Dr John Roberts1, Richard Hall2, Francisco Encinas-Viso1, Florence Bravo1, Jennifer Soroka3, Foyez Shams3, Liz Milla1, Francesco Martoni4, Alejandro Trujillo-Gonzalez3
1Commonwealth Scientific & Industrial Research Organisation, Canberra, Australia, 2Ministry for Primary Industries, Wellington, New Zealand, 3University Of Canberra, Canberra, Australia, 4Agriculture Victoria Research Division, Bundoora, Australia
Biography:
Dr John Roberts is a Senior Research Scientist at the CSIRO and leads a Bee Genomics team. With his team and collaborators he has been developing eDNA approaches using beehives for cross-industry biosecurity surveillance.
Abstract:
The parasitic mite, Varroa destructor, is a worldwide problem for honey bees (Apis mellifera). The recent spread of this pest to Australia, one of the few varroa-free honey bee populations remaining, highlights the importance of effective biosecurity methods for managing incursions. Detection of varroa mite environmental DNA (eDNA) could be a valuable complementary tool to increase the sensitivity and cost-effectiveness of varroa surveillance as it spreads to new areas. Using our newly developed qPCR assay for V. destructor we demonstrate that varroa eDNA can be sensitively detected in honey samples and surface swabs of hive entrances and brood frames. We deployed eDNA testing on New Zealand hives, where V. destructor is established, across a range of mite infestation levels. We also showed that varroa eDNA can be detected during the initial invasion of hives, using varroa-free hives introduced from the Chatham Islands to Wellington New Zealand. Further, we deployed eDNA testing on Australian hives at the invasion front of V. destructor in New South Wales. Using a predictive modelling framework, we estimated that these eDNA methods can detect varroa eDNA field concentrations between 1.8 and 10 copies per sample with 95% probability. Incorporating eDNA surveillance methods into Australia’s management response to V. destructor can help limit the spread to new areas. Further development of these methods for routine monitoring in established areas could also support beekeeper mite management.