Milky Spore is one of the products recommended by the Amazon book, Home Improvement Solutions : What Every Homeowner Should Know.
Milky Spore is a bacterium that infects and kills grubs. You apply milky spore to your lawn and water it in so grubs become infected by swallowing a spore when feeding on grass roots. The grub is killed 7 to 21 days later. As the grub decomposes billions of new spores will be introduced into the soil from one grub.
As the spores multiply in your soil, they spread to cover the entire lawn. As time passes, the spores will spread to neighboring lawns. This bacterium becomes more effective over time and has a life span of 15 years.
Milky Spore is approved by the EPA. It is a safe material to kill grubs. It is not toxic to insects, birds, pets or humans. It will not affect wells, ponds or streams. Also, it is harmless for food crops.