Two endosymbiotic bacteria, Wolbachia and Arsenophonus, in the brown planthopper Nilaparvata lugens

The brown planthopper Nilaparvata lugens harbors intracellular fungal yeast-like symbionts and endosymbiotic bacteria, with the latter mainly comprising Wolbachia and Arsenophonus. In this study, Wolbachia or Arsenophonus were detected in all 15 brown planthopper populations collected from China and Southeastern Asian countries. Furthermore, Polymerase Chain Reaction (PCR) analysis of the individuals in a population that was infected by both Wolbachia and Arsenophonus showed that each individual was infected by only one of the two symbiotic bacteria. Real-time quantitative PCR showed that both endosymbionts are mainly localized in the mycetocytes of the fat body. Reciprocal crosses between the Wolbachia ⁺ and Arsenophonus ⁺ brown planthopper populations showed that both bacteria were maternally transmitted. Our results showed that the brown planthopper populations are extensively infected by Wolbachia or Arsenophonus, and the two bacteria may be exclusive in each host individual. This finding might be helpful for further studies on the biological functions of the endosymbiotic bacteria and will deepen our understanding of the complicated symbiosis system in this host.