We often get asked this question. White grubs are the immature forms of several types of beetles, one of which you probably know, the Japanese Beetle! These beetles spend the majority of their lives underground, feeding and growing primarily on turf roots and organic material in the soil profile. As summer approaches they pupate and emerge as flying beetles. During that time they feed on above ground plant parts and then return to the soil to lay eggs, which then become more grubs.
The diagram below shows the life cycle of a Japanese beetle:
How Grubs Damage Your Lawn
The damage to turf results from them reducing the root system of your lawn, which shows up as drought stress or even turf that simply rolls up as the roots have been eaten by the grubs. You can prevent grub damage through a grub treatment we apply in the mid-summer, preventing the beetle eggs from hatching.