Sod Webworms: The Real Culprit Behind Dead Patches and White Moths

Identification

2 dozen dead patches spreading 2–3 years. GrubEx applied (ineffective). Little white moths fly when mowing. = Sod webworms (caterpillars of those moths).

Damage Pattern

• Early spring: small dead patches.
• Summer: thinning, irregular dead patches (late June–August).
• Prefers sunny, hot, dry slopes. Shade rarely attacked.
• Mistaken for drought stress.
• Recovers with irrigation + light organic fertilizer.

Control

• GrubEx doesn't work on webworms.
• Check local garden center for specific webworm insecticide (e.g., spinosad, Bacillus thuringiensis).
• Best: natural predators. Avoid broad-spectrum pesticides—kill beneficials (big-eyed bugs, earwigs, rove beetles).

Renovation

Scratch and seed NOW. Fall is perfect. GrubEx residue won't harm new seed. Establish thick turf to resist future infestations.