All grasses
Larvae (of Adult May or June beetles), are white, C-shaped grubs with distinct, brown heads and three pairs of legs near the front end. Larvae or grubs about 1 to 1.5 inches long when fully grown, C-shaped when at rest with many folds or wrinkles in front half of body. Read end of body often slightly larger in diameter than rest and may be bluish or blackish in color. (Grubs of the pillbug or weevils are legless.)
Larvae feed on dead organic matter and on the roots of most grasses, causing browning and dying of the grass in localized spots or in large irregular-shaped arreas. Where infestations are heavy, the grass roots may be entirely eaten away and the turf may be rolled back like a carpet. Damage may be severe in September and October when the grubs are reaching maturity, and the growth of bermuda grass is slowing down.
Chemical controls for all common root-feeding species of grubs should be applied in late summer or early fall (mid-August through September) in Oklahoma.