Several species of caterpillars are called sod webworms and in the larval stage they can be highly destructive pests of lawns. The caterpillars live in silk-lined tunnels constructed in the thatch near the soil surface. They chew grass blades off just above the thatch line, and are mainly active at night. The adults of sod webworms are often called lawn moths because they fly in a jerky zigzag pattern a few feet above the lawn.
Click on images to view full-size
Identification and Control Information
- Turfgrass Science: Sod Webworm (PDF)—Michigan State University
- Entomological Notes: Sod Webworms in Home Lawns (PDF)—Penn State Cooperative Extension
- Utah Pests Fact Sheet: Sod Webworms (PDF)—Utah State University Extension
[Photos, left to right: University of California IPM Program; Ontario Ministry of Agriculture, Food and Rural Affairs; unknown]