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

Abstract

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 Oligonychus 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 Oligonychus 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 Oligonychus samples lacking males, including a previously claimed sample of O. pratensis from SA. High genetic variations were detected in two Oligonychus species: O. afrasiaticus (McGregor) (nine ITS2 and three COI haplotypes) and O. tylus Baker and Pritchard (four ITS2 and two COI haplotypes). In addition, ITS2- and COI-based phylogenetic trees confirmed the subdivision of the genus Oligonychus. In conclusion, integrative taxonomic approaches are vital to resolve the closely related Oligonychus species, identify the samples lacking male specimens, and assess phylogenetic relationships within and among species.

Molecular Identification of the Diversity of Insects, Spiders, Lizards, Birds and Mammals of Tuensang District, Nagaland, India

“…Recently, the DNA barcoding approach based on the cytochrome c oxidase subunit I (COI) gene present in mitochondrial DNA has become adopted as a global biological identification method for all species due to its accuracy when compared to existing classical taxonomic methods 21 . This approach uses DNA extraction, sequencing and barcoding for genomic characterisation 8 , and it has become as an efûcient and reliable tool for identifying, conûrming and resolving closely related taxa 19 . Molecular techniques are increasingly employed in conservation of biological diversity in response to the alarming extinction of different species.…”