Bumble Bees of Montana
Bombus (Thoracobombus) fervidus (Fabricius, 1798) Yellow Bumble Bee
Bombus fervidus is known to be widespread coast-to-coast across the mid-latitudes of North America (Williams et al. 2014). It is also widespread in Montana, known from counties across the whole state.
Montana Distribution: Records from Dolan et al. (2017) (gray) with correctionsand additional records added after publication (red).
Diagnosis
Bombus fervidus is easy to identify by its longer-than-wide cheek, black hairs on the face, and yellow hairs on abdominal T1-T4. The sides of the thorax are also mostly yellow.
Similar Species
This species is most easily confused with B. californicus, B. appositus, and B. borealis. However, B. appositus has yellow hairs on the face, the sides of the thorax are predominantly black, and T5 is yellow. Bombus borealis has a yellow face and the sides of the thorax are predominantly black. Bombus californicus has some black on T1-T3, though sometimes that black is confined to small patches on the sides of T2.