Molecular and morphological identification of two species of mites of the family Pachylaelapidae Berlese (Acari: Mesostigmata) in Guilan province

Mites of the family Pachylaelapidae Berlese, 1913 are a group of predatory mites with free-living species, feeding on arthropods and soil-inhabiting nematodes. Identification of these mites is difficult, because of morphological similarities in a significant number of species and also the fact that new taxons descriptors have referred to some morphological features that have not sufficient distinction criteria to differentiate them from close taxons. Therefore, the use of new identification methods can be helpful in this context. In the present study, along with identification, based on morphological characteristics and size (morphometric identification), we used a molecular method, based on the sequencing of the internal transcribed spacer (ITS) gene to identify two species Olopachys compositus Koroleva, 1976 and Olopachys caucasicus Koroleva, 1976. After DNA extraction, ITS region were amplified and sequenced, using the appropriate primers and afterward the sequences were recorded in GeneBank. Alignment of sequences was performed and the genetic differences between species was calculated as 2.3 percent. As a result of these investigations, in addition to the separation of the two species O. compositus and O. caucasicus based on morphological differences, the molecular method also well confirmed the difference between these two species.