The Jack Beardsley mealybug, Pseudococcus jackbeardsleyi Gimpel & Miller (Hemiptera: Pseudococcidae), a globally devastating, invasive polyphagous insect, causes great damage to many fruits, ornamentals, vegetables, and food crops worldwide. It is of Neotropical origin and has invaded throughout America and in parts of Asia, Africa and Oceania, and is still expanding its invasion ranges. Therefore, a method for quick and correct identification of this invasive species is crucial for quarantine and spreading interruption of it. In present study, we report the first record of P. jackbeardsleyi on the Chinese mainland, which would cause great damage to many crops. The identification of P. jackbeardsleyi was verified via morphological characters and DNA barcoding. One pair of species-specific polymerase chain reaction (SS-PCR) primers was designed based on variations in the sequences of the mitochondrial cytochrome c oxidase subunit I gene among P. jackbeardsleyi and 28 other mealybug species. No cross-reaction was detected among 21 closely related species using this SS-PCR assay, demonstrating the specificity of this marker. Furthermore, this method was successfully applied to detect individuals from different developmental stages and adult debris across four geographic populations of P. jackbeardsleyi, showing the high stability of the assay. Additionally, the detection limit of the marker was 55.94 ± 5.05 pg/μl of P. jackbeardsleyi DNA, illustrating the high sensitivity of the assay. The SS-PCR assay developed in this study provides a rapid, simple and reliable method for the identification of P. jackbeardsleyi, which should be crucial in the plant quarantine, early detection and sustainable management of this globally invasive pest.