Japanese beetles, huh???
Well, there are two ways, natural, hand pickin' and squeezing (or just dump 'em in a bucket of ____________ oh, I forgot, Chemical Bob told me... (I want to say water and turpentine.) I usually just do plain ole water, but they swim around and around and around.
Now, Chemical Bob and I'm sure a few other's will tell you to Sevin Dust them or some other poision. But I have children in my garden and they're right under foot and pickin' things they're not suppose to pick.
(My youngest one gave me two hand picked zucchini's....... Grrrrrr!! I was a little miffed as they were just starting to be about the size to pick, but I'd picked two earlier and thought I'd leave them to grow for a day or two more....) Any ways, I can't use the stuff, I personally just wouldn't feel right doing it with the kids.
I'm a nature girl!!!
The other gardeners can tell you other methods!! But I'll stick to the ole squish~squish method....

Welcome again!!!
Weezie