Black-and-gold bumble bee (Bombus auricomus) often yields exclamations about its size compared to other bees. These large, striking bumble bees are hard to miss, and are often heard before they are seen. Queens emerge late in the year, and found small nests that senesce quickly; new gynes are seen starting in mid-summer. Look for this long-tongued species on flowers with deep corollas like bee balm (Monarda spp.), thistles (Cirsium spp.), and clovers (Trifolium spp.).
Emergence later than most bumble bees. Active May through September. Colonies begin producing males and gynes (future queens) by late June and July; one new generation of reproductive individuals per year.
Predominately in mid-Atlantic, with recent records indicating spread north into southern New England.
Size >>honey bee
Gynes: very large; long malar space; yellow vertex hairs; black band across thorax created by yellow anterior half and thin yellow posterior band; T1 mostly black; T2-T3 entirely yellow, T4+ all black; noticeably short, “evenly trimmed” hair across body; dark wings
Workers: like gynes, but smaller
Males: resemble females but with bug-eyed appearance and mostly yellow T1. Color of males is much brighter and more amber than that of females.
- B. pensylvanicus is similar sized but has black hairs on vertex, entirely black posterior half of thorax, and mostly yellow hairs on T1.
Typically occupies open habitats like meadows, grasslands, and suburban gardens; not associated with forests. Eusocial nests are typically small (only 10-20 workers at any time), and often built on the surface of the ground.
Generalized, but long-tongued and seems to prefer flowers with deep corollas like thistles (Cirsium spp.), Fabaceae (e.g. clovers [Trifolium spp.]), wild bergamot (Monarda spp.), and garden zinnias (Zinnia spp.)
No known cleptoparasites.
Frison, T.H. 1917. Notes on Bombidae, and on the life history of Bombus auricomus Robt. Ann. Entomol. Soc. Amer. 10: 277-288.
Page last updated:
February 22, 2023