Sod Webworms Jacksonville FL: Identification & Treatment
Quick answer: Sod webworms show up as ragged, notched grass blades and scalped-looking patches that appear almost overnight, often mistaken for drought stress or mowing damage. The giveaway is small tan moths flushing up in short bursts when you walk the lawn at dusk — unlike chinch bugs, which cause more uniform yellowing that spreads gradually from a central point.
Sod webworms Jacksonville lawns deal with are one of the most misdiagnosed lawn pests in the area — the damage is often mistaken for drought stress or mowing scalp until it’s already spread across a large section of turf.
How to Identify Sod Webworm Damage
- Ragged, notched grass blades that look chewed rather than cleanly cut
- Scalped-looking patches that appear suddenly, often overnight
- Small tan or brown moths flying up in short, erratic bursts when you walk across the lawn at dusk
- Green fecal pellets visible in the thatch layer near damaged areas
When Sod Webworms Are Active in Jacksonville
Sod webworm moths are most active at dusk and through the night during the warm months, typically from late spring through early fall. Because the larvae feed at night and hide in thatch during the day, damage is often noticed before the pest itself is ever seen — by the time patches are visible, the larvae have usually been feeding for one to two weeks.
Sod Webworms vs. Chinch Bugs: Telling Them Apart
Both pests cause brown patches in St. Augustine grass, but the pattern differs. Chinch bug damage spreads gradually outward from a central point and often starts in the hottest, sunniest part of the yard. Sod webworm damage tends to appear more suddenly, with a scalped or notched texture to individual grass blades rather than the uniform yellowing chinch bugs cause. If you’re unsure which one you’re looking at, our full diagnostic guide walks through both side by side.
Treatment & Prevention
Targeted insecticide application timed to when larvae are actively feeding is the most effective treatment. Because sod webworms feed at night, treatment timing matters more here than with some other pests — applying in late afternoon or evening, ahead of active feeding, generally produces better results. Reducing thatch buildup through periodic dethatching also removes some of the habitat sod webworm larvae rely on, making a lawn less attractive to them in the first place.
See our full lawn pest control guide for how sod webworms compare to the other pests we treat most in Jacksonville.
Catching Sod Webworms Before Damage Spreads
The Dusk Moth-Flush Test
Walking across a suspect lawn area at dusk and watching for small tan moths flying up in short bursts is one of the simplest ways to confirm active sod webworm moths are present and laying eggs in that area.
Why Thatch Reduction Helps Prevent Recurrence
Sod webworm larvae shelter in thatch during the day, so lawns with heavier thatch buildup tend to support larger populations. Reducing thatch through periodic dethatching removes some of that shelter and makes the lawn less hospitable long-term.
Treatment Timing for Night-Feeding Pests
Because larvae feed at night, applying treatment in late afternoon or early evening — ahead of active feeding — generally produces better results than a morning application that has more time to break down before pests become active.
Frequently Asked Questions
How fast can sod webworms damage a lawn?
Visible scalped patches can appear within one to two weeks of an active infestation, since larvae feed continuously through the night once established.
Will sod webworm damage grow back on its own?
Once the active infestation is treated, healthy St. Augustine or Zoysia typically fills back in on its own over several weeks, though severely damaged areas may need overseeding or patching.
Are sod webworms and chinch bugs the same thing?
No, they’re different pests with different damage patterns. Chinch bugs cause more uniform yellowing that spreads outward, while sod webworm damage looks more notched and scalped in texture.
Think You Have Sod Webworms?
Send us a photo and we\u2019ll confirm before you spend a dime on treatment.