Uncommon.

Queen:
Worker:
Male:

Frison (1917) noted that B. auricomus is unique among Bombus species in that the queen lays each egg into a separate egg cell, rather than laying batches of eggs into a single wax-pollen mass as is usual for the genus. Colony size is small, with only about 35 workers. The species is not a common bumble bee in Illinois.

Queens: . Workers: . Males: .