Japanese beetles. These beetles are absolutely destroying our roses, hibiscus, hydrangea and red maple. I am so very upset. We have the traps and have sprayed what is best in their management? should I have the lawn treated for larvae and if so what time of year. Thank you. Jill. Welland Ontario.
As far as Japanese beetle control is concerned, I do not recommend traps unless your property is large enough so that you can place the traps far away from any vegetation that you want to protect (or better yet, persuade your neighbours to put some on their property!).
There are several formulations effective against the grubs (milky spore – a fungus, BTI – a bacterium, and nematodes), but these will only work on the area where applied; there is nothing to prevent adult beetles emerging from untreated areas near you to invade your property.
Click here for the best advice on Japanese beetle control (including methods, materials, and timing of applications) in your area that I have been able to find.