| Ants are one of the most dominant families of arthropods on Earth, with more than 12,000 described species. Their life histories range from tiny, cryptic, and nearly eyeless ground dwellers, to almost two-inch long hunters with one of the most painful stings known to man. Despite their ubiquity, and our knowledge that most if not all animals rely upon microbial symbionts, ant bacterial communities remain understudied. The work presented in this dissertation expands our knowledge of the microbial communities present in thirteen tropical arboreal ant species. First, I explore the presence and putative function of culturable Actinobacteria in three ant-plant-fungi mutualisms. I show that these three disparate ant species are host to Actinobacteria that may serve as protective or nutritional symbionts. Next I characterize and compare the bacterial communities of different species pairings of Cecropia-obligate Azteca ants. I found that the bacterial communities of these ants were not correlated with Azteca species, Cecropia species, or geographic location. Life stage may explain some of the differences and similarities in these ants, but there are likely other variables, such as varied rates of predation, that I am unable to account for that may better explain our data. Lastly, we explore the effect of host species, nesting strategy, and diet on microbial communities of seven arboreal ant species at La Selva Biological Station. Microbial community composition was highly correlated with host species, but not genera or subfamily. Likewise, correlations can be drawn between trophic level and the presence, or absence, of particular bacterial community members. |
