So, for all the pretty I have gotten from my runner beans, there aren't ANY pods growing out there...and there should be. I have noticed a few ants running up and down the vines, but to my way of thinking, they can't account for the lack of beans all by themselves. A closer inspection found a bunch of little dark spots gathered in the corners and elbows of the vines and twine holding them up.
Some research on the internet found that these are commonly called blackfly, and they are a type of aphid. The ants are around because the essentially milk the aphids...they dig the sweet juice that that aphids produce as they suck on the plants. To ensure they get to keep that juice, the ants protect the aphids.
I'm still not sure that these blackfly's are 100% responsible for the lack of beans, but, they probably aren't helping. The two methods of making them go away are getting rid of the ants, predatory bugs come back, OR getting rid of the blackfly's, which is what I am trying to do. When I find a bunch like that, I blast them with a soap/water mixture.
I figure we'll give this a few days before considering scarier chemical options.