Phylogeography of Diaphorina citri (Hemiptera: Liviidae) and its primary endosymbiont, 'Candidatus Carsonella ruddii': an evolutionary approach to host-endosymbiont interaction.

Background: In insects, little is known about the co-evolution between their primary endosymbionts and hosts at the intraspecific level. This study examined co-diversification between the notorious agricultural pest Diaphorina citri and its primary endosymbionts (P-endosymbiont), 'Candidatus Carsonella ruddii' at the population level.
Results: Maximum likelihood, haplotype network, principal components and Bayesian clustering identified three lineages for D. citri and its P-endosymbiont: a Western clade containing individuals from Pakistan, Bhutan (Phuentsholing), Vietnam (Son La), USA, Myanmar and China (Ruili, Yunnan); a Central clade, with accessions originating from Southwest China, Bhutan (Tsirang) and Bangladesh; and an Eastern clade containing individuals from Southeast Asia, and East and South China. A more diverse genetic structure was apparent in the host mitochondrial DNA than their P-endosymbionts; however, the two sets of data were strongly congruent.
Conclusion: This study provides evidence for the co-diversification of D. citri and its P-endosymbiont during the migration from South Asia to East and Southeast Asia. We also suggest that the P-endosymbiont may facilitate investigations into the genealogy and migration history of the host. The biogeography of D. citri and its P-endosymbiont indicated that D. citri colonized and underwent a secondary dispersal from South Asia to East and Southeast Asia. © 2018 Society of Chemical Industry.
(© 2018 Society of Chemical Industry.)