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 definition, they are found from Canada through Argentina. However, there is current disagreement whether the Protandrena in South America belong to different genera, in which case the genus extends only as far south as Panama.

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