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.
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!
See individual species accounts for more details and images.