Abstract
Honey bees are agriculturally important, both as pollinators and by providing products such as honey. The sustainability of beekeeping is at risk through factors of global change such as habitat loss, as well as through the spread of infectious diseases. In China and other parts of Asia, beekeepers rely both on native Apis cerana and non-native Apis mellifera, putting bee populations at particular risk of disease emergence from multi-host pathogens. Indeed, two important honey bee parasites have emerged from East Asian honey bees, the mite Varroa destructor and the microsporidian Nosema ceranae. As V. destructor vectors viral bee diseases, we investigated whether another key bee pathogen, Deformed Wing Virus (DWV), may also have originated in East Asian honey bee populations. We use a large-scale survey of apiaries across China to investigate the prevalence and seasonality of DWV in managed A. mellifera and A. cerana colonies, showing that DWV-A prevalence was higher in A. mellifera, with a seasonal spike in prevalence in autumn and winter. Using phylogenetic and population genetic approaches, we show that while China and East Asian DWV isolates show comparatively high levels of genetic diversity, these bee populations are not a source for the current global DWV epidemic.
Highlights
Honey bees play a vital role in agriculture and food security through the pollination of crops as well as the production of honey and other related goods such as royal jelly and honey bee-collected pollen
The estimated true colony-level prevalence of Deformed Wing Virus (DWV)-A in Chinese A. mellifera populations reaches 45.7% (95% Confidence Interval (CI) 35.6– 56.2%), whereas the true colony-level prevalence of DWV-A for A. cerana is estimated only at 5.6% (0–18.3%); this estimation takes into account the uncertainty of PCR-based pathogen detection, conservatively assuming a PCR assay sensitivity and specificity of 95%32
We found DWV-B in two A. mellifera colonies out of a total of 117, resulting in an estimated true colony-level prevalence of 0–0.83%; we found no evidence for DWV-B presence in the 50 A. cerana colonies tested
Summary
Honey bees play a vital role in agriculture and food security through the pollination of crops as well as the production of honey and other related goods such as royal jelly and honey bee-collected pollen. East Asia is the epicentre of disease emergence for bees: both the Varroa mite and the gut parasite Nosema ceranae have jumped from the Asian honey bee A. cerana to the European honey bee A. mellifera in East Asia in the last century and have spread globally This raises the question of whether East Asian honey bee populations may serve as a source or reservoir for other emerging bee pathogens such as DWV. We test the hypothesis that Chinese managed A. cerana populations are part of the phylogenetic source population for the current global Varroa-associated DWV epidemic, as suggested by this Asian bee population’s role in the emergence of N. ceranae and in particular DWV’s novel vector, the Varroa mite V. destructor. If Chinese managed honey bees serve as a source for the current global DWV epidemic, we expect to find higher ancestral genetic variation in this DWV population To test these predictions, we use a large-scale multi-year survey of both European and Asian honey bees across China. Using phylogenetic and population genetic approaches, we show that while China and East Asian DWV isolates show comparatively high levels of genetic diversity, these bee populations are not the ancestral source for the current global DWV epidemic
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
