Rusty-patched Bumble Bee Bombus affinis Cresson, 1863Endangered (Federal)  -  S1 (Highly state rare)    Synonyms: Rusty Patched Bumble Bee.
Kingdom Animalia   >   Phylum Arthropoda   >   Class Insecta   >   Order Hymenoptera   >   Family Apidae   >   Genus Bombus   

Status:

In 2017, the Rusty-patched Bumblebee (Bombus affinis) had the dubious distinction of being the first bee to be listed as federally Endangered. This formerly common bee species went into rapid and steep decline in the mid 1990s into the 2000s for reasons that are not entirely clear. Many historical sites that were traditionally occupied yearly failed to yield any bees despite intensive, targeted searches by experts. Theories for the decline include the introduction of a pathogen from managed colonies of commercial bumblebees used for crop pollination, habitat fragmentation, or pesticide use (Williams et al. 2014).

Relationships:

Research on samples from two nests in Minnesota by Simanonok, et al. (2024) supports the view that the Rusty-patched Bumble Bee is a generalist forager and will collect pollen from a variety of native and non-native host plants.

There are 15 records in the project database.

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A male Rusty-patched Bumble Bee in Tucker Co., West Virginia (11/1/2018). Collected by Justin DeVault. Photo by USGS PWRC. (MBP list)

A male Rusty-patched Bumble Bee in Tucker Co., West Virginia (11/1/2018). Collected by Justin DeVault. Photo by USGS PWRC. (MBP list)

A male Rusty-patched Bumble Bee in Tucker Co., West Virginia (11/1/2018). Collected by Justin DeVault. Photo by USGS PWRC. (MBP list)

A male Rusty-patched Bumble Bee (dorsal) collected in Racine, Wisconsin, by W.L. Macior. Photo by USGS PWRC. (MBP list)

A male Rusty-patched Bumble Bee (face) collected in Racine, Wisconsin, by W.L. Macior. Photo by USGS PWRC. (MBP list)

A male Rusty-patched Bumble Bee (lateral) collected in Racine, Wisconsin, by W.L. Macior. Photo by USGS PWRC. (MBP list)

A queen Rusty-patched Bumble Bee (dorsal) collected by L.W. Macior in Racine, Wisconsin (1965). Photo by USGS PWRC. (MBP list)

A queen Rusty-patched Bumble Bee (face) collected by L.W. Macior in Racine, Wisconsin (1965). Photo by USGS PWRC. (MBP list)

A queen Rusty-patched Bumble Bee (ventral) collected by L.W. Macior in Racine, Wisconsin (1965). Photo by USGS PWRC. (MBP list)

A queen Rusty-patched Bumble Bee (head) collected by L.W. Macior in Racine, Wisconsin (1965). Photo by USGS PWRC. (MBP list)

A female Rusty-patched Bumble Bee in Long Island, New York (3/1/2018). Collected by Roy Lantham. Image processed by Greta Forbes. Photo by USGS PWRC. (MBP list)


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