Flight of the Bumblebee

source: BBC News

Researchers at the University of Oxford have been studying the bumblebee's (Bombus sp.) flight mechanics with the aid of high speed photography. They found that the relatively heavy insect is not a graceful flyer in the manner of the hummingbird, perhaps the epitome of flight evolution, but uses brute force to stay aloft. Bumblebee wings flap independently 130 or more times a second, powered by large flight muscles that make up most of the insect's thorax. Research into pollinators is increasing as the decline in native bee species make their crucial role in agriculture evermore apparent to humans. Experts have put a number on bees' pollination services of $3 billion annually in the United States alone. How they would be replaced if they go extinct is not clear to scientist or agriculturalists. Chinese farmers have already resorted to manual pollination in some cases. Bumblebees are especially suited for tomato crops which they "buzz pollinate", shaking the pollen loose from the tomato bloom. They are hardier than honey bees and forage at low temperatures, often when it is raining or windy. Bumblebees are social, but make new nests underground every year. They also appear to "plan" their foraging journeys according to University of London scientists studying bumblebee flight patterns in a Surrey enclosure. Flight is energetically very expensive so bees must minimize distances they fly, yet honey bees can fly a round trip of 20kms.

The causes of bumblebee decline are controversial. In Europe intensive farming and prolonged pesticide use are considered the primary causes by apian expert Dave Goulson, who formed the Bumblebee Conservation Trust to aid the insects' survival. Habitat such as hedges where bumblebees like to nest were ripped out during the "Dig for Victory" campaign during WWII.  Bad weather and lack of food in the early spring also take a heavy toll on "bomblebees". Now, Britian is facing a bee shortage. British scientists are importing short-haired bumblebees from Sweden in an effort to repopulate the island. This species of bumblebee went extinct in England in 1988.

In the United States both wild and domesticated bees are suffering population declines, but the subject of cause has become embroiled in political fights over the use of neonicotinoids which were finally banned in Europe on an experimental basis. Since 2006 the US government estimates 10 million bee hives have collapsed. This past winter beekeepers reported hive losses of 40 to 50%. Neonicontinoids are used on 95% of corn and canola crops and the majority of cotton, sorghum and sugar beets and about half of soybeans. A recent report on "Honey Bee Health" issued by the Department of Agriculture attributed the cause of honey bee decline to a combination of factors including pesticides, but concludes the major cause of bee death is the parasitic mite Varroa destructor. The US is nowhere near banning neonicotinoid use and in fact the EPA recently approved the unconditional registration of another pesticide which agency classifies at toxic to bees. The agency dismissed concerns of beekeepers and environmentalists about sulfoxaflor, a systemic pesticide that persists in the environment like neonicotinoids. It's neurological effect on honeybees is also similar. The agency choose to simply limit its application rate, a use limitation often ignored in the field. A California study found that 80% of the state's waterways are contaminated with pesticides. The refusal of the EPA to recognize the toll chronic pesticide--not just neonicotinoids--poisoning is exacting on bee health is a testament to the strength of the chemical lobby in Washington. When it comes to pollinators like bees which are responsible for a third of the food humans consume, we are all "stakeholders".