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Rusty Patched Bumble Bee

Bee Identification: Is it a rusty patched bumble bee?

 

If you think you have seen a rusty patched bumble bee, please try to take photographs (photos from the top, side, and head are helpful; see Bee Photography Tips) and upload to bumblebeewatch,  beespotter.org and/or bumblebee brigade. Experts will provide or verify identifications, if it's possible, from the photos.

 

There 21 species of bumble bees in the eastern United States and 48 species in the entire U.S. If you think you have observed a rusty patched bumble bee, below is information to help you with your identification. At the bottom of this page are links to helpful bumble bee identification guides. For more details about how to identify the rusty patched bumble bee, see these guides and Appendix C in our Survey Protocols for Rusty Patched Bumble Bee.

 

Standard insect anatomy terms are used to describe bees for identification. Follow this link to the Xerces Society page that illustrates bumble bee anatomy for identification purposes: https://www.bumblebeewatch.org/anatomy/

 

Queens, Workers and Males

All rusty patched bumble bees have a mostly yellow upper thorax with a black spot or band between the wings that may extend toward the back in a v-shape.

 

The bottom of the thorax is black (not shown on this illustration).

 

 

 

Workers and Males

In workers and males, the first abdominal segment is yellow, and the second has a a patch of rusty hairs on the front portion of the segment, with yellow hairs on the back and sides.

 

Workers can be seen in the field several weeks after nest establishment, throughout the summer, into early fall (late June-September). Males are in flight in late summer and fall (August-September).

 

 

Illustration of a rusty patched bumble bee queen.Queens

Rusty patched bumble bee queens are entirely yellow on the first two abdominal segments and the rest of the abdominal segments are black.

 

The timing for observing queens depends on your geographical location. For example, in southern Wisconsin, queens, distinguished by larger size and other characteristics described above, are in flight in spring (roughly mid March - May) and then again in late summer and fall.

 

Rusty patched bumble bee illustrations by Elaine Evans, University of Minnesota.

 

 

Rusty patched bumble bee

 

In this photo of a rusty patched bumble bee, the yellow thorax with a black spot between the wings that extends toward the back, can be seen.

 

The rusty patch, which is an area of rust-colored hairs, is on the front of the second abdominal segment with yellow hairs on the sides and towards the back of the segment.

Rusty patched bumble bee

Photo courtesy of Susan Day; UW-Madison Arboretum

 

Can Be Confused With

Rusty patched bumble bees can be confused with the: brown-belted bumble bee (Bombus griseocollis), half-black bumble bee (B. vagans), lemon cuckoo bumble bee (B. citrinus), and confusing bumble bee (B. perplexus).

 

Brown belted bumble bee

Brown-belted Bumble Bee

(Bombus griseocollis)

 

Rusty patched bumble bees are most commonly confused with brown-belted bumble bees.

 

The second abdominal segment of the brown belted bumble bee has brown hairs towards the front and black hairs on the sides and back.

 

The brown-belted bumble bee is common in the eastern United States.

Brown-belted bumble bee

Photo by Kim Mitchell; USFWS

 

Helpful bumble bee identification guides

 

Bumble Bees of the Eastern United States by the U.S. Forest Service Adobe PDF Icon

 

Guide to MN Bumble Bees: Females by the Minnesota Bumble Bee Survey and University of Minnesota Bee SquadAdobe PDF Icon

 

Guide to MN Bumble Bees: Males by the Minnesota Bumble Bee Survey and University of Minnesota Bee Squad Adobe PDF Icon

 

Pocket Guide to Identifying the Rusty Patched Bumble Bee by the Xerces Society Adobe PDF Icon

 

Bee Identfication from Survey Protocols for Rusty Patched Bumble Bee: Appendix C Adobe PDF Icon

 

Bee Photography Tips from the Wisconsin Bumble Bee Brigade Volunteer Guide Adobe PDF Icon

 

Standardized Bee Photography from Survey Protocols for Rusty Patched Bumble Bee: Appendix A Adobe PDF Icon

 


Rusty Patched Bumble Bee Home

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Last updated: August 17, 2018