My green beans did well in the beginning but in the last few days the leaves have been eaten off, bugs of some kind but what would be common in this area?

The area is fenced against all but an overzealous deer or stubborn coon, so I doubt it's a mammal issue, that and the bites are tiny but plentiful.

Will the bean plant grow new leaves from the remaining green stalk, or do I need to reseed.?

I did a search within this site and did not find this issue addressed.

Tiny bites, clear through, all over? If so, could be flea beetles. Pyrethrin spray in the evening might help, I don't know if insecticidal soap would help, but you might try a Google or forum search.

If you are growing Bush beans then I say don`t worry about them not growing. Second year growing and I had that happen. The bean plants are VERY hardy once they get going. Heck after there big, leaves and branches break\fall off often.

Where the row was once full germination and had the first triangular leaf, now has only 30% leafed stalkes and the rest are stubs or gone completely.