Milky Spore contains spores of the bacteria Paenibacillus popilliae (formerly Bacillus popillae), which work specifically against the grub stage of the Japanese beetle (Popilia japonica). It poses no threat to people, animals, plants or beneficial insects. When Milky Spore is introduced into the soil, it will lie dormant until grubs begin feeding on roots where the bacteria is present. Once ingested, the spore multiplies inside the grub with a single spore creating up to 3 billion new spores in each host grub. As the grub decomposes, the billions of spores it contained are released back into the soil to start the whole process again. Over time, Milky Spore fills out the soil creating a soil environment that Japanese beetles simply cannot survive in. Kills Japanese beetles within a week 1 lb for 350 sq. ft. 20 lbs treats up to 7,000 sq. ft.
