New report finds that bumble bees have undergone dramatic declines

Contacts:

  • Scott Hoffman Black, Executive Director, The Xerces Society for Invertebrate Conservation, (503) 449-3792
  • Dr. Robbin Thorp, Professor emeritus, University of California Davis, (530) 752-0482

Portland OR: An extensive review of bumble bee studies and surveys from across the U.S. show that three formerly common bumble bee species are experiencing steep declines.  The report compiled information from more than three dozen scientists and citizen monitors and found that populations of the rusty-patched, yellowbanded and western bumble bee have all sharply dropped in the last decade.

The declines are especially alarming in light of the loss of honey bees to Colony Collapse Disorder. Bumble bees are important pollinators and can be an excellent insurance policy when honey bees are in short supply.

Read the complete Status Review >>

  • The rusty-patched bumble bee (Bombus affinis) was once common and widespread across 26 Eastern and Midwestern U.S. states and two Canadian provinces. This study indicates that this bumble bee has undergone a dramatic decline across most of its former range.
  • The yellowbanded bumble bee (Bombus terricola) was once regularly found in 21 Eastern and Midwestern U.S. states and seven Canadian provinces. Although some individuals were found in isolated parts of its range between 2005 and 2008, this study suggests that this bumble bee has drastically declined in large parts of its range.
  • The western bumble bee (Bombus occidentalis) was once among the three most common bumble bees in the western U.S.; it was widespread across 14 western U.S. states and four Canadian provinces. While it is still be found in some areas in the northern and eastern parts of its historic range, this report reveals that the bumble bee has undergone a dramatic decline in British Columbia, Washington, Oregon and California.

While the cause of these declines is still undetermined, we conclude that an escaped exotic disease organism carried by commercially reared bumble bee colonies is the most likely cause of these widespread losses. The authors believe that it is important for the USDA’s Animal and Plant Heath Inspection Service to begin regulating the movement of native bees within the U.S. to ensure that we can prevent the unnecessary spread of disease to these valuable pollinators.

Read the complete Status Review >>
Read more about bumble bees in decline >>


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