Sod Web Worm

Order / Family: Lepidoptera / Pyralidae

Visual signs of damage

Signs of damage will appear as thinning yellow areas, sometimes starting as small palm sized spots that will grow together although sometimes may begin by covering a larger area. It would be noticed as stunted growth, turning to the appearance of brown, drought stressed turf and then it will die off. Sometimes the pest can be visible if you lift up the damaged turf exposing the soil underneath.

Damage occurs as the larvae of the sod web worm feeds on the outside of the grass blade at the base. This causes and interruption in the ability for the plant to take up water and nutrients therefore causing drought conditions for the turf even though there may be plenty of moisture in the soil. Overwatering will not cure this problem.

Pest Description

The adult sod web worm is a small moth about ¾-1 inch long. It can be gray, white or tan in appearance and it folds its wings back on its own body appearing long and narrow. You may notice them flying around erratically as you mow or walk around on the lawn. Their lifespan is anywhere from six to eight weeks from egg to adult, creating up to 3 generations per year. They are active more at night fluttering around the lawn dropping on average 60 eggs per night. The eggs are dropped at random all through the turf area falling down into the thatch where they hatch and then begin tunneling and feeding.

The larvae of the sod web worm color will vary depending on the species. They may be green, brown, gray, light tan with spots and possibly hair. The larvae are roughly ¾ of an inch in length.


I’d like to tell you that a healthy turf will keep these pests out of your yard but unfortunately they do not discriminate between healthy and unhealthy lawns. A healthy lawn will definitely be able to sustain a larger amount of sod web worms as opposed to a lawn that is currently stressed and unhealthy. Keeping your lawn well watered and providing a stable and balanced nutrition plan will help combat the problem before it starts. Pest control in Salt Lake City Utah can be tricky. Prevention is a much better approach than curative.

If the infestation reaches a point where it overwhelms the turf and signs of damage begin to show then a curative treatment may be necessary. There are products available through hardware stores, and nurseries that may help. Your local lawn care professional can also help with proper diagnosis and provide treatment options that will ease your mind and restore your lawn to its proper form.

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