Synonyms and other taxonomic changes
formerly placed in Psithyrus, which is now considered a subgenus of Bombus - see links below
Size
Female: 16-19 mm. Male 13-16 mm.
Range
Commonly encountered in Canada and forested areas of the western United States, but rarely found in the northeastern United States where restricted to northern and montane sites
Food
Social parasites of other bumble bees. Both sexes regularly visit flowers for nectar including composites. The Hosts section of its
Discover Life species page lists known floral associations based on specimen records and images.
Print References
Michener, Charles D. 2007. (2nd ed.) The Bees of the World. 1,016 pp. Johns Hopkins University Press. [advertised
here]
Internet References
common name reference; PDF doc (Committee on Common Names of Insects, Entomological Society of America)
discussion on subgenus Psithyrus plus list and distribution of world species (Natural History Museum, UK)
world bee genera plus synonyms and subgenera; list based on Michener, 2000 (Doug Yanega, U. of California at Riverside)
