Search

Varroa destructor , a parasitic mite of honey bees, is also a vector for viral diseases. The mite displays high host specificity and requires access to colonies of Apis spp . to complete its lifecycle. In contrast, the Deformed Wing Virus (DWV), one of the many viruses transmitted by V. destructor , appears to have a much broader host range. Previous studies have detected DWV in a variety of insect groups that are not directly parasitized by the mite. In this study, we take advantage of the discrete distribution of the Varroa mite in the Hawaiian archipelago to compare DWV prevalence on non- Apis flower visitors, and test whether Varroa presence is linked to a “viral spillover”. We selected two islands with different viral landscapes: Oahu, where V. destructor has been present since 2007, and Maui, where the mite is absent. We sampled individuals of Apis mellifera , Ceratina smaragdula , Polistes aurifer , and Polistes exclamens , to assess and compare the DWV prevalence in the Hymenoptera community of the two islands. The results indicated that, as expected, honey bee colonies on Oahu have much higher incidence of DWV compared to Maui. Correspondingly, DWV was detected on the Non- Apis Hymenoptera collected from Oahu, but was absent in the species examined on Maui. The study sites selected shared a similar geography, climate, and insect fauna, but differed in the presence of the Varroa mite, suggesting an indirect, but significant, increase on DWV prevalence in the Hymenoptera community on mite-infected islands. [ABSTRACT FROM AUTHOR]

The article discusses a study on the factors contributing to the decline in the populations of honeybees in the U.S. such as the Varroa destructor mite and the deformed wing virus (DWV). Topics include the reemergence of the pathogen Apis Mellifera due to the spread of V. destructor, the impact of vegetable crops' diseases on productivity, and the role of humans in the spread of the varroa mite, European honeybee and DWV.

The combination of Deformed wing virus (DWV) and Varroa destructor is arguably one of the greatest threats currently facing western honey bees, Apis mellifera. Varroa's association with DWV has decreased viral diversity and increased loads of DWV within honey bee populations. Nowhere has this been better studied than in Hawaii, where the arrival of Varroa progressively led to the dominance of the single master variant (DWV-A) on both mite-infested Hawaiian Islands of Oahu and Big Island. Now, exactly 10 years following the original study, we find that the DWV population has changed once again, with variants containing the RdRp coding sequence pertaining to the master variant B beginning to co-dominate alongside variants with the DWV-A RdRp sequence on the mite-infested islands of Oahu and Big Island. In speculation, based on other studies, it appears this could represent a stage in the journey towards the complete dominance of DWV-B, a variant that appears better adapted to be transmitted within honey bee colonies. [ABSTRACT FROM AUTHOR]