Hi, I'm looking at controlling Japanese beetles on my 6 roses. I read Mikl Brawner's article, and I'm not interested in toxic solutions (I have a small child and want to protect bees). Right now, I am collecting them off the roses every day, and I'm considering Milky Spore, but it sounds like that's going to be best done In Aug/Sept and will not have immediate results. Any advice?
Boulder County Colorado
Thanks for contacting the MG Help Desk. There are several treatment options, one of which is "mechanical," exactly what you're doing. Here is a fact sheet from the CSU Extension Office about Japanese Beetles with information about control of adults and larvae:
As for Milky Spore, it takes 7-10 years to establish in the soil (it is a fungus that infects lavae), however it is effective in controlling the larvae over time.