Abstract: 【Aim】 The purpose of this study is to accurately identify an emerging pest mite in the pear orchard in Shandong Province, East China, and lay the foundation for its further research and effective control. 【Methods】 The morphological characteristics of female adult mites were directly observed by stereomicroscope, and the slides of male adult mites were prepared to observe the aedeagal characteristics for morphological identification. The genomic total DNA was extracted from a single female adult mite. The mitochondrial cytochrome oxidase subunitⅠ(COⅠ) gene, and the internal transcribed spacer 1 (ITS1) gene and the internal transcribed spacer 2 (ITS2) gene of nuclear ribosomal DNA were amplified with mitespecific primers and sequenced. The obtained sequences were aligned using Blastn on NCBI. The related sequences with high identity to the obtained sequences were downloaded to construct the phylogenetic trees and calculate the genetic distances for molecular identification. 【Results】 The results showed that the female adult mite on pear trees was born with tubercles on the dorsum, which can be identified as the genus Panonychus pest mite. The characteristics of the aedeagus of the male pest mite were very similar to those of the citrus red mite, Panonychus citri. The COⅠ, ITS1 and ITS2 gene sequences of the pest mite were highly similar to the corresponding sequences of P. citri, with the nucleotide sequence identity of more than 99%. The genetic distances between the pest mite and P. citri calculated based on COⅠ, ITS1 and ITS2 gene sequences were much lower than that between it and the other species of Panonychus. On the phylogenetic trees based on COⅠ, ITS1 and ITS2 gene sequences, the pest mite on pear tree clustered in the same branch with P. citri, with very high bootstrap values (99%, 99% and 100%, respectively). 【Conclusion】 The emerging pest mite that broke out in the pear orchard in Shandong Province was determined to be P. citri based on the morphological characteristics combined with the molecular data, indicating that the distribution range of P. citri in China has moved northward, and great attention needs to be paid to this phenomenon.

Key words: Panonychus citri, pear orchard, pest mites, identification, aedeagus, COⅠ, ITS1, ITS2