The typical form is very similar to B. centralis in that a yellow T1-T2 contrast with a red T3-T4, but flavifrons has a longer malar space and black hairs intermixed on the scutum anterior to the black interalar band.
Widely distributed in North America. Well known from the Pacific Northwest and high elevations in the Rocky Mountains.
Tends to be more humid and forested or at higher elevations than cnetralis.
Long-tongued for its subgenus so visits flowers with rather long corolla tubes.
The Hosts section of its Discover Life species page
lists known associations based on specimen records and images.