http://www.digitaljournal.com/article/307838

Study: New bee viruses found; normal colonies also infected

Posted Jun 11, 2011 by Elizabeth Cunningham Perkins
During a ten-month study of healthy honey bees, scientists identified four new viruses and established a baseline for studying bee colony collapse, revealing that all the bacteria and viruses previously linked to the disorder also live in normal colonies.
A honey bee consumes flower nectar and carries pollen along; many food crops depend upon honey bees ...
A honey bee consumes flower nectar and carries pollen along; many food crops depend upon honey bees for pollination.
Jon Mitchell/Flickr.com
University of California, San Francisco (UCSF) scientists tracked viruses in 20 honey bee colonies belonging to a large commercial beekeeping operation that transports more than 70,000 hives across the United States to pollinate crops, looking to discover what bacteria and viruses infect non-collapsing colonies, to establish a baseline for further study of Colony Collapse Disorder, according to ScienceDaily.
The research team's findings have been published in June 7 issue of the online journal of the Public Library of Science, PLoS ONE.
According to the published paper:
Following the transported honey bee colonies across the country, the scientists tracked 27 different honey bee viruses, discovering four that were previously unknown.
The researchers sampled frequently, using advanced, comprehensive detection methods and obtained detailed results at the molecular level, allowing them to identify specific microorganisms.
Their new research demonstrated that viruses previously proposed as causes of Colony Collapse Disorder are part of the spectrum of pathogens found in healthy honey bee colonies.
In addition to the viruses, a diversity of other organisms infected or lived with the normal test bee colonies, year round: a parasitic fly known as phorid, four types of mites and six species each of fungi and bacteria.
In a written statement, senior author and professor of biochemistry and biophysics at UCSF Joe DeRisi, said of this study's findings, "We brought a quantitative view of what real migrating populations look like in terms of disease. You can’t begin to understand colony die-off without understanding what normal is.”
According to the USDA, scientists have been focusing on several possible causes of the honey bee decline that began disturbing food crop production in 2006: modification of foraging habitats; malnutrition from inadequate forage; varroa mite infestations; poisoning by crop or mite-control pesticides; stresses caused by bee management practices; emerging or new diseases; and immune stress caused by one or more factors on this list.
A digital journalist reported in September 2010 on a Canadian study that suggested climate change has contributed to declining bee populations.
But other scientists have been claiming a complex interaction of several causes has brought about Colony Collapse Disorder, Wired Science reported in January 2010.