Plagues,
Pestilences and Diseases
Mystery Die Off: SCIENTISTS said say they have identified
four new viruses in honey bee colonies.
* From: AFP
* June 08, 2011 12:05AM
CALIFORNIAN scientists said yesterday they have identified four
new viruses in honey bee colonies, a finding that could help
solve the mystery of mass bee die-offs in some parts of the world.
The previously unknown viruses turned up during a 10-month study
of a commercial beekeeping operation that included more than
70,000 hives and 20 colonies that were transported across the US
to pollinate crops.
The colonies appeared healthy and did not see any of the mass
deaths that have eradicated as much as 30 percent of the US
population of honey bees since 2006.
Understanding the 27 unique honey bee viruses - including four new
ones and others possibly involved in colony collapse - and how
they circulate in healthy populations could offer scientists a
baseline for further study.
"You can't begin to understand colony die-off without
understanding what normal is," said senior author Joe DeRisi,
professor of biochemistry and biophysics at the University of
California, San Francisco.
Honey bee colony declines in recent years have reached 10 to 30
percent in Europe, 30 percent in the US and up to 85 percent in
Middle East, according to a UN report on the issue released
earlier this year.
Honey bees are critical to global agriculture. They pollinate more
than 100 different crops, representing up to $83 billion in crop
value world wide each year and roughly one-third of the human
diet.
According to co-author Michelle Flenniken of the study published
in the online journal PloS One, the patterns of infection show
that more than one factor is likely to blame for colony collapse.
"Clearly, there is more than just exposure involved," said
Flenniken.
"We noticed that specific viruses dominated in some seasons, but
also found that not all of the colonies tested positively for a
virus at the same time, even after long-distance transport in
close proximity."
The researchers also found six species of bacteria and six fungi,
four types of mites and a parasitic fly called a phorid, which had
not previously been seen in honey bees outside California.
Among the four newly discovered viruses was one that "turned out
to be the primary element of the honey bee biome, or community of
bacteria and viruses," said the study, identifying it as a strain
of the Lake Sinai virus.
Hundreds of millions of its viral cells were "found in each bee in
otherwise healthy colonies at certain times of the year," said the
research.
"Here's a virus that's the single most abundant component of the
bee biome and no one knew it was there," said DeRisi said.
World health experts believe some combination of parasites, viral
and bacterial infections, pesticides, and poor nutrition resulting
from the impact of human activities on the environment have all
played a role in the bees' decline.