This one looks like Phymata maculata, which is supposed to be restricted to the west coast. It looked like it might be a little smaller than the Phymata pennsylvanica I usually see.
6.3 mm
On blooming Baccharis sarothroides. Has been a very dry year and very little was flowering. There was a stretch of wash with a few stands of Baccharis that were blooming though, and pollinators were centered on it.
My first time seeing Phymata in Arizona. Southwestern Arizona in particular seems to lack observations on iNat.