Japanese Beatles

I have a major Japanese Beatle population on a tree in my back yard. I hung a trap about 20 feet away and it filled up in 4 hours. I put another one out the next day and it also filled up. Then I read that I may be attracting more beatles than I'm catching. How do I get rid of them?

Dawn Dishwashing Detergent mixed with water in a Sprayer. As for getting rid of them, they will be gone in the next 2 weeks.