Wasp with Black Back from Davis Mountains TX High Desert - Polistes comanchus -
Near Fort Davis/Alpine area in Texas, Texas, USA September 10, 2015
This looks like it may be different from the Polistes aurifer. It was one of a group of wasps (which I think were Polistes dorsalis) going for a cactus. I think the red on it's back is part of the cactus and not a mark.