Researchers in Washington have discovered that a mushroom extract may be an effective treatment for reducing levels of at least two viruses implicated in the collapse of honey bee colonies around the world. When the bees were fed the extract, the bee colonies experienced a 79-fold reduction in deformed wing virus and a 45,000-fold reduction in Lake Sinai virus.
The viruses are spread by Varroa mites, which are found in most honey bee colonies and which put stress on the bees’ immune systems and make them more susceptible to disease.
“Our greatest hope is that these extracts have such an impact on the viruses that they may help Varroa mites become an annoyance for bees rather than causing huge devastation,” said Steve Sheppard, an entomology professor at Washington State University.
The Fomes and Ganoderma fungi used in the study had previously been found to have antiviral properties by Sheppard’s colleagues, who initially studied how they might fight viruses in humans. The new study suggests they may be effective in bees.
The extract comes from the fungi’s mycelia, the underground networks of fine white filaments. “We don’t know what the active ingredients are,” Sheppard said, “and we don’t know if it boosts the bees’ immune system or if it’s actually fighting off the viruses itself. That’s the next area of research.”
The researchers tested the mushroom extract by diluting it in sugar water and feeding it to the bees – first to caged honey bees and later to small colonies in the field. They are now conducting larger field studies and working with the U.S. Department of Agriculture to figure out how to make the extract available to beekeepers.
“The most encouraging aspect of this research is that we, for the first time, have something that reduces viruses in honey bees,” said Sheppard. “If we can get it – as part of an overall management scheme – into the hands of beekeepers, it could be of great benefit.”
While it is unknown whether native bees would benefit from the extract as well, Sheppard said that native bees are facing many of the same problems as honey bees.
Fungi Perfecti, a company that grows mushrooms for food and wellness products and was a partner in the research, is planning to work with citizen scientists to build feeding stations to make the extract available to wild bees. The company also plans to produce 50,000 doses of the extract in the coming year for further research and testing, and it believes it can eventually ramp up its production to make the extract available in large quantities for beekeepers.