Try spraying with clay. This won't poison anything, and insects object to getting a mouth full of dirt. Worked great on our trees (apple and cherry) but we haven't had many Japanese beetles this year. Good luck! and whatever you do, Don't let anybody talk you into lure traps. Then you will get everybody's beetles.
By
06/25/2010
A few years ago, I had a ton of Japanese Beetles and they just kept eating my plants. I bought Spectracide's Bag-A-Bug trap and hung it on a tree on the edge of my property. WooHoo! No Japanese Beetles for over two years now. You can find the Bag-A-Bug at any hardware store.