June 8, 2011

Scientists Find Four New Viruses In Honey Bee Colonies

California scientists said on Tuesday that they found four new viruses in healthy honey bee colonies.

This finding could help solve the mystery of mass bee die-offs in some parts of the world.

Understanding the 27 unique honey bee viruses 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," senior author Joe DeRisi, professor of biochemistry and biophysics at the University of California, San Francisco, said in a statement.

According to a U.N. report on the issue, honey bee colony declines in recent years have reached 10 to 30 percent in Europe, 30 percent in the U.S., and up to 85 percent in the Middle East.

Honey bees are critical to global agriculture and pollinate over 100 different crops, which represents up to $83 billion in crop value globally.

Michelle Flenniken, co-author of the study, said the patterns of infection show that more than one factor is likely to be blamed for colony collapse.

"Clearly, there is more than just exposure involved," Flenniken said in a statement.

"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 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 of California.

The study said 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."

The research said hundreds of millions of its viral cells were "found in each bee in otherwise healthy colonies at certain times of the year."

"Here's a virus that's the single most abundant component of the bee biome and no one knew it was there," DeRisi said in a statement.

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 played a role in the bees' decline.

Findings are reported in the June 7 issue of the Public Library of Science ONE (PLoS ONE)


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