Morphological and Molecular characterization of Mealybugs (Hemiptera: Coccomorpha: Pseudococcidae) Associated with Hibiscus rosa-sinensis (Malvaceae)

Complexities of the identification of mealybugs may compromise effective management practice for these pests. Hibiscus species (Malvaceae) are frequently attacked by different mealybug species globally. Nevertheless, little information is available concerning the mealybug fauna associated with H. rosa-sinensis in Malaysia. The aim of this study was to identify the mealybug species infesting the H. rosa-sinensis by morphological and DNA barcoding. The DNA barcoding study was performed by comparing the sequencing of the universal barcode DNA region, cytochrome c oxidase subunit I (COI), and ribosomal (18S and 28S). The nucleotide sequences confirmed the mealybug species, with the closest BLAST match in the GenBank queries sharing above 97% support. Based on taxonomic characterization by using scanning electron microscopy and DNA barcoding, three mealybug species, Paracoccus marginatus, Maconellicoccus hirsutus, and Phenacoccus solenopsis were confirmed in this study. DNA barcoding, along with the detailed external ultra-structural analysis of the mealybugs, could add a new dimension for identifying the mealybug species rapidly and more accurately. Ultimately, this study will help in decision-making in management practice for mealybugs.