Genetic Diversity of Palm Weevils, Rhynchophorus Species (Coleoptera: Curculionidae) by Mitochondrial COI Gene Sequences Declares a New Species, R. bilineatus in Qassim, Saudi Arabia

The red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae), is still one of the most important invading harmful pests of date palms worldwide. R. ferrugineus is attacking 40 palm species worldwide. This study highlighted the genetic biodiversity of Rhynchophorus species, as well, their damage in Qassim province/Saudi Arabia. R. ferrugineus, is seen as a single species in all date palm farms in Saudi Arabia. RPW adults display remarkable morphological variation; consequently, R. ferrugineus forms have huge genetic diversities that may be led to the presence of new species and/or haplotypes. In the last decades, the totality of RPW species that invaded the Arab Gulf Area was almost R. ferrugineus. Out of more than 1000 adults, separated into 27 phenotypes used for the genetic studies based on Microsatellites and Mitochondrial Cytochrome Oxidase subunit I (COI) sequences. COI analyses provide definitively clear supported data, for the existence of two predominantly allopatric Rhynchophorus species in Qassim, namely R. ferrugineus and Rhynchophorus bilineatus Montrouzier. The dominant species was R. ferrugineus with 80%, while R. bilineatus constituted 20%. R. ferrugineus involved eight haplotypes, whereas the new expected species R. bilineatus had only two and the most harmful haplotype is haplotype-1 of R. bilineatus. Based on COI analyses, this study determined two Rhynchophorus species in Qassim, of which R. bilineatus is the 1st species reported in Saudi Arabia, Arab gulf countries, and the Mediterranean Basin. Therefore, this study declares that the species of R. bilineatus is considered the 1st record Rhynchophorus species at Qassim, Saudi Arabia.