During a survey of the eriophyoid mites in Lorestan province of Iran two new eriophyoid mites described and illustrated: Aceria poldokhtariensis Lotfollahi & Bahirai sp. nov. from Populus euphratica Oliv. (Salicaceae) and Aceria torilarvensis Lotfollahi & Bahirai sp. nov. from Torilis arvensis (Huds.) Link (Apiaceae). They are the first eriophyoid mites collected on P. euphratica and T. arvensis respectively, and the later one is the first Aceria species found on plants of genus Torilis.

This paper includes descriptions and illustrations of two new species namely Leipothrix mazandaranicussp. nov. and Aceria punicaesp. nov. found on Urtica dioica L. (Urticaceae) and Punica granatum L. (Lythraceae), respectively, in Sari county, Mazandaran province, North of Iran. They are the second Leipothrix species from the plants of family Urticaceae and the second Aceria species from plants of the genus Punica.

Chiggers have been studied throughout the world for their role in disease transmission. Venezuela has the largest chigger diversity in South America. In a review of Venezuelan genera, two monotypic genera described from Robinson's Mouse Opossum collected in Falcon State and after examination of the types of both genera, it was found that Delmohius hardyi Brennan and Goff and Carebareia johnstoni Goff and Brennan are the same species. Therefore, we are proposing the synonymy of Delmohius with Carebareia.

During a review of the Tick Collection of the Gorgas Memorial Institute of Panama, of 6,624 Ixodidae analyzed, 255 presented abnormalities. We detail morphological abnormalities and gynandomorphism in adults of 16 species: Amblyomma auricularium, A. calcaratum, A. dissimile, A. mixtum, A. naponense, A. cf. oblongoguttatum, A. ovale, A. sabanerae, A. tapirellum, A. varium, Dermacentor nitens, Haemaphysalis juxtakochi, Ixodes auritulus, I. tapirus, Rhipicephalus microplus, and R. sanguineus s.l. No abnormalities were found in A. coelebs, A. geayi, A. longirostre, Amblyomma nodosum, A. pacae, A. cf. parvum, A. pecarium, A. rotundatum, Dermacentor imitans, D. latus, D. panamensis, Haemaphysalis leporispalustris, I. affinis, I. bequearti, I. bocatorensis, I. boliviensis, and I. luciae. This represents the first findings of these phenomena in A. auricularium, A. calcaratum, A. naponense, A. ovale, A. sabanerae, A. tapirellum, A. varium, D. nitens, H. juxtakochi, I. auritulus, and I. tapirus. Local abnormalities were more frequent than general malformations. Amblyomma dissimile had the highest percentage of individuals with malformations, including specimens with two or more local abnormalities and gynandromorphism. It is possible that these malformations may go unnoticed or confused with loss appendages or mechanical damage.

Population outbreaks and failures in controlling Tetranychus urticae Koch (Acari: Tetranychidae) were reported on ornamental plants in Miami-Dade County, Florida. We compared the susceptibility of two T. urticae field populations collected from commercial nurseries with a laboratory population to one new generation (cyflumetofen) and two conventional (abamectin and pyridaben) acaricides. The field populations were collected from hibiscus (Hibiscus rosa-sinensis, Malvaceae) and croton (Codiaeum variegatum, Euphorbiaceae). Resistance ratios based on LC₅₀ values of the field and laboratory populations revealed high resistance levels to the two conventional acaricides (9.64 and 19.28-fold abamectin, 12.34 and 34.08-fold pyridaben), and low levels (1.88 and 2.39-fold) of cyflumetofen resistance in the hibiscus and the croton populations, respectively. Rotation of acaricides with different modes of action and biological control should be implemented to mitigate T. urticae resistance problems in ornamentals in south Florida.

The results of a survey of Eriophyoidea mites on wild and cultivated Solanaceae plants in Central Brazil are presented. Five new taxa associated with plants in the genus Solanum are described and illustrated. They include one new genus with type species belonging to Phyllocoptinae, Calacarini—Viginticus lupusmalumgen. nov. & sp. nov.; two new species in the Eriophyinae, Aceriini—Aceria solanisp. nov. and Paraphytoptus tuberacutussp. nov., all of them associated with Solanum lycocarpum St. Hil.; and one new species in the Phyllocoptinae, Athocoptini—Aculus michereffisp. nov., associated with Solanum acanthodes Hook.. New host plants for the tomato russet mite, Aculops lycopersici (Tryon 1917), are reported. In addition, the first record of Calacarus speciosissimumFlechtmann, 1999 for Brazil and from Capsicum as host plants, and the first record of Rhynacus lippius Duarte, Chetverikov & Navia, 2016, on solanaceous plants are presented; supplementary descriptions of these species were elaborated. Diagnostic traits for Calacarus mites collected on Solanaceae plants around the world are summarized.

Predator-prey interactions have long been of great interest to ecologists. Although the direct consumptive effects have received extensive research, indirect influences of odour derived from their conspecifics and prey on predators have largely been underestimated and overlooked. In this study, the indirect effects of predator-prey interactions were determined with predatory mites Neoseiulus cucumeris and its factitious prey Tyrophagus putrescentiae. The responses of immature N. cucumeris to mixed odour with their conspecifics and prey were determined in a laboratory experiment. Our results showed that the mixed odour with their conspecifics did not demonstrate any obvious influences on the survival rates, developmental periods, predation rates and activities of the predatory mites. Intriguingly, the predators prolonged their protonymphal stage and consumed more prey eggs when exposed to mixed odour with their prey. Our results indicated that the mixed odour with their conspecifics was weak and its influence was insignificant for this species, but the prey odour showed a signifcant influence on the growth and consumption rates of immature predators, which highlighted that the indirect influences of predator-prey interactions on the predator were substantial and cannot be neglected.

A survey of the mite fauna on citrus was conducted in 542 dooryard trees in the following counties: Dade (24), Broward (127), Palm Beach (68), Martin (35), St. Lucie (20), Indian River (11), Collier (23), Lee (37), Charlotte (20), Sarasota (67), Manatee (18), Pinellas (59), Polk (32), and Highlands (1) to update our knowledge of the mite complex on Florida citrus. We also sampled 25 varietal citrus trees at two research centers in Polk and Dade Counties. A third block of ‘Tahiti’ lime trees was sampled at the Tropical Research & Education Center in Dade County. At least 787 commercial citrus trees were also sampled in Florida between 2009 and 2014. Here we report the frequency and occurrence of the Tetranychoidea, Tarsonemidae and Tydeoidea on those trees. Previous field studies of the Tarsonemidae and Tydeoidea on citrus in Florida between 1993-2003, a horticultural mineral oil (HMO) field study during 1994–1996 and M. H. Muma from 1961-1975 are included for comparison. Eutetranychus species near orientalis was collected from a lemon tree in Broward County. This is a new record of this species on Florida citrus. Additional new records of mites on Florida citrus include Tarsonemidae: Fungitarsonemus setillus Sousa et al, Tarsonemus confusus Ewing, and Tarsonemus waitei Banks; Tydeoidea: (Iolinidae)- Parapronematus n sp, Neopronematus n sp; (Triophtydeidae): Triophtydeus immanis Kuznetzov, T. n sp; (Tydeidae): Afrotydeus n sp, Brachytydeus sp near australiensis, B. n sp, Pretydeus sp near reticulatus, and Tydeus sp near munsteri. Seven species of tarsonemids were collected from dooryard and varietal block citrus during the 2009-2014 survey compared with one species from commercial citrus trees. A total of 27 species of Tarsonemidae were collected from citrus in Florida between 1954 and 2014. Thirteen species of Tydeoidea were collected from dooryard and varietal block citrus trees during the 2009-2014 survey compared with 4 species from commercial citrus trees. A total of 31 species of Tydeoidea were collected from citrus in Florida between 1961-2014. The roles that different species of tarsonemid and tydeoid mites have as plant feeders, fungivores, mycophages, or predators of one or more phytophagous mites are discussed.

We found four species of oribatid mites belonging to family Oppiidae from Babeldaob Island of Palau Republic, which is an island country located in the western Pacific Ocean. Two new species, Anomaloppia babeldaobensissp. nov. and Oxyoppia palauensissp. nov. are described from litter and soil in a secondary forest of Palau, and supplementary descriptions of two hitherto known species, Arcoppia corniculifera (Mahunka 1978) and Arcoppia hammeraeRodríguez & Subías, 1984 are provided, which are reported for the first time from the Oceania region. Following the descriptions and comparisons, aspects of the taxonomy, distribution and habitat ecology of studied species are discussed.

A new species, Gamasodes pachysetis Yao & Jin sp. nov., is described based on deutonymphs and adults from Jiangsu and Taiwan provinces, China. A nominal species, Gamasodes spinigerTrägårdh, 1910, new to China, is redescribed also based on deutonymph and adults from Guizhou Province. A key to Gamasodes species of China is presented.

Two new species of oribatid mites of the genus Pilobates (Oribatida, Haplozetidae) are described on the basis of adult specimens sampled from Andasibe-Mantadia National Park of eastern Madagascar. Pilobates staryisp. nov. differs from Pilobates africanusErmilov & Starý, 2020 by the presence of long tutoria, comparatively short interlamellar setae, minute and setiform notogastral setae, 15 pairs of notogastral setae including c₃ on pteromorphs, elongate notogastral sacculi, and anterodorsal process on leg trochanters IV. Pilobates parastaryisp. nov. differs from P. staryisp. nov. by having long interlamellar setae, adanal setae ad₁ and ad₂ and anal setae an₁ with curved tips, heavily sculptured notogaster, and well developed triangular ventrobasal tubercle on leg tibiae I. A revised generic diagnosis of Pilobates is presented.

Diflubenzuron, a benzoylphenylurea insecticide that interferes with chitin biosynthesis, causes arthropods to moult abnormally and die. However, its mechanism of action in Tetranychus cinnabarinus is still unclear. In order to explore the effects of different sublethal concentrations of diflubenzuron on T. cinnabarinus, we conducted a high-throughput RNA-seq technology to identify the variations in transcriptomic profile of T. cinnabarinus larvae. The results revealed that 470 and 49 differentially expressed genes were identified in LC₅₀- and LC₇₀-treated groups, comparing with the control. We also identified and analyzed the detoxification enzymes involved in the transcritome of T. cinnabarinus, including 34 cytochrome P450 genes, 17 glutathione-s-transferase genes (GSTs), 12 acetylcholinesterase genes (AChEs) and 9 ABC transporter genes. In addition, differentially expressed genes analysis showed that the gene expression levels of detoxification enzymes were generally enhanced. At the same time, seven and 11 genes were involved in chitin synthesis and degradation ways, respectively. The expression level of most genes involved in chitin synthesis and degradation pathway were generally up-regulated after exposure to sublethal concentrations of diflubenzuron. Moreover, for transcriptome validation, the mRNA expression results of ten specially expressed genes by quantitative real-time PCR demonstrated that these gene expression trends were consistent with that of the transcriptome data. Together, all these results suggested that sublethal concentrations of diflubenzuron exposure affected gene expression of major detoxification enzymes and chitin metabolism genes in T. cinnabarinus. These findings may be helpful to further understand the possible molecular mechanism of benzoylphenylurea insecticides in T. cinnabarinus, as well as in other spider mites.

Field surveys were conducted in the plum orchards, in the vicinity of Hamedan. Two new species of eriophyoid mites were found and described for the first time from this region: Diptacus hamedanicussp. nov. and Tetra prunurasp. nov. Both new species infest Prunus domestica (L.) (Rosaceae) and are vagrant on host plant; no symptom was detected.

A new species, Phytoseius feresi Demite & Cavalcante sp. nov. (Acari: Mesostigmata: Phytoseiidae) is described and illustrated based on adult females and males. It was found in association with plants in natural vegetation in Itacoatiara and Silves, Amazonas state, Brazil. This new species is a member of the purseglovei species group and differs from all other species of this group by possessing all dorsal setae, except Z5, and the ventral seta JV5 smooth. We propose a redefinition of the purseglovei species group in order to include the new species. In addition, a key to world species of the purseglovei species group is provided.