The Transmission of Deformed Wing Virus during Honey Bee Mating

In honey bees, multiple mating of queens with often more than 20 drones, known as polyandry, is extreme. At the colony level, polyandry can provide fitness gains through better division of labor and disease resistance. For the honey bee queen polyandry may pose a risk, for instance through sexually transmitted diseases. Deformed wing virus (DWV) is an important contributor to colony losses, especially following the spread of the invasive parasitic mite, Varroa destructor. In this experiment, we investigate if healthy honey bee queens may potentially become infected during natural mating with drones. As the queen returns to her colony following mating, the endophallus of the last drone often remains as a "mating sign". Endophalli were removed and examined to demonstrate that drones highly infected with DWV can compete with healthy drones for mating. By further analysing queen bodies and the stored sperm in the spermatheca of the same queens four weeks after the onset of oviposition, we find high titers of DWV infections occur in a fraction of queens, resulting from mating with drones carrying a high viral titer. Colony losses are frequently contributed to queen loss or failure. The transmission of DWV during the polyandrous mating may cause queen losses, especially since drone brood is particular attractive for the varroa mite.