Newly Discovered Virus May be Killing Bees - Study
Date: 07-Sep-07
Country: US
Author: Maggie Fox, Health and Science Editor
While the virus probably does not alone account for what
scientists call colony collapse disorder, or CCD, it could help
explain what is happening to bees across the United States,
they said.
The virus, called Israeli acute paralysis virus, or IAPV,
was discovered in Israel in 2004 and is new to science.
CCD hit an estimated 23 percent of all beekeeping
operations in the United States during the winter of 2006-7.
"These beekeepers lost an average of 45 percent of their
operations," the researchers wrote in their report, published
in the journal Science.
Beekeepers do not find bees dead -- they simply find the
hives nearly empty, with the queens alone and workers gone.
Honeybees originally imported from Europe are used to
pollinate US$14.6 billion worth of fruits, nuts and other US
crops annually. Bees also have disappeared from hives in Brazil
and across Europe.
A team led by Dr. Ian Lipkin, an expert in the spread of
infectious diseases at Columbia University in New York, ground
up bee samples from across the United States and compared them
to non-affected bees from Pennsylvania and Hawaii. They also
looked at bees imported from Australia and samples of a bee
product called royal jelly from China.
They then sequenced the genomes -- the entire collection of
DNA -- and looked for genes from bacteria, viruses and
parasites. They found five major bacterial groups, four
lineages of fungi and seven types of viruses.
LOADED WITH VIRUSES
"We found a remarkably high viral burden in bee populations
-- both those that have CCD and not," biologist Edward Holmes
of Pennsylvania State University told reporters in a telephone
briefing.
Only one was always associated with CCD -- IAPV.
"Whether it is a causative agent or a very good marker is
the next major question that we need to address," said Diana
Cox-Foster, an entomology professor at Penn State. A marker
might mean that something else that was making the bees
disappear also helped them become infected with the virus.
Jeffery Pettis of the US Department of Agriculture's Bee
Research Laboratory in Maryland said IAPV was only one of
several leads that must still be followed.
"I hope no one goes away with the idea that we have
actually solved the problem," Pettis told the briefing.
"I still believe that multiple factors must be involved in
CCD." Perhaps interactions among parasites, viruses and
nutrition could be involve, he said.
IAPV can by transmitted by the varroa mite, a parasite
known to affect US bees.
Lipkin said in a telephone interview the next step is to
infect healthy bees with IAPV and see if their colonies then
collapse, as seen in CCD.
Cox-Foster said the team was also looking at other possible
causes of CCD, although some leads were being pursued more
urgently than others.
"We have very little evidence that the radiation from
cellphones could impact bees," she said.
She said tests also have shown that genetically modified
crops have no ill effects on bees, although chemical pesticides
could be adding stress.
As for why the bees disappear, Cox-Foster said they may
deliberately avoid returning to the hive when they begin to
feel ill, perhaps to protect their sisters and the queen.