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Honeybees - Bees Vanish, and
Scientists Race for Reasons
ALEXEI BARRIONUEVO
NY
Times
Tuesday April 23, 2007
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.
So far, known enemies of the bee world, like the varroa mite, on
their own at least, do not appear to be responsible for the unusually
high losses.
Genetic testing at Columbia University has revealed the presence
of multiple micro-organisms in bees from hives or colonies that
are in decline, suggesting that something is weakening their immune
system. The researchers have found some fungi in the affected bees
that are found in humans whose immune systems have been suppressed
by the Acquired Immune Deficiency Syndrome or cancer.
“That is extremely unusual,” Dr. Cox-Foster said.
Meanwhile, samples were sent to an Agriculture Department laboratory
in North Carolina this month to screen for 117 chemicals. Particular
suspicion falls on a pesticide that France banned out of concern
that it may have been decimating bee colonies. Concern has also
mounted among public officials.
“There are so many of our crops that require pollinators,”
said Representative Dennis Cardoza, a California Democrat whose
district includes that state’s central agricultural valley,
and who presided last month at a Congressional hearing on the bee
issue. “We need an urgent call to arms to try to ascertain
what is really going on here with the bees, and bring as much science
as we possibly can to bear on the problem.”
So far, colony collapse disorder has been found in 27 states, according
to Bee Alert Technology Inc., a company monitoring the problem.
A recent survey of 13 states by the Apiary Inspectors of America
showed that 26 percent of beekeepers had lost half of their bee
colonies between September and March.
Honeybees are arguably the insects that are most important to the
human food chain. They are the principal pollinators of hundreds
of fruits, vegetables, flowers and nuts. The number of bee colonies
has been declining since the 1940s, even as the crops that rely
on them, such as California almonds, have grown. In October, at
about the time that beekeepers were experiencing huge bee losses,
a study by the National Academy of Sciences questioned whether American
agriculture was relying too heavily on one type of pollinator, the
honeybee.
Bee colonies have been under stress in recent years as more beekeepers
have resorted to crisscrossing the country with 18-wheel trucks
full of bees in search of pollination work. These bees may suffer
from a diet that includes artificial supplements, concoctions akin
to energy drinks and power bars. In several states, suburban sprawl
has limited the bees’ natural forage areas.
So far, the researchers have discounted the possibility that poor
diet alone could be responsible for the widespread losses. They
have also set aside for now the possibility that the cause could
be bees feeding from a commonly used genetically modified crop,
Bt corn, because the symptoms typically associated with toxins,
such as blood poisoning, are not showing up in the affected bees.
But researchers emphasized today that feeding supplements produced
from genetically modified crops, such as high-fructose corn syrup,
need to be studied.
The scientists say that definitive answers for the colony collapses
could be months away. But recent advances in biology and genetic
sequencing are speeding the search.
Computers can decipher information from DNA and match pieces of
genetic code with particular organisms. Luckily, a project to sequence
some 11,000 genes of the honeybee was completed late last year at
Baylor College of Medicine in Houston, giving scientists a huge
head start on identifying any unknown pathogens in the bee tissue.
“Otherwise, we would be looking for the needle in the haystack,”
Dr. Cox-Foster said.
Large bee losses are not unheard of. They have been reported at
several points in the past century. But researchers think they are
dealing with something new — or at least with something previously
unidentified.
“There could be a number of factors that are weakening the
bees or speeding up things that shorten their lives,” said
Dr. W. Steve Sheppard, a professor of entomology at Washington State
University. “The answer may already be with us.”
Scientists first learned of the bee disappearances in November,
when David Hackenberg, a Pennsylvania beekeeper, told Dr. Cox-Foster
that more than 50 percent of his bee colonies had collapsed in Florida,
where he had taken them for the winter.
Dr. Cox-Foster, a 20-year veteran of studying bees, soon teamed
with Dennis vanEngelsdorp, the Pennsylvania apiary inspector, to
look into the losses.
In December, she approached W. Ian Lipkin, director of the Greene
Infectious Disease Laboratory at Columbia University, about doing
genetic sequencing of tissue from bees in the colonies that experienced
losses. The laboratory uses a recently developed technique for reading
and amplifying short sequences of DNA that has revolutionized the
science. Dr. Lipkin, who typically works on human diseases, agreed
to do the analysis, despite not knowing who would ultimately pay
for it. His laboratory is known for its work in finding the West
Nile disease in the United States.
Dr. Cox-Foster ultimately sent samples of bee tissue to researchers
at Columbia, to the Agriculture Department laboratory in Maryland,
and to Gene Robinson, an entomologist at the University of Illinois.
Fortuitously, she had frozen bee samples from healthy colonies dating
to 2004 to use for comparison.
After receiving the first bee samples from Dr. Cox-Foster on March
6, Dr. Lipkin’s team amplified the genetic material and started
sequencing to separate virus, fungus and parasite DNA from bee DNA.
“This is like C.S.I. for agriculture,” Dr. Lipkin said.
“It is painstaking, gumshoe detective work.”
Dr. Lipkin sent his first set of results to Dr. Cox-Foster, showing
that several unknown micro-organisms were present in the bees from
collapsing colonies. Meanwhile, Mr. vanEngelsdorp and researchers
at the Agriculture Department lab here began an autopsy of bees
from collapsing colonies in California, Florida, Georgia and Pennsylvania
to search for any known bee pathogens.
At the University of Illinois, using knowledge gained from the
sequencing of the bee genome, Dr. Robinson’s team will try
to find which genes in the collapsing colonies are particularly
active, perhaps indicating stress from exposure to a toxin or pathogen.
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.
INFOWARS:
BECAUSE THERE'S A WAR ON FOR YOUR MIND
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