Abstract
Inorganic components have been widely applied as geographical traceability biomarkers of plant derived food and phytophagous insects. Helicoverpa armigera (H. armigera) (Lepidoptera: Noctuidae), a global economic pest, has been shown to be able to migrate long distances but the detailed migration paths are still unclear. Herein, the levels of 10 minerals (Mg, Al, K, Ca, Mn, Fe, Cu, Zn, Cr and Sr) in 32 H. armigera adults from different growing backgrounds were evaluated by inductively coupled plasma – optical emission spectrometry (ICP-OES). The discrimination of these insects from five groups was realized by using principal component analysis (PCA) and canonical discriminant analysis (CDA). The results showed that H. armigera from different growing backgrounds discriminated by PCA and CDA achieved high accuracy values of 84.4% and 100.0%, respectively. Additionally, cross-validation was utilized to check the confidence of the CDA results with an accuracy of 81.3%. The present study shows that geographical discrimination established by chemometric analytical methods achieves high confidence in terms of the identification of the phytophagous insect H. armigera. The application of this pattern may contribute to resolving migratory insect issues in the near future.
Acknowledgements
Sincere thanks are also provided to Huijuan Liu from Nanjing University for her generous support for the use of ArcGIS.