Identification of three internal feeders from Korla fragrant pears by quantitative real-time polymerase chain reaction

Abstract

Cydia pomonella, Euzophera pyriella Yang, and Grapholitha molesta are destructive pest species of Korla fragrant pears in Xinjiang. They are also quarantine pests of concern in a number of countries. Identification of these small pest larvae by morphological characters is difficult, and misidentifications will influence appropriate quarantine decisions. Here, a 520 bp fragment of mitochondrial cytochrome oxidase subunit I (COI) was first amplified and sequenced from each species, and a diagnostic region was observed. Subsequently, the species-specific primer and probe sets of quantitative real-time PCR (qPCR) were designed, which amplified a 114–116 bp fragment of COI genes. This method was validated by amplification DNA extracted from single, multiple, and mixed pest samples. Results indicated that this method allows rapid discrimination and reliable identification of larvae, pupae, and adult specimens of all three species, which could help the international export trading of Korla fragrant pears and related products.