Brief Bio: Sasha started his research as a bee behavioral biologist at Cornell, publishing his first papers with his friend and mentor, Tom Seeley. After a decade in the wilderness, studying mostly ants, Sasha re-engaged with bees, their parasites and diseases thanks to an Australian Research Council Future Fellowship, which brought him to the Australian National University.

Social insects, genomic, evolution, host-parasite-virus dynamic

Bees facing Varroa and viruses over space and time: a historical study

Populations must resist the arrival of new parasites and diseases or face extinction. How host genetics affects the progression of disease remains poorly understood. Honey bees have faced numerous anthropogenic stressors, including the arrival of varroa mites that vector deadly viruses, making them an excellent model to study these processes. We investigated this process using a unique historical time series data set where from three bee populations, in Mexico and the southern US. These populations were sampled by the US Department of Agriculture between 1988 to 2001 in order to monitor the arrival of Africanized honey bees, with samples from feral colonies cryogenically frozen. The Africanized bees indeed arrived in each population, though at different times. By contrast varroa mites arrived near-simultaneously in each. As a result, these samples allow us to examine changes taking place in populations over the time course of early varroa infestation while investigating the effects of genetic background. RNA-seq of the bees allowed us to investigate their genetic background as well as to uncover viral population dynamics. We found that the effects of bee genetics on viral levels and community composition to be significant, but relatively minor. However, the arrival of Varroa has increased the number of detectable viruses in bees overall. These data suggest that the dynamics between bees, varroa and viruses are complex with multiple proximal factors possibly leading to observed declines.