The evolution of parasite resistance in the western honeybee: Apis mellifera
My research focuses on the evolution of parasite resistance in the western honeybee: Apis mellifera.
Originally a parasite on the Asian honeybee (Apis cerana), the Varroa mite switched hosts to infect its sister species A. mellifera sometime in the past century. Since then, it has spread to devastate honeybee colonies globally. In 2016 only a few remote islands and oases have no reported infestations.
Honeybee colonies infested with Varroa typically die within three years of infection meaning treatment with acaricides has become a necessary practice for many beekeepers. While acaricide treatments help hives to survive Varroa infestations, there is a risk of them contaminating bee products and, more worryingly, they provide a selective pressure for the evolution of acaricide-resistant Varroa whilst removing the selective pressure for the evolution of Varroa resistant honeybees.
Where honeybee populations have been left untreated with acaricides, colony losses in the first three years can be severe but stable host-parasite relationships do evolve. I focus on these populations to try and better understand the genetic basis for the evolution of Varroa resistance in honeybees as well as the potential these populations have for use in breeding programmes.