There are bacteria and beneficial nematodes available that are effective. They are best purchased mail order or through the web, since they have very little shelf life in the garden center.

Once you apply milky spore or nematodes forget about applying any pesticides or herbicides to your lawn ( this is where the grubs are found) for the years to come because you will kill off the maturation of your biological controls.
From this time on look for and hand pick off any beetles you see on your plants to lessen phermonal attraction and do not use those attractant trap bags, they are a calling card to your garden for these beetles.