Most prominent in Colorado. Grass becomes sparse and dies out in large patches. Two generations each season. Dingy or gray worms with dark spots on backs. During the day they are on the surface in web tunnels and at night they emerge to cut off grass blades.
Occasional infestations, white grubs are the grubs of May and June beetles. They are white or gray with 3 pairs of legs. Adult beetles feed on trees and shrubs and cut off the roots of grass causing browning and death.
Eggs are laid on grass stems and they create small dead patches. You know bugs are present when grass is lifted and there is sawdust-like material at the broken ends.
Millermoth grubs, feed at night, hide under debris in daytime, eat leaves and crowns of grass.
Usually cause little damage, clean-up is more for aesthetic purposes.
Mites, cinch bug, slugs.