Extracted from Jonathan Koch, James Strange,Paul Williams.2012. Bumble Bees of the Western United States. A product of the U.S. Forest Service and the Pollinator Partnership
with funding from the National Fish and Wildlife Foundation|
Select food plant genera: Ebilobium, Lupinus, Rubus, Rosa,
Tongue Length: Medium
Distribution: Almost exclusive to Pacific coastline in the U.S.
except for populations found in the Sawtooth wilderness of
Can be confused with B. flavifrons, B. mixtus, and
Females (queens and workers, colors refer to ‘hair’)
Thorax anterior to the wing bases black and yellow
intermixed (clouded), scutellum black, sometimes with
yellow/white intermixed laterally, T1-2 yellow, T3 black,
T4-5 with pale hairs, face square.
Mid leg basitarsus with the distal posterior corner
rounded. Cheek length longer than broad. Hair of the
face and top of head with black and yellow intermixed,
ocelli large and at supraorbital line. On the side of the
thorax, the lower anterior surface with black and yellow
intermixed (cloudy). Corbicular fringes long and with
yellowish-red hairs. Hair length medium and uneven.