I’ve read that milky spore disease will get rid of Japanese beetles, but I cannot seem to find a retailer that carries milky. spore powder. Are you aware of any in the GTA? Have you tried it? Does it work in our area? Is it legal to use in Canada?
There are two ways to get rid of these nasty beetles – either destroy their larvae (grubs) or the adults.
Milky spore, which is the bacteria Bacillus popilliae, has been used to control Japanese beetle grubs, but is not effective in our climate as soils are too cold in the spring. From my research, milky spore is not registered in Canada.
Beneficial nematodes (roundworms that eat grubs) can be used – select ones that feed specifically on Japanese beetle grubs.
A tried-and-true way of getting rid of adult beetles is to knock them off the plants into a container of soapy water – they will drown. This is best done in early morning or in the evening, when the beetles are more likely to be settled on the plants.
See the following for additional information:
- University of New Hampshire White grubs – Pest fact sheet
- Ontario Ministry of Agriculture, Food & Rural Affairs. Japanese beetles in nursery and turf
- Ask a Master Gardener. Japanese beetles