Adult billbugs are about 1/2 inch long weevils. They damage lawns in midsummer when the grass is under stress from heat and drought. The damage often is not apparent until later, when the unaffected grass begins to recover from the heat stress. By the time damage is discovered, it is usually too late to treat.
Damage usually first appears as yellow spots only a few inches in diameter, but these spots gradually become larger as feeding continues. Heavy infestations completely destroy the roots, and the grass can be rolled back like a carpet. Moles, skunks, and armadillos feed on the grubs and may damage the lawn searching for them.