First of all, get rid of the bags! They attaract more beatles. The next thing you want to do is treat your yard for grubs. Jap. beatles come from grub worms. You can treat the yard this fall or next spring. Or you can put down milky spore for grubs. It last 10 to 20 years where normal grub killers last 1 season. Sevan is a good spray if you want to spray them. You can also hand pick the beatles from your plants, if possible and put them in a bucket of water. I have never tried them as bait. Web worms that form on trees in the fall are good gill bait.