Damage from Billbugs and Crane Fly eating the roots of your lawn can be unsightly. The best way to defend against this damage is prevention. We recommend three treatments each season with a quality insecticide. Be sure to read the label and follow the application rates recommended. Under-applying can result in low or no control. Over-applying can lead to the insect building resistance to the insecticide. It is also recommended that you change the insecticide (active ingredient) you use for each treatment to prevent resistance to any one product. The best time to apply treatment is May through August approximately four to five weeks apart. Lawns with past insect damage tend to need treatment each year.