bugs on beans
Here is the insect problems page from our website's Grow It Eat It section, which includes profiles on veggie pests: http://extension.umd.edu/growit/insect-pests-vegetables
The most common insect problem on beans is Mexican bean beetle. Click on that profile. It gives you several non-chemical solutions to controlling them. Using row cover works very well.
If Mexican bean beetles is not what your pest, look for it in the profiles. If you can't find it, send us photos of your insect pest and we can identify it. Then we'll be able to give you specific recommendations.