Make a Japanese beetle trap
My neighbor had a tree ruined by Japanese beetles and another one under attack. She made a potion that's doing a good job of killing the beetles before they succeed. She took a gallon milk container and cut off the top leaving the handle in tact. The potion she poured into the container was a cup of water with 1/4 cup of sugar and a packet of yeast. She added a mashed up banana and hung it on a branch about 3-4 feet above the ground. The beetles die in the potion and her tree appears safe.