a half and inch to three inches of dying turf.

To know if an area in your yard is being attacked by sod web worms, examin the damaged spot and part the grass with your fingers (in the area where damaged turf meets healthy grass). Keep an eye open for small green pellets on the soil surface - these are larvae excrements and indicates that larvae had traveled there. You may also mix one gallon water with 2 tablespoons dish soap and pour it onto the area. This will cause the webworm to come to the surface.