The globally invasive cotton mealybug Phenacoccus solenopsis Tinsley, has recently invaded several Chinese regions, and continues to expand its range.  This mealybug is a polyphagous insect pest, with at least 200 host plants from 63 families, including cotton, food crops, fruits, ornamental plants, tobacco, and vegetables.  Here, we describe the first finding of P. solenopsis in Shandong Province, and investigate the abundances of its natural enemies (predator Coccinella septempunctata L. and parasitoid Aenasius bambawalei Hayat).  All three species were detected from ornamental and weed species in Linyi, Shandong, in September 2018, and were positively identified using DNA barcoding.  BLAST analysis revealed significant identity (99.38–100%) between sequences of P. solenopsis obtained in this study and those published in the past.  This invasive pest represents a major potential threat to agri-horticulture in Shandong, which is a key province of China for production and export of many vegetables, flowers, fruits, and other crops.  This mealybug species has a wide range of potential distribution in Shandong and is easily dispersed with agricultural and horticultural transport products.  Further monitoring and management strategies are required to limit the spread of this pest species.

The globally invasive cassava mealybug Phenacoccus manihoti Matile-Ferrero is a pernicious pest of cassava, and its recent introduction into Asia has raised considerable alarm.  To slow or prevent further invasion, an accurate, simple, and developmental-stage-independent detection method for P. manihoti is required.  In the present study, a PCR method based on a species-specific mitochondrial DNA cytochrome oxidase I (SS-COI) marker was developed for rapid identification of P. manihoti.  One pair of SS-COI primers (PMSSZW-1F and PMSSZW-1R) was designed based on sequence variations in the COI gene among P. manihoti and related mealybug species.  Specificity of the primer pair was validated on 21 closely related species.  Sensitivity tests were performed on four immature developmental stages and female adults.  Efficacy tests demonstrated that at the relatively low concentration of (135.2±14.7) pg μL^–1 resuspended DNA, the specific fragment was detected in all replicates.  Furthermore, the SS-COI primer pair was assayed on three populations of P. manihoti from major exporting countries of cassava.  The PCR assay was proved to be a rapid, simple, and reliable molecular measure for the identification of P. manihoti.  This tool will be useful for quarantine, monitoring, and management of this invasive pest.