Comparison of the Bacterial Symbiont Composition of the Formosan Subterranean Termite from its Native and Introduced Range

We investigated the bacterial composition in the gut of Formosan subterranean termites (FST), Coptotermes formosanus Shiraki, collected from southern China (native range) vs. Louisiana, U. S. (introduced range) using 16S rRNA gene sequencing. Overall, we identified 213 bacteria ribotypes from thirteen phyla. The enemy release hypothesis could not be invoked to explain invasion success of FST since no pathogens were found among the bacterial gut community regardless of geographic origin. Invasion of new habitats did not significantly change the bacteria composition. Apparently, the tight co-evolutionary link between termites and their gut flora maintains a certain association of species and functional groups. Ribotype richness, bacteria diversity, and proportions of detected phyla were not influenced by geographic origin of FST samples; however, these parameters were affected by storage of the samples. Ethanol storage of termite samples (5 yrs) increased the relative proportions of gram-positive bacteria versus gram-negative bacteria.