When disturbed, the beetles fold their legs and drop to the ground. Hold a can containing rubbing alcohol or water with detergent below the infested leaves. The beetles will drop into the container and be killed. Covering with floating row covers can protect prized roses and ripening fruit. Japanese beetle traps are not recommended.
Traps can actually increase damage by attracting more than they kill.
A number of birds such as grackles, cardinals and meadowlarks feed on adult beetles. Two native predator insects and a couple of introduced parasites may help to keep Japanese beetle populations in check. Protect natural enemies by keeping the use of conventional pesticides to a minimum. Although damage looks devastating, Japanese beetle feeding rarely kills plants. Therefore, confine control of beetles to shrubs and small trees near main building entrances and other important landscape locations where damage is obvious.