Genetic diversity and population structure of Diaphorina citri (Hemiptera: Liviidae) in Sichuan Province, China

Diaphorina citri Kuwayama (1908), the Asian citrus psyllid (ACP), is a major pest of citrus crops, responsible for transmitting the bacterium that causes Huanglongbing (HLB), a disease devastating to citrus industries worldwide. Despite extensive research on its population genetics in other regions, the genetic structure of D. citri in Sichuan Province, China, remains poorly understood, complicating the development of effective pest management strategies. This study aims to fill this gap by investigating the genetic diversity and population structure of D. citri using genome-wide single nucleotide polymorphisms (SNPs). Three natural populations of D. citri from southeastern Sichuan were sequenced, revealing a total of 7,010,305 SNPs and relatively low genetic differentiation among populations. Phylogenetic analysis identified two primary genetic groups with limited gene flow, supported by principal component analysis (PCA) and Admixture analysis. The populations exhibited high genetic diversity, with notable variations in nucleotide diversity and inbreeding coefficients. Functional enrichment analysis highlighted genes involved in cellular processes and stress response, which may contribute to local adaptation. These findings provide valuable insights into the evolutionary dynamics of D. citri and suggest that genetic diversity and selective pressures play a key role in its adaptability. The results underscore the importance of considering genetic variation in the development of targeted and sustainable pest management strategies in southeastern China.