Collapse Of Honeybee Colonies Could Be Due To Unique Virus-Fungus Combination
U.S. researchers say they have found a unique combination of viruses and fungi, which could explain the collapse of the colonies, a mysterious disease that is destroying the hive colonies around the world.
Document their findings was published online on October 6 in the journal PLoS ONE.
The first author Dr. Jerry Bromenshenk, a bee expert and research professor of biology at the University of Montana (UM) Department of Biological Sciences in Missoula, said in a statement that they do not know for sure if the two pathogens, fungus called Nosema ceranae and a virus called the insect iridescent virus ( IIV), the cause of Colony Collapse Disorder "(CCD), or colonies with CCD are more susceptible to them.
"It's work, but it may be the most important step forward in the search for the causes of CCD in the previous three years," said Bromenshenk.
IIV infecting bees abdomen and is called rainbow because of damaged tissue appears blue-green or purple. It is similar to a virus first reported in India 20 years ago, and another found in the moth, researchers say.
Once the spores inside, ceranae Nosema distributed in the gut bees. It was first described in 1996 and identified as a disease of bees in 2004 in Spain.
Virus or fungus can make bees sick, but researchers suspect that this is when the two come together, that the colony collapses.
Co-author Dr. Robert Kramer, fungal pathologist at Montana State University (MSU) in Bozeman, said that their data indicate an association between these pathogens and their way of thinking that "the bees get an infection from one or the other, and this leads to the bees to become stressed, which then allows secondary infections to come in and cause disease more effectively. "
The term Colony Collapse Disorder or CCD was invented after a sharp rise in the disappearance of bee colonies in North America in late 2006. In 2010, the CCD again devastated bee colonies in the U.S., assuming the problem was not solved and is not going away.
Bromenshenk said that most other researchers in the U.S. and other parts of the world have focused on RNA viruses associated with bees, to find what causes CCD, but the IIV is a DNA-containing virus, and that "fundamental differences" point of CCD research "New Direction" he said.
For the study, researchers sent samples of Montana zero dead bees for the U.S. Army-supported laboratory at Aberdeen proving ground in Maryland, called the Edgewood Chemical and Biological Center.
At Edgewood, they used liquid chromatography mass spectrometer proteomics to identify and count about 30000 proteins in each sample.
It is with this massive collection of data, which they eventually found a match and Nosema ceranae IIV in all samples of CCD, but not in uninfected controls.
The researchers concluded that:
"These findings involved co-infection by IIV and Nosema in honey bee colony decline, giving confidence in the older studies that point to the IIV, interacting with Nosema and mites, as the probable cause of the loss of bees in the U.S., Europe and Asia."
"We next need to describe the IIV and Nosema, what we found and to develop management practices for reducing losses of honey bees," they added.
Meanshile, which may beekeepers to protect their bees?
Co-author Dr. Colin Henderson, who made a statistical analysis of data, as well as a lecturer in the UM College of Technology, said that the safest way, as long as there is no effective treatment is the destruction of infected colonies, and adhere to a standard quarantine procedures such as disinfection of equipment and testing imported bees before adding them to the colony.
According to researchers, some beekeepers have noticed that the CCD outbreak seems to be followed by long periods of cool, wet weather, and more problems seem to occur in areas with frequent fog or in the mountains where the weather is a little cooler.
Bromenshenk said the placement of colonies in warm and sunny spot appears to help prevent outbreaks of CCD.
Even if it turns out that it is not this duo pathogen that causes CCD, the opening of IIV in the North American bees are important, said Bromenshenk:
"It warrants further investigation, it is a completely different category of viruses than those who looked at before. This is a unique discovery."
A full team of researchers on the project included the bees specialists UM, fungal pathologists at MSU, insect virus experts at Texas Tech University in Lubbock, and the Institute of Ecology, AC, in Xalapa, Veracruz, Mexico.
Bromenshenk and his colleagues also made a lot of work for the Missoula-based company Bee Alert Technology, they have created for technology licensing of bees found at the UM.
"Iridovirus and microsporidia-related drop in honey bee colonies." Bromenshenk JJ, Henderson CB, Wick CH, Stanford MF, Zulich AW et al. 2010. PLoS ONE 5 (10): e13181. DOI: 10.1371/journal.pone.0013181