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.
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 University, 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.
