Varroa mites and viruses are the currently the high-profile suspects in collapsing bee colonies. Therefore, seasonal variation in varroa load and viruses (Acute-Kashmir-Israeli complex (AKI) and Deformed Wing Virus (DWV)) were monitored in a year-long study. We investigated the viral titres in honey bees and varroa mites from 23 colonies (15 apiaries) under three treatment conditions: Organic a...

Deformed wing virus (DWV) is a honeybee pathogen whose presence is generally associated with infestation of the colony by the mite Varroa destructor, leading to the onset of infections responsible for the collapse of the bee colony. DWV contaminates bee products such as royal jelly, bee-bread and honey stored within the infected hive. Outside the hive, DWV has been found in pollen loads collect...

Regulation of gene expression in the brain plays an important role in behavioral plasticity and decision making in response to external stimuli. However, both can be severely affected by environmental factors, such as parasites and pathogens. In honey bees, the emergence and re-emergence of pathogens and potential for pathogen co-infection and interaction have been suggested as major components...

Microbial pathogens are thought to have a profound impact on insect populations. Honey bees are suffering from elevated colony losses in the northern hemisphere possibly because of a variety of emergent microbial pathogens, with which pesticides may interact to exacerbate their impacts. To reveal such potential interactions, we administered at sublethal and field realistic doses one neonicotino...

Across the Northern hemisphere, managed honey bee colonies, Apis mellifera, are currently affected by abrupt depopulation during winter and many factors are suspected to be involved, either alone or in combination. Parasites and pathogens are considered as principal actors, in particular the ectoparasitic mite Varroa destructor, associated viruses and the microsporidian Nosema ceranae. Here we ...

European honey bees (Apis mellifera) are critically important to global food production by virtue of their pollination services but are severely threatened by deformed wing virus (DWV) especially in the presence of the external parasite Varroa destructor. DWV exists as many viral strains with the two major variants (DWV-A and DWV-B) varying in virulence. A single plasmid standard was constructe...

The ectoparasitic mite, Varroa destructor and the viruses it vectors, including types A B of Deformed wing virus (DWV), pose a major threat to honey bees, Apis mellifera . Analysis 256 mites collected from same set field colonies on five occasions May October 2021 showed that less than half them, 39.8% (95% confidence interval (CI): 34.0 - 46.0%), were able induce high (overt) level DWV infecti...

The ectoparasitic Varroa destructor mite is a major contributor to the ongoing honey bee health crisis. Varroa interacts with honey bee viruses, exacerbating their pathogenicity. In addition to vectoring viruses, immunosuppression of the developing honey bee hosts by Varroa has been proposed to explain the synergy between viruses and mites. However, the evidence for honey bee immune suppression...

Evidence of inter-species pathogen transmission from managed to wild bees has sparked concern that emerging diseases could be causing or exacerbating wild bee declines. While some pathogens, like RNA viruses, have been found in pollen and wild bees, the threat these viruses pose to wild bees is largely unknown. Here, we tested 169 bees, representing 4 families and 8 genera, for five common hone...