In mid-spring to late summer, pale areas appear on the lawn, usually under trees. Damaged areas are first light yellow, then die and turn brown, surrounded by an orange to tan border. Clusters of tiny green insects may be seen on the upper surface of the grass blades at the edge of the damaged area. Greenbugs are about 1/16 inch long and pale yellow to green with black eyes. Like other aphids, greenbugs feed by sucking sap from grass blades. They inflict additional damage by injecting a toxin as they feed.
Greenbugs are not difficult to control, but can do a great deal of damage if left uncontrolled.