Below is a link to an extension article on bean beetles that might provide the info you're looking for. It looks like they aren't too bad if they don't build up their numbers.

Do you have chickens? If you do, let them so some cleanup: let them into the area and then go along the plants and tap them to make the beetles fall to the ground, where the chickens can get them. I would let the birds in first, maybe draw them to the area with a spoonful of scratch, THEN start tapping the leaves, so they can see the tasty morsels fall and grab them before they take cover.

But I wouldn't let the birds roam unescorted or for too long, as they will dig soil away from the bean plant roots.

Sue

Here is a link that might be useful: U of MN: Bean leaf beetles home garden

Thank you Sue! Yes - this is just what I was looking for. I wish I had chickens to put around the beans... That would definitely be a good way to reduce the population of beetles. I think I'm going to mulch more heavily around the roots in hopes that it makes it a less appealing place for the beetles to lay eggs in the soil. Still thinking on getting some guineas...

Thanks so much for your help - this was a good article.
Cindy