Molecular-Based Taxonomic Inferences of Some Spider Mite Species of the Genus Oligonychus Berlese (Acari, Prostigmata, Tetranychidae)

DNA barcoding technology using short DNA sequences has emerged as an efficient and reliable tool for identifying, confirming, and resolving closely related taxa. This study used ITS2-rDNA and mtCOI DNA sequences to confirm the identity of eight species, representing 68 spider mite samples, collected mainly from Saudi Arabia (SA) and some from Mexico, Pakistan, USA, and Yemen. The intraspecific nucleotide divergences of the studied species ranged from 0% to 1.2% for ITS2 and 0% to 2.9% for COI. However, the interspecific nucleotide divergences were distinctly higher than the intraspecific ones and ranged from 3.7% to 51.1% for ITS2 and 3.2% to 18.1% for COI. Furthermore, molecular data correctly confirmed the species identity of 42 samples lacking males, including a previously claimed sample of from SA. High genetic variations were detected in two species: (McGregor) (nine ITS2 and three COI haplotypes) and Baker and Pritchard (four ITS2 and two COI haplotypes). In addition, ITS2- and COI-based phylogenetic trees confirmed the subdivision of the genus . In conclusion, integrative taxonomic approaches are vital to resolve the closely related species, identify the samples lacking male specimens, and assess phylogenetic relationships within and among species.