Diversity, Tissue Localization, and Infection Pattern of Bacterial Symbionts of the White-Backed Planthopper, Sogatella furcifera (Hemiptera: Delphacidae).

The white-backed planthopper (WBPH), Sogatella furcifera (Horváth), is a destructive pest of rice. Bacterial symbionts play an important role in insect hosts, especially hemipteran hosts. This study was designed to examine the bacterial symbionts of the WBPH using 16S rDNA high-throughput sequencing. A total of 63 and 177 operational taxonomic units (OTUs) were identified in females and males of three WBPH populations, respectively. These OTUs included bacteria of 75 genera from 11 phyla, where Wolbachia, Cardinium, and Asaia were the dominant genera, accounting for over 97.99% of all the symbiotic bacteria. Fluorescence in situ hybridization detected Wolbachia, Cardinium, and Asaia in the salivary glands, guts, testes, and eggs of the WBPH, indicating the potential for both horizontal and vertical transmission. Moreover, the infection pattern of the three dominant bacterial symbionts was detected in six WBPH populations. The frequencies of Wolbachia infection of females and Cardinium infection of both sexes were over 96.7%. Wolbachia infection of males ranged between 46.7 and 63.3%, which was significantly lower than that observed for females. Asaia infection of both sexes varied substantially among the populations. These results indicate that the complex host-symbiotic bacteria interaction is influenced by host sex and geographical origin and potentially by the transmission modes of the symbionts.