The most important means of limiting grub injury is to grow a vigorous lawn. Healthy, well-watered lawns can tolerate grub feeding more easily than weakly growing lawns. White grubs, however, are among the most difficult soil insect pests to control.
Large grubs are highly resistant to insecticides.
More importantly, since grubs feed in the soil, it is very difficult to get adequate amounts of insecticide into the root zone to contact the white grubs. Under typical conditions, control of white grubs often fails to exceed 75 percent. Even this amount of control requires a couple of weeks to become evident. Thatch depth is important to insecticide performance for white grub control. Treatments made in conjunction with soil aeration should increase the effectiveness.