Found on Delphinium. This subspecies is a generalist on a variety of flowers and ranges mostly over the Western states to the Pacific coast. Black-gray; this queen shows the colors B-NotaGbG-TergaGGGGGB w/black center of meso-notum surrounded by gray hair; L.W.Macior (1974) found nests in the Front Range of the Colorado Rockies at elevations of 1880 - 2900 m (5900 - 9500 ft). Peggy Ann Byron (1980) states that this subspecies is relatively uncommon in Colorado and has been collected here in low numbers throughout the state from the plains to the subalpine zone. B. nevadensis auricomus is the eastern form of this species.