Bate's Well Rd, BLM 1085 arroyo, Pima County, Arizona, USA December 4, 2017 Size: 1/4 in
I have seen similar Sweat bees several times this fall, with the shiny green thorax and head and striped abdomen. Around 1/4 in long. This piece of arroyo has been quite moist and still has some flowers, lots of berries and blooming Condalias and Rambling Milkweed.