The Yellow bumble bee, Bombus fervidus, is, in Washington state, very much an east side species.
I have encountered it primarily in SE Washington, in and around the Blue Mountains.
Please reference the Embedded Range Maps page to better interpret
# of observations per ecoregion.
Field ID tips
Identification of the Yellow bumble bee, Bombus fervidus, is relatively straight-forward.
- area between wings (alar) black
- T1 = yellow
- T2 = yellow
- T3 = yellow
- T4 = yellow
- T5 = black
- T6 = black
This is a sturdy bumble and easily noticed as it buzzes through the mountain wildflowers.
The yellow form of the California bumble bee will be very similar to the Yellow bumble bee, but shows some black on T2 and T3. There is disagreement about whether the California bumble bee is a subspecies of the Yellow. The two distinct forms come together in the Willamette Valley of Oregon, and you can see some of the mixed patterns that result.
White-shouldered bumble bee, B. appositus, will have distinctly different color shoulders (white) relative to the golden yellow of the abdomen.
The Nevada bumble bee, B. nevadensis shows a lot of yellow on it’s thorax and T1, T2 and T3. T4 and T5 will be black.
Males of several other species are yellow. See example below. Look for the lack of a corbiculum.