West Lafayette, Indiana
August 20, 2008
A combination of pathogens,
pesticides and parasites may underlie such a massive
disappearance of honeybees that agricultural production may be
threatened, says a Purdue
University researcher.
Greg Hunt, a Purdue apicultural researcher and geneticist, is
collaborating with 19 scientists from around the country to
launch an in-depth study of bees' behavior, lives, illnesses and
deaths to define the syndrome known as colony collapse disorder
(CCD). The investigators' goal is to find ways to restore bee
colonies and keep them safe.
Hunt and his team are using genomics to investigate honeybee
diseases and to indentify genes that make the insects resistant
to a particularly harmful parasite and to pathogens. Other
project collaborators will do genetic testing and observe bees
in laboratories and in colonies as they try to discover what's
causing losses of whole colonies.
"This project is about honeybee health because it is likely more
than one factor is involved in CCD," Hunt said. "It's a mystery
whether colony collapse is truly something new or whether it's a
combination of factors."
Colony collapse disorder is not a disease, it's a syndrome, he
said. A disease is caused by a known pathogen while a syndrome
is a set of symptoms. At least 24 states, Canada and most
European countries have reported cases of CCD; Indiana is not
among them.
"There could be a lot of things that make bees forget where they
live and not return to the hive," Hunt said. "They could have
any number of diseases that might potentially cause these types
of symptoms. But in the experience of researchers and beekeepers
looking at colony collapse disorder, it seems to be something
new."
Bees carry pollen to flowering plants, including everything from
wildflowers to the food we eat, so that plants are fertilized
and can produce fruits and vegetables. Loss of honeybees could
be devastating for many plants, especially food crops.
Hunt and his team at Purdue will develop diagnostic genetic
tools to detect diseases and monitor honeybees. They will search
for viral proteins and study at virus genomes. They also will
study bee genomes to develop more breeding programs in which the
pollinators are resistant to mites and pathogens.
Varroa mites play a large part in dwindling bee colonies because
not only are the parasites weakening the bees, but they also
transmit viruses to the bees. The already weak bees then succumb
more easily to the viruses.
"Varroa mites are the worst problem in beekeeping worldwide in
my opinion because it's so virulent," Hunt said.
In addition to Varroa mites, another contributor to the bees'
disappearance is Nosema, a type of fungus that causes disease
when bees ingest the Nosema spores, Hunt said.
What is now known as colony collapse disorder came to the
forefront in summer 2006 and winter of 2006-2007 when high death
rates of bee colonies suddenly occurred. Before the arrival of
the mites in the 1980s, beekeepers expected to lose about 10
percent of their hives annually. Now some are losing as many as
90 percent.
The Apiary Inspectors of America
report that last winter 35 percent of U.S. bee colonies were
lost in the United States. Purdue lost 10 percent of its hives
last year, which is about normal, Hunt said.
If high hive losses continue, it could be devastating to
agriculture. Approximately 1.3 million beehives are needed every
year just to pollinate the almond plants grown in California.
It's estimated the number of beehives in the country is only a
little more than 2 million.
Nineteen other researchers and their labs from 17 institutions
are part of the collaboration. Keith Delaplane from the
University of Georgia-Atlanta is the principal investigator. The
institutions in addition to Purdue and the University of Georgia
are: UCLA-Riverside; the Connecticut Agricultural Experiment
Station; Cornell University; Kentucky State University;
University of Maine; University of Massachusetts; Michigan State
University; University of Minnesota; University of
Nebraska-Lincoln; Pennsylvania State University; the University
of Tennessee; The USDA Baton Rouge, La., Bee Laboratory; USDA
Weslaco, Texas, Bee Laboratory; and Washington State University. |
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