Benefits of socially transmitted versus environmentally acquired microbes for bees

Monday, November 14, 2022

10:54 AM – 11:06 AM PT

Location: Vancouver Convention Centre, Meeting Room 304/305

Presenting Author(s)

Alexia N. Martin

PhD Student
University of California
Davis, California

Co-Author(s)

Rachel L. Vannette

University of California
Davis, California

Bees interact with and in some cases benefit from a diverse community of microbes, which can be obtained through social transmission or the environment. Social bees, including bumble bees, contain a core gut microbiota, which is a permanent community of microbes that reside within the bee gut, are transmitted socially, and positively affect host health; however, bees can also acquire environmental microbes from their diet, including the bacteria and fungi that reside within the nectar and pollen of flowers. Despite the observation that social transmission of microbes is imperfect and environmental microbes are nearly ubiquitous in nectar and pollen, the potential impacts of socially versus environmentally acquired microbes on overall pollinator health has not been evaluated. This study assesses how socially and environmentally acquired microbes establish within Bombus impatiens and affect bee health, and how the host responds to microbes transmitted via each route. 2x2 factorial experiments were performed on B. impatiens microcolonies to selectively introduce a gut microbiota and/or nectar microbes. Survivorship, reproduction, and lipid stores were measured to assess microcolony health and fitness, and DNA extractions and amplicon sequencing were performed on segmented bee guts to evaluate microbial establishment. The results of this study will inform how social and environmentally transmitted microbes affect host health, fitness, and gut bacterial community. Since many macroorganisms encounter both environmental and socially transmitted microbes, this study provides a framework for similar work in other organisms.