A blurb from UC, below --

Here is a link that might be useful: bean weevils

I suspect it's partly rotate crops, also be certain to remove all crop debris at end of season.

More from UC -

Here is a link that might be useful: bean weevil

Thanks for the info... I actually wasn't here to remove old crop debris last year, which may be part of the problem.. I removed the debris early spring... I grew beans this year where I grew squash last year....

I know all beans are toxic to a certain extent... I noticed these bugs like the supposedly less toxic beans more than the more toxic beans... Same species of beans (lima) but different cultivars...

I also have one isolated white seeded hyacinth bean plant that I'm growing this year and it's having a hell of a time growing seed.. I got one good seed out of the 20 pods that it has grown so far this year... I grew the purple type last year and there were NO weevil problems and perfect seed...