Beetles – Milky Spore

Q: Is it to late to apply milky spore this fall? I had lots of beetles flying around my outdoor lights in summer.

A: Your first step is to identify the beetles you saw around the lights. Japanese beetles are not typically attracted to lights but chafer beetles are. Milky spore disease does not control chafer beetle grubs. Even if you do have Japanese beetles, it’s getting really late to apply it. Milky spore disease works best when soil temperatures are above 65 degrees. The soil temperature map for Georgia, www.georgiaweather.net, shows that soil in your area is rapidly cooling. You must also have an active population of Japanese beetles in the first few inches of your soil. At this time of year, grubs are digging deeper into the soil preparing to go dormant for winter. Even if you apply the disease spores properly in mid- to late summer, it takes a couple of years to become effective. Remember too that Japanese beetles in your landscape may be flying in from your neighbors’ untreated lawn or pasture. As you can tell, I’m not a big fan of using milky spore disease powder: it’s too expensive for the minimal control it achieves.