Diversity of red palm weevil, Rhynchophorus ferrugineus Oliv. (Coleoptera: Curculionidae) in the Kingdom of Saudi Arabia: studies on the phenotypic and DNA barcodes

The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier), is the most deleterious pests of palms worldwide, including date palms in the Kingdom of Saudi Arabia (KSA). An understanding of RPW diversity is crucial for designing management strategies of this pest. In this study, collections of RPW from date palm plantations were made in six known RPW-infected regions of KSA. The main objectives of the study were to characterize the RPW diversity in KSA using pronotal markings and cytochrome oxidase subunit I (COI) gene. The results showed that based on pronotal markings, 18 different color morphs of RPWs were found, while based on the COI gene, it could be separated into three main haplotypes. Pronotal marking and COI gene diversity revealed that the Riyadh and Eastern Regions were the major RPW diversity hotspots and the primary sources for subsequent RPW introductions into other regions of KSA.