| Popis: |
There has been continued concern regarding the sustained levels of overwinter colony losses experienced by beekeepers in Canada. Although not entirely attributable to one single cause, these losses have been repeatedly linked to the parasitic mite, Varroa destructor, and thus a concerted effort towards their control has been ongoing. Many jurisdictions in North America have adopted an integrated pest management (IPM) approach to Varroa control, with the primary aim of maintaining mite levels below critical thresholds, above which there is a decreased likelihood for colony survival. Developing and optimizing IPM strategies is reliant on a comprehensive understanding of the biology, risk-factors, and distribution of the pest across the population to efficiently allocate resources and target interventions. Until now, the distribution of Varroa in Ontario has not been presented in the literature. The purpose of this thesis is to enhance the current state of Varroa surveillance across the province of Ontario by providing missing population-level context of the distribution of honey bee colonies and mites across space and time. Through geospatial interpolation of registered honey bee colonies, a province-wide population distribution map is presented, essential for standardizing future epidemiological studies, and permitting further insight into the implications of population density on colony health. Using spatial scan statistics and geostatistical modelling, a continuous depiction of the distribution of Varroa mite infestation intensities is developed and several regions of substantially increased risk are highlighted. Through time series analyses, a repeating seasonal pattern of provincial Varroa mite levels is described and evidence is presented to suggest an association between mite counts and weather variables at a 7-week lag interval. As a culminating project for this thesis, a practical information dashboard is developed for all members of the beekeeping community, to disseminate the key findings of these presented works, and enable, potentially, the future collection and analysis of improved quantities of data through citizen science. The results presented in this thesis offer valuable information for guiding future research and policy decisions regarding V. destructor in Ontario, while simultaneously demonstrating the methods available for the assessment of diseases in honey bees or other animal species. Ontario Agri-Food Innovation Alliance |
