Sod Webworm Control: How to Identify, Prevent, and Get Rid of Sod Webworms

Also known as lawn moths, sod webworms are some of the most common problems in many homes. Through larval feeding, they make the lawn unattractive and causes damages to other plants as well. To prevent the devastating effects of their presence, it is necessary to learn about how to get rid of sod webworms.

The sod webworms are at their most destructive in their larval stage. At this point, they have an average length of one inch and the color will vary depending on their species. The most common colors are brown, gray, and green. They also have dark spots on their body. Once they transform in an adult, on the other hand, their length is about ¾ inch on average. When they are resting, they fold their wings to cover their body. They also have two extended points on their head that look like a snout. Adult sod webworms are not a problem since they do not cause damages to the lawn.

Sob Webworm

A Sob Webworm is Eating the Grass

Sod Webworm’s Habitat

They prefer places where it is hot and sunny, but with little shade. When they are adults, they rest on the surface of the turf during the day and in the afternoon, they scatter their eggs while flying in a zigzag motion. After laying eggs, they will hatch within one week. The larvae will cost the most damage and they usually appear from April to May. Also, the larvae of sod webworms will do most of the infestation at night. They wreak havoc not only in garden lawns, but also in golf courses and sports fields.

Identifying Sod Webworm’s Damage

Plants Affected

Sod webworms affect different species of turfgrass, specifically those that survive in the warm season. Some of the most common hosts include centipede grass, Bermuda grass, St. Augustine grass, Bahia grass, and Zoysia grass, among others.


Below are some of the most common tell-tale signs that sod webworms are present and causing an infestation, and hence, requiring immediate action:

  • The appearance of brown spots on the turf is one of the first indicators of the presence of sod webworms. Aside from the color, after close inspection, you will notice that it is turning bald. They will look dry and unattractive.
  • Having grass that is shorter than the usual is also a common symptom. This usually happens in the spring. The larva will feed on the top of the grass, which will make it thinner.
  • The appearance of frass is also something that you should watch out for. This green fecal matter is excreted by the sod webworm.

Results of Infestation

The infestation of sod webworms happens the most when they are in their larval stage. During the first four instars or stages of the larvae, they feed only on the surface of the grass. They chew all the way to the blades in the later stages. With this, aside from the appearance of the symptoms noted above, they make the patches of turf go bald. It first dries out, and eventually, the grass disappears on the surface. This is a big problem in sports fields and golf courses, especially if the infestation is severe. The damages may be hard to notice during drought because some people might assume that the cause of the problem is the hot weather and not the sod webworms.

Damaged Grass

Damaged Grass by Sob Webworms

How to Get Rid of Sod Webworms

Natural and Organic Solutions

The elimination of webworms does not need to be toxic. Here are some of the natural methods that can deliver promising benefits:

  • One of the best things that you can do is to use endophyte enhancer, which is a part of most integrated pest management programs. Endophytes are beneficial fungi that will provide a protective barrier in the turfgrass. This makes them more resistant not only to sod webworms, but also other pests and diseases.
  • A mixture of soap and water will also do the trick, although it is more of a monitoring procedure than an elimination process. Pour the mixture of mild dish soap and water in the lawn. If you see more than 15 sod webworms, this is an indication that you should consider more powerful alternatives.
  • Encouraging parasites is also a good solution. This will work best at home, such as in driveways or in the garden. Among others, some of the most effective are beneficial nematodes. They will suppress the larvae before they can damage your turf. Within just 48 hours after its application, parasitic nematodes will kill sod webworms.
  • The use of products that contain Bacillus thuringiensis is also effective. Unlike conventional sprays, it is a biological pesticide. This means that it will kill only the pest and not the other insects in the garden. It is safe for pets and the environment, even for humans.
  • Another biological pesticide that will deliver impressive results is It is also made from a soil bacterium that will cause toxicity amongst insects. It attacks the nervous system of the pest once it gets in contact with the pesticide. This results in paralysis, and within one to two days, they will die.

Chemical Solutions

In severe cases of damage, many resort to the use of chemical solutions to deter further infestation, such as in golf courses and other areas wherein having green and healthy lawn is a must. In using chemical control, however, caution is necessary because of its toxic ingredients, which can harm both humans and the environment, not just the target pest. It is also best to spray insecticide in the late afternoon. This is the time wherein the larvae are most active.

How to Prevent Sod Webworms

Among others, proper maintenance of the lawn is perhaps the best thing you can do to prevent the infestation of sod webworms. The healthier the grass is, the more resistant it will be towards damages. It will survive minor damages. However, make sure to avoid overfertilizing and overwatering. If the soil is moist, it becomes a more attractive place for adult sod webworms to lay their eggs. The reduction of excess thatch also aids in the prevention of the presence of these pests. This means that they won’t find a place that will act as their shelter.

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