Latest CCD

[Kurt Bower]

WASHINGTON, Sept. 6--A team led by scientists from the U.S.
Department of Agriculture's Agricultural Research Service (ARS),
Pennsylvania State University (PSU), and Columbia University (CU) has
found an association between colony collapse disorder (CCD) in honey
bees and a honey bee virus called Israeli acute paralysis virus,
according to a paper published in the journal Science this week.

ARS entomologist Jeffery S. Pettis, research leader of the agency's
Bee Research Laboratory in Beltsville, Md.; Diana L. Cox-Foster, a
professor in the PSU Department of Entomology; and W. Ian Lipkin,
director of the Center for Infection and Immunity at the Columbia
University Mailman School of Public Health, led the team that did
genetic screening of honey bees collected from 30 colonies with CCD
and 21 colonies with no CCD from four locations in the United States.

The genetic screening allowed the researchers to identify pathogens
to which the sampled honey bees had been exposed. In total, the honey
bees--both CCD and non-CCD honey bees--were found to harbor six
symbiotic types of bacteria and eight bacterial groups, 81 fungi from
four lineages, and seven viruses.

The search for potential pathogens was done using a new means of
sequencing the genetic material from the healthy and unhealthy bees.
This technology, termed high-throughput sequencing, allows for an
unbiased look at DNA from all the organisms, bacteria, fungi and
viruses present in the bees. Then the DNA sequences are searched
against known genomic libraries for best matches. This gives a very
precise picture of the organisms present, at least to the family or
genus level. Often specific species can be identified, and unknown
organisms--if present--can also be catalogued for further study. The
sequencing work was led by Michael Egholm, vice president of 454 Life
Sciences Corp. of Branford, Conn., followed by a large group effort
to further identify specific groups of microorganisms.

The only pathogen found in almost all samples from honey bee colonies
with CCD, but not in non-CCD colonies, was the Israeli acute
paralysis virus (IAPV), a dicistrovirus that can be transmitted by
the varroa mite. It was found in 96.1 percent of the CCD-bee samples.

This is the first report of IAPV in the United States. IAPV was
initially identified in honey bee colonies in Israel in 2002, where
the honey bees exhibited unusual behavior, such as twitching wings
outside the hive and a loss of worker bee populations. IAPV has not
yet been formally accepted as a separate species; it is a close
relative of Kashmir bee virus, which has been previously found in the
United States.

"This does not identify IAPV as the cause of CCD," said Pettis. "What
we have found is strictly a strong correlation of the appearance of
IAPV and CCD together. We have not proven a cause-and-effect
connection."

Even if IAPV proves to be a cause of CCD, there may also be other
contributing factors--which researchers are pursuing--that stress the
bee colony and allow the virus to replicate.

The next step is exposing healthy hives to IAPV and seeing if CCD
develops.

CCD became a matter of concern in the winter of 2006-2007 when some
beekeepers began reporting losses of 30 to 90 percent of their hives.
While colony losses are not unexpected during winter weather, the
magnitude of loss suffered by some beekeepers was highly unusual.

The main symptom is finding no or a low number of adult honey bees
present with no dead honey bees in the hive. Often there is still
honey in the hive and immature bees (brood) are present.

Pollination is a critical element in agriculture, as honey bees
pollinate more than 130 crops in the United States and add $15
billion in crop value annually. There were enough honey bees to
provide pollination for U.S. agriculture this year, but beekeepers
could face a serious problem next year and beyond if CCD becomes more
widespread and no treatment is developed.

More information about CCD can be found at http://www.ars.usda.gov/is/
br/ccd/.

ARS is the U.S. Department of Agriculture's chief scientific research
agency.