Ever seen a green metallic sweat bee?

The colors are exquisite. 

This is a female Agapostemon on a purple coneflower at UC Davis.  They are called "sweat bees" because they are attracted to human perspiration.

The genders are easy to distinguish. The males have a striped abdomen. 

Green sweat bees are among the bees featured in the book, "California Bees and Blooms: A Guide for Gardeners and Naturalists," co-authored by the University of California team of Gordon Frankie, UC Berkeley; Robbin Thorp (1933-2019) UC Davis; and UC Berkeley affiliates Rollin Coville (photographer and entomologist) and Barbara Ertter (plant specialist). Frankie, Thorp, Coville and Ertter (and others) also published "Native Bees Are a Rich Natural Resource in Urban California Gardens" in California Agriculture.

Oh,  those bee-utiful bees. They are not only conspicuous, but charming and often camera-cooperative.