Tropical Sod Webworm
Caterpillars that chew St. Augustine grass blades to the ground overnight.
In Florida, Tropical Sod Webworm (Herpetogramma phaeopteralis) rates as a high concern. Rhino Pest Management is a licensed (#JB242881) and insured lawn & ornamental service company serving Florida's Treasure & Space Coast, rated 5.0★ by 16 Google reviewers. The estimate is always free — (772) 589-6842.
Photo: Pranav Chandra Bose (CC0) · Wikimedia Commons
The larvae (caterpillars) are 15–20 mm, green to brown with a row of dark spots along the sides. Adults are small (about 12 mm), buff-colored moths that zigzag low over the lawn at dusk. Damage appears as if the turf was scalped.
The thatch layer of St. Augustine and Bermuda grass lawns. Tropical sod webworm has multiple generations per year in Florida and is active spring through fall.
- Grass blades chewed or clipped at the base — damage looks like scalping
- Tan moths flying in a zigzag pattern inches above the lawn at dusk
- Green caterpillars found in the thatch when grass is pulled apart
- Rapid damage expansion overnight in summer and fall
Sod webworm can destroy large sections of lawn in days during warm weather. St. Augustine grass is the primary target in Florida, and repeated infestations can kill turf permanently.
Should I call today?
Yes, get it looked at promptly. Tropical Sod Webworm causes damage or health problems that compound while you wait, and the cost of that damage is the part that actually gets expensive — not the treatment. An inspection is free, so there's no reason to guess.
Rhino's lawn program treats webworms at the first sign of damage, timed to larvae feeding in the thatch — not the adult moths — for the fastest turf recovery.
Our Lawn & Ornamental Service serviceMore lawn, tree & shrub pests
Scientific source
For the biology behind this page, the University of Florida's IFAS Extension publishes a detailed Featured Creatures profile of this species — free to read, and written by entomologists in this state:
Tropical Sod Webworm Herpetogramma phaeopteralis Guenée — UF/IFAS Extension