Geographic variation and diversity of bacterial endosymbionts in Asian citrus psyllid, Diaphorina citri, from Iran.

BACKGROUND

The Asian citrus psylla (ACP, Diaphorina citri), a destructive insect, poses a significant threat to citrus industries worldwide. As the primary vector of huanglongbing (HLB), ACP infestations have caused devastating economic losses and declines in citrus production across many regions. Despite the role of endosymbionts in psyllid biology and HLB transmission, their geographic distribution in Iran remains uncharacterized. In this study, the composition of bacterial endosymbiont communities associated with ACP was examined across four geographic regions in Iran (Sarbaz, Roudan, Faryab, and Jahrom).

RESULTS

Using 16S rRNA gene sequencing and quantitative real-time polymerase chain reaction (qPCR), the presence and abundance of bacterial endosymbionts, including Carsonella, Profftella, and Wolbachia, were confirmed in both nymphal and adult stages of this insect across all populations. Other bacteria, such as Diplorickettsia, Hamiltonella, and Lactobacillus, were identified only in certain populations. Phylogenetic analysis, principal component analysis (PCA), and heatmap clustering highlighted geographical variation in the abundance and diversity of endosymbionts, with the Jahrom population exhibited considerable geographical variation than other regions.

CONCLUSION

Our results revealed significant geographic variation in the prevalence of key bacterial taxa, including Wolbachia and Carsonella. In addition, we report for the first time the presence of Hamiltonella defensa and Diplorickettsia in this insect vector, offering potential targets for microbiome-based pest control strategies tailored to local ACP populations. These findings underscore the importance of understanding how endosymbionts shape ACP biology and its ability to transmit pathogens, and they highlight the potential for innovative pest control approaches, such as manipulating symbiont populations to reduce ACP fitness or disease transmission. © 2025 Society of Chemical Industry.