Journal Article (Refereed)
Deformed wing virus implicated in over-wintering honeybee colony losses
Martin, S 2009, 'Deformed wing virus implicated in over-wintering honeybee colony losses', Applied Environmental Microbiology.
The world-wide decline in honeybee colonies during of the past 50 years has often been linked to the spread of the parasitic mite, Varroa destructor (Varroa), and its interaction with certain honeybee viruses. Recently in the U.S.A. dramatic honeybee losses (colony collapse disorder) have been reported, however, there remains no clear explanation for these colony losses, with parasitic mites, viruses, bacteria, and fungal diseases all being proposed as possible candidates. Common characteristics that most failing colonies share is a lack of overt disease symptoms and the disappearance of workers from what appears to be normally-functioning colonies. In this study, we used quantitative PCR to monitor the presence of three honeybee viruses, deformed wing virus (DWV), acute bee paralysis virus (ABPV) and black queen cell virus (BQCV) during a one year period in 15 asymptomatic, Varroa-positive honeybee colonies in Southern England, and 3 asymptomatic colonies confirmed to be Varroa-free. All colonies with Varroa underwent control treatments to ensure that mite populations remained low throughout the study. Despite this, multiple virus infections were detected, yet only a significant correlation between DWV viral load and over-wintering colony losses were observed. The long held view has been that DWV is relatively harmless to the overall health status of honeybee colonies unless it is in association with severe Varroa infestations. Our findings suggest that DWV can potentially act independently of Varroa to bring about colony losses. Therefore, DWV may be a major factor in over-wintering colony losses.
Applied Environmental Microbiology