Sod Webworm

Sod webworm larvae feed on grass, creating small brown patches in lawns throughout Western Washington during summer months. The tan to brown caterpillars with darker heads hide in silk-lined burrows in the soil and grass thatch during the day, emerging at dusk to feed on grass blades. Adult moths are tan or gray and often seen fluttering.

Monitor lawns in June for brown patches and webbing in thatch. Scout by flushing larvae with soapy water to determine if treatment is needed. Maintain healthy turf through proper watering and avoid excess nitrogen. Beneficial organisms naturally suppress populations.