The reason why we felt we needed to write a blog post about “The Truth About Sod Webworms” is because of some misleading advertisments from local garden centers encouraging customers to buy insectides to combat sod webworms based on inaccurate information.
Seeing pale brown moths flying out of your grass is not a tell tale sign of sod webworms. In fact, these sob webworm moths do not cause damage to turf at all. A second inaccuracy is that “spider webs” in your lawn are a tell tale sign of sod webworms. Sod webworms don’t weave webs. Having moths and/or spiderwebs in your lawn does not mean you have sod webworms that will destroy your lawn. Save your money. If damage does occur, consult with a lawn care professional to correctly identify the reason.
Sod webworms are a common surface feeding insect that can damage lawns in Michigan. They live in virtually everyone’s lawn, but most of the time we never notice damage because there aren’t enough webworm larvae or the lawn is healthy and strong enough to repair itself. No harm, no foul. However, there are times when sod webworms become a problem and damage turf. Damage usually manifests itself as irregular dead patches that spread over time. The grass blades seem to cut off at the crown and sometime you can see little balls of worm dropping or frass. They particularly like Kentucky Bluegrass. The best way to treat sod webworms is to treat maintain a healthy lawn and only use turf insecticides if damage begins to occur.