At what time of year do Japanese beetles enter the ground to become grubs in Michigan Livingston co. I'd like to spray insect killer when it will be most effective.
Livingston County Michigan
Japanese beetles show up in late June or early July and land on plants. Handpicking beetles off plants can be effective. There are pesticides that can be used. There is a good website that explains control methods and has many informative articles about this insect. The site is canr.msu.edu and click on the upper right hand corner and search Japanese beetles.