Japanese beetles pose no danger to people and animals, but they do damage trees and other plants. Japanese beetles eat away at the leaves, resulting in a tree full of lacy or skeleton-looking leaves. This leaves the tree unable to adequately soak in the sun to photosynthesize it into energy. Kill Japanese beetles on trees before they cause irrevocable damage.
Place buckets of soapy water under the limbs you can reach and shake them. This is best done in the morning while the beetles are still sluggish. The beetles will fall into the bucket and die. Reducing the number of beetles on your tree will attract fewer beetles.
Spray an insecticide designed to kill Japanese beetles on the tree's leaves. Spray all the leaves, including the ones that do not contain beetles or do not have damage. Pesticides that work well to kill Japanese beetles contain cyfluthrin, esfenvalerate or carbaryl. Reapply the pesticide as indicated on the label. Some need to be reapplied after two to three weeks, others after two to three days.
Set out Japanese beetle traps that attract and trap the beetles inside. Place the traps near trees or other areas of your yard that do not contain plants or trees that attract beetles. For example, silver maples, boxwoods, tulip trees and magnolia trees seldom experience Japanese beetle damage. Be aware beetle traps often attract more beetles than they eliminate, which is way you should place them away from plants.