Cannibalism and intraguild predation (IGP) are two common interactions occurs in animal kingdom which influence their population structure and dynamics. Neoseiulus barkeri (Hughes) and Scolothrips takahashii (Priesner) are important natural enemies of citrus red mite Panonychus citri (McGregor). However, little was known about their interactions and how the availability of extraguild (EG) prey P. citri modulated their interactions. In this study, we determined incidences of cannibalism and intraguild predation of these two predators when different densities of extraguild prey P. citri were available. Our results showed that incidences of both cannibalism and IGP and were significantly reduced in the presence of the extraguild prey. The intraguild predation between N. barkeri and S. takahashii was bidirectional, but N. barkeri was a predominant intraguild predator over S. takahashii. The S. takahashii fed on immobile N. barkeri egg, and N. barkeri fed on inactive prepupa and pupa of S. takahashii, but the conspecifics seldom did. Our results indicated that the interactions of predators decreased significantly when prey was available. The predatory mite N. barkeri was a stronger interspecific competitor. The results of this study may be useful in developing effective biological control strategies against P. citri.

Typically, females of eriophyoid mites of the large conifer-associated genus TrisetacusKeifer 1952 have long spermathecal tubes, which are at least twice as long as the spermathecae. In this paper, we report on four Trisetacus species collected in the USA from Cupressaceae that possess atypical short spermathecal tubes and demonstrate a distinct reduction trend in leg chaetotaxy when setae l′ and/or bv II may be absent, and setae ft′ II are very short. They are: 1) Trisetacus virginianusn. sp. and 2) T. thujae (Garman 1883, = T. thujivagransSmith 1977asyn. nov.) from indigenous North American conifers Juniperus virginianus and Thuja occidentalis, respectively, and 3) Trisetacus maculatusn. sp. and 4) T. morgantownensisn. sp. from Japanese endemics, Chamaecyparis pisifera and C. obtusa, respectively, introduced to the USA. In these four Trisetacus species, the spermathecal apparatus consists of two drop-shaped segments, each about 2.5–3 µm long and about 2–2.5 µm wide, and resembles that of Boczekella, a nalepellid genus restricted to pinacean genera Larix and Pseudolarix. A new subgenus, Brevithecusn. subgen., is erected within the genus Trisetacus to accommodate the four Trisetacus species from Cupressaceae. Future molecular phylogenetic studies are needed to test whether Brevithecus is nested within Trisetacus or represents a separate genus, which may be a sister to either Trisetacus or Boczekella.

Haemaphysalis is the second largest ixodid tick genus. We decided to identify the Iranian Haemaphysalis species with the analysis of mitochondrial (COI & 16S rRNA) and nuclear (ITS2) gene sequences. Finally, 21 PCR products were sequenced, successfully. Phylogenetic trees were analyzed using BEAST software and Bayesian Inference method. Ha. sulcata and Ha. punctata were well differentiated using the 16S rRNA, COI and ITS2 genes. According to 16S rRNA and COI phylogenetic trees Ha. inermis is situated as an ancestral clade.

Phytophagous mites represent a diverse group of Arachnida, however, the patterns of their interactions with their host plants remain little explored. Herein we compare structural patterns of plant-phytophagous mite networks of forest and open habitats in Brazil. We adopted network size, network connectance and network modularity to characterize plant-mite network structure. We analyzed 11 plant-mite networks composed by 106 mite species, 96 host-plant species, and 342 distinct interactions. Tetranychidae and Eriophyidae were the most speciose mite families while Euphorbiaceae and Fabaceae were the most relevant host-plant families, hosting 67 and 16 mite species, respectively. We did not find any differences in network size and modularity between biomes and habitat types. However, network connectance was lower for open vegetation habitats than for forest habitat networks. Open areas can constrain the selection of defensive traits by plant species, leading phytophagous mites to consume plant species more selectively, which generates low connectivity in networks of these environments. The small number of plant-mite networks described here highlights the need for more efforts to increase knowledge about plant mites in Brazilian natural vegetation.

A new species, Allocaeculus sirwanisp. nov. (Trombidiformes: Prostigmata: Caeculidae) is described based on adult females from Marivan city, Kurdistan Province, Iran. The new species can be distinguished from other species by the following features: the bothridial setae (bo) filiform; dorsal body setae clavate; setae c₁, a₂, d₁, d₂, e₁, e₂ present; setae c₁ normal; adanal and pseudanal plates each bearing three pairs of setae; un-pair seta hs present; palp tarsus with seven setae; epimeral setal formula 3-2-2-4/5 and spinose setal formula of leg I 3-2-1-1-2. Also, an identification key to known species of Allocaeculus is provided.

A new species of oribatid mites of the family Cepheidae is described based on adults from rainforest in Chile. Sadocepheus nortonroyisp. nov. differs from Sadocepheus foveolatus by the larger body size, the presence of transverse notogastral ridge and divergent lamellar cusps, and the location of notogastral setae on the notogastral surface. Explanations on placement of some species in Sadocepheus are presented. An identification key to known species of Sadocepheus is given.

The introduction and establishment of an invasive species in a new habitat represents a major threat to biodiversity and ecosystem structure. A recent example of a mite that has become an invasive species is the red palm mite, Raoiella indica Hirst (Acari: Tenuipalpidae). After its introduction in the Americas, this species has considerably expanded the number of hosts and has been reported as a key pest of some of these. In the present study we investigated the possibility of mitefauna alteration on coconut leaflets (abundance and diversity) mediated by the introduction and establishment of R. indica. A survey was conducted over a period of 1 year in two areas of coconut cultivation: one infested and one free of R. indica. The results of the present study suggest that the introduction of R. indica modifies the mitefauna existing in coconut leaflets. Differences were detected in the abundance and diversity of mites at the level of the taxonomic categories (family and species) and at the level of the trophic groups (predators, herbivores and mites with undefined feeding mode). Additionally, in plants infested by the invasive species, a similar pattern was observed between the fluctuation of the phytoseiid mites and other tenuipalpid mites. In these plants, the density of the tenuipalpid mites (including R. indica) was also the variable that most contributed to explain the fluctuation of phytoseiid mites. This suggests that the invasive species, R. indica, acts as a keystone species, structuring the mitefauna in coconut plants.

Dermanyssus gallinae (De Geer) (Mesostigmata: Dermanyssidae) is one of the most important hematophagous ectoparasites of laying hens. Chemical acaricides are the basis of a control program of this mite. In addition to their relative efficiency, there are many side effects associated with these chemical products. In an effort to generate more options for the mite control, entomopathogenic fungi were evaluated for use in the control of D. gallinae in laboratory and field conditions. Conidia suspensions of Beauveria bassiana strains were applied to mites (1×10⁸ viable conidia/ml). Out of 39 strains, four isolates were selected according to their acaricidal activity (confirmed mortality ≥70%). Growth and reproduction parameters on culture media and fungal development at different temperatures were also evaluated. Finally, the efficacy of the selected strain was determined in a commercial laying hen house. A suspension of conidia (1 × 10⁹ viable conidia/ml) was sprayed around the cages. Seven days later, another suspension was applied. A control group was sprayed with water. Paper towel traps were used to estimate the mite population before and after treatments. Mite traps were placed one week before the first fungal application and changed weekly for up to three weeks after application (-7; 0; 7; 14 and 21 days). In lab studies, B. bassiana strain Unioeste 88 was the most effective, causing 73.8% mortality and showing high conidia production (7.1 × 10⁸ conidia/colony and 7.7 × 10⁸ conidia/g, respectively, on PDA and rice). There was no fungal development at temperatures ranging from 35 to 45 °C. In the field test, the fungus reduced the mite population efficiently (64.8%), while the mite population increased by 281% in untreated plots. B. bassiana strain Unioeste 88 has the potential to be commercially used to control the poultry red mite.

Knowledge of the impact of acaricides on predatory mites is crucial for integrated pest management (IPM) programs. The sublethal effect of propargite was assessed against the subsequent generation of treated Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) fed on Tetranychus urticae Koch (Acari: Tetranychidae) under laboratory conditions [26 ± 1 °C, 70 ± 3 % RH and 16:8 (L:D) h]. A leaf disc bioassay was employed to assess the sublethal concentrations (LC₁₀, LC₂₀, and LC₃₀) of propargite (Omite® 57% EC, MAHAN, Iran) on A. swirskii. The results revealed that sublethal concentrations of propargite significantly affected the total life span and longevity of the treated females of A. swirskii. Reproductive and total fecundity of the subsequent generation were also affected by sublethal concentrations. All concentrations caused a significant reduction in oviposition days, compared to the control. The intrinsic rates of increase (r) of A. swirskii treated with sublethal concentrations of propargite and distilled water were 0.126, 0.122, 0.115, and 0.129 d^-1, respectively. Our findings revealed that propargite had no significant effect on life table parameters of treated mites in comparison to the control. Sublethal effects of propargite and its impact on A. swirskii are discussed.

Glutathione S-transferases (GSTs) are phase II detoxification enzymes, which function via combining with pesticidal molecules and catalyzing the conjugation of molecules by thiol of glutathione, so as to protect tissues from oxidative stress damage. In the tick Haemaphysalis longicornis, glutathione S-transferases (HlGST and HlGST2) have been previously identified. However, the relationship between the transcription of glutathione S-transferases and the essential oil treatment in ticks remains unexplored. Hence, in the present study, the transcription profiles of HlGST and HlGST2 mRNAs were evaluated in H. longicornis after exposure to Cymbopogon citratus essential oil. At 24 h post-exposure of H. longicornis to different sublethal concentrations of C. citratus essential oil, there was significant difference (P = 0.0001) in the transcription of HlGST. Tukey's test showed that HlGST was significantly induced after treatment with 1% C. citratus essential oil (P = 0.0002); whereas no significant difference (P = 0.3551) was detected after treated by 2% C. citratus essential oil. No significant difference (P = 0.4555) in the transcription of HlGST2 between the treatment and the control group of 50% ethanol. Nevertheless, the down-regulation of HlGST2 in the treatment groups versus the untreated control group was not significant (P = 0.1208). The above results imply that the essential oil can modulate the expression of GST mRNA, therefore, further understanding of the underlying mechanisms of the GST at the molecular level could contribute to the development of effective control measures for ticks and tick-borne diseases.

Razgthrombium ganjiigen. et sp. nov. (Acari: Neothrombiidae) is described and illustrated based on larval from soil and litter, Razg village, Birjand city, South Khorasan province, Iran. Also, a key to genera of Neothrombiidae of the world (larva) is presented.

The objective of the present study was to determine the mite fauna associated with Myrtaceae from Cariri, a microregion with peculiar climatic conditions in the center of the Caatinga Domain in northeastern Brazil. Samples were collected in eight municipalities in Cariri region. In each municipality, five collection sites equidistant at approximately 10 km were established. The sampling was carried out in two periods, rainy season (March to April 2013) and dry season (September to October 2013). A total of 3.831 mites distributed in 14 families, 39 genera and 46 species were recorded. The Phytoseiidae was the dominant predatory mite family with 11 species. The most common phytoseiid species was Euseius concordis (Chant), followed by Euseius citrifolius Demark & Muma and Euseius alatus De Leon. Among the phytophagous mites, two families were the most abundant: Tenuipalpidae and Tetranychidae. Our results indicated that Myrtaceae in Caatinga Domains hosts a considerable diversity of potentially important predatory mites for the control of phytophagous species.

During the field study of eriophyoid mites from autochthonous plants in semi-arid and arid environment in East Iran (Birjand, South Khorasan, from 2016 to 2017), four new Aceria species (Trombidiformes: Eriophyoidea: Eriophyidae) were collected. They are Aceria halothamnisp. nov. on Halothamnus auriculus (Moq.) Botsch. (Amaranthaceae), Aceria acanthophyllisp. nov. on Acanthophyllum sordidum Bunge ex Boiss. (Caryophyllaceae), Aceria samolisp. nov. on Samolus valerandi L. (Primulaceae), Aceria aeluropisp. nov. on Aeluropus littoralis (Gouan) Parl. (Poaceae). In addition, Aceria atriplicisWilson & Oldfield, 1966 was also found on Atriplex leucoclada Boiss. (Amaranthaceae), which is a new record for Iran. All these species are illustrated and described herein. They appear to be vagrants and no symptom was observed on their infested plants.

In this work, we describe the male of Scutopalus tomentosusRocha, Skvarla & Ferla, 2013 and a new species Armascirus amazoniensis Wurlitzer & Silva sp. nov. from specimens collected on coconut crop, Cocos nucifera L. (Arecaceae), cultivated in state of Pará, into the Amazonic biome, Brazil.