Biodiversity of mites (Acari) is currently the field of extensive studies all over the world. Each year many papers with descriptions of new taxa, based largely on external morphology, are published. since the DNA barcoding system, using predominantly the nucleotide sequence of cytochrome oxidase subunit i (coi), has been proposed as an effective method for distinguishing the animal species (Hebert et al. 2003), some taxonomists begun to apply this approach in their investigations. Numerous studies show that the coi sequences of even closely related species differ by ca. ten fold the intraspecific variability and interspecific distance usually equals to or is higher than 3% (D ≥ 0.03 -Sbordoni 2010), making it possible to identify most metazoan species with high confidence. Recently the D1-D2 region of the nuclear 28s rrNA gene has been proposed as a reliable barcode marker complementing analyses based on mitochondrial coi (sonnenberg et al. 2007, Martin et al. 2010, skoracka and Dabert 2010.it is necessary to mention that the barcoding revolution and concept of DNA taxonomy have been widely debated in the past decade and besides the enthusiastic voices which saw in it a tool of unequivocal judge in taxonomic indecisions, it also provoked voices of opponents, who pointed out some deficiencies and limitations in the methods employed by Hebert et al. (2003). they concerned mainly abandoning both morphological data and other crucial species descriptors in favour of a narrow molecular identification system and disregarding the nature of speciation events, different roles of genetic system, natural selection and evolutionary time (sperling 2003(sperling , tautz et al. 2003(sperling , Will and rubinoff 2004(sperling , sbordoni 2010. However, there is a general agreement that molecular data play indisputable role in the analysis of biodiversity and that sequence of the mitochondrial coi gene associated with nuclear DNA sequences are the markers most commonly and successfully used in phylogenetic, phylogeographic and population studies.DNA barcoding is particularly valuable approach in cases, where classical identifying based on morphological features is misleading or very difficult. It concerns especially the species, which despite well expressed genetic separation are morphologically indistinguishable or the differences between them are very obscure. in these cases may increase considerably the overall taxonomic diversity (Hebert et al. 2004, Johnson et al. 2008, lumley and sperling 2010.the opposite side of DNA barcoding, much less popularized, is the detecting of 'false' morphospecies and thus decreasing the described number of species (e.g. otsuka et al. 1999(e.g. otsuka et al. , van Niekerk et al. 2004(e.g. otsuka et al. , otranto et al. 2005 have been considered as distinct steno-and monoxenous quill mite species (Acari: Prostigmata: syringophilidae) parasitizing the thrushes of the genus Turdus linnaeus and the European robin Erithacus rubecula (linnaeus), respectively. Morphological and molecular ...
