Japanese Beetle – Milky Spore Disease

Q: Japanese beetles are a big problem for us. One of the people in our subdivision is encouraging us to have a community-wide eradication program using milky spore disease powder. There are 500+ homes in our subdivision and it will cost $100 per home. What are your thoughts? Does it have any merit?

A: Milky spore disease kills the grubs of Japanese beetles once it infects the soil in which the beetles lay their eggs. Your neighbor is on the right track when he advocates a community-wide program. Otherwise, lawns that were not treated could harbor beetles that would affect the rest of the neighborhood.

This approach, though, is not a magic bullet. Your group should first ask these questions: Will people be satisfied with a “cure” that takes years to become fully effective? Are they aware that several other beetles make white grubs in the soil…. and that milky spore will not control them? Is anyone knowledgeable enough to identify the Japanese beetle grubs and monitor their population decline? Are you SURE the milky spore product contains live bacteria? (There was a scandal a few years back when one company was shown to be shipping dead spores in their product.) Fall is the right time to apply milky spore powder – but be sure everyone understands what their contribution to the campaign will and won’t accomplish. You can download an excellent Cornell University Factsheet.