Community structures of Mesostigmata, Prostigmata and Oribatida in broad-leaved regeneration forests and conifer plantations of various ages

The community structures of Mesostigmata, Prostigmata, and Oribatida in the soil of broad-leaved regeneration forests and conifer plantations of various ages were assessed alongside soil and plant environmental variables using three response metrics (density, species richness, and species–abundance distribution). The density and species richness of mites recovered swiftly after clear-cutting or replanting. Oribatid mites dominated the soil mite communities in terms of densities and species richness for both forest types. Soil mite communities in broad-leaved forests was related to forest age, the crown tree communities index, and forest-floor litter weight. In contrast, soil mite communities in the conifer plantation sites were related to various indices of understory plants. The development of the understory plants was synchronized with the silvicultural schedules, including a closed canopy and thinning. Such a conifer plantation management may affect indirectly the community of mites.     

The terrestrial arthropods of Sør Rondane in eastern Dronning Maud Land,Antarctica, with biogeographical notes

Five species of terrestrial arthropods have been found in Sør Rondane inland nunataks of eastern Dronning Maud Land, Antarctica, so far almost a biologically unexplored region. These arthropods comprised one collembolan and four mite species (one oribatid mite and three prostigmatic mite). Their occurrence was restricted to the nunataks in the central and western parts of the region. The same was also observed for the visible vegetation, such as algae and mosses, near nesting-bird colonies. The maximum reorded population density was 859 arthropods/100 ml soil at the nest of snow petrel at Tanngarden, in the northwestern part of the region. The arthropod fauna of Sør Rondane is very similar to that of central Dronning Maud Land, particularly in Gjelsvikfjella and Mühlich-Hofmannfjella. The fauna is, however, different from that of the eastern region, e.g. at Syowa Station and Enderby Land. Different species of collembolans and oribatid mites occur at locations separated by the Lüitzow-Holm Bay and Shirase Glaciers, whereas prostigmatic mites do not show such a difference.     

An experimental assessment of biodiversity and species turnover in terrestrial vs canopy leaf litter

Forest canopies support diverse assemblages of free-living mites. Recent studies suggest mite species complementarity between canopy and terrestrial soils is as high as 80–90%. However, confounding variation in habitat quality and resource patchiness between ground and canopy has not been controlled in previous comparative studies. We used experimental litter bags with standardized microhabitat structure and resource quality to contrast the colonization dynamics of 129 mite species utilizing needle accumulations on the ground vs in the canopy of Abies amabilis trees in a temperate montane forest in Canada. Mite abundance and species richness per litter bag were five to eight times greater on the ground than in the canopy, and composition differed markedly at family-, genus-, and species-level. Seventy-seven species (57%) were restricted to either ground or canopy litter bags, but many of these species were rare (n<5 individuals). Of 49 ‘common’ species, 30.6% were entirely restricted to one habitat, which is considerably lower than most published estimates. In total, 87.5% of canopy specialists had rare vagrants on the ground, whereas only 51.9% of ground specialists had rare vagrants in the canopy. Canonical correspondence analysis of mite community structure showed high species turnover through time and a high degree of specialization for early-, mid-, and late-successional stages of litter decomposition, in both ground and canopy mites. In addition, distinct assemblages of ground-specialist mites dominated each elevation (800, 1000, and 1200 m), whereas few canopy-specialist mites had defined elevational preferences. This suggests that canopy mites may have greater tolerance for wide variation in environmental conditions than soil mites. The degree of species turnover between adjacent mountains also differed markedly, with 46.5% turnover of ground species, but 63.4% turnover of canopy species between the two montane areas. While ground and canopy assemblages are similar in total biodiversity, it appears that local mite richness (alpha diversity) is higher on the ground, whereas species turnover between sites (beta diversity) is higher in the canopy. Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.     

Species diversity and biocenotic relationships of gamasid mites (Parasitiformes,Gamasoidea) in the nests of the field vole <Emphasis Type="Italic">Microtus agrestis</Emphasis> L. of the Karelian middle taiga subzone

The species diversity and habitat relations of gamasid mites from nests of the field vole (Microtus agrestis L.) were studied in the middle taiga subzone of the Republic of Karelia. The fauna of gamasid mites on the field vole, in its nests, and in the forest litter is very diverse, comprising 49 species with a complex taxonomic structure (22 genera, 12 families) and a variety of life strategies (necrophages, zoophages, and hematophages). The fauna of gamasid mites is most diverse in the nests of M. agrestis and includes both primitive free-living forms and specialized obligatory (epizoic) parasites. The group with the highest diversity of mite species is that from the nest of M. agrestis, with the diversity index amounting to 2.65 (30 species, 18 genera, 11 families).     

Mite (Acari; Arachnida) diversity of two native plants in fragments of a semideciduous seasonal forest in Brazil

Studies to determine mite species richness in natural environments are still scarce, and have been conducted mainly in tropical ecosystems. The aim of this study was to determine the species richness of mites on two common native plants in fragments of the semideciduous seasonal forest in the Northwest of São Paulo State, Brazil. In each of eight fragments, 10 specimens of Actinostemon communis (Euphorbiaceae) and 10 of Trichilia casaretti (Meliaceae) were selected and marked. In total, 124 species of mites belonging to 21 families were found on the two plants. Tarsonemidae had the highest diversity (34 species), followed by Phytoseiidae (31), Tetranychidae (9) and Tenuipalpidae (8). Species accumulation curves for the two sampled plants did not reach an asymptote, even with the large sampling effort. Hence, it is estimated that a greater sampling effort may lead to an increase in species richness compared with what was found in this study. The richness of this mite fauna suggests that preservation of these plant species is important to maintain the mite diversity in these forest fragments.     

松嫩草原中度退化草地不同植被恢复方式下土壤螨类群落特征的差异

应用类群数、个体密度、多样性指数和MI指数等多个群落参数,研究不同植被恢复方式下松嫩草原中度退化草地土壤螨类群落特征的差异。研究结果表明,与过度放牧样地相比,种植苜蓿和围栏封育样地的土壤环境相对优越,它们拥有较高的土壤螨类类群数、个体密度和群落多样性以及中气门螨类MI指数。在土壤螨类群落结构所有参数中,多样性指数(H′)和中气门螨类MI指数,种植苜蓿和围栏封育样地均明显高于过度放牧样地,这些差异反映了种植苜蓿和围栏封育对中度退化草地土壤螨类的群落结构具有明显改善作用。然而研究结果也显示,围栏封育样地土壤螨类群落多样性指数(H′)和中气门螨类MI指数尽管明显高于过度放牧样地,但是依然显著低于种植苜蓿样地,表明选择种植苜蓿较围栏封育可能更利于松嫩草原中度退化草地土壤螨类群落的恢复与重建。     

Mites in house dust and human allergoses

The literary data on the study of the house-dust mites during the period from 1864 till 1983 are given. The methods of the house dust samples collection in flats and the methods of the house-dust mites isolation from the house dust are evaluated. The house-dust mites fauna including more than 130 species is described. The synantropic mites-pyroglyphides are the main part of the fauna, the stored products mites and predatory cheyletid and gamasid mites occur regularly. The rest part of the fauna consists of the different mites got into house by chance. The literary data on the influence of temperature and relative humidity on the development and growth of the mite population are given. The house-dust mites feeding and digestion processes bearing relation to the formation of the mite allergen are reviewed. The original data complete the literary data on the fauna and distribution of the house-dust mites in Moscow.     

Carcases and mites

Mites are involved in the decomposition of animal carcases and human corpses at every stage. From initial decay at the fresh stage until dry decomposition at the skeletal stage, a huge diversity of Acari, including members of the Mesostigmata, Prostigmata, Astigmata, Endeostigmata, Oribatida and Ixodida, are an integral part of the constantly changing food webs on, in and beneath the carrion. During the desiccation stage in wave 6 of Mégnin’s system, mites can become the dominant fauna on the decomposing body. Under conditions unfavourable for the colonisation of insects, such as concealment, low temperature or mummification, mites might become the most important or even the only arthropods on a dead body. Some mite species will be represented by a few specimens, whereas others might build up in numbers to several million individuals. Astigmata are most prominent in numbers and Mesostigmata in diversity. More than 100 mite species and over 60 mite families were collected from animal carcases, and around 75 species and over 20 families from human corpses.     

Diversity and biogeography of southern African intertidal Acari

Abstract Aim The aims were (1) to describe the diversity and geographical distribution of the intertidal mite fauna of southern Africa, and (2) to show how species richness, endemism and geographical patterns of this fauna (comprising taxa of variable terrestrial ancestry) compare with typically marine faunas. Location and methods To assess intertidal mite diversity and endemism, records (published and unpublished) were compiled for a variety of habitats (mainly rocky shores and mangroves), between Swakopmund (Namibia) and Inhambane (Mozambique). The geographical study was based on a dedicated sampling programme from rocky shores, at nine localities between Elandsbaai (on the west coast) and St Lucia (on the east coast). Results Eighty‐two species of marine mite, from thirty‐three genera, are currently known from southern Africa. The majority belong to the earlier marine ancestral Halacaridae (forty‐eight species), with the Ameronothroidea and Hyadesiidae collectively comprising seventeen species. In constituting three faunistic provinces, corresponding with the west (Atlantic), south and east coast (Indian) regions, the mite fauna conforms with trends for the southern African marine fauna in general. Species richness was greatest in the southern province, which deviates from the general pattern of increase from west to east, but is similar to that of some invertebrate taxonomic groups. Conclusions Despite their relatively recent marine connections, marine mites show typical geographical distributions, comparable with those of other rocky‐shore biota in southern Africa. The marine faunistic provinces are ‘insular’ and apparently remain largely intact, across taxonomic groups and with increased taxonomic resolution.     

棉花不同栽培方式对卵形异绒螨种群密度的影响

卵形异绒螨是棉蚜的一种外寄生性天敌,研究结果表明,呋喃丹和甲拌磷处理的种子中卵形异绒螨种群波动趋势,与非杀虫剂各种子处理田一致,药剂处理田的天敌数量与非药剂处理田无显著差异（Ｐ〉０．０５）,单作露地棉田的螨量高于棉,麦套种和地膜覆盖田;卵形异绒螨随着翅蚜向露地棉田在迁移量为９０．７头／ｍ＾２．２４ｈ向覆盖田的迁移量为３６．０头／ｍ＾２．２４ｈ随着棉田连作时间的延长,卵形异绒螨的种群密度呈逐渐增加的     

中国云南小兽寄生革螨的群落结构和空间分布

寄生在小兽体表的革螨可能是传播肾综合征出血热和立克次体痘等人兽共患病的媒介。本文报道了云南省28个县(市)小兽体表革螨的野外调查结果, 运用物种数、平均丰富度和Shannon多样性指数对小兽寄生革螨的群落特征和沿环境梯度的空间分布进行了研究, 并用系统聚类分析法 (SPSS 16.0软件)对18种主要小兽的革螨群落相似性进行了比较。在云南省28个县(市)共捕获到小兽14 544头, 隶属于5目（啮齿目、食虫目、攀鼩目、兔形目、食肉目）10科35属67种, 在捕获的小兽体表采集到革螨80 791头, 经鉴定属于10科33属112种。结果分析表明: 主要的宿主动物为黄胸鼠 Rattus tanezumi、齐氏姬鼠Apodemus chevrieri和大绒鼠Eothenomys miletus;纳氏厉螨Laelaps nuttalli、毒厉螨L. echidninus和贵州厉螨L. guizhouensis为革螨的优势种。齐氏姬鼠A. chevrieri、社鼠N. confucianus和黄胸鼠R. tanezumi体表寄生的革螨种类最多;臭鼩鼱Suncus murinus、齐氏姬鼠A. chevrieri和灰麝鼩Crocidura attenuata的革螨群落多样性最高。聚类分析结果表明, 大部分革螨群落的相似程度与相应小兽的亲缘关系及所处生态环境的相似性是基本一致的, 分类地位和生境选择相似的小兽, 它们的革螨群落也被聚为一类。革螨物种数沿纬度梯度的水平分布呈现两个峰值, 最大峰值出现在25°~26°N之间;沿海拔梯度的垂直分布呈单峰分布格局, 峰值在海拔2 000~2 500 m之间。革螨和小兽的多样性沿纬度梯度和海拔梯度的空间分布趋势也均表现出随着纬度和海拔的升高而先升高后降低的单峰型分布格局, 峰值分别出现在北纬25°~27°N和海拔2 000~2 500 m之间。结果提示云南革螨群落种类丰富, 多样性高。云南革螨物种数和多样性的分布格局可能直接受到古北和东洋两区系边缘效应的影响。     

The influence of household pets on the composition and quantity of allergenic mite fauna within Irish homes: a preliminary investigation

Allergenic mites are responsible for inducing hypersensitive reactions in genetically predisposed people worldwide. Mites in dust from 30 Irish homes with pets (dogs, n = 23; cats, n = 7) were compared with those in 30 homes without pets. House dust mites constituted 78% of all mites recorded, with Dermatophagoides pteronyssinus (Acariformes: Pyroglyphidae) representing 57–72% of mites in furniture and mattresses in both home types compared with only 22% of mites in pet beds. Although storage mites accounted for just 13% of all mites recorded, they represented 46% of mites recorded in pet beds. Median levels of the dust mite allergen Der p 1 (µg/g) in dust samples from mattresses in homes without pets were significantly greater than in mattresses from homes with pets, reflecting the greater densities of D. pteronyssinus found in the former home category. Mite species richness was greater in homes with pets (17 species) than in homes without pets (13 species). This suggests that although the presence of pets can result in a wider variety of epidemiologically important mite species within households, increased competition among mite species may result in a more balanced mite fauna in the home, inhibiting the dominance of any one species and hence lowering allergen‐associated risks.     

Influence of spatio-temporal resource availability on mushroom mite diversity

Although biodiversity in nature is of fundamental importance because it improves the sustainability of ecosystems, communities of microscopic organisms are generally excluded from conservation targets for biodiversity. Here, I hypothesize that mushroom mite species richness is correlated with both spatial (i.e., mushroom size) and temporal (i.e., longevity of fruiting bodies) resource availability. I collected fruiting bodies in an old-growth forest over 4 years to collect mites and insects inhabiting the mushrooms. Mites were collected from 47 % of the fruiting bodies and approximately 60 % of the mite species were collected only once. Mite species richness was significantly correlated with the availability of long-lasting fruiting bodies. For example, bracket fungi contained more mite species than ephemeral fruiting bodies. Insect presence was also correlated with mushroom mite richness, probably as phoretic hosts and food resources for predacious mites. On the other hand, mushroom size seemed to be less important; small fruiting bodies sometimes harbored several mite species. Although mite species richness was correlated with mushroom species richness, mushroom specificity by mites was not clear except for a preference for long-lasting fruiting bodies. Therefore, I suggest that a constant supply of coarse woody debris is crucial for maintaining preferred resources for mushroom mites (e.g., bracket fungi) and their associated insects (mycophilous and possibly saproxylic insects).     

Regional factors rather than forest type drive the community structure of soil living oribatid mites (Acari, Oribatida)

Most European forests are managed by humans. However, the manner and intensity of management vary. While the effect of forest management on above-ground communities has been investigated in detail, effects on the below-ground fauna remain poorly understood. Oribatid mites are abundant microarthropods in forest soil and important decomposers in terrestrial ecosystems. Here, we investigated the effect of four forest types (i.e., managed coniferous forests; 30 and 70 years old managed beech forests; natural beech forests) on the density, diversity and community structure of oribatid mites (Acari). The study was replicated at three regions in Germany: the Swabian Alb, the Hainich and the Schorfheide. To relate changes in oribatid mite community structure to environmental factors, litter mass, pH, C and N content of litter, fine roots and C content of soil were measured. Density of oribatid mites was highest in the coniferous forests and decreased in the order 30 years old, 70 years old, and natural beech forests. Mass of the litter layer and density of oribatid mites were strongly correlated indicating that the litter layer is an important factor regulating oribatid mite densities. Diversity of oribatid mites was little affected by forest type indicating that they harbor similar numbers of niches. Species composition differed between the forest types, suggesting different types of niches. The community structure of oribatid mites differed more strongly between the three regions than between the forest types indicating that regional factors are more important than effects associated with forest type.     

Mites (Acari: Laelapidae) associated with sigmodontinae rodents in Entre Ríos Province, Argentina.

The richness, diversity, abundance and prevalence of mite species associated with sigmodontine rodents of different species in Entre Ríos province, Argentina are studied. Five of the six species of mites were reported for the first time in the study area. The richness and diversity of mites was higher on Oligoryzomys flavescens and O. delticola than on Akodon azarae. Androlaelaps rotundus was dominant and exhibited higher values of mean abundance and prevalence on A. azarae, Mysolaelaps microspinosus on O. flavescens and Gigantolaelaps mattogrossensis on O. delticola.     

Genetic structure of a phytophagous mite species affected by crop practices: the case of Tetranychus urticae in clementine mandarins

Tetranychus urticae Koch is a cosmopolitan mite considered as the most polyphagous species among spider mites. This mite is a key pest of clementine mandarins in Eastern Spain, where Spanish clementine production concentrates. Crop management practices can affect the population dynamics of this mite and, consequently, its impact on the orchard. Microsatellite markers were used to study mite population genetics from two commercial orchards which had been managed differently following Integrated Pest Management (IPM) or Organic Pest Management (OPM) schemes during four consecutive years. A multiplex system including 20 microsatellite loci was designed specifically and allowed an efficient and inexpensive genotyping of individual mites. We found that the IPM population had a stronger fluctuation of population structure and higher genetic diversity compared to OPM population. Thus, our study concludes that crop management has an impact on the population genetics of T. urticae which may be related to the alternation of some acaricides under IPM.     

How to catch foliage-dwelling spiders (Araneae) in maize fields and their margins: a comparison of two sampling methods

The foliage‐dwelling spider fauna was collected in maize fields and on stinging nettles in adjacent margins in Bavaria, South Germany. Two different sampling methods were evaluated: drop cloth sampling and suction sampling. The overall catch was dominated by juvenile spiders, web‐building spiders, and spiders of the families Theridiidae, Linyphiidae, Tetragnathidae and Araneidae (in decreasing order). Field margins harboured more species than maize fields, whereas the total spider abundance was higher in the maize crop. Web‐building spiders such as Theridiidae and Linyphiidae were prominent in maize by individual numbers. Suction sampling with a small suction device proved to be a more efficient and consistent sampling method for foliage‐dwelling spiders than drop cloth sampling. Density and species richness of foliage‐dwelling spiders in maize was shown to be fairly high, implying that spiders of higher strata may play a more important role in biological control than suspected up to now.     

Mean annual population density of Collembola and Acari in the soil and litter of three indigenous South Australian forests

A quantitative study of the soil and litter fauna of three South Australian low open forests was made for two years. The soil and vegetation of the sites were similar but the mean annual rainfall of the areas differed; 635, 690 and 1050 mm/y, respectively for the ‘dry’, ‘medium’ and ‘wet’ sites. Monthly samples were taken of litter, and the upper 0–4 cm and lower 4–8 cm soil layers, and the method used to estimate the numbers of active animals is also described. Mean annual population densities of Collembola and Acari were greatest at the medium site (9.5 and 48.6 × 10³/m², respectively) and least at the dry site (4.9 and 35.1 × 10³/m², respectively) and values are discussed in relation to site organic carbon content. Over all the sites, between 11–21, 67–75 and 10–15% of the collembolan populations, and 10–13, 66–72 and 16–21% of the acarine populations inhabited the litter layer and upper and lower soil layers respectively. Isotomidae were the most abundant collembolan family in each level at each site, but the overall proportion of Entomobryidae increased from the dry to wet site. Prostigmata were the most abundant acarine order in each level at two sites. Cryptostigmata were dominant in the litter layer of the wet site, and their overall proportion increased from the dry to wet site. Seasonal density changes were similar on all sites with minima in the summer and maxima in the winter months. The results obtained here combined with those from other published investigations indicate a trend of faunal population change over various ecosystems in Australia. Prostigmatid mites and iso-tomid Collembola dominate at arid sites. As sites become less arid and the amount of soil organic matter increases, the proportion of cryptostigmatid and mesostigmatid mites increases, and other groups of Collembola, particularly Entomobryidae, become more frequent.     

Beat sampling accuracy in estimating spruce spider mite (Acari: Tetranychidae) populations and injury on juniper

The use of a standardized beat sampling method for estimating spruce spider mite, Oligonychus ununguis (Jacobi) (Acari: Tetranychidae), densities on a widely used evergreen ornamental plant species, Juniperus chinensis variety 'Sargentii' A. Henry (Cupressaceae), was examined. There was a significant positive relationship between total spruce spider mite densities and spider mite densities from beat sampling on juniper. The slope and intercept of the relationship may be used by pest managers to predict total spider mite densities on plants from beat sample counts. Beat sampling dramatically underestimates the total number of spider mites on a foliage sample. The relationships between spruce spider mite feeding injury and spider mite density estimates from beat sampling juniper foliage and total spider mite counts on foliage were also examined. There was a significant positive relationship between spruce spider mite density as estimated from beat sampling and injury to the plants. There was a similar positive relationship between the total number of spruce spider mites and injury to the plants, suggesting that a pest manager could use beat sampling counts to estimate plant injury and related thresholds. These findings have important implications to decision-making for spruce spider mite control, especially as it relates to threshold levels and determining rates of predator releases. Further assessment of the effectiveness of beat and other sampling methods across multiple spider mite- host plant associations needs to be examined to enable pest managers to select sampling plans that are feasible and reliable.     

亚热带不同树种组成森林中土壤甲螨群落结构特征: 以江西新岗山为例

在全球环境变化的大背景下, 生物多样性丧失日益加剧。土壤动物作为生物多样性重要组成之一, 受到广泛的关注。位于我国江西省新岗山的亚热带森林生物多样性与生态系统功能实验样地(BEF-China)是全世界25个森林生物多样性控制实验样地之一。本研究自2019年9月至2022年4月在BEF-China两个不同树种组成的样地(A样地和B样地)内采样, 共获得甲螨23,704头, 隶属于34科50属61种。本文分析和对比了两个样地内甲螨群落结构的差异, 及其多度、物种丰富度、Shannon多样性指数的季节性差异; 通过Pearson检验探讨了甲螨多度与环境因子的关系。结果表明: 在A、B两个不同树种组成的森林生态系统内, 土壤甲螨群落结构及其季节动态具有显著差异。具体表现在: A样地奥甲螨科、罗甲螨科、若甲螨科和尖棱甲螨科的相对多度高于B样地; B样地菌甲螨科、盖头甲螨科和礼服甲螨科的相对多度高于A样地。A样地中夏季和秋季甲螨多度、物种丰富度和Shannon多样性指数显著低于春季和冬季; 而B样地中秋季甲螨多度和物种丰富度与春季差异不显著。Pearson检验结果显示, 凋落物木质素含量与单翼甲螨科和菌甲螨科多度呈负相关关系, 而与奥甲螨科多度呈正相关关系。菌甲螨科多度与土壤和凋落物同一理化因子的相关性基本相同(碳氮比除外), 但与凋落物碳氮比呈正相关关系而与土壤碳氮比呈负相关关系。