Varroa destructor Parasitism and Genetic Variability at Honey Bee (Apis mellifera) Drone Congregation Areas and Their Associations With Environmental Variables in Argentina

Alberto Galindo-Cardona,  Alejandra C. Scannapieco, Romina Russo, Karen Escalante, Martín Geria, Nicolás Lepori, María M. Ayup, Irina Muntaabski, María C. Liendo, Lucas Landi, Tugrul Giray & A. Carolina Monmany-Garzia

Frontiers in Ecology and Evolution, 8, 394. 

Link to the paper: https://www.frontiersin.org/articles/10.3389/fevo.2020.590345/full 

Male honeybees (Apis mellifera), mate with queens in mysterious sites called Drone Congregation Areas (DCA). These DCA persist in the same place for years, even when males live for only three months. Honeybees are under serious threat in many places of the world and given that we have largely ignored DCA when studying bees, we do not know to what degree they play a role in the occurrence of serious honeybee pests, such as the mite Varroa destructor, and in shaping the genetic composition of surrounding colonies. We searched for DCA and described mite parasitism and genetic composition in males gathered at those sites in two ecoregions in Argentina (i.e., subtropical and temperate). The mean proportion of Varroa was ca. 3 in 1,000 at the apiaries, and ca. 2 in 100 at the DCA. Using satellites images and topographic and climate databases we described the environmental characteristics of DCA in the ecoregions and found that though DCA were located in highly variable sites in terms of environment, relative humidity and precipitation in the previous week of sampling were positively correlated to mite infestation. More genetic diversity was detected in the DCA compared to the surrounding apiaries, particularly in the subtropical ecoregion, where high prevalence of Africanized mitochondrial lineages was detected. European lineages were mostly found in apiaries and DCA in the temperate region. The study of DCA emerges as a tool for investigating not only honey bee reproduction and conservation, but also the impact of the environment on bee epidemiology.