The flight of the bumble bee: Why are they disappearing?

A U.S. Department of Agriculture (USDA) scientist is trying to learn what is causing the decline in bumble bee populations and also is searching for a species that can serve as the next generation of greenhouse pollinators.

Bumble bees, like honey bees, are important pollinators of and are used to pollinate greenhouse crops like peppers and tomatoes. But colonies of Bombus occidentalis used for greenhouse pollination began to suffer from disease problems in the late 1990s and companies stopped rearing them. Populations of other bumble bee species are also believed to be in decline.

Entomologist James Strange is searching for solutions at the Agricultural Research Service (ARS) Pollinating Insects-Biology, Management and Systematics Research Unit in Logan, Utah. ARS is USDA's chief intramural scientific research agency, and this research supports the USDA priority of improving agricultural sustainability.

Many greenhouse growers now use commercially produced Bombus impatiens, a generalist pollinator native to the Midwest and Eastern and Canada. But scientists are concerned about using a bee outside its native range, and some western states restrict the import and use of non-native bees. If B. impatiens were to escape and form wild colonies in the western United States, they could compete with for food and resources and expose native to pathogens they are ill equipped to combat.

Strange has been studying a pretty, orange-striped generalist named Bombus huntii, native to the western half of the country, that could be used in greenhouses in the western United States. He is determining how to best rear B. huntii in a laboratory setting, a vital step in commercializing it.

To understand the decline of B. occidentalis, Strange and his colleagues also have been tracking its habitat range and . Evidence gathered so far shows that the range and populations of B. occidentalis have declined, that it is not as genetically diverse as it used to be, and that it has higher pathogen prevalence than other bee species with stable populations. The results were recently published in the Proceedings of the National Academy of Sciences.

The researchers also have assembled a large database with information on more than 80,000 Bombus specimens representing 10 species throughout the country, including B. occidentalis. With Geographic Information System (GIS) modeling technology, they were able to construct historic and current range maps of several bumble bee species. The mapping process is described in the Uludag Bee Journal.

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More information: Read more about this research in the August 2011 issue of Agricultural Research magazine.
Provided by United States Department of Agriculture
Citation: The flight of the bumble bee: Why are they disappearing? (2011, August 11) retrieved 15 September 2019 from
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Aug 11, 2011
Ask Monsanto, they sure know the reasons of the decline of the bee and bumble bee populations.

Aug 11, 2011
Ask Monsanto, they sure know the reasons of the decline of the bee and bumble bee populations.
It's my theory, too. IMO the bees, bumblebees or even some bats are poisoned with GMO pollens. These GMO pollens aren't toxic for bees, but they contain a foreign proteins of soil bacteria, which the immune systems of bees tries to fight with - but without success, because these proteins cannot be killed and they're coming with food again and again. It forces the immune system to gradually increase the number and level of antigens, which is the principle of so called allergization. Such excited immune system can initiate a violent allergic reaction even in contact with proteins, which are quite harmless under normal circumstances.

The problem is, this kind of allergy develops slowly and it makes the bees/bats vulnerable during their hibernation in winter.

Aug 11, 2011
Hopefully there is something to fill the niche. This is bad news. This year I haven't seen a single Honeybee in my garden. A lot of Bumblebees though. A few of some really small green bees too.

Aug 12, 2011
The problem with bees and bumble bees is that once they disappeared, they are gone for good. It's not that we can make new ones in a factory and replace them, like we do with fish. So what would Monsanto shareholders do once the bees disappear? They will just invest in sheep or horses or whatnot.

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