How to get rid of sod webworms?

Managing Sod Webworm Infestations in Charlotte Lawns

Sod webworms are lawn moth caterpillars that tunnel through thatch and feed on grass blades during summer months. In the Charlotte Piedmont region, these pests are particularly problematic in late July through August when heat stress weakens turf defenses. Damaged areas appear as irregular brown patches with visible webbing and silk tunnels. Early intervention prevents widespread turf loss and maintains lawn density through fall.

Identification and Detection

Look for small brown caterpillars (⅛-½ inch) moving through thatch or webbed tunnels near soil surface. Gently part grass and inspect the thatch layer for silk webbing and fecal pellets. Adult moths are small, tan or brown, and attract to lights at dusk. When infestations reach 10+ webworms per square foot, chemical treatment becomes necessary. Scout lawns in late June for early populations before damage spreads.

Treatment Strategies

1. Preventive applications: Apply pyrethroid insecticides in late June before peak larval activity
2. Curative treatments: Use carbaryl or spinosad when active webworms are observed feeding
3. Organic option: Bacillus thuringiensis (Bt) products target young larvae effectively
4. Cultural control: Maintain proper mowing height to expose webworm tunnels
5. Thatch management: De-thatch in early spring to reduce webworm habitat

In Charlotte's warm climate, multiple generations of webworms may occur annually. Monitor lawns throughout summer and apply follow-up treatments if damage continues. Healthy, vigorous lawns recover from minor webworm damage within weeks.