Hi Kim, are your green beans on the ground? You need to train them up high enough so that they aren't touching the ground. This way, the pillbugs can't get to them.
I have both pole, and bush beans. The pole beans are trellised. I mostly have problems with the younger plants and especially as they are trying to break through the ground.
Kim, you have to have moist conditions to have pill bugs. Alabama Cooperative Extension has suggestions here: