Milky Spore is an effective non-toxic  one time application for Japanese beetles. Apply one teaspoonful every four feet in a checker board pattern on your lawn.  Usable anytime the ground is not frozen. Ten year performance guarantee on the Japanese Beetle Grub. Not harmful to man, animals or the environment, safe to use around waterways. Kills the grub stage of the Japanese Beetle. Natural bacteria eats the grub from the inside. Does not harm beneficial insects.  Apply just before it rains or water in gently for about fifteen minutes.