Recombinants between Deformed wing virus and Varroa destructor virus-1 may prevail in Varroa destructor-infested honeybee colonies

We have used high-throughput Illumina sequencing to identify novel recombinants between deformed wing virus (DWV) and Varroa destructor virus-1 (VDV-1), which accumulate to higher levels than DWV in both honeybees and Varroa destructor mites. The recombinants, VDV-1VVD and VDV-1DVD, exhibit crossovers between the 5’-untranslated region (5’-UTR), and/or the regions encoding the structural (capsid) and non-structural viral proteins. This implies the genomes are modular and that each region may evolve independently, as demonstrated in human enteroviruses. Individual honeybee pupae were infected with a mixture of observed recombinants and DWV. The strong correlation between VDV-1DVD levels in honeybee pupae and the associated mites was observed, suggesting that this recombinant, with a DWV-derived 5’-UTR and non-structural protein region flanking VDV- 1-derived capsid encoding region, is better adapted to transmission between V. destructor and honeybees than the parental DWV or a recombinant bearing the VDV-1-derived 5’-UTR (VDV-1VVD)

A New Threat to Honey Bees, the Parasitic Phorid Fly Apocephalus borealis

Honey bee colonies are subject to numerous pathogens and parasites. Interaction among multiple pathogens and parasites is the proposed cause for Colony Collapse Disorder (CCD), a syndrome characterized by worker bees abandoning their hive. Here we provide the first documentation that the phorid fly Apocephalus borealis, previously known to parasitize bumble bees, also infects and eventually kills honey bees and may pose an emerging threat to North American apiculture. Parasitized honey bees show hive abandonment behavior, leaving their hives at night and dying shortly thereafter. On average, seven days later up to 13 phorid larvae emerge from each dead bee and pupate away from the bee. Using DNA barcoding, we confirmed that phorids that emerged from honey bees and bumble bees were the same species. Microarray analyses of honey bees from infected hives revealed that these bees are often infected with deformed wing virus and Nosema ceranae. Larvae and adult phorids also tested positive for these pathogens, implicating the fly as a potential vector or reservoir of these honey bee pathogens. Phorid parasitism may affect hive viability since 77% of sites sampled in the San Francisco Bay Area were infected by the fly and microarray analyses detected phorids in commercial hives in South Dakota and California's Central Valley. Understanding details of phorid infection may shed light on similar hive abandonment behaviors seen in CCD

Predictive Markers of Honey Bee Colony Collapse

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 used long term monitoring of colonies and screening for eleven disease agents and genes involved in bee immunity and physiology to identify predictive markers of honeybee colony losses during winter. The data show that DWV, Nosema ceranae, Varroa destructor and Vitellogenin can be predictive markers for winter colony losses, but their predictive power strongly depends on the season. In particular, the data support that V. destructor is a key player for losses, arguably in line with its specific impact on the health of individual bees and colonies

Characterisation of deformed wing and slow paralysis virus transmission by Varroa destructor

EThOS - Electronic Theses Online ServiceGBUnited Kingdo