They showed up last year but was told too late to do much about them. They were in my raspberry plants. I do not have a large garden…but a third of it is raspberries. Can you recommend how I can get rid of them? Traps? Sprays? Other. I did try and hand pick them last year…but guessing there will be more this year.
Thank you for contacting the Toronto Master Gardeners.
We have answered numerous Japanese beetle questions over the years. The following response is from one of our archived posts:
Japanese beetles love hot dry weather. They lay their eggs in the soil under lawns. The larvae will overwinter in the soil and continue feeding as the weather warms in the spring. Once the larvae are full grown, they will pupate and emerge as adults in late June and early July. The adult beetle will continue to feed on foliage through July and August.
Your control strategy should be multi-pronged. Adult beetles emit a pheromone that helps them find each other. Getting rid of the adults can slow your infestation. Experts say that the best method for control is to hand pick them in the early morning or late evening when they are less likely to be flying, and simply knock them into a pail of soapy water, where they will drown.
You can also try to prevent an infestation next year by treating your lawn for larvae. You can apply beneficial nematodes to your lawn in late summer. Nematodes are a type of roundworm that feeds on grubs. Be sure to select a type of nematode specific to the larvae of Japanese beetles, and to apply as per manufacturer’s instructions.
There are also pheromone traps that will attract adult beetles. However, there is always a risk that these traps will attract more beetles from surrounding areas to your yard. They are most effective in large yards where you can direct the beetles far away from your plants.
We receive numerous questions on the control of Japanese beetles. Just enter the term “Japanese beetle” into the Search Box on the main page of our website. You will find numerous pages on this very topic.
Good Luck !