Background first, I live in Southern Illinois (zone 6), about two years ago the western migration of these beetles got to our area, the first year wasn't too bad, last year was bad and I am assuming this will be even worse as they get more established.
I have see the people using the traps, however its split amongst the friend of mine that use them, some saying they work some say they think they just attract more. I had to use Sevin dust on the beans and grapes last year to save the plants. Has anyone out there had any luck with anything else?

Fortunately for me, I have never had to deal with Japaense Beetles.
Traps do have the risk of attacking some that don't get exterminated and then you don't really solve the problem. I would use traps if you could use them away from your garden area. If that is possible.

In the fall you can use Milky Spores which is a bacteria that will kill them in the soil.

It is too late for that now and Neem II by Green Light is what I found in my searching around for a solutions.

They also lay eggs underneath leaves. As a kid growing up, I remember having the job of going and looking for potato bug eggs are look similar are are underneath leaves as well. While this is an imperfect and labor intensive soluitons, a little bit of a few different things will hopefully help you get the problem under control. Good luck.

Don, I also live in Illinois (mid-state),

My father used Milky Spores two years in a row during the fall and has seen a big difference in the number of beetles. Only a few which seemed to be coming from the yards of others. Many that I know have tried the traps, only to draw more and more of them onto their property. We only saw a few on our property this past year, the year before there were millions of them flying around. We just built in 2006, so we're in the process of building out the landscaping, flower, fruit, and vegetable gardens. Our neighbors sprayed liquid Seven on their trees and that seemed to provide a barrier for them. I'm not sure I want to put any chemicals on the fruit or vegetables, so I'll be looking for alternatives as well if they are much of a pest this year.

Best of luck and lets keep in touch (I'll add your garden to my Watch list)

Tawny911

Hello All
I have a bit of an update to my original entry. I heard on a local news program that plain 'ol flour works well as a "deterrent" to the beetles, it seems that when the little guys eat the stuff, it swells in their stomach and gives them a case of terminal indigestion, so to speak. So I figured what can it hurt, I powdered the tops of my green bean plants, one of their culinary favorites, and what do you know, the next day, dead bugs! Now in interest of full discloser it does appear that they ingest the flour along with the leaf they are eating so you will still have some damage and I am not sure of any long term affects on the soil (bacteria, fungal growth, etc) the flour might have, but this appear, to be a good alternative to traps, or sevin.
SO now I’m thinking self-rising flour hmm…………………

Thanks for the flour advise. I only had a few this year on my grape vines. Not sure what has made the difference. Added the milky spores to the yard, but thought it would take several years to see the true affects. Mix information regarding the true affects of the milky spores and length of time it lasts (10 to 20 years). Also, if it does come up through the plant so the beetles are discouraged in eating the leaves. Have you heard of anything on this? I'll try the flour next year if I have any signs of the little ugly bugs. I'm sure the garden clubs I'm in will be interested in this flour idea as well.

Thank you so very much for sharing.

Milky spore does an excellent job of killing the beetles while in their grub stage; however it does nothing to the flying adults.

There are two products that will repel the adults, food grade diatomaceous earth and cedar oil. Both are natural products and can be used on plants and fruits alike.