West side of Sierra Vista, Cochise County, Arizona, USA May 7, 2010
I realize there may be too much pollen covering the bees to permit further identification. These were in a very large residential cactus garden with many species in bloom. The blossom is prickly pear (Opuntia sp). The elevation is approx. 4,500' The bees never stopped moving so I was shooting at a rapidly swirling mass and hoping for the best.
Disclaimer: Dedicated naturalists volunteer their time and resources here to provide this service. We strive to provide accurate information, but we are mostly just amateurs attempting to make sense of a diverse natural world. If you need expert professional advice, contact your local extension office.