Coevolution stabilizes the honey bee–Varroa destructor–virus system on islands

For 65 years, the ectoparasitic mite Varroa destructor, along with the deformed wing virus (DWV) it vectors, has killed millions of Apis mellifera honey bee colonies globally. The coevolution of the ‘bee–mite–virus’ system in Hawaii over 17 years has been closely followed. Resistance to V. destructor evolved in the free-living honey bees on Oahu by detecting and removing a high proportion of mite-infested brood cells, as seen in other mite-resistant honey bees. On Big Island, miticides remain widely used, so on both islands, DWV prevalence decreased, but a more virulent recombinant form evolved. Thus, coevolution on Oahu has produced a new stable ‘bee–mite–virus’ state that has been exploited by beekeepers and provides a global solution to the V. destructor problem.