Most moths like Miller moths, for example, are not any cause for alarm. Crambus moths, however, are the adults of sod webworms and where there are adult moths there are sod webworms feeding on leaves and stems in turf grass. These moths are pretty easy to identify because of their long “snout” and angular body shape. Their coloring can vary greatly from white to having a pattern on their wings and size from about a half inch to over an inch long.
Every lawn has a few sod webworm adult moths which is normal and not cause for concern. A 2000 square foot lawn has 2-3 for example. Walking through grass, these moths should not be flying up all over in lawns which indicates an infestation level. I was at a park, with our dog, walking in the grassy areas, and I observed dead patches of turf and Crambus moths flying up every 2-3 feet in an entire section of the park. This is infestation level and needs addressing before further damage is done. The sod webworms live in the thatch layer and eat on the underside of leaves and stems and start with small patches and can kill off larger sections if left untreated. Please remember a few moths are common and do not need any type of treatment.