Evaluation of Genetic Diversity in Quill Mites of the Genus Syringophiloidus Kethley, 1970 (Prostigmata: Syringophilidae) with Six New-to-Science Species.

Simple Summary: Morphology and barcode data were used to estimate the diversity and genetic variability of fourteen putative species of the genus Syringophiloidus Kethley, 1970. In most cases, both sources of information were consistent. The only exception was S. amazilia Skoracki, 2017, which according to our results is most likely a population of S. stawarczyki Skoracki, 2004, and probably should be treated as its junior synonym. The further findings of our study are six new-to-science species described herein. We indicate that both the host phylogeny and distribution can drive the evolution of quill mites. Our results increase the knowledge of quill mite diversity and provide some premises to formulate and further test evolutionary, ecological, and epidemiological inquiries. Quill mites (Acariformes: Syringophilidae) are poorly explored bird parasites. Syringophiloidus Kethley, 1970, is the most specious and widespread genus in this family. It is believed to contain mono-, steno- and poly-xenous parasites and thus seems to be an exemplary for studies on biodiversity and host associations. In this work, we applied the DNA barcode marker (mitochondrial cytochrome c oxidase subunit I gene fragment, COI) to analyze the species composition and host specificity of representatives of fifteen Syringophiloidus populations parasitizing fifteen bird species. The neighbor joining analyses distinguished thirteen monophyletic lineages, almost completely corresponding to seven previously known species recognized based on morphological features, and six new-to-science species. The only exception is S. amazilia Skoracki, 2017, which is most likely conspecific with Syringophiloidus stawarczyki Skoracki, 2004. The intraspecific distances of all species were not higher than 0.9%, whilst the interspecific diversity ranged from 5.9% to 19.2% and 6.3–22.4%, inferred as the distances p and K2P, respectively. Although all putative species (except S. amazilia) are highly supported, the relationships between them have not been fully resolved and only faintly indicate that both host phylogeny and distributions influence the phylogenetic structure of quill mite taxa. [ABSTRACT FROM AUTHOR]