Implications of varroa mite establishment for Australian plants and their persistence

The European honeybee (Apis mellifera) is a highly abundant introduced pollinator with widely established feral populations across a large proportion of Australia. Both managed and feral populations contribute significantly to the pollination of many native plant species but have also disrupted native plant-pollinator dynamics. Varroa mite (Varroa destructor), a parasite associated with the collapse of feral or unmanaged European honeybee populations globally, has recently become established in Australia and will inevitably spread across the country. If feral honeybee populations decline significantly, there may be a range of effects on Australian native plant species, including pollination dynamics and seed set. This would have potential implications for the risks faced by native species, particularly those already threatened. However, the exact effects of a decline in feral honeybees on native plants are uncertain as the role of honeybees in Australian ecosystems is poorly understood. We identify potential consequences of the spread of varroa mite and highlight the large knowledge gaps that currently limit our understanding of the subsequent impacts on the Australian flora.