Length: 12-14 mm
Rasheed et al. (2008) studied a number of species of Syrphid flies that mimic wasps, honeybees, and bumblebees. While their general conclusion was that most Syrphid flies do not sound very much like the hymenoptera species they resemble, they did report that Eristalis flavipes is an exception, and does indeed sound like bumblebee species.
Eristalis flavipes is found in northern states from coast to coast, but there are many apparent gaps in its range. It has been reported from British Columbia and Ontario, but not from the provinces in between. In West Virginia it may be near the southern part of its range. The photos here were taken in the Canaan Valley, West Virginia, where many more northerly species of plant and animal are common.
Other species in this genus on the American Insects Diptera pages include Eristalis aeneus, E. arbustorum, E. dimidata, E. tenax, and E. transversa.
American Insects site