Drivers or passengers? Characterizing the gut bacteria of locusts

Locusts undergo solitarious-to-gregarious phase change, allowing them to swarm and cause plagues resulting in immense destruction. The mechanisms driving phase change are complex with visual, tactile, dietary, and olfactory cues playing roles. In other systems, gut microbiota modulate host behaviors including diet preference, response to environmental cues, and mate finding. Thus, it is plausible that gut microbiota play a role in locust behavioral plasticity (phase change). However, before pinpointing a specific mechanism or bacterium responsible for enabling phase change, it is critical to determine if lab-reared animals are sufficiently representative of wild locusts. I performed gut dissections, DNA extractions, and 16S amplicon sequencing of 5^th instar lab-reared and wild-caught South American locusts, Schistocerca cancellata, to characterize the normal flora. Preliminary DNA sequencing data of whole guts suggest major differences in richness and abundance of microbiota based on rearing environment (lab-reared vs wild). Additionally, Weissella sp., previously mentioned as a possible driver of gregarization in a congeneric locust species, was virtually absent in wild-caught gregarious locusts. These data suggest Weissella may be overrepresented in lab-reared locusts. To build on this study, I am currently working to compare lab-reared locusts from different labs and additional wild-caught populations. I predict that lab-rearing will produce consistent artifacts in the gut microbiota and that field population of locusts will have more diverse and variable gut microbiota. This work will provide the foundation for future studies to further explore the possible role of gut bacteria in phase change. This work was supported by NSF # 2021795.