The larvae stage of billbugs do the most damage to turf, they attack the root structure & stem of the grass. The damage tends to happen during periods of drought and may be misdiagnosed as such.
Adult size: about 3/8th inch
Damaging Stages: Larvae
Signs of Damage: Hollowed out blades of grass that break easily at the base or crown when pulled on. The damaged turf will start as patches of yellow or dead grass that may spread. Damage Usually Occurs: June - August
Damage usually occurs during times of summer drought and can often be mistaken that or other culprits. Damage ranges from small, circular patches of straw-colored turf die back to complete destruction by August. The lawn will first yellow and then turn straw colored; when pulled, it will break at the crown of the plant. Stems of the turf will also be hollowed due to the larvae burrowing.