Deformed wing virus is a recent global epidemic in honeybees driven by Varroa mites

Abstract

Deformed Wing Virus (DWV) and its vector Varroa destructor, which emerged last century, are a major threat to the world’s honeybees. While Varroa’s dramatic impacts on colony-level DWV epidemiology is evident, we have little understanding of wider DWV epidemiology and the role that Varroa has played in its global spread. A phylogeographic analysis shows that DWV is globally distributed in honeybees, having recently spread from a common source, the European honeybee Apis mellifera. DWV shows epidemic growth and transmission that is predominantly mediated by European and North American honeybee populations and driven by trade and movement of honeybee colonies. DWV is now an important re-emerging pathogen of honeybees undergoing a worldwide man-made epidemic, fuelled by the novel direct transmission route provided by the Varroa mite.