Bumble Bee Conservation
On February 10, 2010, a broad coalition of scientists submitted a letter to the USDA’s Animal and Plant Health Inspection Service (APHIS) requesting that they create new regulations to protect wild bumble bees from threats posed by commercial bumble bees. The letter was signed by over 60 scientists with research on bumble bees and other bees, including: Charles D. Michener, Ph.D., author of The Bees of the World; Bernd Heinrich, Ph.D., author of Bumblebee Economics; David Goulson, Ph.D., author of Bumblebees: Their Behaviour, Ecology and Conservation, James Thomson, Ph.D., co-author of The Natural History of Bumble Bees; and May Berenbaum, Ph.D., Chair of the National Research Council Committee on the Status of Pollinators in North America. Letters of support were also submitted by native plant societies, sustainable agriculture organizations and conservation organizations.
On January 12, 2010, The Xerces Society, Defenders of Wildlife, Natural Resources Defense Council and Dr. Robbin Thorp submitted a petition to the USDA’s Animal and Plant Health Inspection Service (APHIS) requesting that they create new regulations to protect wild bumble bees from disease. In order to prevent the spread of disease to wild populations of agriculturally significant bee pollinators, petitioners asked APHIS to use its authority to regulate the movement and health of commercial bumble bees. Specifically, petitioners requested that APHIS create rules prohibiting the movement of bumble bees outside of their native ranges and regulate interstate movement of bumble bee pollinators within their native ranges by requiring permits that show that bumble bees are certified as disease-free prior to movement. Read more about this action. Read the petition.
A recent status review by Dr. Robbin Thorp and The Xerces Society established that at least four species of formerly common North American bumble bees have experienced steep declines; two of those species teeter on the brink of extinction. A major threat to the survival of these wild bees is the spread of diseases from commercially produced bees that are transported throughout the country.
For a brief summary of this issue, read our fact sheet.
In the late 1990′s, bee biologists started to notice a decline in the abundance and distribution of several wild bumble bee species. Three of these species (western bumble bee, rusty patched bumble bee, and yellowbanded bumble bee) were once very common and important crop pollinators over their ranges. Franklin’s bumble bee was historically found only in a small area in southern Oregon and northern California, and it may now be extinct. The dramatic decline in wild populations of these species occurred about the time that a disease outbreak was reported in populations of commercially raised western bumble bees, which were distributed for greenhouse pollination in western North America. The timing of this suggests that an escaped exotic disease organism may be the cause of this widespread loss.
There are a number of threats facing bumble bees, any of which may be leading to the decline of these species. The major threats to bumble bees include: spread of pests and diseases through commercial bumble bee rearing or other methods, habitat destruction or alteration, pesticides, invasive species, and climate change.
Commercial bumble bee rearing may be the greatest threat to B. affinis, B. occidentalis, B. terricola, and B. franklini. In North America, two bumble bee species have been commercially reared for pollination of greenhouse tomatoes and other crops: B. occidentalis and B. impatiens. Between 1992 and 1994, queens of B. occidentalis and B. impatiens were shipped to European rearing facilities, where colonies were produced then shipped back to the U.S. for commercial pollination. Bumble bee expert Robbin Thorp has hypothesized that these bumble bee colonies acquired a disease (probably a virulent strain of the microsporidian Nosema bombi) from a European bee that was in the same rearing facility, the buff-tailed bumble bee (Bombus terrestris). The North American bumble bees would have had no prior resistance to this pathogen. Dr. Thorp hypothesizes that the disease then spread to wild populations of B. occidentalis and B. franklini in the West (from exposure to infected populations of commercially reared B. occidentalis), and B. affinis and B. terricola in the East (from exposure to commercially reared B. impatiens). In the late 1990′s, biologists began to notice that B. affinis, B. occidentalis, B. terricola, and B. franklini were severely declining.
Where these bees were once very common, they were nearly impossible to find. B. impatiens has not shown a dramatic decline; Robbin Thorp hypothesizes that B. impatiens may serve as a carrier of an exotic strain of Nosema bombi, although it may not be as severly affected by the disease as B. affinis, B. occidentalis, B. terricola, and B. franklini. B. affinis, B. occidentalis, B. terricola, and B. franklini are closely related to each other (they all belong to the subgenus Bombus sensu stricto).
All bumble bees belong to the genus Bombus within the family Apidae. The family Apidae includes the well-known honey bees and bumble bees, as well as carpenter bees, cuckoo bees, digger bees, stingless bees, and orchid bees. B. affinis, B. terricola, B. occidentalis, and B. franklini all belong to the same sub-genus of Bombus, Bombus sensu stricto.
Bumble bees are important pollinators of wild flowering plants and crops. As generalist foragers, they do not depend on any one flower type. However, some plants do rely on bumble bees to achieve pollination. Loss of bumble bees can have far ranging ecological impacts due to their role as pollinators. In Britain and the Netherlands, where multiple bumble bee and other bee species have gone extinct, there is evidence of decline in the abundances of insect pollinated plants. Bumble bees are also excellent pollinators of many crops. Bumble bees are able to fly in cooler temperatures and lower light levels than many other bees, and they perform a behavior called “buzz pollination,” in which the bee grabs the pollen producing structure of the flower in her jaws and vibrates her wing musculature causing vibrations that dislodge pollen that would have otherwise remained trapped in the flower’s anthers. Some plants, including tomatoes, peppers, and cranberries, require buzz pollination. Read more.
xerces
org) and send a photo if you have observed the western bumble bee (Bombus occidentalis), Franklin’s bumble bee (Bombus franklini), the rusty-patched bumble bee (Bombus affinis), or the yellowbanded bumblebee (Bombus terricola), so that we can piece together the current distribution of these bees. If you do research on bumble bees, have incidental bumble bees in your collection, or have student insect collections from the past few years, it would help us to know if you have or have not seen these bees. It is as important for us to document where these bees were formerly common, but not recently collected, as it is to document where they were collected. Please visit the individual species pages to see the former range of each of these bees.
If you have seen a bumble bee nest, please take a few minutes to fill out a survey about your observations. The results of this survey will increase our understanding of bumble bee nesting biology.
A number of scientists and citizen monitors have contributed their unpublished records of bumble bees or other information to this effort; we greatly appreciate their collaboration:
Bernd Heinrich, Professor Emeritus, University of Vermont
Chiho Kimoto and Sandy DeBano, Oregon State University, Hermiston Field Station
Chris Maier, Connecticut Agricultural Experiment Station
Christina North, University of Illinois
David W. Inouye, University of Maryland
Dale Reimer, retired
Doug Golick, University of Nebraska
Elaine Evans
Elizabeth Elle, Simon Fraser University
Howard Ginsburg, USGS Patuxent Wildlife Research Center
James Strange, USDA-ARS Logan-Bee Lab
Jennifer Grixti and Colin Favret, University of Illinois
Jodi DeLong, freelance writer
John Neff, Central Texas Melittological Institute
Kevin Alexander, Western State College of Colorado
Larry Stevens, Museum of Northern Arizona
Lee Solter, Illinois Natural History Survey
Liz Day
Matthew Bowser, Kenai National Wildlife Refuge
Michael Otterstatter, University of Toronto
Mike Quinn
Pete Schroeder, Southern Oregon University
Ralph Cartar, University of Calgary
Rebecca Irwin, Dartmouth College
Robbin Thorp, Professor Emeritus, U.C. Davis
Robert Jacobson
Robert Jean and Peter Scott, Indiana State University
Sheila Colla, graduate student of Laurence Packer, York University
Sam Droege, USGS Patuxtent Wildlife Research Center
Steve Hendrix and Chris Gienapp, University of Iowa
Sydney Cameron, University of Illinois
Sue Sheehan, Fermilab, Batavia, IL
T’ai Roulston, Research Associate Professor, University of Virginia