Detection of Grapholitha molesta and Carposina sasakii based on environmental DNA and its field application.

BACKGROUND: Grapholitha molesta and Carposina sasakii are notorious pests that damage fruits, and are ranked among the most high-priority control targets in orchards. Chronic mixed infestation of these two economically destructive species not only pose formidable challenges to integrated pest management efforts, but also have substantial impacts on global fruit trade. Therefore, a non-destructive, rapid and efficient identification technology is urgently needed. In comparison with conventional detection methods, the environmental DNA (eDNA) approach does not require direct contact or capture of organisms and can monitor multiple species simultaneously. In this study, an innovative eDNA-based methodology was developed and optimized for precise detection of G. molesta and Carposina sasakii, and was finally applied to assess their infestation levels across different orchards.

RESULTS: The results demonstrated that eDNA with the highest concentration and quality was obtained through a filtration process combining a 10 μm mixed cellulose ester (MCE) membrane and a 0.45 μm cellulose acetate (CA) membrane, after soaking the victim pulp for 15 min. The primers developed for these two species of fruit moths exhibited high sensitivity, with minimum detection limits of 0.1 and 0.01 ng/ul, respectively.

CONCLUSION: The eDNA-based technology successfully detected the target moth species in orchards, regardless of whether the fruit was damaged by one or more moths. This study provided a critical theoretical foundation for the development of non-destructive fruit pest testing technology, and also offered valuable references for eDNA research on other species, which will be vital to the field monitoring of fruit-boring moths. © 2025 Society of Chemical Industry.