Protandrena is a genus of mining bees in the family Andrenidae. Depending upon whose definition of the genus one follows, there are anywhere from 50 to 180 described species in Protandrena; traditional classifications recognize 7 subgenera, some of which are sometimes elevated to genus rank, and other classifications place many of these species in the related genus Pseudopanurgus (e.g.), leaving Protandrena with a much smaller constituency. In the most inclusive (Wikipedia)