Sevin dust or spray seems to work, but it will also kill the bugs that you want to keep.

hand-picking is what i do. they are clumsy flyers and also gregarious so it is fairly easy to catch a cluster of them. i simply get a large plastic cup, partially fill with warm water and liquid soap and gently place it under them as they rest on the leaves. do not disturb them until your cup is in a position directly beneath the insects.
use your other hand to knock them off into the cup. their usual pattern is to drop downward so they go right into the cup. the soap keeps them from floating and they will drown or you can pour them out and stomp them. could also add a drop or two of your favorite insecticide as a faster acting cocktail for them. :-)
i probably caught about 50 this morning before coming to work and i'll bet there will be two times that many when i get home on the shrubs. they seem to be appearing in large numbers this season.

Drats! I've been dreading the JB season. I, too, am a hand collecter. I am planning on drowning some to see if the birds eat them when I pour them on the lawn.

The best way to eradicate Japanese beetles and other beetles without harming invironment is to use a natural fungi. Go to www.arbico.com. They sell a natural fungi powder which is mixed with water and sprayed or sprinkled on the ground around plants. The fungi enters the eggs which the female beetle lays in the ground and destroys the grubs. Lasts a lot of years. Also destroys other grubs which are in the ground and also iris borer. Good to destroy grubs in lawns as well. I have used it for years. Comes under the name of "Doom" and other names. Available also through Gardeners Supply.com. This year you won't see a big difference, but next year you will not have any beetles or very few. Good luck

Managing JB

I pile all of mine into a toy boat in a tub full of ice water and play Titanic. They only scream for a minute or two when the boat starts sinking.

Anaturelover, Doom is Milky Spore, a bacterium inoculant and not a natural fungus. It does not work in all kinds of soils and no one should waste their money and time on this avenue unless you've done some research for your area.

It is not, for example, recommended for the heavy clay soils of Northern Alabama! It's just not effective.

Drats...they aren't here yet, but I guess they are coming soon! I have handpicked the last two years. Three years ago I bought the traps and attracted every one for miles! Billions and billions! I've been spraying the roses with Shieldall and rotenone...will see if it does any good. They really like pickeral rush, and all congregate on it. It becomes my sacrificial plant and I go hunting each morning.

Thanks to all of you. This morning I had my kids knock them off into bowls of soapy water. I promised to pay them a nickel per beetle-which made them quite ethusiastic. They caught a few hundred! And I have lots more. One of my neighbor's has put out a trap, which I think is the cause of the problem or it could be the relatively cool, wet weather we've had so far. There have never been so many beetles in my garden before. Susan.