Invasion of Sod Webworms by Ashley Grubb

Last night while letting my dog use the bathroom in my backyard, I momentarily felt like I was in some strange indie rock, bug-related music video. The sun was setting, and each step I took released a cloud of little white moths out of the grass to flutter all around me. The novelty of the situation wore off pretty quickly once it hit me that they were the by-product of sod webworms…. Are you kidding me nature?!?!?! In the time frame of about a month and a half, I’ve had to battle fire ants, chinch bugs, and now, sod webworms. Is there some kind of badge or bragging rights I get for this? Like when you catch a redfish, trout, and flounder all in one fishing trip to the coast? Should I post a selfie with my grass on Facebook?
All kidding aside- I’m guessing that if I get to enjoy all these wonderful insects, you probably do too. Here’s the scoop on what to do if you are walking through moth-filled grass as well.

Sod webworms begin their lives over-wintering in your lawn in little tunnels. Once temperatures start to warm up in the spring, they end their hibernation and begin feeding on turf grass as they grow and mature. Once they’re full grown, the worms pupate in little cocoons and emerge 1 to 2 weeks later as moths in the summer. Once they have found a mate, females fly low over the lawn scattering eggs. Here’s the bad news…each female can lay several hundred eggs. Within a week, all of these eggs will hatch and worms will resume feeding on your lawn. They can have up to 3 generations a year in our area.
If you are just seeing browning in your lawn and trying to determine the cause of the damage, try looking down in the grass and see if you see any little worms feeding on the blades of grass. Another good indicator is if you are seeing little piles of green wet-looking balls stuck to the grass blades or down in the grass. That would be webworm poop. Gross! Don’t touch it! You can also spray a suspicious looking patch of damaged grass with insecticidal soap. The soap will irritate the webworms and cause them to come up to the surface level of the grass where they can be spotted and annihilated.
Now for the good news- they sod webworms be controlled and killed relatively easily and organically. Once you have moths, they won’t be feeding on your lawn- you don’t necessarily have to worry about trying to kill them. What you want to plan for is the generation of web worms that will hatch about a week after you see the moths. These are the guys that are going to cause the damage and are also the easiest part of the webworm life cycle to kill.
I would recommend using a product containing Bt (Bacillus thuringiensis), spinosad, insecticidal soap, or in severe cases pyrethrin or bifenthrin. The easiest way to apply these products is to spray in liquid form on your lawn. Be sure to spray in the late afternoon or evening, as webworms generally do most of their feeding at night and you want to make sure they ingest the poison. Should you decide to use a granular application, be sure to water in the granules immediately after spreading? I would make my first application one week to 10 days after seeing lots of moths. Just for extra insurance, I’d make a second application at the 2 week mark, and then also at any time during the season if I notice that more webworms have appeared.
Enchanted is stocked with lots of webworm killing options and ready to help you with all of your lawn care needs. Come see us!