First records of Endeostigmata and Sphaerolichina mites (Acari: Sarcoptiformes and Trombidiformes) from the Iberian Peninsula and the Canary Islands

ABSTRACT Endeostigmata and Sphaerolichina mites from the Iberian Peninsula and the Canary Islands are reported for the first time. A total of seven families, 14 genera and 16 species have been collected from oak and pine forests of Navarra (northern Spain) and other habitats of the Canary Islands. A key to families and genera identified in this study is presented.RESUMEN Primeras citas de ácaros Endeostigmata y Sphaerolichina (Acari: Sarcoptiformes and Trombidiformes) de la Península Ibérica e Islas Canarias. Este artículo es el primero que se dedica al estudio de los ácaros Endeostigmata y Sphaerolichina de la Península Ibérica y las Islas Canarias. Un total de siete familias, 14 géneros y 16 especies han sido recolectados en robledales y pinares de Navarra (Norte de España) y otros biotopos de las Islas Canarias. Se adjunta una clave para la identificación de las familias y géneros de estudio

DIVERSIDAD DE MICROARTRÓPODOS (ÁCAROS Y COLÉMBOLOS) DE MUSGOS CORTICÍCOLAS EN LA SELVA BAJA DE NICOLÁS BRAVO, QUINTANA ROO.

The diversity of microarthropods (mites and springtails) in corticolous moss was compared in the floodable lowland Nicolás Bravo, Quintana Roo, included six sampling, carried out in dry, rainy and north season of 2011. 28 families of microarthropods from corticolous moss were recorded, among which the Galumnidae (52.36%), Isotomidae (10.45 %) and Scheloribatidae (9.68%) families were the most abundant, making up 72%, further that showed their maximum abundance at rainy season. There was temporal variation in the density of microarthropods (F (2, 27) = 10.62, p<0.05); the highest density was found at rainy season. The highest diversity was recorded between dry and north season. The highest similarity was observed between rainy and north season (71.58%). For the families Isotomidae, Phytoseiidae, Trombididae, Scheloribatidae and Galumnidae there was a positive correlation between moisture from moss and density while the density of Anystidae and Caeculidae was negatively correlated with moss moisture.Se compara la diversidad de los microartrópodos (ácaros y colémbolos) en musgos corticícolas de una selva baja inundable de Nicolás Bravo, Quintana Roo, para las temporadas de secas, lluvias y nortes de 2011. Se registraron 28 familias de microartrópodos corticícolas, entre las cuales Galumnidae (52.36%), Isotomidae (10.45%) y Scheloribatidae (9.68%) fueron las más abundantes, representando el 72%, además que mostraron su máxima abundancia en la temporada de lluvias. Se determinó que hay una variación temporal en la densidad de microartrópodos (F (2,27) = 10.62, p<0.05); la mayor densidad se encontró en la temporada de lluvias. La mayor diversidad se registró entre la temporada de secas y nortes. La mayor similitud se observó entre las temporadas de lluvias y nortes (71.58%). Para las familias Isotomidae, Phytoseiidae, Trombididae, Scheloribatidae y Galumnidae se encontró una correlación positiva entre la humedad del musgo y las densidades, mientras que la densidad de Anystidae y Caeculidae mostraron una correlación negativa con la humedad del musgo

Prairie spiders of Alberta and Saskatchewan

In the prairie ecozone of Alberta and Saskatchewan, 356 species of spiders in 2 I families have been collected. The 10 families with the most species were Linyphiidae (30%), Gnaphosidae (13%), Salticidae (8%), Theridiidae (8%), Lycosidae (8%), Dictynidae (6%), Thomisidae (6%), Araneidae (5%), Philodromidae (5%) and Clubionidae (3%). These 10 families constituted 91% of the spider biodiversity. In the grassland region ofthe prairie ecozone, there were relatively more species of Gnaphosidae, Lycosidae, Theridiidae, Thomisidae, Dictynidae and Philodomidae and fewer Linyphiidae and Clubionidae than for all provincial ecozones combined. The percentages in the parkland region of the prairie ecozone tended to be intermediate

SOIL MITES AND NEMATODES COMMUNITY STRUCTURE IN A CONVENTIONAL AND NO-TILLAGE CHRONOSEQUENCE, COMPARED TO GRASSLANDS

Understanding the impact of long-term conventional tillage and no-tillage practices on soil biota is useful for estimating the level of disturbance in agroecosystems. An investigation was conducted in a long-term field experiment under no-till and conventional tillage management with a wheat-fallow rotation and in undisturbed grasslands, in the southwestern Canadian Prairies of Saskatchewan, at two different locations: Swift Current and Central Butte. The primary goal of the research was to compare the soil community structure of the nematodes and mites between long-term agro-management regimes and between long-term agro-management regimes and the native prairie land. After over 35 years of conventional tillage practices, both nematode and mite communities were negatively impacted. Thus, the increased soil disturbance (CT, conventional tillage) led to lower diversity and weaker soil nematode community structure than reduced soil disturbance (NT, no-till). The nematode maturity index (MI) revealed a more stable environment in the NT system. Oribatid mites dominated the soil mite community's relative density and genera diversity, regardless of agricultural management. Overall our results showed a positive relationship between crop rotation, reduced soil disturbance, and soil Acari's diversity and maturity in long-term agro-management regimes. Also, long-term agricultural practices (CT, NT) significantly altered the community structures of nematodes and mites compared to those from undisturbed grasslands. Thus, the highest number of identified nematode genera (68) was under native prairie (NP) systems. Nematode diversity and maturity decreased with the intensity of land cultivation. Farming impacted the diversity and community structure of Acari as well. Thus, the highest number of identified mites genera (53) was observed in NP systems, and the most mature community structure was also found in the grasslands. Oribatid mites dominated the soil mite communities in terms of relative density and genera diversity in agricultural land and in terms of diversity in the native prairies. A significantly higher proportion of Prostigmata was observed in grasslands, and a significantly lower proportion of Mesostigmata was attested in the CT system. Overall, the nematode and mites communities analysis affirmed that the tillage system significantly decreased the diversity of nematodes and mites, favoring a weaker organization of their communities. Consequently, their functional metabolic footprint had been severely altered compared to communities in native grasslands

Origin and higher-level diversification of acariform mites – evidence from nuclear ribosomal genes, extensive taxon sampling, and secondary structure alignment

Abstract Background Acariformes is the most species-rich and morphologically diverse radiation of chelicerate arthropods, known from the oldest terrestrial ecosystems. It is also a key lineage in understanding the evolution of this group, with the most vexing question whether mites, or Acari (Parasitiformes and Acariformes) is monophyletic. Previous molecular studies recovered Acari either as monophyletic or non-monophyletic, albeit with a limited taxon sampling. Similarly, relationships between basal acariform groups (include little-known, deep-soil 'endeostigmatan' mites) and major lineages of Acariformes (Sarcoptiformes, Prostigmata) are virtually unknown. We infer phylogeny of chelicerate arthropods, using a large and representative dataset, comprising all main in- and outgroups (228 taxa). Basal diversity of Acariformes is particularly well sampled. With this dataset, we conduct a series of phylogenetically explicit tests of chelicerate and acariform relationships and present a phylogenetic framework for internal relationships of acariform mites. Results Our molecular data strongly support a diphyletic Acari, with Acariformes as the sister group to Solifugae (PP =1.0; BP = 100), the so called Poecilophysidea. Among Acariformes, some representatives of the basal group Endeostigmata (mainly deep-soil mites) were recovered as sister-groups to the remaining Acariformes (i. e., Trombidiformes + and most of Sarcoptiformes). Desmonomatan oribatid mites (soil and litter mites) were recovered as the monophyletic sister group of Astigmata (e. g., stored product mites, house dust mites, mange mites, feather and fur mites). Trombidiformes (Sphaerolichida + Prostigmata) is strongly supported (PP =1.0; BP = 98–100). Labidostommatina was inferred as the basal lineage of Prostigmata. Eleutherengona (e. g., spider mites) and Parasitengona (e. g., chiggers, fresh water mites) were recovered as monophyletic. By contrast, Eupodina (e. g., snout mites and relatives) was not. Marine mites (Halacaridae) were traditionally regarded as the sister-group to Bdelloidea (Eupodina), but our analyses show their close relationships to Parasitengona. Conclusions Non-trivial relationships recovered by our analyses with high support (i.e., basal arrangement of endeostigmatid lineages, the position of marine mites, polyphyly of Eupodina) had been  proposed by previous underappreciated morphological studies. Thus, we update currently the accepted taxonomic classification to reflect these results: the superfamily Halacaroidea Murray, 1877 is moved from the infraorder Eupodina Krantz, 1978 to Anystina van der Hammen, 1972; and the subfamily Erythracarinae Oudemans, 1936 (formerly in Anystidae Oudemans, 1902) is elevated to family rank, Erythracaridae stat. ressur., leaving Anystidae only with the nominal subfamily. Our study also shows that a clade comprising early derivative Endeostigmata (Alycidae, Nanorchestidae, Nematalycidae, and maybe Alicorhagiidae) should be treated as a taxon with the same rank as Sarcoptiformes and Trombidiformes, and the scope of the superfamily Bdelloidea should  be changed. Before turning those findings into nomenclatural changes, however, we consider that our study calls for (i) finding shared apomorphies of the early derivative Endeostigmata clade and the clade including the remaining Acariformes; (ii) a well-supported hypothesis  for Alicorhagiidae placement; (iii) sampling the families Proterorhagiidae, Proteonematalycidae and Grandjeanicidae not yet included in molecular analyses; (iv) undertake a denser sampling of clades traditionally placed in Eupodina, Anystina (Trombidiformes) and Palaeosomata (Sarcoptiformes), since consensus networks and Internode certainty (IC) and IC All (ICA) indices indicate high levels of conflict in these tree regions. Our study shows that regions of ambiguous alignment may provide useful phylogenetic signal when secondary structure information is used to guide the alignment procedure and provides an R implementation to the Bayesian Relative Rates test.http://deepblue.lib.umich.edu/bitstream/2027.42/113097/1/12862_2015_Article_458.pd

Insects and Related Terrestrial Invertebrates of Ellef Ringnes Island

Reports results of collecting and observing arthropod fauna over a 25-day period in July-Aug. 1960 at the Polar Continental Shelf Project base at Isachsen, where the summers are unusually cold. Some 75 species are believed present in an environment closely approaching the limits of biotic tolerance, and detailed descriptions are given of most of these (Latin names), with their characteristic habitats and global distributions. They include spiders, mites, springtails and insects, particularly midges. The view is elaborated that only those species able to withstand frequent interruptions of development in various stages and a life cycle extending over several years are able to survive. Specimens at all stages of development were found simultaneously. Other adaptations to extremely severe environmental conditions were mentioned. The role occupied by the lemming Dicrostonyx groenlandicus is described, as the habits of a third of the arthropod species are linked with it. The very low flying habits of some species are noted. The age of the entire island biota is placed within the last 200 years, and the source area considered to be the islands to the east, principally Axel Heiberg, the means of dispersal being wind, ice rafts, mammals and birds

Soil mite biodiversity: its relationship to grass species and influence on decomposition in the Konza tallgrass prairie

2005 Summer.Includes bibliographical references.Human activities are responsible for unprecedented extinction rates and global change. Species are disappearing faster than we can record their existence and before we determine their role in ecosystems. In no other system on Earth are we more uncertain about the true diversity of organisms and their roles than in soils. I have examined soil mite (Acari) species at the Konza Prairie Biological Station (KPBS), Kansas, USA, an uncultivated tallgrass prairie, to determine what mechanisms are responsible for their diversity, how alien invasive grasses may impact them, and what role their diversity plays in decomposition. The hypotheses that soil mite species richness, abundance and taxonomic diversity is greater beneath grasses in dicultures (different species) compared to monocultures (same species), beneath grasses of higher resource quality (lower C:N) compared to lower resource quality, and beneath heterogeneous mixes of grasses (C3 andC4 grasses growing together) compared to homogeneous mixes (C3 or C4 grasses) were tested using natural occurrences of grass species as treatments. Increased grass diversity supported a more species and phylogenetically rich soil mite fauna. This relationship was significant at depth but not in the upper soil horizon. Soil mite richness increased nonlinearly with grass species richness suggesting that simple extrapolations of soil faunal diversity based on plant species inventories may underestimate the richness of associated11lsoil mite communities. The proportion of mite size classes in dicultures was considerably different than those for monocultures. These data suggest that interspecific root competition results in increased mite habitat, abundance and diversity. There was no difference in soil mite richness between grass combinations of differing resource quality, or resource heterogeneity. Soil mites sampled beneath six native and one alien-invasive species of grass were similarly abundant, species rich, diverse, and taxonomically distinct. There was no evidence that the community composition of soil mites was specific to grass species or that a significant number of mite species had affinities for different grass species. The soil mite community was weakly related to soil environmental conditions. Only oribatid mites were related to, marginally, the species of grass present. The alien invasive grass species did not support a successionally younger mite fauna and had no influence on mite community structure, possibly because it had not substantially altered the soil environment. Rates of cotton strip decomposition (percent cotton strip tensile strength loss per day, CTSL), and soil mite abundance and species richness were measured at high and low fire frequency sites of the KPBS. Likelihood-based and information theoretic approaches were used to examine strength of evidence in data for models of CTSL representing the Null, Rivet and Redundant hypotheses of biodiversity and ecosystem function (BEF). The Null model including temperature, moisture and saturating effects in the total abundance of predatory mites (Mesostigmata) had more support in the data than any other models. Models representing Rivet and Redundant patterns of BEF settled on parameter values distinct from the Null models but had less support in the data regardless of which mite group was being considered. A significant trend was observed in the models' residuals from low fire frequency sites trends not observed in high fire frequency sites. I speculate that annually burned sites more closely emulate the agricultural system the models were originally designed for than low fire frequency sites, accounting for differences in model performance. Biophysical properties on low fire frequency sites such as increased litter cover, different soil carbon constituents or a different microbial community may regulate decomposition in a manner not accounted for by only soil temperature and moisture driving variables

The Impact of Beneficial Organisms in Corn Agroecosystems

Corn is one of the world’s, and Nebraska’s, most important crops. Millions of acres are planted to corn each year in the Cornhusker State. However, each year there are a plethora of arthropod, weed, and microorganism pests that rob farmers of reaching their maximum yield potential. There are many options available to manage these pests in corn agroecosystems, but one option is often underutilized: beneficial organisms. For each pest, there are a variety of natural enemies that can assist in mitigating the damage caused by pests. Many beneficial organisms exist, and they can be grouped by the type of pest they target: arthropods, weeds, or pathogens. Natural enemies in each of these groups range from large and conspicuous to microscopic. For example, lady beetles and nematodes can prey upon arthropod pests, ground beetles and certain fungi help control weeds, and some mites and bacteria target plant pathogens. Beneficial organisms should be one tool used in Integrated Pest Management (IPM) programs. Taking advantage of natural enemies is more important than ever due to pesticide bans and resistance. Conservation biological control, which is readily available and relatively easy to implement, is one way farmers can maximize the impact of beneficial organisms. This method of conserving natural enemies can be achieved by reducing pesticide use or using selective pesticides, conserving and planting vegetation to supply resources to beneficials, using less-toxic pest management alternatives (e.g., planting Bt corn), and adopting reduced tillage practices such as no-till to preserve essential resources. One important example that highlights the impact of beneficial organisms in corn agroecosystems is their role in the management of spider mites, which are often a problem in hotter and drier areas. While there are other methods available to manage spider mites, some of these, such as pesticides, can be harmful to beneficial organisms. Therefore, growers and agronomists must consider multiple factors when creating and implementing IPM programs. Advisor: Gary L. Hei

Acari of Canada

Summaries of taxonomic knowledge are provided for all acarine groups in Canada, accompanied by references to relevant publications, changes in classification at the family level since 1979, and notes on biology relevant to estimating their diversity. Nearly 3000 described species from 269 families are recorded in the country, representing a 56% increase from the 1917 species reported by Lindquist et al. (1979). An additional 42 families are known from Canada only from material identified to family- or genus-level. Of the total 311 families known in Canada, 69 are newly recorded since 1979, excluding apparent new records due solely to classification changes. This substantial progress is most evident in Oribatida and Hydrachnidia, for which many regional checklists and family-level revisions have been published. Except for recent taxonomic leaps in a few other groups, particularly of symbiotic mites (Astigmata: feather mites; Mesostigmata: Rhinonyssidae), knowledge remains limited for most other taxa, for which most species records are unpublished and may require verification. Taxonomic revisions are greatly needed for a large majority of families in Canada. Based in part on species recorded in adjacent areas of the USA and on hosts known to be present here, we conservatively estimate that nearly 10,000 species of mites occur in Canada, but the actual number could be 15,000 or more. This means that at least 70% of Canada’s mite fauna is yet unrecorded. Much work also remains to match existing molecular data with species names, as less than 10% of the ~7500 Barcode Index Numbers for Canadian mites in the Barcode of Life Database are associated with named species. Understudied hosts and terrestrial and aquatic habitats require investigation across Canada to uncover new species and to clarify geographic and ecological distributions of known species