Two-lined spittlebug

From Wikipedia: Nymphs feed on various grasses (including centipedegrass, bermudagrass and corn) from within foam (consisting of their own spittle) produced from juices of their host plant. Adults feed on the leaves of both native and introduced species of holly, as well as on the leaves of the eastern redbud tree. It is a pest of forage grasses and turf grasses such as those grown for lawns and its consumption of these plants causes economic damage throughout the southeastern United States.