Sod Webworm Damage

Lawn damaging caterpillars have already been spotted this year in large numbers.  We have received many more calls about Sod Webworm Damage this year than in seasons past. You may notice small moths, which are uncontrollable, flying in your lawn. These Migratory Moths randomly lay eggs, producing caterpillars. The sod webworm damage from these caterpillars make the lawn appear like it was mowed too short. It is important to note that damage from these insects will generally recover within 2 -3 weeks during the growing season. Also, please understand the adult moths itself does not eat the grass, and when in numbers are just a simple nuisance.

Sod webworm larvae or caterpillars are grayish tan with brown heads. They have tiny dark spots on their body. They reach 3/4 to 1 inch when fully grown. Sod webworms hibernate in the thatch and soil as partially developed larvae.  According to The University of Florida IFAS/Extension, these worms reside in silk lined tunnels in the thatch and soil.  Larval activity usually resumes in April or early May.

Tropical sod webworm larvae are destructive pests of warm season turfgrasses in our area.  The first sign of sod webworm damage is often caused by differences in grass height in areas where larvae are feeding.

The sod webworm damage usually occurs at night when the worms feed, their counterpart, the army worm feeds during the day and are a little larger than the sod webworm.

You can find sod webworms by parting the grass and looking for a small C-shaped worm curled up in a green pile of their excrement at the thatch level.  What you will have found is the larval stage of the sod webworm moth.  It’s the larval stage that will crawl through the grass and chew the blades down to the root zone.

Treatment requires two treatments in order to break the life cycle of the insect.  As the eggs hatch out, that next cycle of worms will need to be treated.  The reason it’s best to call a professional exterminator is due to the volume of material that is needed to control the sod webworms.

The Peninsular technician will inspect the lawn to determine where the sod webworm has started to eat the lawn.  This is usually a brown color that is shorter than the rest of the lawn, almost as if a weed eater has attacked that area of the lawn.

During the application we start at the far corner of the lawn and treat in a back and forth pattern almost as if we are mowing. This will thoroughly treat the entire lawn with insecticide.