Bumble Bees of Montana
Bombus (Bombias) nevadensis Cresson, 1874 Nevada Bumble Bee
Bombus nevadensis is considered common throughout its range, which is in the western U. S. from the Pacific Coast east to the Great Plains (Koch et al. 2012). In Montana, this species is widespread.
Diagnosis
Bombus nevadensis is a large bumble bee with short, even hair. The face is predominantly black and there is not a strong band of black hairs between the wings-- either the black band has many yellow hairs intermixed or the band is reduced to a black circle in the middle. Abdominal T2 and T3 (and usually T1) are yellow while the sides of the thorax are predominantly black.
Similar Species
This species is most easily confused with B. auricomus and B. fervidus. Bombus auricomus has a strong band of black hairs between the wings, with few to no yellow hairs intermixed. Bombus fervidus has yellow hair, not black, on T4 and also has a strong band of black hairs between the wings.