Sod Webworms: Identification and Treatment in Georgia
Sod webworms quietly thin your lawn over weeks while hiding in thatch tunnels. Learn how to detect them and why evening treatment gets the best results.
Pest profile
What Are Sod Webworms?
Sod webworms are caterpillars that chew grass blades at night and hide in silk-lined tunnels in the thatch during the day. They produce multiple generations per year in Middle Georgia’s warm climate, and populations build through the summer. Damage is gradual but persistent — the lawn thins out over weeks rather than collapsing overnight like armyworm damage.
Identification
How to Identify Sod Webworms
Small, slender caterpillars about 3/4 inch long, greenish-tan with dark spots along the body
Hide in silk-lined tunnels in the thatch layer during the day
Adult moths are small, buff-colored, and fly in a low zigzag pattern just above the grass when disturbed
Green frass (excrement pellets) visible in the thatch near feeding sites
Adults fold their wings tight against the body when at rest, giving them a tubular appearance
Damage signs
How Sod Webworms Damage Your Lawn
Damage Signs
Small, irregular brown patches that gradually merge into larger thin areas
Grass blades chewed off unevenly, leaving ragged stubs at varying heights
Damage is more gradual than armyworms — the lawn thins over weeks, not days
Worst in areas with thick thatch, which provides webworm shelter
Detection Methods
The soapy water flush: mix 2 tablespoons of dish soap in a gallon of water and pour over a 4-square-foot area in the evening. Webworms emerge from their silk tunnels.
Watch for small buff-colored moths flying in a zigzag pattern over the lawn at dusk. Heavy moth activity means eggs are being laid.
Part the grass and look for green frass pellets and silk-lined tunnels in the thatch layer.
Check for irregular browning in areas with thick thatch — webworms prefer heavy thatch for shelter.
Treatment
How We Treat Sod Webworms
We apply insecticide in the late afternoon or evening when webworms are actively feeding near the surface. Timing the application to feeding hours dramatically improves results. We also recommend addressing heavy thatch through dethatching or core aeration, which removes the shelter webworms rely on. Multiple generations may require follow-up treatments through the summer.
Urgency level
Emergency or Routine Treatment?
Sod webworm damage is routine, not emergency-level. The lawn thins gradually over weeks, giving you time to catch and treat it. That said, multiple generations per summer means populations compound if left unchecked. Treat when you confirm their presence — don’t wait for major damage.
Affected grasses
Grass Types Vulnerable to Sod Webworms
Why Attaboy
Professional Sod Webworms Treatment from Attaboy
Common questions
Frequently Asked Questions About Sod Webworms
What are the small moths flying over my lawn at dusk?
Those are sod webworm moths laying eggs. The moths themselves don’t damage the lawn — it’s the caterpillar larvae that hatch from the eggs. Heavy moth activity means webworm populations are building.
How are sod webworms different from armyworms?
Sod webworms are smaller, less numerous, and cause gradual damage over weeks. Armyworms are larger, travel in swarms, and can destroy a lawn in 48 hours. The detection method (soapy water flush) works for both.
Does dethatching help prevent sod webworms?
Yes. Webworms build silk-lined tunnels in thick thatch for daytime shelter. Reducing thatch through dethatching or core aeration removes their hiding spots and makes insecticide treatment more effective.
When should I treat for sod webworms?
Treat when you confirm their presence through soapy water flush or see consistent moth activity at dusk. Applications work best in late afternoon or evening when the caterpillars are feeding near the surface.
Take action
Stop Sod Webworms Before the Damage Spreads
Every day you wait is another day pests feed on your lawn. Get professional insect control backed by our free re-treatment guarantee.
