Parasitic mite blamed for honey bee decline

Researchers at the University of Sheffield have shown the Varroa mite has caused Deformed Wing Virus (DWV) to proliferate in honey bee colonies.

This association is now thought to contribute to the world-wide spread and probable death of millions of honey bee colonies.

The decline in bee populations in this country is estimated to have the potential to cost the econ- omy millions in lost pollination with bee levels having declined by as much as a third in some areas.

The research conducted in Hawaii by researchers from the University of Sheffield and other scientific groups shows the virus increases its frequency among honey bee colonies from 10 per cent to 100 per cent.

This change was accompanied by a million-fold increase in the number of virus particles infecting each honey bee and a huge reduction in viral strain diversity leading to the emergence of a single virulent DWV strain.

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 beekeepers; 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.”