D3004: Tragedies of tolerance: Guidance for the evolutionary management of honey bee health in the context of parasite spillover

In the face of high rates of honeybee losses due to parasitic Varroa mite infestations, beekeepers across the Americas and Europe place ever-increasing emphasis on breeding allegedly ‘Varroa resistant’ honeybee stock. Unfortunately, tolerance of Varroa and the viruses they vector is the likely outcome of current ‘survivor stock’ selection regimes, commonly suggested by the recently popularized ‘Darwinian beekeeping’ approaches. We argue that honeybee breeding must be informed by evolutionary knowledge of host resistance evolution and infectious diseases. This infographic will illustrate a roadmap of the evolution of tolerance to parasites in honeybees, which poses the risk of three tragedies for their wild bee counterparts. (1) Spillover incidence will increase in frequency due to the greater number of infected honeybees in the landscape. (2) The average infected honeybee will be more infectious due to higher pathogen replication rates. (3) When spillover occurs, the infection is more virulent in the wild bee species due to higher replication rates and lack of nutritional provisioning. However, these risks are circumvented by the evolution of resistance to Varroa in managed honeybees. Resistance is the expected outcome of programs selecting for specific bee phenotypes such as hygienic bees and mite-biters; and the predicted outcome for the proposed method of culling colonies above a certain Varroa infestation threshold championed by Tom Seeley. While tolerance is therefore dangerous for surrounding pollinator communities, it is not inevitable. This poster will highlight actionable strategies for honeybee breeding which will benefit beekeepers’ own bees and the wild bees they interact with.