Lawn Insects – Bluegrass Sod Webworm

(Parapediasia teterrella)

The Bluegrass Sod Webworm, also known as Parapediasia teterrella, is lawn insect that can be found in both a caterpillar- and moth-like form affecting Kentucky bluegrass, perennial ryegrass, fine fescue, and creeping bentgrass. In the U.S., the Bluegrass Sod Webworm can be found throughout much of the Northeast and Midwest.       

Identifying Bluegrass Sod Webworm -

In adult form, Bluegrass Sod Webworm has a white head and snout that are gray to light brown on the undersides. The forewings have seven spots along the wing tip and a curved, brownish-orange line runs across the wing, just inside the tip. The veins are usually distinctly lighter in color. Larvae have blackish-brown head capsules and a translucent, yellowish body. The body will appear green after feeding. Adults may be seen flying out of the turf when disturbed.

Turf damage caused by the Bluegrass Sod Webworm starts off as thinning of the turf, followed by small brown patches appearing in the lawn. As the larvae develop, these spots may become several inches in diameter. A close examination of the turf will reveal short green stubs of turf left by the grazing larvae. Silk-lined tunnels in the thatch or upper soil may also be found.

Severe infestations may result in large, irregular patterns of sparse turf. The overall damage is sometimes considered to be a form of “scalping,” similar to the consequences of mowing a lawn too low. Well maintained turf will often tolerate this, but stressed turf may die as the crowns are exposed to sunlight. Damage is often found on south-facing slopes.

Bluegrass Sod Webworm Life Cycle -

Two generations of Bluegrass Sod Webwormper year is normal in cool-season and transition zone states. The second generation larvae overwinter in silk-lined chambers in the soil. Some sod webworm species have only one generation per year, but these also overwinter as larvae. 

Bluegrass Sod Webworm

Bluegrass Sod Webworm Control -

It's best to kill insects, grubs and other pests before they have a chance to cause damage to your lawn. Scotts LawnService recommends our exclusive Scotts® GrubEx® and Ortho® Max™ Pro insect control products, which will kill a wide variety of lawn damaging pests. Ortho® Max™ Pro eliminates destructive, bothersome insects including the Sod Webworm, without disturbing the earthworms that are beneficial to your lawn's health.

Scotts LawnService is the trusted industry leader for professional quality lawn care. Our exclusive lawn care products include premium grass seeds and professional-grade fertilizers; our lawn service teams are comprised of highly trained, industry-certified professionals. Contact a representative today for Bluegrass Sod Webworm control options available in your area and to learn how you can enjoy a lush, thicker lawn that only Scotts LawnService can deliver.