Researchers around the world have attributed the shrinking global bee population to everything from cell phones to pesticides, but a team from the University of Sheffield has recently discovered that parasitic mites are ‘turbo-charging’ a virus that is currently responsible for killing honey bees all around the world.
The virus, known as the Deformed Wing Virus, has been spreading rapidly through the world’s honey bee population, and is thought to be single-handedly responsible for the death of millions of colonies.
The Sheffield team has been working with other teams from the Marine Biological Association, the Food and Environment Research Agency and the University of Hawaii, and they have discovered that the virus was caused by the Varroa mite. The mite is also responsible for increasing the frequency of the pathogen from 10% to 100%.
The mite has also increased the potency of the virus, by causing a million-fold increase in the number of virus particles infecting each honey bee, as well as a massive reduction in viral strain diversity. This has essentially lead to the emergence of a single virulent DWV strain.
In his report, which is in the latest issue of Science, Dr. Stephen Martin, of the University of Sheffield’s Department of Animal and Plant Sciences said: “Just 2,000 mites can cause a colony containing 30,000 bees to die. The mite is the biggest problem worldwide for bee keepers; it’s responsible for millions of colonies being killed.
“Understanding the changing viral landscape that honey bees and other pollinators face will help beekeepers and conservationists worldwide protect these important insects. We have discovered what happens at the start of an infection. The goal is to understand how the infection comes about so that we can control it.”
Deformed Wing Virus is naturally transmitted in bees through feeding or sex, but the mite-enhanced disease now shortens the life span of the bees — meaning they die before they can reproduce. The virus has already become established across the Hawaiian Islands and is expected to spread further across the world. What is worse is that even after the mites are removed from the bees, the virulent pathogen strain remains.
The bee’s role in our daily lives is critical, as pollination is essential for the planet’s ecosystems — not to mention our agriculture industry. In the US alone, the current monetary value of honey bees as commercial pollinators is estimated at about $15-$20 billion annually.