Population genetic structure and dispersal patterns of the globally invasive codling moth (Cydia pomonella) in China

BACKGROUND: The codling moth Cydia pomonella, is a notorious invasive pest that poses a serious threat to China’s apple industry, especially in key growing regions such as the Loess Plateau and Bohai Bay. To effectively manage this pome fruit pest, it is necessary to investigate its genetic variation and genetic structure and infer its dispersal patterns in China. Using population genetics analysis combined with an ensemble species distribution model, we aimed to reconstruct dispersal pathways in China.RESULTS:We analysed 24 populations (22 from China and 2 from Pakistan) via ten nuclear microsatellite loci, which demonstrated high genetic diversity and significant differentiation. We also employed an ensemble model to predict future potential distributions and shifts in suitable habitats. Two spatially explicit genetic clusters were detected.One genetic group includedNortheast China, Gansu, and northernXinjiang populations. The other group comprised populations from Inner Mongolia, southern Xinjiang, and Pakistan. MIGRATE-N analysis revealed low bidirectional gene flow between most populations. The predictions for 2021–2040 suggest increases in the optimal areas of 8.53×10⁴ km², 24.66×10⁴ km², and 10.61×10⁴ km² under the three climate scenarios. The geometric center of the suitable area moved northwards before shifting southwards. The human impact index (HII) was identified as the primary factor influencing pest distribution.CONCLUSION: High genetic diversity and two distinct genetic clusters were identified, revealing significant genetic differentiation between northern/northeastern and northwestern populations.Ensemble models project a northwards shift in suitable areas, with the human impact index (HII) identified as the primary driver. Our integrated approach provides a genetic and spatial framework for developing region-specific pest management strategies.