The 2010 petition by the Xerces Society and Dr. Robbin Thorp, Professor Emeritus at University of California–Davis.
Update: As of August 2019, the USFWS has proposed to list Franklin’s bumble bee (Bombus franklini) as an endangered species under the U.S. Endangered Species Act (ESA), making it the first bee in the western U.S. to be officially recognized under the ESA. See our press release on the progress of this petition.