Variation in Bacterial Communities Associated with the Cotton Fleahopper On Two Host Plants Across Texas, USA

Herbivorous insects are known to harbor microbial symbionts that can provide several ecological advantages. For example, in some insects bacterial symbionts allow them to use otherwise inadequate host plants. Such mutualistic associations can lead to the formation of genetically divergent host-associated populations of insects. Previous studies have indicated the presence of host-associated genetic differentiation (HAD) in the cotton fleahopper (CFH), Pseudatomoscelis seriatus (Miridae), associated with two host plants: cotton and horsemint. We investigated the potential role of microbial diversity in HAD using 454 pyrosequencing of bacterial 16s ribosomal subunit DNA to characterize the bacterial communities associated with CFH from populations utilizing cotton and horsemint across Texas. We detected both geographic and host-plant associated patterns of bacterial community diversity, variation and composition. Notably, we also found that the facultative endosymbiotic bacteria, Wolbachia, thought to be widespread in many insects, was absent in all populations except one in Weslaco, TX. Further phylogenetic analysis of Wolbachia sequences from this site indicated the presence of two different Wolbachia strains in cotton-associated and horsemint-associated CFH populations. This preliminary study indicates that symbiotic associations of insects might play an important role underlying genetic structure in herbivorous populations.