It kills grubs after causing their normally clear blood to become milky in appearance. The milky disease spores live in the soil for long periods, ready to infect and kill successive broods of Japanese beetle grubs as they move about in the soil, feeding on plant roots. The disease is harmless to human beings, warmblooded animals, other insects, and plants. Milky spore powder is available commercially. Infected grubs are incorporated into dust mixtures that can be spread over lawns and other infested areas to kill healthy grubs.
Treatments are most effective when they are made on a community-wide basis.
Do not use on areas treated with insecticides. Attractants and traps are available for trapping these beetles. These methods may provide satisfactory control in some gardens. Trapping is more satisfactory for surveying beetle presence than controlling them. Extensive larval and adult damage may occur within 10 to 20 feet of traps collecting many beetles.