Sphenophorus species The larvae of this pest damage lawns by hollowing out the grass stems and chewing off the roots. They can destroy an entire lawn. In May, the adults lay eggs in holes they chew in grass stems. The newly hatched larvae feed inside the stems, hollowing out the stem and crown and leaving fine sandlike excrement. Large larvae feed on roots.
Small damaged areas usually recover if the billbug larvae are killed. Water and fertilize the lawn to stimulate new growth. Reseed or resod large areas. Maintain proper soil moisture and lawn fertilization.