We report on a new phytoptid mite species, Oziella viscida n. sp., collected in Western Crimea from sea rush, Juncus maritimus (Juncaceae), and give supplementary descriptions of two rarely encountered nalepellid species of the genus Trisetacus from pines: T. confusus Livshits & Vasilieva, 1982 (in ) from needle sheaths of Pinus nigra ssp. pallasiana (Pinaceae), an endemic subspecies restricted to Crimea, and T. brevisetus Livshits & Sekerskaya, 1982 (in ) from needle sheaths of Pinus brutia ssp. pityusa (Steven) Silba, a relatively isolated subspecies of Turkish pine (P. brutia Tenore) growing in Georgia, Caucasus and Crimea. Oziella viscida n. sp. is remarkable in that most specimens were found inhabiting the basal part of leaves and stems of J. maritimus, an area covered by a transparent, sticky exudate apparently secreted by the plant epidermis. The mites were completely embedded in this substance and, rather than crawling with their legs, were observed moving through the viscous material while bending their opisthosoma in a serpentine or wormlike manner—an adaptation that appears to be currently unreported in eriophyoids and possibly reminiscent of locomotion of ancestral “protoeriophyoids” associated with soil. In comparison to females, males of O. viscida n. sp. and T. confusus have a more distinct prodorsal shield pattern consisting of a larger number of longer lines. Three new barcode gene sequences were obtained: MZ220550 (Cox1, O. viscida n. sp., 1159 bp), MZ224497 (18S, 2012 bp, T. brevisetus), and MZ224498 (18S, 2013 bp T. confusus). A BLAST search of the 18S sequences of T. brevisetus and T. confusus shows them as slightly closer to other 18S sequences of Trisetacus from Pinaceae (95.5%–96.3% identity) than to Trisetacus from Cupressaceae (93.6%–94.0% identity). Comparison of sequences of nalepellids currently present in GenBank suggest that a complete 18S sequence KJ841938.1 (2252 bp) from China belongs to an identified Trisetacus from Pinaceae rather than to Setoptus koraiensis as labelled, highlighting the necessity to review carefully the sequences of Eriophyoidea prior to using them in phylogenetic analyses, as well as the need to recollect and resequence S. koraiensis to clarify the nature of the problematic data from GenBank assigned to this species.

Three species of chigger mites, which are supposed to be agents of human trombiculiasis in Europe, have been studied based on museum collections and specimens collected by the authors. Trombicula toldti Winkler, 1953 has been transferred to the monotypic genus Blanciella Vercammen-Grandjean, 1960. The type species of this genus, Blanciella deschiensi (), was synonymized with Blanciella toldti comb. nov., and B. toldti was re-described. Lectotype of B. toldti was designated based on the type material donated to Zoological Institute RAS (St. Petersburg, Russia). The lectotype of Kepkatrombicula desaleri () was found in Muséum National d'Histoire Naturelle (Paris, France), and the previously designated neotype of K. desaleri has been set aside. Both B. toldti and K. desaleri have been recorded for the first time in Switzerland infesting goats (Capra hircus L., 1758). Human parasitism by Neotrombicula inopinata () in the UK has been confirmed for the first time with an examined museum specimen.

Descriptions of three new species of oribatid mites (Oribatida) of the family Galumnidae—Galumna (Galumna) panguanaensis sp. nov., G. (Neogalumna) moroi sp. nov. and Pergalumna (Pergalumna) neryae sp. nov.—are presented, based on materials collected from upper soil and leaf litter in the primary evergreen lowland rainforest of Amazonian Peru.

Two new species of the feather mite genus Proctophyllodes (Analgoidea: Proctophyllodidae) are described from two passerine birds (Passeriformes) in China: Proctophyllodes scleroticus sp. nov. from the Brandt's Mountain Finch Leucosticte brandti pallidior (Fringillidae) and P. micrurus sp. nov. from the White-rumped Snow Finch Onychostruthus taczanowskii (Passeridae). Proctophyllodes scleroticus sp. nov. belongs to the tricetratus species-group, and differs from the most similar species P. petroniae by the following characters: in male, the genital sheath is heavily sclerotized, peach shaped, and extending to the level of setae g, anal suckers are surrounded with a pair of membranes, and terminal lamella is relatively greater, and in female, lobar shield is divided into two independent shields by the anal opening and anal opening extends beyond the level of setae ps1, terminal appendage is long. Proctophyllodes micrurus sp. nov. belongs to the musicus species-group, and differs from the most similar species P. saltatoris by the following characters: in male, genital arch and the anterior part of opisthogastric shield are about the same width, anal suckers are surrounded with a pair of membranes, genital organ extends to the anterior 1/3 of the level of setae g and setae ps3, terminal lamella are located closely to each other and slightly greater, and in female, lobar shields are medially divided into two halves, terminal appendages are small, about 1/10 of setae h3, edge of the cleft is almost horizontal.

In this paper we describe and illustrate Zercon hamaricus sp. nov. based on all postembryonic stages obtained from soil samples and laboratory cultures. The new species belongs to a species group in which dorsal setae J1–J4 in females are short and similar in length, and J5 are considerably longer. In most species of this group opisthonotal setae J5 and Z4 are clearly displaced anteriorly. Zercon hamaricus sp. nov. is most similar to Z. forsslundi and to a less extent to Z. polonicus . The females of Z. forsslundi, Z. polonicus and Z. hamaricus sp. nov. can be distinguished based on the range of J5, the length and character of the Z and S-series setae, the distance between setae Z5 and the location of gdZ3. We also include comparative information on other related species of Zercon. The new species is one of the six known species that have clearly visible sexual dimorphism in opisthonotal chaetotaxy.

A new species of zerconid mites, Prozercon caspiansis sp. nov. is described based on female, male, and protonymph specimens collected from different forestland areas in Mazandaran Province, northern Iran. In addition, the male and larval specimens of P. dominiaki Błaszak were found in the same region and described for the first time. An updated key for the Iranian Prozercon species is provided, and the situation of the Iranian genera and species of the family is briefly discussed.

We report on one new species, Aceria asphodelinis n. sp., from inflorescences of Asphodeline taurica (Pall. ex Bieb.) Kunth (Xanthorrhoeaceae), one new combination, Paraphytoptus chondrillae () n. comb. (transferred from Aceria), from deformed inflorescences of Chondrilla juncea L. (Compositae), and six new records of eriophyine mites (Eriophyoidea, Eriophyidae, Eriophyinae) in southeast Crimea: Aceria peucedani () from flowers of Seseli tortuosum L. (Apiaceae), Aceria salviae () from inflorescences of Salvia tesquicola Klokov & Pobed. (Lamiaceae), Aceria erinea () and Aceria tristriata () from leaf galls of Juglans regia L. (Juglandaceae), Eriophyes calycobius () from buds of Crataegus monogyna Jacq. (Rosaceae), Eriophyes pyri () from parenchymatous leaf galls (“blisters”) of Pyrus communis L. (Rosaceae). Partial mitochondrial Cox1 sequences (1155 bp, 385 amino acids) of six Aceria and Eriophyes species are provided (GenBank accession numbers: MW691978–MW691983; MW851284). Aceria salviae, previously reported as a gall-former, was found to be vagrant, causing no visible damage to the host plant. Data from the literature suggests that it may be quite common for conspecific eriophyoids to differ in their ability to cause galls on closely related hosts. We provide several hypotheses that may explain this phenomenon and highlight the need for testing them via field experiments as well as molecular methods. We also advocate for broader usage of barcoding techniques in the taxonomy of Eriophyoidea and underline the importance of increasing the number of publicly available barcodes for various eriophyoid taxa.

Two new species of the feather mite genus Trouessartia (Analgoidea: Trouessartiidae) are described from tyrant flycatchers (Tyrannidae) in Argentina: Trouessartia salvadori sp. nov. from the White-crested Tyrannulet Serpophaga subcristata (Vieillot) and T. gonzalezacunai sp. nov. from the Vermilion Flycatcher Pyrocephalus rubinus (Boddaert). Trouessartia salvadori sp. nov. is close to T. longiducta and most clearly differs from the latter in having, in males, the genital apparatus with wedge-shaped hyaline extensions and the anterior genital papillae situated more distant from the midline than posterior ones, and in females, setae h1 not extending beyond the margin of the interlobar membrane, and the posterior part of the hysteronotal shield bearing well outlined ovate lacunae except in the narrow median area. Trouessartia gonzalezacunai sp. nov. is similar to T. savanae , but is distinguished from that species in having, in males, the terminal lamellae shaped as a fishtail, the epiandrum shaped as a goblet, the apophyses of adanal apodemes represented by thick spine-like tubercles, and in females, setae h1 minute spiculiform about 10 long, and the external copulatory tube shaped as a small rounded tubercle near the margin of interlobar membrane.

The stable fly, Stomoxys calcitrans (L.), is one of the main pests of livestock in Brazil, especially in areas where cattle is raised next to sugarcane (Saccharum spp.) fields in which vinasse is used as a fertilizer. Knowledge about the predatory mites associated with this parasite in the field may be helpful in designing programs to control it biologically. Mites of the family Macrochelidae are known to attack fly immatures, and thus could be helpful in reducing the population of the stable fly in the field. The aim of this paper is to report the macrochelid species found in surveys conducted in northwestern São Paulo state, where the fly is known to be present, including a new species here described, Holostaspella paulista Borges & Azevedo sp. nov., to provide complementary descriptions of the other species collected, and to present a key to the caelata group of Holostaspella. In total, 2,946 macrochelid specimens were collected from 264 samples of soil-litter or soil-cow obtained from two areas of sugarcane plantations, a pasture area and a disturbed patch of the Atlantic Forest in 2018 and 2019. Four species of Macrocheles, two of Holostaspella and one of Glyptholaspis were identified. The predominant species was Macrocheles merdarius (Berlese).

The presence of the red palm mite Raoiella indica Hirst, was recorded on açaí, Euterpe oleracea Mart. (Arecaceae), in Porto Seguro, Bahia State, northeastern Brazil. We evaluated the population dynamics of R. indica from September 2019 to February 2020. The population outbreak and most severe damage caused by R. indica was observed in February, a period of highest temperatures and low relative humidity. This is the first report of damage caused by the red palm mite on E. oleracea in Brazil. Management practices must be implemented to avoid intercropping açaí with other hosts of this mite e.g. coconut, banana and palm trees in order to minimize the occurrence and damage of R. indica on such agrosystems.

A new genus Mengzongella gen. nov. is described to accommodate a new species M. tertia sp. nov. based on two males collected in Guangxi, China, from the leaf litter of a giant bamboo thicket (Bambusa chungii syn. Lingnania chungii). The new genus belongs to the family Urodinychidae based on the shape of the gnathosomal setae h1, shape of the chelicerae and the presence of the cheliceral node. The new genus differs from the previously described ones by deep transversal dorsal furrows, the shape of the dorsal and ventral setae and the undulate inner margins of the marginal shield. Two previously described Japanese species [Urodiaspis sandankyoensis () and Urodiaspis yonakuniensis ()] are transferred to the new genus as Mengzongella sandankyoensis () comb. nov. and Mengzongella yonakuniensis () comb. nov.

Temporary ponds are specific freshwater habitats in which the characteristic fauna of aquatic organisms is formed. One of the large groups of invertebrates in temporary water bodies is water mites. In this work, water mites were studied in three different types of temporary ponds in the vicinity of the city of Tyumen, Western Siberia. The studies were carried out in two periods with a long time interval between them: in 2008–2010 and 2018–2019. In total, 33 species of water mites from 7 families were identified in the studied ponds. All ponds were dominated by vernal mite species typical for this type of water bodies. Also, they were characterized by similar seasonal dynamics of numbers. The species composition and the number of mites in different ponds varied, which is associated with different physicochemical parameters and the fauna of invertebrates, which served as food objects and hosts for the adults and larvae. Despite the small size and periodic drying of the ponds, the fauna of the mites inhabiting them has changed little over the long period of time that separates the studies. Only in one pond, which became permanent due to the rise of groundwater, significant changes in acarofauna were observed. Considering such constancy of the fauna of water mites of temporary ponds, they can be used as bioindicators of the ecological state of water bodies.