A new species of the genus Aegyptobia Sayed, 1950 (Acari: Trombidiformes: Tenuipalpidae), namely Aegyptobia carmania sp. nov. is described and illustrated based on females and males collected from Haloxylon ammodendron (Amaranthaceae) in Southern Iran (Kerman Province). The genus Dolichonobia Smith Meyer, 1974 and subgenus Reckia Wainstein, 1960 are recorded for the first time from Iran. In addition, eight species are recorded for the first time from Iran.

During a study of predatory mites in Urmia, Northwestern Iran, the female and male of a new species, Stigmaeus dokeri sp. nov. (Acari: Stigmaeidae), were collected from soil under oak trees. The specimens of the following species, S. malekii Haddad Irani-Nejad, Bagheri & Khanjani, 2006, S. boshroyehensis Khanjani, Izadi, Asali-Fayaz, Raisi, Rostami & Doğan, 2010, S. miandoabiensis Bagheri & Zarei, 2012 and S. marandiensis Bagheri & Ueckermann, 2011, were re-examined. We propose that S. boshroyehensis syn. nov. is a junior synonym of S. malekii. We also found S. miandoabiensis and S. marandiensis having bifurcate terminal eupathidium on palptarsus instead of tridentate in the original descriptions.

We describe a new monotypic genus in the mite family Eviphididae, Platyphis Joharchi & Halliday gen. nov., to accommodate a new species, P. montreuili Joharchi & Halliday sp. nov., from specimens collected on a rare earth-boring dung beetle species, Enoplotrupes bieti (Oberthür) (Coleoptera: Geotrupidae) in Nepal. The new genus differs from all other genera of Eviphididae by having an expansive anal shield. Other distinctive features of the new genus include the moderately narrow deutosternal groove with five rows of denticles, and the internal malae with thick and moderately long fimbriae.

Areas of natural vegetation can favor biodiversity since they have a higher number of native plants and less impact of human activities compared to areas with agricultural crops. Orange and pine forestry stand out among the important monoculture crops for Brazilian agribusiness. In the orange crop, agrochemicals are used to control pests; in pine, there is no need to apply agrochemicals as often, however, biodiversity can be impacted by allelopathic effects of the plant. There are some mite families associated with these environments; among them the cunaxid mites present are associated with both the soil and the litter, feeding on springtails, nematodes and other small organisms. The objective of this study was to evaluate the cunaxid diversity associated with Natural Vegetation (NV), Pine Forestry (PF) and Orange Cultivation (OC) in the municipalities of Mormaço and Soledade, state of Rio Grande do Sul, Brazil. Three litter and soil collections were carried out at 12 random sampling points, in previously demarcated areas within each environment. In total, 330 cunaxids were collected, 57.6% in NV, 32.7% in OC and 9.7% in PF. Among the species found, Coleoscirus tuberculatus Den Heyer, Cunaxa n. sp., Neobonzia n. sp. and Pulaeus quadrisolenidius Castro & Den Heyer were exclusively associated with NV, while Rubroscirus sp. only with OF and Dactiloscirus sp. with OC. The most abundant species was Neocunaxoides ovatus Lin, Zhang & Ji, with 130 specimens and the rarest was Neobonzia n. sp., with only one specimen.

The invasive tomato spider mite, Tetranychus evansi (Acari: Tetranychidae) is one of the major pests of the solanaceous plants worldwide. The phytoseiid predatory mite Amblyseius swirskii (Acari: Phytoseiidae) is one of the most commonly used predatory mites for augmentative biological control of several important pests in protected crops. Despite its frequent usage in a range of greenhouse crops including tomatoes, several biological characteristics and foraging behaviors of this predator such as functional and numerical responses, have not been studied on T. evansi. In this study, the functional and numerical responses of A. swirskii to four different biological stages (eggs, larvae, protonymphs and deutonymphs) of T. evansi were evaluated under laboratory conditions. The significantly negative P₁ values and the type of functional response curves clearly indicate that A. swirskii exhibited a Type II functional response to T. evansi regardless of prey stage. The highest attack rate (α=0.070 h^-1) and the shortest handling time (T_h=0.426 h) were determined when the predator fed on protonymph and larva, respectively. The highest daily mean number of eggs (1.10±0.10) laid by A. swirskii was obtained at 120 egg density. No significant difference was determined in egg production of the predatory mite among different life stages within the same prey density except 10 prey density. In addition, there was also no difference among prey densities within the same biological stage, except egg stage. According to the results, A. swirskii may not be directly recommended for the biological control of T. evansi on tomato. However, when its inundative release is considered, it may help and improve the success of biological control of T. evansi, especially at early stages of infestations.

In the present study, we evaluated and compared the in vitro biological parameters of the evolutionary stages of R. microplus (female, eggs, and larva) from two extreme regions of Brazil: Santa Rita (SR) northeast region and Bagé (BG) southern region. For this, all stages were maintained at 23, 27, and 32°C with a relative humidity (RH) of 65, 80, and 100%. The mean incubation period was 43.7 to 53.7 days (SR population) and 59.0 to 56.1 days (BG population) at 23°C and 18.0 to 19.3 days (SR population) and 16.8 to 21.2 days (BG population) at 32°C. Eggs incubated at 23°C (65, 80, and 100% RH) of SR and BG populations showed a similar egg hatching percentage (P > 0.05). The egg hatching percentage of the SR population (30.5 to 98.0%) was always higher than that of the BG population (8.7 to 85.5%; P < 0.05) when incubated at 32°C and 65, 80, or 100% RH. Deleterious effects on the larval survival period from SR and BG were observed under all experimental conditions (temperature and RH), especially at 23 and 32°C. However, they were more intense on larvae at 32°C (all RH). Under 80 and 100% RH, the mean period of larval survival did not exceed 65 days, being shortest for the BG population (mean: 42.7 days [80% RH] and 55.1 days [100% RH]) compared with the SR population.

One new genus and three new species of eriophyid mites (Eriophyidae) from Eastern Thailand were described. They are Khitchakuta chanthaburinae gen. nov. & sp. nov. on Acacia pennata (L.) Willd. (Leguminosae), Abacarus phaitongus sp. nov. on Dendrocalamus asper (Schult.) Backer (Poaceae), and Aculus kafakii sp. nov. on Dendrophthoe pentandra (L.) Miq. (Loranthaceae).

A new species, Galendromus (Mugidromus) agreste sp. nov., was described and illustrated, based on adults of both sexes. Specimens were collected on plants in an Altitudinal Atlantic Forest area of the Caatinga biome, located in the Agreste region of the state of Pernambuco, Brazil. Intraspecific variations in insertion of ventral setae are reported, and an updated identification key for the species of this subgenus is also provided.

Two new species of feather mites are described from the Rusty-capped Fulvetta Schoeniparus dubius (Hume) (Passeriformes: Pellorneidae) in India (Meghalaya): Proterothrix manolelii Constantinescu sp. n. (Proctophyllodidae: Pterodectinae) and Trouessartia asiatica Constantinescu sp. n. (Trouessartiidae). Proterothrix manolelii belongs to the paradoxornis complex (wolffi species group) in having, in males, seta e of tarsus I lanceolate and the aedeagus long and whip-shaped. Among the other six species of the paradoxornis complex, this species appears to be closest to P. alcippeae Mironov, Literak, Hung & Capek, 2012 from the Rufous-throated Fulvetta, Schoeniparus rufogularis (Mandelli) (Passeriformes: Pellorneidae). Males of Proterothrix manolelii are distinguished from the latter in having the pentagonal structure formed by epimerites of propodosoma completely closed, the opisthosomal lobes almost three times longer than wide at base, and setae mGI and mGII lanceolate. Females of P. manolelii have the sternum about 1/3 of the total length of epimerites I, and the primary spermaduct is thickened only in distal 1/3. Trouessartia asiatica is the first species of the genus described from a bird host in the family Pellorneidae. Males of T. asiatica are clearly differentiated from related species described from birds in the family Leiotrichidae (T. cyanouropterae Constantinescu, 2016, T. alcippeae Constantinescu, 2016, and T. pauciseta Constantinescu, Chişamera, Motoc, Gustafsson, Zou, Chu and Adam, 2021), in the position and shape of the genital setae g, which are enlarged in basal 2/3^rd and located far distantly from the base of genital apparatus, posterior to bases of setae 4a. Females of this species are clearly distinguished in the shape of the primary spermaduct, which is thickened along its entire length.

The cacao bud mite, Aceria reyesi (Nuzzaci), has been identified as the causal agent of the ‘engurruñadera del cacao’, characterized by the apparent accumulation of stipules on the buds, followed by die-back, with premature fall of leaves, shortening of internodes and proliferation of lateral branches, or witches'-broom, resulting in production losses or even in the death of plants. Our objective was to evaluate four response variables (numbers of leaves/plant, stipules/bud, internodes/branch and branches/plant) that could be indicative of a possible reversion of the ‘engurruñadera’ after the application of the acaricide abamectin and/or pruning. Two experiments were carried out between November 2020 and April 2021 in a greenhouse at UESC, with cacao seedlings of the genetic group ‘Forastero’ (cacao ‘Common’) infested with A. reyesi and showing typical symptoms of the ‘engurruñadera’. The first experiment was conducted with 4 treatments and 8 replicates, with the application of (1) Abamectin + pruning, (2) Abamectin without pruning, (3) Water + pruning and (4) Water without pruning (control). Sprays were carried out fortnightly with an Abamex® solution (18 g/L of abamectin, in a concentration of 2 mL/L of distilled water + neutral detergent). Pruning was performed only once, at the beginning of the experiment, by removing the apical 10 centimeters of all plant branches. Response variables were evaluated one day before the application of the treatments (Day 0), and afterward (∼Days 75 and 150 after the first evaluation, respectively). The second experiment was conducted with 2 treatments and 12 replicates, with the application of (1) Abamectin (treated) and (2) Water (control). Pulverizations and evaluations were carried out as in the first experiment. The number of leaves/plant and internodes/branch were the only response variables that indicated some reversion of the ‘engurruñadera’ in both experiments among treated and control groups, although only 150 days after the application of abamectin and/or pruning. The number of branches/plant showed a significant increase from 75 days after the treatments with pruning, and no difference was found among treated and control groups in terms of numbers of stipules/bud in both experiments. We concluded that the numbers of leaves/plant and internodes/branch seem to be adequate monitoring tools to indicate the reversion of the ‘engurruñadera’ after the application of abamectin and/or pruning. Pruning was effective in the reversion of symptoms of the ‘engurruñadera’ on cacao seedlings as well as the abamectin application of a 2 mL dose of Abamex® per liter of water fortnightly.

Arthropods from class Arachnida constitute a large and diverse group with over 100,000 described species, and they are sources of many proteins that have a direct impact on human health. Despite the importance of Arachnida, few proteins originating from these organisms have been characterized in terms of their structure. Here we present a detailed analysis of Arachnida proteins that have their experimental structures determined and deposited to the Protein Data Bank (PDB). Our results indicate that proteins represented in the PDB are derived from a small number of Arachnida families, and two-thirds of Arachnida proteins with experimental structures determined are derived from organisms belonging to Buthidae, Ixodidae, and Theraphosidae families. Moreover, 90% of the deposits come from just a dozen of Arachnida families, and almost half of the deposits represent proteins originating from only fifteen different species. In summary, our analysis shows that the structural analysis of proteins originating from Arachnida is not only limited to a small number of the source species, but also proteins from this group of animals are not extensively studied. However, the interest in Arachnida proteins seems to be increasing, which is reflected by a significant increase in the related PDB deposits during the last ten years.

With the aim of obtaining more information about eriophyoid mites of Iran, eriophyoid fauna of Montpellier maples (Acer monspessulanum L.) in Khan valley, Baranduzchay-ye Jonubi Rural District, Urmia county, West Azerbaijan Province, Iran was studied. In total, four eriophyoid species were identified; two of them, Aceria azerbaijaniensis Lotfollahi et Mohammad-Doustaresharaf sp. nov. and Cecidophyes aceressulani Lotfollahi et Mohammad-Doustaresharaf sp. nov., were new in science. A. azerbaijaniensis sp. nov. is the third Aceria species found on Sapindaceae plants in Iran. C. aceressulani sp. nov. is the third Cecidophyes species in Iran and the first Cecidophyes species found on Sapindaceae plants of Iran. In addition, Rhyncaphytoptus saccharini Keifer, 1959 herein was recorded for the first time in Iran.

Arrenurus (Arrenuridae) is the most species-rich genus of mites with about 1000 named species that inhabit standing, and to a lesser extent, running water habitats around the world. To date, distinguishing species of Arrenurus has been based on male reproductive morphology. Here, we use morphological and molecular approaches to examine species boundaries among 42 named species of Arrenurus, including four named species that have colour variants (red and green A. americanus, and red and blue A. intermedius, A. manubriator and A. apetiolatus), and two unnamed morphospecies. In this study, we examine male genital structures with the use of SEM techniques, and apply mitochondrial (COI barcode region) and nuclear (28S rRNA) gene fragments to test whether male morphology reflects species boundaries in Arrenurus assessed by molecular analyses. Our results reveal that male reproductive morphology parallels species boundaries as judged by molecular data. We discuss the cases of genetically poorly diversified, yet morphologically clearly defined named species. Moreover, we show that based on the species we examined, colour morphs within otherwise morphologically similar specimens represent within-species variation and, in the absence of other diagnostic traits, colour itself can be misleading in distinguishing species. Our outcomes on molecular taxonomy of Arrenurus provide a background for testing hypotheses about speciation rate in water mites.

Metabelba (Pateribelba) flagelliseta Bulanova-Zachvatkina, 1965 is redescribed based on the newly sampled material from Crimea and investigation of the specimens from the collection of Bulanova-Zachvatkina. Metabelba (Metabelba) pseudoflagelliseta Kolesnikov & Murvanidze sp. nov. is described from Caucasus, Georgia. Both species have similar morphology, characterized by flagellated notogastral setae and same set of tubercles, but differ by presence or absence of apophysis P and shape of the dorsal seta on femora III–IV. Considering the importance of these morphological characters we assign these species to different subgenera.

Typhlodromus (Typhlodromus) tulinae sp. nov. Döker is described based on specimens collected from Carpinus betulus L. (Betulaceae) in Ordu Province on the Black Sea coast, Turkey. The new species can be easily distinguished from all known species of the subgenus by the combination of the following morphological characters: dorsal shield with three pairs of solenostomes (gland pores), peritreme extending to region between j3 and z2, sternal shield with two pairs of setae, ventrianal shield with four pairs of preanal setae and no preanal solenostomes, movable digit of chelicera with two teeth, genu II with eight setae, and spermatheca with large bulbous atrium and saccular calyx. A key to separate the Turkish species of the subgenus is also provided.

In the paper, we presented ptyctimous mites collected from Nearctic (Canada, USA), Neotropical (Dominicana), Palaearctic (Scotland, Italy, Russia, Nepal, Egypt), Afrotropical (Ethiopia, Gabon, Congo, Mozambique, Madagascar, Réunion), South Africa, Oriental (Maldives, Vietnam, Malaysia, Indonesia, China) and Australasian (Papua New Guinea, Australia, New Zealand) regions. Information of Mesoplophora (Parplophora) flavida Niedbała, 1985 and M. (P.) polita Niedbała, 1985 phoretic on different insects (Coleoptera: Passalidae) are presented. A new species Atropacarus (Hoplophorella) additus Niedbała sp. nov., is described from Madagascar. Supplementary descriptions and some remarks of ten species from six genera are given (including two paratypes of previously synonymous species). Information on the distribution and location of 85 species of 18 genera is also presented. Fifty-three species were found for the first time in the zoogeographical region or given country.

The family Oripodidae is not well known in South Africa with only one species, Oripoda sumonyii, described and recorded. This paper reports five genera from South and describes a new species, Cryptoribatula austroafricana sp. nov., from yellow lichen on boulders on a beach. The new species differs from the other two species from the genus mainly in the number of notogastral, genital and aggential setae. The male and female of the new species differ slightly from each other. A generic diagnosis is provided as well as selected characteristics of all Oripodidae genera.