Sunny is right...a natural way to rid yourself of the J. Beetles is to go out early in the morning, place a plastic sheet down & shake the plant. (the beetles will have dew on their wings early in the AM and cannot fly away so easily) then drown the beetles you get in a pail of soapy water. In the fall rake up your a*garden soil so that starlings can easily eat the grubs, thus cutting down on the adult beetles the next year.
Also, plant cloves of garlic around the perimeter of your garden. Beetles do not care for garlic.
Other insecticides are products that contain the chemical cyfluthrin, bifenthrin, deltamethrin and permethrin.
Read labels carefully as different products are used at different times. Plus as I mentioned in my previous post, you need to be aware of the time span between spraying an insecticide and harvesting your crop.
Avoid planting roses
, linden, grapes, sassafras, Hollyhocks
and horse chestnut as beetles love these.
A local plant nursery could help you chose plants that the Beetles would not harm.
personally, I would not use the beetle traps. IMO, they draw more beetles than they trap.