Ed Lentz of the Hardin County extension office tells how to control Japanese beetles, which are now prevalent in the Ada area. He writes:

Control options for Japanese beetles can be as easy as removal by hand if populations are low.  The removal of the first beetles that arrive in an area will often reduce populations. These early beetles act as scouts and inform other beetles of good feeding areas. 

Japanese beetle traps generally are not an effective control method. The pheromone bait used in these traps may actually bring more beetles to an area than are captured in the trap.  

Many insecticides are effective in controlling Japanese beetles.  Retail products vary by name, but the active ingredients should be cyfluthrin, bifenthrin, deltamethrin, lambda cyhalothrin, esfenvalerate, permethrin, and carbaryl. 

Pyrethroid products, such as permethrin and bifenthrin, should be effective for 2 to 3 weeks.  Carbaryl (Sevin) provides protection for about 10 to 14 days. Neem oil and products containing spinosad are organic insecticide options.  

Whatever product is selected, it must have Japanese beetle control listed on the label. Read and follow all label directions. Do not apply insecticide at a higher rate than listed on the label.