Colletes phaceliae, f, side, Pennington Co, SD_2016-02-02-11.23
Colletes phaceliae, the Phacelia Cellophane Bee, is primarily a western bee of the U. S. (1). It is a generalist bee and feeds on most families of flowers (1). Phacelia Cellophane bees are active in the Summer and early Fall months (1).

Colletes nigrifrons, the Black-Headed Cellophane Bee, is a bee species that we don’t know much about. The majority of records come from the Rocky Mountains of the U.S., though most of these records are from old collections (1920-1976) (1). Recently this bee was found here in Yellowstone, so we hope that there are still populations thriving at the park. Like most Colletes, it is a summertime bee, and appears to be a generalist on many different families of flowers (1). Original public domain image from Flickr