Sod webworms

Eastern Grass-veener (Crambus laqueatellus)
Sod Webworm - Pediasia trisecta

Sod webworms comprise several different species of lawn-damaging caterpillars. These caterpillars are the immature larvae stage of various moths known collectively as "snout moths" and "lawn moths." The moths have distinctive, snoutlike projections on their heads, and they're often found clinging to grass blades, heads pointing down, with their wings rolled tight. Lawn moths don't damage grasses, but their hungry larvae do. Sunny locations are hardest hit.

Identification: Sod webworm moths are dingy white, gray or tan with snoutlike projections and wingspans up to 1 inch. They fly in short, zig-zagging spurts. Sod webworm larvae grow to 3/4 to 1 inch long and vary in color, depending on the species. They have dark heads and small dark spots along bodies that range from gray or pinkish brown to green.

Signs/Damage: These leaf-chewing pests shear grass off at the thatch line, eating entire stems or dragging them into webbed, silk-lined thatch tunnels for later meals. Damage typically starts as irregular spots marked by very short grass, which goes from green to brown without yellowing. The spots enlarge quickly and grass dies.

Control: Sod webworms are night feeders. Maximize your impact by treating during late afternoon or early evening, right before these pests come out to feed. GardenTech® brand offers several highly effective products to kill sod webworms by contact and keep protecting for up to three months:

  • Sevin® Insect Killer Granules treat sod webworms above and below the soil line. Apply the ready-to-use granules with a regular lawn spreader and water immediately, according to product label directions for sod webworms. This releases the active ingredient to reach the pests in thatch and as they feed.
  • Sevin® Insect Killer Ready to Spray attaches to a common garden hose to simplify treating larger lawn areas. The product measures and mixes automatically as you spray, providing thorough, uniform lawn coverage. For best results, mow your lawn at 3 inches or less before spraying.
  • Sevin® Insect Killer Concentrate, used with a pump-style sprayer, is ideal for treating lawns and surrounding shrubbery, where moths may hide, and spot treating areas with sod webworm activity. Give special attention to exposed thatch and grass surrounding suspected damage.

Tip: Watch for bird activity in affected lawn areas. Starlings and other birds feed on sod webworms and similar turf-damaging insects, leaving probing holes in damaged turf.

Always read product labels and follow the instructions carefully.

GardenTech is a registered trademark of Gulfstream Home and Garden, Inc.

Sevin is a registered trademark of Tessenderlo Kerley, Inc.

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