Bee Researchers Find Major New Suspect For Colony Collapse Disorder – UM News – The University Of Montana


Jerry Bromenshenk, biology research professor, UM Division of Biological Sciences, 406-544-9007, 406-541-3160, ;
Colin Henderson, Applied Arts and Sciences faculty member, UM College of Technology, 406-243-7843, 406-541-3160, ;
Bee Alert Technology Inc., 406-541-3160,

Bee Researchers Find Major New Suspect For Colony Collapse Disorder

Oct. 06, 2010


University of Montana honeybee researchers and their partners have discovered a one-two-punch combination that may cause Colony Collapse Disorder, a mysterious malady that is depopulating beehives around the globe.

UM biology Research Professor Jerry Bromenshenk said his research group has learned that a honeybee virus previously unknown to North America, as well as a fungal pathogen, were found in all their samples collected at hives afflicted by CCD from 2006 to 2009. Those two pathogens were not found in the control groups – colonies with no history of CCD in Montana and Australia.

“We truly don’t know if these two pathogens cause CCD or whether the colonies with CCD are more likely to succumb to these two pathogens,” Bromenshenk said. “It’s a work in progress, but it may be the most important advance in the search for the cause of CCD in the previous three years.”

The research was published Oct. 6 in PLoS ONE, a scientific journal found online at

The first of the suspect pathogens, insect iridescent virus (IIV), is similar to a virus first reported in India 20 years ago, as well as a virus found in moths. It afflicts the abdomens of bees and is called iridescent because infected host tissues may take on a bluish-green or purplish hue.

The fungus is called Nosema ceranae. With this pathogen, the bee ingests spores that allow the fungus to spread in the gut. Either the iridescent virus or the fungus by itself can make bees sick, but together they might be too much for most bee colonies.

“From our data, there seems to be a correlation between the presence of these two pathogens together,” said Robert Cramer, a research partner and fungal pathologist at Montana State University-Bozeman. “We envision the bee gets an infection from one or the other, and this causes the bees to become stressed, which then allows the second infection to come in and more effectively cause disease.”

Bromenshenk said most researchers worldwide investigating the cause of CCD studied RNA viruses associated with honeybees. The insect iridescent virus his team correlated with the disorder is a DNA virus.

“This is a fundamental difference that takes CCD research in a whole new direction,” he said.

The research group’s samples of ground-up honeybees were analyzed at the Edgewood Chemical Biological Center, a U.S. Army-backed laboratory based at the Aberdeen Proving Grounds in Maryland. Edgewood has developed a liquid-chromatograph proteomics mass-spectrometry device, which identified and quantified as many as 30,000 proteins in each sample. This voluminous dataset revealed the iridescent virus and fungus were present in all CCD samples.

The team of UM bee specialists and MSU fungal pathologists eventually grew to include insect virus specialists at Texas Tech University and the Instituto de Ecologia, A.C., in Mexico. Much of the work was done at Bee Alert Technology Inc. in Missoula, a private company Bromenshenk and his partners started that licenses honeybee technologies discovered at UM.

So if the paired pathogens do cause CCD, what can beekeepers do to prevent the disorder and the mysterious disappearance of their bees?

Until an effective treatment can be developed, it may be prudent to eliminate infected colonies, said Colin Henderson, a faculty member at the UM College of Technology who did the statistics work related to the project. Standard quarantine practices, such as testing imported bees before they are added to colonies and disinfection of equipment, also likely would help.

Bromenshenk said some beekeepers have reported outbreaks of CCD following extended periods of cool, damp weather. Beekeepers also report more problems in areas with frequent fog or in hills where the weather is cooler. Placing bees in warm, sunny locations appears to help prevent outbreaks.

“Even if it’s not the cause of CCD, the discovery of the iridescent virus in our North American bees is important,” Bromenshenk said. “It warrants additional investigation, as it’s a whole different category of viruses than anyone has looked at before. It’s a unique discovery.”

Bee Researchers Find Major New Suspect For Colony Collapse Disorder – UM News – The University Of Montana.