Dynamics of a bacterial endosymbiont within its insect host population: Distribution of Wolbachia in Diaphorina citri Kuwayama (Hemiptera: Psyllidae) populations in Florida

Due to their ability to affect host reproduction, endosymbiotic bacteria of the genus Wolbachia have been studied extensively across a broad range of species. Recently, manipulation of Wolbachia spp. in some insect vectors has shown potential as a method for mediating pathogen transmission. The Asian citrus psyllid, Diaphorina citri (Hemiptera: Psyllidae), is the vector of Ca. Liberibacter asiaticus, the causal agent of citrus greening (huanglongbing, HLB). Although Wolbachia occur naturally in D. citri, little is known about the abundance of Wolbachia in individuals or in populations of this insect. To estimate the infection rate of Wolbachia ssp. in D. citri, we developed a SYBR Green-based qPCR assay, using an absolute standard curve based on the Wolbachia outer surface wsp protein gene. Using this assay, we demonstrated differences in Wolbachia infection rates of D. citri among Florida psyllid populations. Our data also indicated that male D. citri harbor higher Wolbachia infection rates compared to females, suggesting natural spatial and sex related patterns of Wolbachia infection among D. citri populations.