PCR-RFLP analysis for identification of Tetranychus spider mite species (Acari: Tetranychidae).

A polymerase chain reaction (PCR)-restriction fragment length polymorphism (PCR-restriction fragment-length polymorphism)-based method for species identification was applied to 14 Tetranychus spider mite species, which were dominant species intercepted at Japanese import plant quarantine. We sequenced the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA (rDNA), which included the partial ends of the 18S and 28S ribosomal RNA genes, 5.8S ribosomal RNA gene, and two internal transcribed spacers (ITS1 and ITS2) for 15 populations of the 14 species. We analyzed the recognition sites of four restriction endonucleases, which had been proposed for discrimination of Japanese Tetranychus species, and constructed a scheme for Tetranychus species identification by PCR-restriction fragment-length polymorphism. We then applied the scheme to 245 individuals from 199 populations, most of them were from foreign countries. As a result, all 14 species were correctly identified using PCR-restriction fragment-length polymorphism. This demonstrates the usefulness of the PCR-restriction fragment-length polymorphism method for the worldwide identification of Tetranychus species.