There are a few different ways to control grubs in your lawn, here we will outline those methods.
The first method is to use a synthetic grub control. There are many products available which serve this purpose, such as grub-ex, kill-a-grub, etc., but they all work on basically the same principal.
They are found in a granular form which can be spread with a common lawn spreader. Most of these products also rely on water to carry them down into the root zone where the grubs reside, so though watering in is not always necessary, it is usually helpful to do so. The granules should be applied when the grubs are young and actively feeding, (usually in the Spring or Fall) to provide better kill rate.
The second method is to control the adult beetles with liquid insecticides such as Sevin or Bug-B-Gon Max before they can lay the eggs of the next generation of grubs. Unfortunately this method doesn’t always prove to be effective because, although you may kill all the beetles in your yard, those from neighbouring areas may still come and lay in your yard.
The final approach is to use Milky Spore, a biological agent which attacks the grubs. This method is not as fast acting as the aforementioned two, but is far longer lasting (up to 20 years!!).
Milky Spore is available in both a powder and a granular form. The granules can be dispersed with a spreader, so are a far more convenient method, but must be applied 3 times for full effectiveness.
The powder must be placed by hand every 5sq. feet, so is a tedious and laborious task, but once it’s done no re-application is necessary.