Synonyms and other taxonomic changes
Orig. Comb: Apis pensylvanicus De Geer, 1773
Bombus pennsylvanicus is an unjustified emendation of the original spelling of the species name.
In typical females the thoracic dorsum is yellow anteriorly and black posteriorly and the first three tergal segments are yellow contrasting with black distal segments. The malar space is long and the legs gangly. B. auricomus has a similar color pattern but often has conspicuous yellow hairs on the vertex (vs. black in pensylvanicus), a (variable) patch of yellow on the thoracic dorsum posteriorly (in pensylvanicus these hairs black or a more diffuse admixture of black and yellow), ocelli lower on the face (vs. high in pensylvanicus) and with more extensive black hairs on T1 so the abdomen appears somewhat banded (vs. dorsal surface of T1 consistently yellow in pensylvanicus). Males can be extremely similar to B. fervidus, as they often have extensive yellow on the thoracic dorsum posteriorly, but the interalar band is broader and more diffuse, the sides of the thorax are usually more extensively black posteriously, and the abdomen may be pale-tipped (variable). B.pensylvanicus averages larger but has a shorter malar space. The most extensively yellow B. pensylvanicus females can also be confused with B. fervidus but T4 is black in the former and yellow in the latter.
Eastern North America, from Quebec to Florida west to Colorado, Texas and locally to New Mexico; the closely related sonorus, often classified as a subspecies, occurs in the southwestern United States west to coastal California.
TX-FL-MD-CO / Ont (BG data)
Associated with large fields
Late emerging. Mostly: May-Oct (BG data)
Likes clover (Trifolium
) and sunflowers ([i]Helianthus/i]). The Hosts section of its Discover Life species page
lists known floral associations based on specimen records and images.
Has declined severely at the northern margin of its range, where now absent from or at best very rare at many historical localities, but still routinely found in its core range to the south as evidenced by the many Bugguide images.
Despite its name this species is not our most widespread species, as it is now rarely encountered in the northern portion of its historical range.
Warriner, M.D. 2011. Bumblebees (Hymenoptera: Apidae) of remnant grasslands in Arkansas. Journal of the Kansas Entomological Society 84(1): 43-50.
common name reference; PDF doc
(Committee on Common Names of Insects, Entomological Society of America)