Yellow-Faced Bumble Bee?

This bumble bee was visiting our native buckwheat patch several days ago.

From a distance I thought it was a Yellow-Faced bumble bee Bombus vosnesenskii

As I took these photos, zooming in I realized that the bee actually looked different in marking and coloring.

The Bombus vosnesenskii normally would be completely black with yellow face and a yellow stripe near its tail.

This bee has brown and black stripes.

After referring to my bee "bible" 'California Bees & Blooms' by Gordon W. Frankie, Robbin W. Thorp, Rollin E. Coville and Barbara Ertter, I was still stumped.

I started to think that perhaps this is actually a Cuckoo bee, one of those that steal nests and food from other bee species. After viewing bee photos and numerous entomology websites and still coming up with no answers, I finally turned to a local pollinator group of which I'm a member on facebook, posting these same photos.

It turns out that this bee is indeed a Yellow-Faced bumble bee.

Based on the loss of hair on top of the thorax and worn out wings, this is an elderly bee.

Wear and tear on the abdomen resulted in what look like lighter bands of hair.

Something new is learned every day, when you pay attention to what goes on around you.