This wasp seemed to be kind of old and tired. Look how tattered his wings are.
On this chilly, cloudy day, he was moving slowly, and I was able to get really close to him. Unfortunately, without the sun, the blue iridescence of his body wasn't visible.
When he got tired of having me in his face, he flew to the ground and just walked around a while. I'd never seen one on the ground. They do make burrows in the ground, but I think this old fella just didn't have the energy to fly around much.