December 17, 2021

April Sharp (North Carolina State University)

Does a medicinal pollen diet restore pollination services by parasitized bees?

Fall 2021 Graduate Student Award in Pathogenic and Commensal Organisms


As pollinator populations continue to decline, there is a critical need for innovative and effective conservation strategies to sustain natural ecosystems and food security. Parasites present a significant threat to populations of wild and managed bees, an effect that is exacerbated by climate change, habitat loss, and nutritional stress. Parasites reduce bees’ ability to navigate flowers while foraging; however, it is not well understood to what degree parasitism affects pollination success and subsequent plant yield. Longstanding evolutionary relationships between plants and their herbivores have been found to produce medicinal effects that reduce intestinal pathogens in pollinators. For example, consumption of a sunflower pollen diet significantly reduces parasitism in the common eastern bumble bee. However, it is unknown whether losses to pollination services caused by parasitism persist in bees even after reduction or eradication of the infection. I propose to study the effects of bee parasitism on the pollination success and yield of a focal crop and evaluate whether the expulsion of intestinal parasites by a sunflower diet restores the pollination services of bees to pre-infection levels. To do this, I will conduct caged pollination trials with bees of increasing parasitic infection levels that are assigned diets of either sunflower pollen (medicinal) or wildflower pollen (control). I will then measure the resulting pollination success (pollen deposition) and crop yield produced by bees from various pathogen and diet treatments. This research will contribute to our understanding of how increasing parasitism of bees will impact agricultural production.