Linda, I'm a newbie, but my bean plants usually get what I think are flea beetles. Not sure, but they eat little holes in the leaves.
Welcome to TN!

There's not much you can do until you find out what bug is doing the damage. Go out about an hour after dark with a flashlight to see if you have slugs, that will eliminate them as a suspect. Try to hold off on spraying a wide-spectrum bug killer, it will kill good bugs AND bad.

agree with rockguy. Don't spray! Flea beetles leave little holes, other beetles take bigger bites, and spread dx.
Check plants in morning, evening, and at night with flashlight to see if you can find the culprit.
A row cover until until flowering can help with this.