Sitka bumble bee, Bombus sitkensis

Field ID tips

The thorax area in front of the wings (anterior thorax) is cloudy-a mixture of yellow and black hairs. The rear of the thorax (scutellum) is black. It may show some yellow on the sides as in the picture above.

The two front segments of the abdomen (T1, T2) are yellow. T3 is black. The end of the abdomen (rear of T4, T5, T6) has faint orange/pale hairs.

Similar Species

Two species that should be ruled out are Yellow head bumble bee, B. flavifrons and Fuzzy-horned bumble bee, B. mixtus. In the first instance, the pale hairs at the end of the tail can be missed (flavifrons). In the second, the red/pale hairs of sitkensis are not as prominent as exhibited by most B. mixtus. Mixtus may also show orange on T3.

Maps are only as good as the dataset used. In this instance Don and David have documented the **Sitka bumble bee** in the NE corner of Washington, an area not highlighted on the map above.

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

As seen in the picture above, the anterior thorax is cloudy, T1 and T2 are yellow. T3 is black. T4 may show lots of black also, but will also have pale hairs. The pale hairs on T5 at the end of the abdomen are also visible.

Tags: bee, bees, Bombus, bumble, Field, ID, identification, Sitka, sitkensis, tips, Washington

This entry was posted on Sunday, July 19th, 2020 at 10:34 pm and is filed under Red at hind end, Red on Abdomen. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.