I live in East Tennessee, USA & recently planted 17 fruit trees (Apples, Pears, Plums, Nectarines, Peaches, Cherries & Pomegranates, which these pests love accept the Pomegranates). My area has lots of Japanese Beatles & have tried everything suggested out there that I could find & nothing worked. Neem oil & Sevin slows them down but doesn't seem to kill them or repel them. I had better results with a cup or small bucket with about an inch of hot water in it. My Young Trees are only about 6-8' tall & thin so it's easy to bend branches to get the Beatles in the bucket. I hold the bucket under the leaves that have lots of Beatles & push them off into the water. the water keeps them from flying away. Of course, a few will fly away while you're trying to get them in the bucket, but you can be sure they will be back! Then I go dump them on the floor of my chicken run & the Beatles are gone in a few seconds! My chickens come running when they see me coming now & some will jump up like a dog trying to get a treat from your hand. I had Thousands of Beatles & they ate most of the leaves while I was figuring it out over the course of 2 weeks, but after a few hours of doing this, now there are only about 10 or so to remove each day I check. Now my trees are sprouting new leaf buds! Not sure how long I will have to do this because I'm sure there are millions more in the area. I do the same thing with my Knockout Roses & Pole Beans in my garden; they love those as well. The chickens will take care of the low branches of the roses, so I only have to do the top. Of course, if you don't have chickens, flushing them down the toilet might be a good option. 

If anyone has better information that is less work, please advise!