Experts and BHG readers answer.
Japanese beetles and grub control
There are a number of good grubkillers on the market. I've used Bayer Advanced Season-Long Grub Control Granules with good effect, though other products also work well.
If you go the organic route and want to try the milky spore disease, keep in mind that it may take several years to get established enough that you notice a difference in the grub population --- though it does work over a much longer period.
---Justin, Senior Garden Editor, BHG.com