Blueberries and the bees: Assessing honey bee health stressors using proteomics

Honey bee (Apis mellifera) pollination is essential for British Columbia’s (B.C.) top fruit export, highbush blueberry (HBB, Vaccinium sect. Cyanococcus), to ensure high fruit sets. Recently, B.C. beekeepers have noticed a decrease in health and strength of their colonies after HBB pollination, leading some to avoid contracts and causing financial strain on HBB growers; however, the risk factors affecting honey bee health in HBB pollination are not yet well defined. Pesticides, pathogens, pests and parasites are all possible effectors of decreased bee health in HBB. The proteome is central to health, and its composition is likely to vary with health status. Proteomics allows for the comparative study of an organism’s proteome in healthy versus diseased state so diagnosis and treatment is feasible. Additionally, proteomic research does not require a large sample size from a living hive to obtain quantitative data. This study combines field and lab work to deduce what the major determinants of bee health in HBB are by observing protein signature change in bees. Two field seasons (2020 and 2021) were used to correlate differences in the proteome of nurse bees before, during, and after HBB pollination, as well as outside of HBB areas as a control. Pesticides and pathogens were also included as variables. Cage trials of individual xenobiotic or pathogen stressors were subsequently performed to validate proteomic changes in order to define the main causes of stress in HBB pollination.