Tyrophagus putrescentiae (Acari: Acaridae) is a destructive pest of edible fungi. Different species of edible fungi have variable effects on the growth, development and fecundity of T. putrescentiae, but it is unclear whether these effects exist in the same species. We used nine cultivars of the oyster mushroom (Pleurotus ostreatus) to evaluate the development and reproduction parameters of T. putrescentiae at 26 ± 1°C and 80 ± 5% humidity. Different P. ostreatus cultivars had significant effects on the immature stages, female fertility, and reproductive lifespan. Total egg-to-adult development time ranged from 10.0 ± 1.2 d (on Po389 cultivar) to 12.5 ± 1.0 d (on Po62 cultivar). Mite mortality ranged from 54.3 ± 4.2% (on Po86 cultivar) to 100.0 ± 0.0% (on Po62 cultivar). The number of eggs laid per female ranged from 3.2 ± 0.4 (on Po45 cultivar) to 9.1 ± 1.1 (on Po86 cultivar). The average lifespan of females ranged from 3.0 ± 0.5 d (on Po45 cultivar) to 16.3 ± 1.7 d (on Po86 cultivar). Host preference of the mite was significantly different among the nine cultivars with a preference for cultivars Po65, Po80, Po389, and Po86. These results indicate that P. ostreatus cultivars significantly affect the biology of T. putrescentiae and the relationship between mite damage and mushroom yield.

Nasal mites of the family Rhinonyssidae are parasites living in the respiratory system of birds. To date there were no record of these mites from representatives of the order Procellariiformes, a numerous grouping of exclusively marine birds that includes albatrosses, petrels, storm-petrels and shearwaters. The paper describes two new species of the genus Rhinonyssus from shearwaters (Procellariidae) found on various shores of Brazil: Rhinonyssus borealis sp. nov. from Calonectris borealis (Cory's shearwater) and R. procellaricus sp. nov. from Puffinus puffinus (Manx shearwater) and Ardenna gravis (Great shearwater). Both described mites are characterized by a large elliptical body and a relatively large and strongly sclerotized with the well-developed caudal extension. Rhinonyssus borealis sp. nov. and R. procellaricus sp. nov. are similar in their general appearance to each other but differ in the size of idiosoma, shape of podosomal and sternal shields and leg chaetotaxy.

A new species of oribatid mites of the family Cepheidae (Oribatida)—Tritegeus janosbaloghi sp. nov.—is described based on adults from soil-litter in Nepalese forest. The generic diagnosis of Tritegeus is updated. An identification key and data on distribution of known species of Tritegeus are provided.

The suppression of pest populations by a predator depends on two basic components of the predator-prey interaction: the functional and the numerical responses of the predator. Such responses can be affected by exposure to acaricides. In the present study, the effects of acaricides (abamectin, azadirachtin, fenpyroximate, and chlorfenapyr) on the functional and numerical responses of the predatory mite, Amblyseius largoensis (Acari: Phytoseiidae) an important natural enemy of the pest mite, Raoiella indica (Acari: Tenuipalpidae), were investigated. The exposure of A. largoensis to acaricides occurred through contact with a surface contaminated with dried acaricide residue. Subsequently, A. largoensis exhibited a type II functional response, which was not altered by exposure of any acaricides. However, exposure to abamectin resulted in a decrease in the average mean numbers of prey consumed by a predator. Exposure to acaricides increased prey handling time by 67%, 25%, 38%, and 35% for abamectin, azadirachtin, fenpyroximate, and chlorfenapyr, respectively. Exposure to abamectin reduced the attack rate of A. largoensis by 52%. The numerical response of A. largoensis was only affected by exposure to abamectin, where just 60% of the females oviposited, and regardless of the prey density, the average mean numbers of eggs/female/day was always less than 0.4. The food conversion efficiency into biomass of A. largoensis eggs decreased with increasing prey density, and this trend was not altered by exposure to any acaricides. However, exposure to abamectin drastically compromised the oviposition of A. largoensis, showing no increase in egg production with increasing prey density.

The diagnosis of the genus Meriadenogamasus Athias-Henriot is updated based on the description of a new species, Meriadenogamasus longisetus Yao & Jin sp. nov., from south of China. This is the first described male mite for the genus. A key to the known species of the genus is provided.

The seventh species of Arculatatrachys, A. pomberoi sp. nov. is described based on female and male specimens collected from leaf litter in Paraguay. The new species differs from congeners by the shape of the dorsal cavities and their appendages. A list and a new key to the known Arculatatrachys species are also presented with four new combinations (Arculatatrachys difoveolata (Hirschmann, 1975) comb. nov.; Arculatatrachys similiarculata (Hirschmann, 1975) comb. nov.; Arculatatrachys newtoni (Kontschán, 2010) comb. nov. and Arculatatrachys darwini (Kontschán & Starý, 2013) comb. nov.).

Animals can adjust reproductive strategies in favour of corporation or competition in response to local population size and density, the two key factors of social environments. However, previous studies usually focus on either population size or density but ignore their interactions. Using a haplodiploid spider mite, Tetranychus ludeni Zacher, we carried out a factorial experiment in the laboratory to examine how ovipositing females adjust their fecundity and offspring sex ratio during their early reproductive life under various population size and density. We reveal that females laid significantly more eggs with increasing population size and significantly fewer eggs with increasing population density. This suggests that large populations favour cooperation between individuals and dense populations increase competition. We demonstrate a significant negative interaction of population size and density that resulted in significantly fewer eggs laid in the large and dense populations. Furthermore, we show that females significantly skewed the offspring sex ratio towards female-biased in small populations to reduce the local mate competition among their sons. However, population density incurred no significant impact on offspring sex ratio, while the significant positive interaction of population size and density significantly increased the proportion of female offspring in the large and dense populations, which will minimise food or space competition as females usually disperse after mating at crowded conditions. These results also suggest that population density affecting sex allocation in T. ludeni is intercorrelated with population size. This study provides evidence that animals can manipulate their reproductive output and adjust offspring sex ratio in response to various social environments, and the interactions of different socio-environmental factors may play significant roles.

In this study two species of soft ticks belonging to the genus Ornithodoros were recorded in three areas in the province of Corrientes, Argentina. Four larvae were identified as Ornithodoros hasei (Schulze, 1935) on Molossus molossus (Molossidae) in Paraje Tres Cerros (Department of San Martín), while 56 larvae were identified as Ornithodoros sp. cf. O. mimon Kohls, Clifford & Jones, 1969 on Eptesicus furinalis and Myotis levis (Vespertilionidae) in Paraje Galarza (Department of Santo Tomé) and Colonia Carlos Pellegrini (Department of San Martín). These last two locations are found within the Esteros del Iberá eco-region. The known distribution range of O. hasei and O. cf. O. mimon is expanded to include the province of Corrientes. Two new ectoparasite-host associations were recorded for Argentina between O. hasei on M. molossus and O. cf. O. mimon on M. levis. The morphological differences together with the results of the phylogenetic analysis show that O. hasei presents genetic similarity with specimens from Brazil, and in Argentina, with ticks from Santa Fe. Instead, Ornithodoros sp. cf. O. mimon recorded in Corrientes and Uruguay belong to a different taxon than the O. mimon recorded in Brazil and Santa Fe, Argentina. Based on this, O. mimon should be considered a complex of species in which the specimens from Corrientes are provisionally considered as Ornithodoros sp. cf. O. mimon until their taxonomic status can be determined.

Haemaphysalis qinghaiensis is an endemic species and mainly inhabiting in the northwestern plateau of China, which can transmit many zoonotic pathogens and cause great harm to animals. In this study, the complete mitochondrial genome (mitogenome) of H. qinghaiensis was assembled through the Illumina HiSeq platform. The mitogenome was 14,533 bp in length, consisting of 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNA genes and 3 noncoding regions (NCRs). The bias towards a high A+T content with 77.65% in mitogenome of H. qinghaiensis. The rearrangement of mitochondrial genes in H. qinghaiensis was consistent with other hard ticks. The phylogenetic analysis based on the concatenation of 13 PCGs from 65 tick mitogenomes showed that the H. qinghaiensis was clustered into a well-supported clade within the Haemaphysalis genus. This is the first complete mitogenome sequence of H. qinghaiensis, which provides a useful reference for understanding of the taxonomic and genetics of ticks.

The ability to endure starvation is important for predatory mite survival and its effectiveness as biological control agent. We studied the longevity and functional response of the prodator mite Neoseiulus californicus (McGregaor) under starvation stress. N. californicus individuals were treated as three groups: the mites were provided with nothing (group I), with fresh bean leaves (group II), and with water (group III) to the larvae, protonymphs, deutonymphs, adult males and females. Functional response of N. californicus to Tetranychus urticae Koch eggs was evaluated after starvation for 0 h, 24 h, 48 h, and 72 h. Results showed that all life stages of N. californicus in group III had the longest survival time among the three groups. Adult females had the strongest ability to endure starvation with a mean survival time of 8.16 d. Females had the ability to lay eggs, but the number of eggs laid was less than a mean of 1.2 eggs per female in the three starvation groups. N. californicus exhibited a Holling's Type II functional response at all hunger levels. The handling time (T_h) and attack rate (α) of the predator were not significantly different in all hunger levels. Predation rate of starved 0 h to 72 h initially increased and then decreased. The highest predation rate was recorded when the predators were starved for 24 h.

Biological characteristics and life table parameters of Eutetranychus orientalis (Klein) were revealed on four different citrus species: grapefruit (Citrus paradisi Macf. cv. Star Ruby), lemon (C. limon (L.) Burm. f. cv. Meyer), mandarin (C. reticulata Blanco cv. Okitsu) and orange (C. sinensis L. cv. Washington Navel) under laboratory conditions. Results show that oviposition period, fecundity, and life table parameters varied significantly depending on the host plant species. Furthermore, host plant species had little effect on immature development, except for the teleiochrysalis and total developmental period, which was significantly shorter on lemon (13.77 days for females, 12.67 days for males). Total mean numbers of eggs laid by E. orientalis was 15.92 on mandarin and 29.78 on lemon. In addition, intrinsic rate of increase (r_m), net reproductive rate (R₀), finite rate of increase (λ) and doubling time (DT) are 0.12 day^–1, 10.41 ♀/♀, 1.13 day^–1 and 5.59 days for lemon, 0.17 day^–1, 22.36 ♀/♀, 1.19 day^–1 and 4.04 days for grapefruit, respectively. However, shortest and longest mean generation times (T_o) were obtained at 18.26 days on orange and 19.37 days on grapefruit. Our results demonstrate that intergeneric differences of Citrus should be considered when determining E. orientalis population abundance and dynamics in field conditions.

Ecological interactions between mites (predatory and phytophagous) and wild plants growing in undisturbed environments play a crucial role to understand their natural settlement, development and dispersion patterns. Pequin chili pepper, Capsicum annuum L. var. glabriusculum, is a low-cost natural resource for local communities living inside Natural Protected Areas (ANP) of Tamaulipas State in Mexico. The aims of this research work were: 1) determine the spatial distribution pattern of predatory and phytophagous mites, 2) determine the spatiotemporal association between predatory and phytophagous mites, and 3) determine the association among different mite species and some phenological stages of Pequin chili pepper. The most abundant phytophagous mites were Tetranychus merganser and Aculops lycpoersici, and the predatory species were Amblyseius similoides, Euseius mesembrinus and Metaseiulus (Metaseiulus) negundinis. Most mite species showed an aggregated distribution pattern according to the plant phenological stages. However, the distribution of mite species throughout time showed different types of aggregation. On the other hand, we found positive associations among A. lycopersici and T. merganser phytophagous mites with A. similoides, E. mesembrinus and M. (M.) negundinis predators mites. The association between plants and mite species were influenced by the phenological stages of Pequin chili pepper. This is an indication of the complexity among trophic-chain interactions that depend largely on the available resources and competition. These two factors serve as foundations for settlement, development and dispersion patterns of certain species.

A new species of Cunaxidae, namely Cunaxa bagualensis Wurlitzer & Ferla sp. nov., is described and illustrated based on females and males collected in soil and leaf litter in the Atlantic rainforest biome in a rural forest fragment in Mormaço county, Rio Grande do Sul state, Brazil. Additionally, Armascirus livingstoni Laniecka & Kazmierski, 2021 is transferred to Dactyloscirus based on some observations.