Lawn Moths, Sod Webworms, and How to Control or Eliminate Them

Larry from Lansing, Michigan asks: “What are the white moths that fly up when I walk through my grass and how can I get rid of them?”

lawn moth, adult sod webwormMoths in the Lawn and What to do About Them

More than likely, the moths are the adult stage of sod webworms that are common in Midwest lawns. While the worms themselves can be mildly destructive to your lawn, it’s the adults that are just plain annoying as they stir up and fly close to the ground every time you walk around.  If you’re enjoying a game of bean bags (corn-hole) or lawn darts, you don’t want them zipping around your Corona now do you?

Most folks don’t care about the mild lawn damage, just the annoying moths, but…

…Damage caused by sod webworms may first appear in early spring as small dead patches of grass among healthy turf areas. As summer progresses, webworm infestation may cause general turf thinning or irregular dead patches in late June into early August. Sod webworms prefer sunny areas and the larvae are often found on south facing hills, where it is warm, sunny and dry. Heavily shaded turf is not often attacked by the larvae.

The most severe damage usually shows up in July and August when the temperature is hot and the grass is not growing vigorously. If you keep your lawn well-irrigated and fertilized, however, you probably will not sustain much damage, even with a heavy infestation. In lawns that are not well-cared for, sod webworm damage is often mistaken for heat and drought stress.

If you are reading this and you ALREADY HAVE DAMAGE from sod webworms, you should treat the lawn immediately with the insecticide I recommend below. You should also get on my lawn fertilization schedule to bring back the health of the turf.

How to Kill Sod Webworms and White Moths in the Lawn

In my lawn, I wipe out the worms that are feeding on the turf, AND I kill the moths that annoy my family when we are enjoying our lawn. (we play a lot of bean bags at our crib!) Many times the moths come from my neighbor, Eric’s lawn, and I am a nice guy and help him out too.

I use a product from Ortho called MAX. It kills a broad range of lawn insects including sod webworm. I usually put down the concentrated liquid mixed in a pump sprayer in Spring, and followup with their granular product in July. This pretty much wipes out the moths and every other annoying bug in my lawn. (but not grubs)

Another super effective product with very low odor is Talstar. The great thing about Talstar is you can also use it on your trees and shrubs to kill Japanese Beetles and Bag Worms. It is a very versatile product that will kill any insect in your lawn and trees and shrubs including ants, fleas, spiders, ticks, and spider mites.

There are also organic controls available for sod webworm, but they are not very effective and twice as expensive. I am a big proponent of organic and environmentally friendly pest control, but they have to work for me to use them, and in this case, they don’t. If you are not annoyed by the moths, then simply keeping your lawn thick and healthy will save it from damage from sod webworms, and that’s very nature-friendly.

This free lawn tip brought to you by Life and Lawns, lawn and turf advice to DIYers from a green industry professional.

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