Determining the geographical origin of Asian longhorn beetle (Anoplophora glabripennis) specimens using stable isotope and trace element analyses

BACKGROUND: An outbreak of EU-quarantine-listed pest Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambicidae), the Asian longhorn beetle, in Kent (UK) resulted in environmentally and financially costly eradication action being taken. In this study the potential of using multi-element stable isotope or trace element analyses to determine the geographical origin of individual specimens has been investigated. RESULTS: The isotope ratios of A. glabripennis individuals for hydrogen varied within and across five locations. Carbon isotope ratios fell within the expected values for C3 plants (trees using the photosynthetic pathway common for moderate climates). Nitrogen isotope ratios indicated separation of UK laboratory from US (New York, Ohio, Massachusetts) beetles, while sulphur isotope ratios distinguished beetles from New York against the other four locations. Three trace elements (TEs) separated UK laboratory-reared beetles from US beetles (Ohio and New York) with approximate to 68% confidence. CONCLUSIONS: Stable isotope and TE analyses show potential to differentiate between newly arrived A. glabripennis individuals and those from previously undetected in-country populations, which would be of immediate practical benefit in making appropriate strategic decisions on surveillance and eradication. Analyses of additional samples from (i) the same populations, (ii) different locations and (iii) a variety of host trees will enhance the overall picture. (c) 2016 Crown copyright. Pest Management Science (c) 2016 Society of Chemical Industry