By Alan Bjerga
Sept. 6 (Bloomberg) -- A virus imported from Australia may be behind the malady that has killed billions of U.S. honeybees in the past year, according to an article released today by the journal Science.
Israeli Acute Paralysis Virus, named for the country in which it was discovered, appears to be a leading indicator of Colony Collapse Disorder, said the study's authors. Other factors may be involved, according to W. Ian Lipkin, one of the researchers, who said the virus has no effective antidote.
``It may be that it's not alone sufficient to cause the disease,'' said Lipkin, an infectious disease specialist at Columbia University in New York. After other viruses were tested, however, ``the only candidate left standing was, in fact, IAPV.''
Colony Collapse Disorder threatens $14.6 billion of U.S. crops, including almonds, apples and cherries. It may cause $75 billion of economic damage if left unchecked, according to the U.S. Department of Agriculture.
The malady was first identified late last year after thousands of U.S. beekeepers found unusually large hive losses. About a quarter of all U.S. beekeepers were affected, on average losing 45 percent of their bees, according to a study in American Bee Journal. CCD has been reported in 35 U.S. states, one Canadian province, and parts of Asia, Europe and South America.
Australian Imports
Colony Collapse Disorder may have started in the U.S. as early as 2004, about the same time a decades-old ban on honeybee imports from Australia was lifted, according to the study.
The restrictions were established to prevent imports of pests that could threaten domestic bees, said Jeff Pettis, an entomologist with the USDA's bee research lab in Beltsville, Maryland, and one of the study's authors.
While studying different bee viruses, the researchers isolated IAPV in a sample of apparently healthy bees from Australia. Every CCD-affected beekeeping operation that was examined either used Australian bees or had mingled with operations that had them, the researchers said. As a result, the USDA is talking with Australia about the status of its bee exports.
Findings Rejected
The Australian government did not respond to requests for comment on the study. A bee industry group rejected the findings.
``We unequivocally reject claims that Australia caused the introduction of Colony Collapse Disorder in the U.S.,'' said Stephen Ware, executive director of the Australian Honey Bee Industry Council in Sydney. Australia's industry is hosting a forum on CCD next week.
Researchers also found IAPV in royal jelly imported from China to feed young bees. Pettis played down links between China and CCD, noting that very little royal jelly is imported for bee feeding in the U.S.
The virus itself likely isn't the sole cause of CCD, said Pennsylvania State University entomologist Diana Cox-Foster, the study's lead researcher.
Australian bees, for example, haven't experienced widespread collapse. The virus in the U.S. may be interacting with additional stressors, especially the varroa mite, which devastates bee immune systems and isn't found in Australia, she said. Pesticides, bee nutrients and the way the insects are transported to fields may also weaken them, she said.
Bee Genes Studied
For the study, the researchers conducted a detailed analysis of bee genes, their hives and their food to determine which germs might likely play a role in colony collapse. They analyzed bees and their environments in four different parts of the country, all affected by CCD, to make a library of genetic material from organisms found in the hives.
The library from CCD-affected hives was compared with data from healthy colonies in Hawaii and Pennsylvania. Material from bees imported from Australia and royal jelly imported from China were also analyzed.
After determining which gene sequences were more likely to be found in affected hives, the researchers searched through a gene database to determine the organisms from which they originated, leading them to the Israeli virus.
More Losses Possible
Pettis said that until more about the malady is understood, researchers can't guarantee there won't be more catastrophic losses.
``Maintain healthy colonies,'' he advised beekeepers, noting that mite-free, well-fed bees will be better able to fight the virus. A five-year USDA ``action plan'' to coordinate research and beekeeper efforts against CCD was announced in July. It may take years to understand and contain the disorder, he said.
``I hope no one goes away with the idea that we've solved the problem,'' Pettis said.
Troy Fore, the head of the American Beekeeping Federation in Jesup, Georgia, said solutions to CCD need to be found soon. More years of catastrophic losses will drive beekeepers out of business, making crop production more difficult, he said.
``You can't be profitable when you lose 60, 70, 80 percent of your bees,'' Fore said. ``We can't sustain these losses.''
The study also included researchers from the University of Arizona, the Pennsylvania Department of Agriculture and from 454 Life Sciences Corp., a unit of Roche Holding AG. It was funded by the National Institutes of Health, the National Honey Board and the Pennsylvania agriculture department.
To contact the reporter on this story: Alan Bjerga in Washington at abjerga@bloomberg.net .
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