Sixteen species of Tetranychoidea, 11 Tetranychidae and 5 Tenuipalpidae are reported in this study. Seven of them are recorded for the first time from Syria: Bryobia gigas, Oligonychus afrasiaticus, O. coniferarum, O. pratensis, Cenopalpus rubusi, Tenuipalpus cupressoides and T. punicae. New host plant records are also reported. Reinstatement of the genus Nuciforaella Vacante is discussed in this study. Detailed descriptions of immature stages and female of Nuciforaella nikitensis are given. A key to the known species of the family Tetranychidae from Syria is provided.

A new species of Tenuipalpus Donnadieu (Acari: Tenuipalpidae), Tenuipalpus odoratus Souza, Castro & Oliveira sp. nov., is described from females, males, deutonymphs, protonymphs and larvae collected on Cedrela odorata L. (Meliaceae) from Ilhéus, Bahia, Brazil. A proposed ontogeny of leg chaetotaxy is also included.

Caeculisoma semispinus Xu & Jin sp. nov. is described and illustrated based on larvae ectoparasitic on Typhlocybinae (Hemiptera: Cicadellidae) from Chongqing Municipality, Hubei Province and Hunan Province, China. A key to the larval species of the genus Caeculisoma of the world is presented.

Amblyseiinae is the largest subfamily of Phytoseiidae with 196 recorded species from China. Two new species, Amblyseius basaensissp. nov. and Transeius guangheensissp. nov., were found by examining the specimens collected from two southwest provinces in China, both near to Vietnam border. Herein, they are described and illustrated based on the female specimens.

A new species viz. Stigmaeus doganisp. nov., collected from soil and litter under Juncus sp. (Juncaceae) and Pinus brutia (Pinaceae) in Denizli and Izmir provinces (the Aegean region of Turkey), is described and illustrated based on adult females. A key to the species of Stigmaeus from Turkey is provided.

Phytoseiidae is the most extensively studied family of predatory mites, some of which are effectively used as biological control agents. Nevertheless, studies of these mites in some Brazilian biomes such as the Pantanal are still scarce. The objective this publication was to assess the diversity of this family in Pantanal vegetation from Mato Grosso do Sul State, Brazil, verifying the importance of the native plants as reservoirs for these mites. Samplings were carried out in five phytophysiognomies of the Pantanal: Cambarazal, Capão (forest islet), Carandazal, Riparian Forest and Paratudal. Thirty-five phytoseiid species were recorded on 40 plant species of 28 families. The most common species were Amblyseius chiapensis De Leon and Euseius concordis De Leon, recorded on 21 and 18 plant species, respectively. Inga vera Willd. (Fabaceae) and Paullinia pinnata L. (Sapindaceae) were the host plants harboring the greatest richness of phytoseiids, 15 and 14 species, respectively. Our results suggest a high diversity of phytoseiid mites in the Pantanal biome. However, as only a small proportion of the total biome area was considered, only a fraction of the mite diversity was probably recovered. Thus, new studies on this biome are needed, especially in other well-preserved native vegetation remnants.

Two new species of oripodoid mites (Oribatida, Oripodoidea) are described from litter in Sri Lanka. Oripoda parajosephineaesp. nov. (Oripodidae) differs from Oripoda josephineaeCorpuz-Raros, 2010 by the presence of elongate phylliform interlamellar setae having setiform apex, and the absence of foveolate rostrum. Protoribates lankaensissp. nov. differs from Protoribates tetrasetosusErmilov, 2016 by smaller body size, and the presence of ciliate bothridial setae, short lamellar setae and having five pairs of genital setae.

The present study is based on oribatid mite material collected from Mayotte island (Comoro Islands, Ethiopian region) in 2011–2016. A new species of the genus Uracrobates (Oribatida, Mochlozetidae) is described; Uracrobates (Uracrobates) mayottensissp. nov. differs from all species of the nominative subgenus by having a rounded rostrum (versus bidentate or pointed). An updated generic diagnosis and an identification key to the known subgenera and species of Uracrobates are presented. A list of all oribatid mite taxa of the Comoro Islands, including 41 species, 30 genera and 19 families, is provided. The genus Phauloppia and the species Edwardzetes novazealandicus are recorded in the Ethiopian region for the first time.

This study examines the heart and its activity in the mite Varroa destructor. Through light microscopy, the duration and frequency of the beat of the mite's heart, which is located over the synganglion, was recorded and analysed. The heart measured 165 µm by 60 µm, and consisted of two lateral trunks, inducing pulses with an average duration of 10 sec and an average frequency of 0.13 Hz. The use of cardiac activity as a new bioassay for accurate assessment of the effect of varroacide compounds was also examined.

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is an important pest of melons. In this laboratory study, we used two-sex life table to evaluate the performance of T. urticae on five melon cultivars (IVF28, IVF118, IVF168, IVF437, and Yangjiaomi). We also evaluated the correlation between mite population growth and morphological characteristics of leaves. The results showed that the total immature time, adult longevity, total longevity, and fecundity of the spider mite differed among the cultivars. On IVF28, the values for the intrinsic rate of increase (r) and the finite rate of increase (λ) were 0.1638 d^-1 and 1.1178 d^-1, respectively, which were significantly lower than the values on IVF168, IVF118, or Yangjiaomi. Values for r and λ tended to be highest on IVF168. In addition, r values for T. urticae were not correlated with trichome density or stomatal density but were negatively correlated with melon leaf thickness. In summary, the different melon cultivars exhibited distinct levels of resistance to T. urticae and the IVF28 cultivar was considered the least favored for the growth and reproduction of T. urticae mites, and such differences of mite performance might be related to the leaf thickness, instead of trichome density or stomatal density.

Two-spotted spider mite, Tetranychus urticae Koch, is a cosmopolitan pest causing economic damage to a wide range of different host plants worldwide. In the present study, bottom-up effects of four common greenhouse plants including cucumber (cultivar “Negin”), tomato (cultivar “Isabella”), eggplant (cultivar “Bell”) and watermelon (cultivar “Crimson”) on biological parameters of this pest were evaluated using age-stage, two-sex life table theory. The obtained results revealed that the durations of different life stages of T. urticae were significantly affected by the host plants tested. Accordingly, the highest and lowest recorded values for duration of total immature stages of this mite were recorded on tomato (12.09 ± 0.25 day) and eggplant (8.37 ± 0.16 day), respectively. The duration of oviposition period was also significantly different and the highest value was estimated on watermelon (14.19 ± 1.26 day). Furthermore, host plants tested significantly affected the mortality of different life stages and the highest immature mortality was estimated on tomato (65.31 ± 4.81 %). The highest and lowest estimated values for intrinsic rate of increase (r) were recorded on cucumber (0.239 ± 0.014 day^-1) and tomato (0.104 ± 0.016 day^-1), respectively. The calculated values for mean generation time (T) were the highest on tomato (17.81 ± 0.53 day) and the lowest on eggplant (13.98 ± 0.28 day). These findings demonstrated that cucumber and tomato had the lowest and highest negative effects on the biological parameters of T. urticae, respectively.

We described two new species collected from Miscanthus spp. in Thailand and Taiwan. One of the new species, Stigmaeopsis inthanonsis Saito, Kongchuensin & Sahara n. sp., was found in Thailand (Inthanon National Park). The other species from Taiwan, named Stigmaeopsis formosa Saito, Chao & Sato n. sp. was previously referred to as T-form or ML form of Stigmaeopsis miscanthi (Saito). Thus 15 species are now involved in the genus Stigmaeopsis. Because five species inhabiting Miscanthus grasses are resemble together, we call them as Stigmaeopsis miscanthi species group. An updated key to all known species of Stigmaeopsis is proposed.

A new vagrant eriophyoid mite species, Setoptus tsugivagusn. sp. Chetverikov (Eriophyoidea, Phytoptidae, Nalepellinae, Nalepellini), is described from the needles of the western hemlock, Tsuga heterophylla (Rafinesque) Sargent (Pinaceae) in Vancouver, Canada. The new species can be distinguished from all other members of Setoptus by a distinct pattern of several short longitudinal ridges on the posterior half of the prodorsal shield. Elements of the anal secretory apparatus (ASA) were observed in adults of S. tsugivagusn. sp., suggesting that the ASA is present in both major phylogenetic lineages of Eriophyoidea (Eriophyidae s. l. and Phytoptidae s. l.). Therefore, this structure could be a synapomorphy for all Eriophyoidea. We briefly discuss the function and morphological variety of the ASA in Eriophyoidea. D2 28S rDNA sequences of four nalepelline species were obtained: Boczekella reticulataBagnyuk 1987 (GenBank accession number MK124605), Nalepella tsugifoliaeKeifer 1953 (MK124606), Setoptus piniBoczek, 1964 (MK124607), and S. tsugivagusn. sp. (MK124608). Molecular phylogenetic analyses of D2 28S rDNA sequences of the mites of the subfamily Nalepellinae confirmed monophyly of the tribe Nalepellini and retrieved Setoptus and Nalepella as polyphyletic. Additionally, our data indicate that 28S rDNA sequence KF782472.1, previously reported to be Trisetacus ehmanni Keifer 1963 by Li et al. (2014), belongs to another species of the genus Trisetacus, possibly T. quadrisetus (Thomas), and the sequence KF782471.1, previously reported to be Trisetacus sp., might belong to T. juniperinus (Nalepa). We also discuss the systematics of nalepellines and their host association with conifers.

Changes in the seasonal activity and age composition of adults and nymphs in populations of the Ixodes ricinus in northwestern Russia have been studied. Adult ticks and nymphs were collected on flag twice a month from April to October in 2014–2016. They were investigated for biological age (light-optical preparations of the midgut after staining fat with Sudan III). DNA isolated from ticks was analyzed using real-time PCR (fluorescent probe technology) for the presence of Borrelia burgdorferi s.l. pathogens based on amplification of the 16SrRNA and Hbb gene fragments.

The season of activity of the adults shows one peak, the largest numbers show up in July–August (September). The population of adults is composed of two generations. The first generation is active from the beginning of the season until nearly its end, mid-October. Until the end of June, young individuals with large fat reserves predominate in the population. From July to the end of September, the adult population is formed mainly of mature individuals. Older individuals in the population appear from mid-July, and become dominating only in August and, mainly, in September. Ticks of the second generation, as young individuals, were recorded from the end of August until the end of the season of activity. The active nymphs were captured from late April until late October. The season of activity of nymphs begins and ends with a 100% content of young individuals. The spring population (April–May) consists of young nymphs, in June the proportions of young and mature are equalized, in July and August the ratio of mature and old nymphs is balanced, in September old individuals prevail, which were not found in October. The first generation is the nymphs who have hatched from August to October during the previous season, and the second one is the nymphs hatching in August of the current year. The lifespan of adults and nymphs can reach 13–15 months. The proportion of infected ticks in May and June is 24.5% and 25%, with the highest rates of in the young (10–12 months) part of population (70–85% of individuals). In July, the number of mature (12–13 months) individuals increases (up to 75–95%), at the same time the average values of infection fall to 20.8%. In August, the shares of mature (45–55%) and old -13–15 months (45–55%) individuals are approximately balanced. Borrelia contamination is also decreasing (14.3%). In September, the number of mature individuals (29.7%) was about 2 times lower than the old ones (65.3%), and the infection rate decreased to 11.4%.

The population of nymphs and adults is composed of two tick generations in the season of activity. The season of activity of adult ticks is holistic; it is not interrupted during the summer months. Infection of adults with Borrelia decreases simultaneously with the ageing of the population.