|What can you tell me about milky spore disease powder to control japanese beetles? Last year my rugosa was a mess and I spent 2 months picking off beetles. I have heard that milky spore disease will control them and will not harm people or pets who spend a lot of time in the garden. Also, how long will it control the beetles once applied?
|Answer from NGA
March 12, 1999
|Milky spore disease infects the grubs while they are in the soil so it will not stop adult beetles which fly in. It needs to be applied over a large area (contiguous acres) and be allowed a number of years to take full effect. Once applied, it remains effective for years. For a more immediate result on your roses (a Japanese beetle favorite) you might consider using Neem applied according to the label instructions.
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