A-Z Index
Statewide
zzusis
WSU Home
WSU Extension
Hortsense
Hortsense Home
|
Hortsense fact sheets
| Lawn and Turf
| Sod webworm
Lawn and Turf
Disease
2,4-D damage
Algae
Anthracnose/Basal crown rot
Brown blight
Brown patch
Curvularia blight (Fading out)
Dog injury
Dollar spot
Fairy ring and mushrooms
Leaf spot
Microdochium patch (Pink snow mold)
Moss
Necrotic ringspot
Powdery mildew
Pythium crown and root rot
Red thread
Rusts
Septoria leaf spot (Tip blight)
Slime molds
Take-all patch
Thatch
Typhula blight (Gray snow mold)
Yellow patch
Insect
Ants
Billbugs
Chinch bugs
Cutworms
European crane fly
Leafhoppers
Moles
Sod webworm
print version
|
pdf version
|
email url
Caption: Sod webworm
Photo by: R.D. Akre
Lawn and Turf : Sod webworm
(revision date: 3/10/2017)
Use Integrated Pest Management (IPM) for successful plant problem management.
Biology
Sod webworms are the larval stage of lawn moths. The adults are slender, grayish-white to tan moths with a wingspan of approximately 1". They typically fly at dusk in erratic patterns over the lawn and are attracted to lights. Mature caterpillars are 3/4"-1" long and grayish or greenish in color with brown spots. They feed at night, hiding during the day in tunnels of grass and debris tied together with webbing. Damage consists of leaf blades chewed off at the base of the plants. Grass shoots may die back, resulting in irregular brown spots in the lawn. Caterpillars and their droppings (frass) are usually present at the base of plants (in the thatch layer) in the damaged areas. Sod webworms are primarily a concern in eastern Washington, although they can be a problem in western Washington in periods of drought. Grasses which produce more thatch are more susceptible to damage.
Management Options
Non-Chemical Management
Natural enemies including birds, ants, spiders, and predacious ground beetles help keep sod webworm populations below damaging levels. When possible, avoid use of broad-spectrum insecticides which kill beneficial insects.
Maintain thatch at proper levels. Thick thatch encourages sod webworms and enhances their damage.
Select non-chemical management options as your first choice!
Chemical Management
IMPORTANT:
Visit Home and Garden Fact Sheets for more information on using pesticides
Insecticides are recommended for reducing the larval stage. They may not reduce the number of moths flying around. Only apply products at the larval stage for reduction in populations. Mow or remove weed flowers before applying.
Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
Bull's-Eye Bioinsecticide
Active ingredient: spinosad (spinosyn A+D) | EPA reg no: 62719-314-56872
ferti-lome Borer, Bagworm, Tent Caterpillar & Leafminer Spray
Active ingredient: spinosad (spinosyn A+D) | EPA reg no: 62719-314-7401
Monterey Garden Insect Spray [Organic]
Active ingredient: spinosad (spinosyn A+D) | EPA reg no: 62719-314-54705
This list may not include all products registered for this use.
Images
+ Show larger images
Caption: Sod webworm
Photo by: R.D. Akre