Revision of torrent mites (Parasitengona, Torrenticolidae, Torrenticola) of the United States and Canada: 90 descriptions, molecular phylogenetics, and a key to species

New records of water mites (Acari, Hydrachnidia) from Portugal revealed by DNA barcoding, with the description of Atractides marizae sp. nov

This study presents the first results of DNA barcoding of water mites from Portugal. DNA barcodes were recovered from 19 water mite specimens morphologically assigned to eight species, seven of them newly reported from Portugal. Two species, Torrenticola hispanica (Lundblad, 1941) and A. cultellatus (K. Viets, 1930) were discovered more than 80 years after they were first described, and Atractides marizaesp. nov. is described as new for science.

A DNA barcode library for the water mites of Montenegro

Water mites (Acari, Hydrachnidia) are a significant component of freshwater ecosystems inhabiting a wide range of aquatic habitats. This study provides a first comprehensive DNA barcode library for the water mites of Montenegro. DNA barcodes were analysed from 233 specimens of water mites morphologically assigned to 86 species from 28 genera and 15 families. In the course of the study, four species, i.e. Lebertiareticulata (Koenike, 1919), Atractidesinflatipalpis K.Viets, 1950, A.latipes (Szalay, 1935) and Parabrachypodamontii (Maglio, 1924) were molecularly confirmed as new for Montenegro and three species, i.e. Protziaoctopora Lundblad, 1954, Pionalaminata (Thor, 1901) and Unionicolaypsilophora (Bonz, 1783) are new for the Balkan Peninsula. Results are analysed using the Barcode Index Number system (BIN) and the Refined Single Linkage (RESL) of BOLD. The BIN assigned sequences to 98 clusters, while the RESL reveal 103 operational taxonomic units (OTUs). Unique BINs were revealed for 72 species (83.7%), whereas twelve species (14%) were characterised by two BINs and two species (2.3%) with three BINs. Amongst the studied taxa, 14 species were found with a high intraspecific sequence divergences (˃ 2.2%), emphasising the need for additional comprehensive morphological and molecu-lar analysis of these species.

Long-term stasis in acariform mites provides evidence for morphologically stable evolution: Molecular vs. morphological differentiation in Linopodes (Acariformes; Prostigmata)

Molecular species delimitation, usually by COI DNA barcoding, shows that cryptic speciation is a common phenomenon observed in most animal phyla. Cryptic species have frequently been observed among all major taxa of mites. The mites of the eupodoid genus Linopodes are cosmopolitan in distribution and are most often found in soil-related habitats. Currently, the genus consists of 22 morphologically similar species, which, in practice, are indistinguishable on the basis of their morphological features. The diagnostic issue of the Linopodes species may be caused by the poor delineation of the species, which need taxonomic revision, or the low morphological variability among cryptic species. In this paper, we present the results of molecular species delimitation carried out using sampled Linopodes populations and the level of morphological inter/intraspecific variation within defined groups. We compared COI, 18S and 28S sequence data together with morphological characters. The molecular delimitation revealed seven well-defined species of Linopodes based on DNA sequences. A well-supported phylogenetic tree revealed the same seven species, while morphological analysis showed negligible phenotypic differentiation among the species revealed. We demonstrate that mites can undergo changes in their DNA accompanied by morphological stasis lasting at least 80 MY.

Acari of Canada

Summaries of taxonomic knowledge are provided for all acarine groups in Canada, accompanied by references to relevant publications, changes in classification at the family level since 1979, and notes on biology relevant to estimating their diversity. Nearly 3000 described species from 269 families are recorded in the country, representing a 56% increase from the 1917 species reported by Lindquist et al. (1979). An additional 42 families are known from Canada only from material identified to family- or genus-level. Of the total 311 families known in Canada, 69 are newly recorded since 1979, excluding apparent new records due solely to classification changes. This substantial progress is most evident in Oribatida and Hydrachnidia, for which many regional checklists and family-level revisions have been published. Except for recent taxonomic leaps in a few other groups, particularly of symbiotic mites (Astigmata: feather mites; Mesostigmata: Rhinonyssidae), knowledge remains limited for most other taxa, for which most species records are unpublished and may require verification. Taxonomic revisions are greatly needed for a large majority of families in Canada. Based in part on species recorded in adjacent areas of the USA and on hosts known to be present here, we conservatively estimate that nearly 10,000 species of mites occur in Canada, but the actual number could be 15,000 or more. This means that at least 70% of Canada's mite fauna is yet unrecorded. Much work also remains to match existing molecular data with species names, as less than 10% of the ~7500 Barcode Index Numbers for Canadian mites in the Barcode of Life Database are associated with named species. Understudied hosts and terrestrial and aquatic habitats require investigation across Canada to uncover new species and to clarify geographic and ecological distributions of known species.