Morrison bumble bee, Bombus morrisoni

Please reference the Embedded Range Maps page to better interpret
# of observations per ecoregion.

I have never encountered the Morrison bumble bee, Bombus morrisoni in the wild in Washington state. I have actively looked. There is evidence that the range of B morrisoni’s has been strongly contracting over the last decade or so. If we have any morrisoni left as a breeding population in Washington, I am concerned about how much longer they will be able to remain and participate on Washington’s landscape.

If you encounter a suspected morrisoni in the field, please get good pictures. A positive ID can be made just from photographs for this species, so it would be better to use a non-lethal approach to documenting any individuals you encounter.

Field ID tips

This is a good sized bumble bee, similar to the Nevada bumble bee.

The Morrison bumble bee has a yellow scutum, alar and scutellum

T1 & T2 are yellow. T3 is mainly yellow but may show some black on the sides.

It has a short cheek.

Similar Species

The Nevada bumble bee is the most similar species. It will show a black dot between the wings and T3 will be all yellow. Relative to the Morrison bumble, nevadensis has a long cheek and therefor a very different face shape.

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Washington's bumble bees

Bumble Bees of Washington State

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