The two bumbles in Washington that I put into this category are:
Other bumbles may show white, but those species are also striped, so look for them in that grouping.
Western bumble bee, Bombus occidentalis
The Western bumble shows white on T4 and T5.
The White-shouldered bumble is a large bumble bee with white on the front of the Thorax and a golden yellow abdomen. Lisa’s father-in-law describes it as “wearing white oversized shoulder pads”. Just in time for football season!
White-shouldered bumble bee, Bombus appositus
See individual species accounts for more details and images.
David,
Your photos are amazing! This is a wonderful website, many thanks for all the hours that you’ve put in and for sharing with others.
Thank you! Labor of love.