|NY Times, April 24, 2007
Bees Vanish, and Scientists Race for Reasons
By ALEXEI BARRIONUEVO
BELTSVILLE, Md., April 23 — What is happening to the bees?
MORE THAN A quarter of the country’s 2.4 million bee colonies have been lost — tens of billions of bees, according to an estimate from the Apiary Inspectors of America, a national group that tracks beekeeping. So far, no one can say what is causing the bees to become disoriented and fail to return to their hives.
As with any great mystery, a number of theories have been posed, and many seem to researchers to be more science fiction than science. People have blamed genetically modified crops, cellular phone towers and high-voltage transmission lines for the disappearances. Or was it a secret plot by Russia or Osama bin Laden to bring down American agriculture? Or, as some blogs have asserted, the rapture of the bees, in which God recalled them to heaven? Researchers have heard it all.
The volume of theories “is totally mind-boggling,” said Diana Cox-Foster, an entomologist at Pennsylvania State University. With Jeffrey S. Pettis, an entomologist from the United States Department of Agriculture, Dr. Cox-Foster is leading a team of researchers who are trying to find answers to explain “colony collapse disorder,” the name given for the disappearing bee syndrome.
“Clearly there is an urgency to solve this,” Dr. Cox-Foster said. “We are trying to move as quickly as we can.”
Dr. Cox-Foster and fellow scientists who are here at a two-day meeting to discuss early findings and future plans with government officials have been focusing on the most likely suspects: a virus, a fungus or a pesticide.
About 60 researchers from North America sifted the possibilities at the meeting today. Some expressed concern about the speed at which adult bees are disappearing from their hives; some colonies have collapsed in as little as two days. Others noted that countries in Europe, as well as Guatemala and parts of Brazil, are also struggling for answers.
“There are losses around the world that may or not be linked,” Dr. Pettis said.
The investigation is now entering a critical phase. The researchers have collected samples in several states and have begun doing bee autopsies and genetic analysis.
The national research team also quietly began a parallel study in January, financed in part by the National Honey Board, to further determine if something pathogenic could be causing colonies to collapse.
Mr. Hackenberg, the beekeeper, agreed to take his empty bee boxes and other equipment to Food Technology Service, a company in Mulberry, Fla., that uses gamma rays to kill bacteria on medical equipment and some fruits. In early results, the irradiated bee boxes seem to have shown a return to health for colonies repopulated with Australian bees.
“This supports the idea that there is a pathogen there,” Dr. Cox-Foster said. “It would be hard to explain the irradiation getting rid of a chemical.”
Still, some environmental substances remain suspicious.
Chris Mullin, a Pennsylvania State University professor and insect toxicologist, recently sent a set of samples to a federal laboratory in Raleigh, N.C., that will screen for 117 chemicals. Of greatest interest are the “systemic” chemicals that are able to pass through a plant’s circulatory system and move to the new leaves or the flowers, where they would come in contact with bees.
One such group of compounds is called neonicotinoids, commonly used pesticides that are used to treat corn and other seeds against pests. One of the neonicotinoids, imidacloprid, is commonly used in Europe and the United States to treat seeds, to protect residential foundations against termites and to help keep golf courses and home lawns green.
In the late 1990s, French beekeepers reported large losses of their bees and complained about the use of imidacloprid, sold under the brand name Gaucho. The chemical, while not killing the bees outright, was causing them to be disoriented and stay away from their hives, leading them to die of exposure to the cold, French researchers later found. The beekeepers labeled the syndrome “mad bee disease.”
The French government banned the pesticide in 1999 for use on sunflowers, and later for corn, despite protests by the German chemical giant Bayer, which has said its internal research showed the pesticide was not toxic to bees. Subsequent studies by independent French researchers have disagreed with Bayer. Alison Chalmers, an eco-toxicologist for Bayer CropScience, said at the meeting today that bee colonies had not recovered in France as beekeepers had expected. “These chemicals are not being used anymore,” she said of imidacloprid, “so they certainly were not the only cause.”
Among the pesticides being tested in the American bee investigation, the neonicotinoids group “is the number-one suspect,” Dr. Mullin said. He hoped results of the toxicology screening will be ready within a month.