#1 Japanese Beetle Control! Milky Spore (Bacillus popilliae) targets and discriminatory works to attack the white grubs of Japanese Beetles. Spreads naturally as each infected beetle larvae dies, decomposes and releases billions of new spores into the soil. Time must be allowed for this process to completely saturate a treated area (2 to 4 years), but only one application is required as the disease continues to multiply on its own, as long as larvae are present. When there is no longer a grub infestation, the disease remains dormant, waiting for subsequent populations. According to the USDA, milky spore disease can suppress the development of large beetle populations. Not harmful to beneficial insects, birds, bees, pets or humans. Will not affect wells, ponds or streams.