Conserved, yet disruption-prone gut microbiota in Neotropical bumblebees

Tuesday, November 15, 2022

2:42 PM – 2:54 PM PT

Location: Vancouver Convention Centre, Meeting Room 213

Presenting Author(s)

NV

Nickole A. Villabona

University of California
Irvine, California

Co-Author(s)

TH

Tobin Hammer

University of California
Irvine, California
AR

Alejandro Reyes

Universidad de Los Andes
Bogotá, Distrito Capital de Bogota, Colombia
NM

Nancy Moran

University of Texas
Austin, Texas

Bumblebees are important pollinators in natural ecosystems and agriculture, but many species are in decline. Temperate-zone bumblebees have host-specific and beneficial gut microbiota, which may have a role in mediating the effects of environmental stressors. However, there is almost no information on gut microbiota of tropical bumblebees, limiting our ability to understand how bees and their microbes respond to environmental change in these ecosystems. Given ecological and life history differences between temperate and tropical bumblebees, these responses could be distinct. Here, we characterized the gut microbiota of four neotropical Bombus species and co-occuring solitary bees in the genus Thygater. We collected wild foraging bees from multiple sites in central Colombia, and used 16S rRNA gene sequencing to characterize gut microbiota. We found that neotropical bumblebees generally harbor microbiota with similar diversity and composition as compared with temperate-zone species. This result suggests that microbiota were conserved during bumblebee dispersal from North America, despite shifts in ecology and life history traits. As has been observed in temperate-zone species, some bumblebees had completely disrupted microbiota. In these individuals, conserved gut bacterial symbionts were replaced by environmental microbes, resulting in a microbial profile more similar to solitary bees than conspecifics. The parasites Nosema and Crithidia were also prevalent and tentatively associated with microbiota disruption. Our findings provide insights into the microbial biogeography of bumblebees and a foundation for studying bee-microbe-stressor interactions in the neotropics.