While many other factors can cause similar symptoms, it is relatively easy to determine if grubs are responsible. Examine the soil around the roots for grubs. Insecticidal Control Insecticidal control of white grubs will only be successful if the chemical reaches the area where the grubs are feeding. Surface applications that do not penetrate into the soil will not be effective. Aerating the infested areas before application may facilitate the movement of insecticides into the soil.
Irrigation is essential following insecticide applications for white grub control.
Repeat irrigation every four or five days to move the insecticide into the soil and to keep the crown area moist to encourage turf recovery. This should enhance the level of white grub control. Do not apply by hand because distribution will be uneven. Calibrate delivery rates before application. Do not depend upon rate charts, although they can be used as a guide.