Billbug damage usually appears in late-June through August.  Light infestations in lawns often produce small dead spots that look like the turf disease, dollar spot. Sometimes the damage looks like irregular mottling or browning in the turf. Heavy infestations can result in complete destruction of the turf.  Damaged turf turns a whitish-straw color. Soil under damaged turf is solid, not spongy as in white grub attacks. To confirm billbug attacks, grasp the affected turf and pull upward. If the stalks break easily at ground level and the stems are hollowed out or are full of packed sawdust-like material, billbugs are the culprit.