New Virus Linked to Bee Colony Collapse Disorder
Still unsettled science.
By Geoffrey Mohan
January 21, 2014, 5:00 a.m.
A rapidly mutating virus has leaped from plants to honeybees, where it is reproducing and contributing to the collapse of colonies vital to the multibillion-dollar agricultural industry, according to a new study.
Tobacco ringspot virus, a pollen-borne pathogen that causes blight in soy crops, was found during routine screening of commercial honeybees at a U.S. Department of Agriculture laboratory, where further study revealed the RNA virus was replicating inside its Apis mellifera hosts and spreading to mites that travel from bee to bee, according to the study published online Tuesday in the journal mBio.
The discovery is the first report of honeybees becoming infected by a pollen-born RNA virus that spread systematically through the bees and hives. Traces of the virus were detected in every part of the bee examined, except its eyes, according to the study.
Commercially cultivated bees pollinate about 90 crops worldwide, a service valued at $14 billion annually. But those colonies have been collapsing, and scientists have attributed that devastation to a deadly cocktail of pathogens, as well as pesticides and beekeeping practices that stress the insect’s immune system.
Why are honeybee colonies collapsing? One hypothesis is that bees are bringing into their hives traces of pesticides called neonicotinoids, whose use has expanded greatly in the past few years. Some scientists believe that these damage the development of the bee larvae, and inhibit the queen’s production of eggs. As a result, these pesticides have already been withdrawn from sale in France, Germany, Italy and Slovenia.
But there are, as yet, no certain answers, and most people agree that several factors are likely to be involved. So a new study by Warwick University, which hopes to unravel the “complex of interacting factors” should sort it all out. Or so you would imagine, in view of the fact that the researchers have been given £1m to do so by the government’s Biotechnology and Biological Sciences Research Council (BBSRC).
But while the university says it will investigate “parasitic diseases caused by the varroa mite” and the “link between these diseases and the quality of pollen and nectar that the bees are feeding on”, there’s no mention of pesticides in its press release. When I phoned Dr David Chandler, one of the Warwick researchers leading the study, he confirmed that there is “no pesticide component in it at all.”