japanese beetles - Ask Extension
I have had a very bad Japanese beetle year. Without exaggeration, I have had hundreds of thousands of them in my birch trees this year. They have to...
Knowledgebase
japanese beetles #877352
Asked July 15, 2024, 4:16 PM EDT
I have had a very bad Japanese beetle year. Without exaggeration, I have had hundreds of thousands of them in my birch trees this year. They have totally obliterated almost every leaf on some of the trees. I have had them in the past in vegetable garden, etc - but never like this. I was reading your article on grubs, etc and it is still unclear to me for the best time to treat. I understand that these beetles have now laid many, many eggs and I would like to both protect my lawn and I would like to prevent another summer of this many japanese beetles. Can you please tell me the best time to treat? Is it to late to treat right now? Will it kill the larvae that has just been laid?
Livingston County Michigan
Expert Response
You can treat in late-summer/fall or next spring to help prevent another summer outbreak.
Here are two MSU articles that list management strategies and timing:
Japanese Beetles - MSU Extension
Japanese beetle: Tips for your lawn - MSU Extension
If you have a large yard they could certainly be coming from your own property, but if you live in a more densely populated area, they may not just be in your yard. As this article notes in the management section, you may want to be sure you have the grubs in a certain area in your soils by digging up to look for them before you treat.
