MICROBIOMES ASSOCIATED WITH LONGHORN CRAZY ANTS DIFFER AMONG BIOMES UNDER SPATIALLY PROXIMATE CONDITIONS IN BIOSPHERE 2

Abstract

Microbial symbionts that shape the physiology and reproductive success of their hosts may vary across environments. However, environmental variation is usually confounded by geographic distances among biomes, as distinct biomes such as rainforests and deserts are typically physically discrete. The proximity of simulated biomes at Biosphere 2, where longhorn crazy ants (Paratrechina longicornis) have invaded extensively, provides an opportunity to study microbe-insect-environment associations across biomes at a highly localized scale. We used amplicon sequencing (metabarcoding) to examine ant-associated microbiomes in the Biosphere 2 tropical rainforest, upper and lower savanna, and coastal fog desert biomes. We detected 800 archaeal and bacterial taxa across 27 phyla, with especially high abundances of Proteobacteria, Firmicutes, Bacteroidota, Planctomycetota, and Actinobacteriota. Ant-microbiome richness and composition differed among and within biomes, highlighting infraspecific variation in this widespread invasive species corresponding to different environments. This finding opens new areas of inquiry about the plasticity of the microbiome in P. longicornis and potential effects of ant microbiota on invasivity.