Last year Japanese beetles over took flowers. Purchase "Kill-A-Bug" this year. Follow directions and have had good defense from beetles so far this year. You have to spray beetles while on plant so keep bottle handy to get when needed. This doesn't seem to bother bees or bumble bees. Only spray beetles when you see them. I would recommend this product.
I have been using this product for 5 years now. It works, although only for about a month. I live in Albuquerque, New Mexico, and we have a very large population cockroaches here. This is a good product; better then any popular products in stores.