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Detailed studies of Chironomidae fauna can yield a reliable tool to evaluate the effects of climatic change and anthropogenic disturbances over freshwater ecosystems. Using modern chironomid remains deposited in surface sediment samples of 27 lakes located in south-central Chile (37° S–41° S), we investigated the spatial distribution and diversity of chironomids in association with climatic and limnological variables. Linear methods and ordination analyses were used to select the best explanatory environmental variables that influence the diversity and distribution of chironomids among sites. We identified 52 chironomid taxa, highlighting Tanytarsini-tribe, Ablabesmyia, and Parapsectrocladius as the most common. Our results suggest air temperature as the most important and significant factor controlling the distribution of chironomids among the Araucanian lakes, followed by water temperature, and dissolved oxygen. The diversity of chironomids is negatively correlated with parameters related to lake productivity. Orthocladiinae and Podonominae subfamilies are most frequent in high-altitude lakes associated with cold temperatures, whereas Chironominae and Tanypodinae are characteristic of lowland-lakes influenced by higher temperatures. Human-induced contamination of freshwater ecosystems and the ongoing climate change in south-central Chile represent the main threat to macroinvertebrates communities, and therefore a challenge to predict the trajectories of chironomid assemblages in the near future.

The work is the first part of a series of articles intended to comprehensively describe the current state of Chironomidae fauna of the Lower Dnipro on the basis of the long-term studies of larval forms of this group of Diptera insects, widely represented in water bodies of this estuary. Based on the current research, the species composition of larvae of Diptera insects of the Tanypodinae (Diptera, Chironomidae) subfamily, represented in the benthic fauna of various water bodies of the Lower Dnipro, is described. The research was conducted on 18 water bodies, located in the delta and pre-delta areas of the Dnipro River. For the delta area, the following water bodies were researched: mainstream of the Dnipro River, the Viryovchina River, KhersonBilozerskyi floodplain area (the Koshova River, Lake Rohozuvate, Lake Bezmen, Lake Chychkuvate, Lake Stebliivskyi Liman), Kardashynskyi floodplain area (the Chaika River, the strait into Lake Kruhle, the Hadiuchka Strait, Lake Kruhle, Lake Kardashynskyi Liman), Velykyi Potyomkinskyi floodplain area (Lake Zakitne and Lake Nazarove-Pohorile) and Holoprystanskyi floodplain area (Lake Liahushache). For the pre-delta area, the mainstream of the Dnipro River, the Kozak River and Lake Sabetskyi Liman were researched. Based on the obtained data, a characteristic for each of the species of Tanypodinae is given, which includes: the distribution; the seasonality; indicators of quantitative development; the abiotic factors and the species of higher aquatic vegetation inherent in the places of detection of the larvae; the area. The mass and the less developed species of Tanypodinae subfamily and their distributional pattern in the water bodies have been determined. The indexes of occurrence in the benthic samples for the larvae of these species were determined. The comparisons of the indexes for individual water bodies, groups of water bodies (streaming system of the Dnipro River, the tributaries and the straits, the Viryovchina River, the pre-delta area, the delta floodplain areas) and for the water bodies as a whole, were made. The species composition of Tanypodinae larvae of anthropogenically polluted areas of the Lower Dnipro, in particular, its differences for the watercourses and lakes, were noted. Key words: Diptera, larvae, fauna, macrozoobenthos, Lower Dnipro, Chironomidae, Tanypodinae.

Denopelopia amicitia Dantas, Hamada & Mendes was described based on the male and pupae collected in the Brazilian Amazon. Here we describe and illustrate the female and larva of this species. At both stages, D. amicitia is similar to Denopelopia atria Roback & Rutter, which is the only species in the genus with all life stages known until now.

Pollution of aquatic ecosystems with waste-water coming from tanneries is a serious challenge worldwide. The purpose of this study was to assess the water quality of Blue Nile River at a tannery in Bahir Dar, Ethiopia, using physicochemical and biological attributes. Four sampling sites were selected along the river based on the degree of degradation and major land-use types. Phyisco-chemical data, water samples, and chironomid larvae were collected monthly from March-May, 2016. Two liters of water were collected from each site and stored in the icebox and transported to Bahir Dar University. Water samples were analyzed for nutrients following standard procedures. Chironomid larvae were collected using a D- Frame net of 500 µm mesh size. One-way ANOVA was used to compare variations in all measured parameters among the sampling sites. Low dissolved oxygen (2.8 mg/l) was recorded at the site where the tannery meets the river. Moreover, the concentration of soluble reactive phosphorus, SRP (25.5±14.3 μg/l) and conductivity (1907.3±39.5 µS/cm) were low in the most upstream site of the river. A total of six Chironomid genera belonging to the subfamilies Chironominae and Tanypodinae were identified. The genus Chironomus dominated the impacted sites that had low dissolved oxygen levels. The other five genera were not found in those impacted sites. The result of this study indicated that the tannery effluent had impact on chironomid distribution as well as on river water quality.

This study was aimed to show whether subfossil Chironomidae (Diptera) may be useful tool for assessing toxicity of heavy metals in the aquatic environment. Investigations were carried out in subsidence ponds affected by the activity of metal mining: (1) the older ones formed before mining activity and (2) the younger one formed after the mine was closed. Waters of ponds were analyzed for physico-chemical parameters, whereas sediments were studied for metals (Cd, Pb, and Zn), pH, organic matter, nutrients (TOC, N-tot, and P-tot), and subfossil Chironomidae. High concentrations of Cd 6.7–612 μg g−1, Pb 0.1–10.2 mg g−1, and Zn 0.5–23.1 mg g−1 were found in the seven analyzed sediment cores. In total, 374 head capsules of Chironomidae larvae, belonging to four subfamilies Chironominae, Orthocladiinae, Tanypodinae, and Prodiamesinae, were determined. Both the diversity and density of Chironomidae change in particular sediment cores and layers. However, these changes were not related to metal concentrations, as shown in the statistical calculations (dendrogram of similarities, Mann-Whitney test, Spearman correlations). The only exception was the negative correlations between Cd, Pb, and Zn concentrations and the density of head capsules of Polypedilum sp. We found that organic matter and nutrient contents were important factors that control the spatial distribution of subfossil Chironomidae, mainly Orthocladiinae. Other factors which may influence subfossil Chironomidae distribution in sediment cores are discussed. To sum up, despite very high Cd, Pb, and Zn concentrations, the Chironomidae community was not clearly altered, therefore subfossil Chironomidae taxa appeared to be not useful for reconstructing dozen-years scale changes in the toxicity of the aquatic environment.

This checklist deals with summarizing all the data on Iranian Chironomidae (Diptera). In total, 34 species from 5 subfamilies are listed as the fauna of Iran: Buchonomyiinae (single species), Chironominae (18 species from 24 genera with some unknown species), Diamesinae (unknown species within 4 genera), Orthocladiinae (8 species from 24 genera with some unknown species) and Tanypodinae (7 species from 10 genera with some unknown species). Three species, Chironomus anthracinus Zetterstedt, 1860, Cladotanytarsus (Cladotanytarsus) mancus (Walker, 1856) and Tanypus punctipennis Meigen, 1818 are new records for the fauna of Iran.

Larval stages of the Chironomidae (Diptera) can be found in almost any aquatic habitat, includ- ing artificial lakes. They form an important fraction of the macrozoobenthos of most freshwater ecosystems. The Mavrovo reservoir as an artificial lake in the Republic of Macedonia, to date, has never been an object of hydrobiological research of this type. For that reason, the purpose of this study was to conduct research on the composition and structure of the chironomid larvae fauna that inhabits the Mavrovo reservoir. The quantitative samples for this research were collected during one year (2017/18), seasonally from five different localities (T1–T5) – T1-Ulazna, T2-Hotel Radika, T3-Middle of the reservoir, T4-Bunec, and T5-Old church (village Mavrovo). According to the results, Chironomidae was represented with five subfamilies, two tribes, and 25 taxa. The subfamilies are Chironominae with the two tribes Chironomini and Tanytarsini, Tanypodinae, Orthocladiinae, Diamesinae, and Prodiamesinae. The dominant taxon is Tanytarsus sp., and besides it, the following taxa: Procladius sp., Chironomus plumosus, Harnischia sp., Polypedilum nubeculosum, and Orthocladius saxicola are characterized by greater community participation. The highest density of chironomid larvae fauna was recorded during the summer, a total of 1013.69 ind/m2, compared to the lowest registered in the spring season which is only 9.78 ind/m2.

Introduction: Chironomidae (Diptera) is the most widespread and abundant aquatic insect family in freshwater ecosystems. Chironomids are considered good indicators of water quality but are seldom identified at the genus level in broad spatial scale studies. Objective: To identify environmental conditions associated with chironomids in an altitudinal gradient. Methods: We compared ecoregions, river types, and seasons, for chironomids in neotropical streams and rivers (18 river sites; 2014-2018; Yungas rainforest and Western Chaco dry forest, Argentina). We used non-metric multidimensional scaling, dissimilarity, envfit analysis and rank-abundance curves. Results: Chironomic “assemblages” matched both ecoregions and river types. However, ecoregions presented a better fit with species composition. The stenothermal taxa of Orthocladiinae were dominant at high elevations and the eurythermal Chironominae in lowland rivers. Altitude, water temperature and conductivity were important. Seasonal differences were smaller than ecoregional differences. Conclusions: Ecoregions, altitude, water temperature and conductivity correlated with chironomid communities. Orthocladiinae were dominant at high elevations and Chironominae in lowland rivers. Introducción: Chironomidae (Diptera) es la familia de insectos acuáticos más extendida y abundante en los ecosistemas dulceacuícolas. Los quironómidos se consideran buenos indicadores de la calidad del agua, pero rara vez se identifican a nivel de género en estudios de amplia escala espacial. Objetivo: Identificar las condiciones ambientales asociadas a los quironómidos en un gradiente altitudinal. Métodos: Comparamos ecorregiones, tipos de ríos y estaciones para quironómidos en arroyos y ríos neotropicales (18 sitios en ríos; 2014-2018; en un bosque tropical de Yungas y un bosque seco del Chaco Occidental, Argentina). Utilizamos escalamiento no métrico multidimensional, disimilitud, análisis de envfit y curvas de rango-abundancia. Resultados: Los “ensamblajes” de quironómidos coincidieron tanto con las ecorregiones como con los tipos de ríos. Sin embargo, las ecorregiones presentaron un mejor ajuste con la composición de especies. Los taxones estenotérmicos de Orthocladiinae fueron dominantes en las elevaciones altas y los euritermales de Chironominae en los ríos de las tierras bajas. La altitud, la temperatura del agua y la conductividad fueron importantes. Las diferencias estacionales fueron menores que las diferencias ecorregionales. Conclusiones: las ecorregiones, la altitud, la temperatura del agua y la conductividad se correlacionaron con las comunidades de quironómidos. Orthocladiinae fue dominante en los sitios altos y Chironominae en los ríos de tierras bajas

espanolEstudios previos realizados en la region, utilizando la comunidad de macroinvertebrados bentonicos y aplicando indices bioticos a nivel taxonomico de ordenes y familias, permitieron determinar la existencia de procesos de impacto antropico y degradacion en los ambientes acuaticos de la cuenca. Estos estudios, pusieron en evidencia la necesidad de trabajar a niveles taxonomicos mas precisos, abarcando la identificacion a nivel de genero y especie de algunos de los organismos predominantes en la comunidad bentonica. En funcion de esto, uno de los objetivos de la presente beca es caracterizar la fauna de insectos quironomidos (Diptera, Chironomidae) para la estacion otono, empleando las tecnicas aprendidas para la determinacion taxonomica a nivel de genero. La informacion obtenida permitira ajustar y mejorar la eficiencia de los indices bioticos de calidad ambiental, disenados y adaptados para el diagnostico y monitoreo en ambientes acuaticos de la region. En este trabajo se procesaron 28 muestras de macroinvertebrados bentonicos de 7 sitios de muestreo localizados sobre la cuenca superior del rio Gallegos. Estas muestras se tomaron en mayo de 2017 y corresponden a la estacion de otono. Se identificaron un total de 10 generos de insectos quironomidos, de los cuales 5 pertenecen a la subfamilia Orthocladiinae, 2 de Tanypodinae y 3 de Chironominae. EnglishPrevious studies realized carried out in the region,using the community of benthic macro- invertebrates and applying bioticindexes at taxonomic level of orders and families,allowed to determine the existence of processes of anthropic impact and degradationin the water environments of the watershed. These studies showed the need to work at more precise taxonomic levels, covering the identification at the level ofgender and species of some of the predominant organismsin the benthic community. Depending on this, one of the objectives of this fellowship is to characterize the fauna of chironomids insects (Diptera, Chironomidae) for the autumn season, using the techniques learned for taxonomic determination at the gender level. The information obtained will allow to adjust and improve the efficiency of the biotic indices of environmental quality, designed and adapted for the diagnosis and monitoring in aquatic environments of the region. In this paper, 28 samples of benthic macro invertebrates were processed from 7 sampling sites located on the upper Rio Gallegos basin. These samples were taken in May 2017 and correspond to the autumn season. A total of 10 genera of chironomids insects were identified , of which 5 belong to the subfamily Orthocladiinae, 2 of Tanypodinae and 3 of Chironominae.

Ablabesmyia cordeiroi Neubern foi descrita originalmente com base em machos coletados na região amazônica, portanto, a fêmea e os imaturos desta espécie são desconhecidos. No presente estudo, os estágios de pupa e larva de A. cordeiroi são descritos e ilustrados. Além disso, uma emenda à diagnose da larva de Ablabesmyia é fornecida. Abalesmyia cordeiroi Neubern was originally described based on adult males collected in the Amazon region; therefore, females and immatures of this species are unknown. In the present study, the pupal and larval stages of A. cordeiroi are described and illustrated. In addition, an amendment to the larval diagnosis of Ablabesmyia is provided.

Chironomidae es uno de los taxones más importantes de los ecosistemas de agua dulce. Las exuvias pupales se utilizan como una forma simple y rápida de obtener información ecológica sobre hábitats acuáticos, autoecología y distribución geográfica de las especies. El objetivo de este estudio fue elaborar una clave de identificación de pupas de Chironomidae presentes en los arroyos de la ecorregión Tributarios del río Paraná y Río de la Plata, integrando información relevada en estudios recientes y con el conocimiento disponible en publicaciones previas. El estudio de las exuvias pupales permitió ampliar el conocimiento de la riqueza taxonómica y la distribución de géneros y especies previamente registrados para la región. Por otro lado, la aplicación de la Técnica de Exuvias Pupales de Chironomidae posibilita identificaciones precisas a nivel de especie/morfoespecie y una reducción del tiempo de muestreo y procesamiento de las muestras resultando eficiente y menos costosa. Esta clave es el resultado del conocimiento de la familia en la ecoregión desde hace varias décadas y constituye un primer aporte al conocimiento taxonómico de Chironomidae a nivel de especie., Chironomidae is one of the most important taxa in freshwater ecosystems. Pupal exuviae are used as a simple and rapid way to obtain ecological information on aquatic habitats and data on autecology and geographic distribution. The objective of this study was to develop a key for the identification of pupal Chironomidae from the ecoregion Tributaries of Paraná and Río de la Plata rivers, integrating information recently in the ecoregion with the knowledge available from previous publications. The study of the pupal exuviae allowed to expand the knowledge of the taxonomic richness and the distribution of genera and species previously registered. On the other hand, the application of the Chironomidae Pupal Exuviae Technique enabled a precise identification at the species/morphospecies level and a reduction in sampling time and sample processing, resulting efficient and less expensive. This key is the result of knowledge of the family in the ecoregion for several decades and constitutes a first contribution to the taxonomic knowledge of Chironomidae at the species level., Instituto de Limnología "Dr. Raúl A. Ringuelet"

The genus Monopelopia Fittkau, 1962 is newly recorded from Oriental China. Monopelopia zhengi Lin sp. n., is described and illustrated based on an adult male from Jianfengling National Nature Reserve, Hainan, China. In addition, an updated key to adult males of Monopelopia is provided.

The diversity and endemism of Australian Tanypodinae (Diptera: Chironomidae) has been unclear from morphological comparisons with well-grounded northern hemisphere taxonomy. As part of a comprehensive study, here we focus on one of the few described endemic genera, Yarrhpelopia Cranston. Extensive and intensive new sampling and newly-acquired molecular data provides clarity for the type species, Yarrhpelopia norrisi Cranston and allows recognition of congeners and potential sister group(s). We describe Yarrhpelopia acorona Cranston & Krosch sp. n., and we recognise a third species from Western Australia, retaining an informal code ‘V20’ due to inadequate reared / associated material for formal description. We recognise a robust clade Coronapelopia Cranston & Krosch gen. n., treated as a genus new to science for two new species, Coronapelopia valedon Cranston & Krosch sp. n. and Coronapelopia quadridentata Cranston & Krosch sp. n., from eastern Australia, each described in their larval and pupal stages and partial imaginal stages. Interleaved between the independent new Australian clades Yarrhpelopia and Coronapelopia are New World Pentaneura and relatives, that allow a tentative inference of a dated gondwanan (austral) connection. Expanded sampling indicates that Y. norrisi, although near predictably present in mine-polluted waters, is not obligate but generally indicates acidic waters, including natural swamps and Sphagnum bogs. The inferred acidophily, including in drainages of mine adits, applies to many taxa under consideration here.

A new species of Nilotanypus Kieffer is described and illustrated based on male, pupa and larva. Nilotanypus yanomami sp. n. was collected at madicolous system in a mountainous region of northern Amazonia. Additionally, the identification key for males is updated and a distribution map for the Neotropical species is provided.

Denopelopia amicitia Dantas, Hamada & Mendes was described based on the male and pupae collected in the Brazilian Amazon. Here we describe and illustrate the female and larva of this species. At both stages, D. amicitia is similar to Denopelopia atria Roback & Rutter, which is the only species in the genus with all life stages known until now. RESUMO Denopelopia amicitia Dantas, Hamada & Mendes foi descrita com base no macho e na pupa coletados na Amazônia brasileira. Aqui descrevemos e ilustramos a fêmea e a larva desta espécie. Em ambos os estágios, D. amicitia é similar à Denopelopia atria Roback & Rutter, que é a única espécie do gênero com todos os estágios de vida conhecidos até agora.

The Chinese species of Macropelopia Thienemann are reviewed. A new species belonging to the subgenus Macropelopia, M. (M.) pergrandis sp. n., is described based on the adult male and pupa. Macropelopia grandivolsella Wang, Cheng et Wang and M. rotunda Wang, Cheng et Wang are synonymized with M. (M.) paranebulosa Fittkau and M. (M.) kibunensis (Tokunaga) respectively, based on reexamination of the type materials. Macropelopia galbina Wang, Cheng et Wang is transferred to the genus Brundiniella, and the male holotype is redescribed.

The family of non-biting midges (Diptera, Chironomidae) represent one of the most common and abundant group in freshwaters, inhabiting a wide variety of habitats and ecological niches. Although there is a long tradition of limnological research in Croatia, to date no extensive species list has been made for this insect family. Thus, we summarized the results of our research and reviewed published data on chironomid fauna of Croatia in various freshwater habitat types, including extreme ones, such as caves, peatbogs or marine littoral. A total of 239 species were recorded representing five subfamilies: Chironominae (125 species) Orthocladiinae (83 species), Tanypodinae (23 species), Diamesinae (6 species) and Prodiamesinae (2 species). The most frequent species were Cricotopus bicinctus, Dicrotendipes nervosus, Synorthocladius semivirens, each found in more than 20% of the studied localities. Ablabesmyia monilis and Procladius choreus represented the most frequent Tanypodinae species, recorded in more than 12% and 17% of the sites, respectively. The research of chironomid ecology, diversity and distribution continues, which will provide new data and information, but this first comprehensive checklist provides a good starting point for those studying Chironomidae or other freshwater Diptera, in Croatia and Europe.

Three new species of Amnihayesomyia are described from China: A. vittata sp. n. and A. tibetica sp. n. each based on the male and female adults, and A. subflava sp. n. based on the male adult. In addition, a key to the known males of this genus is provided.

One new species of Macropelopia Thienemann (Diptera: Chironomidae: Tanypodinae), M. (Macropelopia) patagonica sp. n. is described and figured as adult male. The specimens were collected from the Patagonian Andes, at San Carlos de Bariloche, Argentina. In addition, the generic diagnosis of Macropelopia is emended for the adult male.

The non-biting midge subfamily Tanypodinae (Diptera: Chironomidae) is species-rich, ecologically diverse, and near-globally distributed. Within the subfamily, aspects of generic and species-level taxonomy remain poorly understood, in particular the validity of assignment of Australian and New Zealand taxa to genera erected for northern hemisphere (Holarctic) fauna. Here, we place the austral diversity within this global context by extensive geographical and taxonomic sampling in concert with a multilocus phylogenetic approach. We incorporated sequence data for mitochondrial COI, and nuclear 28S and CAD, and conducted Bayesian and maximum likelihood phylogenetic inferences and Bayesian divergence time estimation. The resolved phylogeny supported many associations of Australian taxa with their proposed Holarctic congeners, with the exception of Apsectrotanypus Fittkau, and validates several taxa as endemic. Three of four New Zealand sampled taxa had their sister groups in Australia; New Zealand Monopelopia Fittkau was sister to a German congener. This included the first record of Procladius Kieffer from New Zealand. Most nodes connecting austral and Holarctic taxa clustered around the Cretaceous-Tertiary boundary (60-80 mya), whereas New Zealand-Australia nodes were generally slightly younger (53-57 mya). Together, these data contribute substantially to our understanding of the taxonomy, systematics and biogeography of the Australian Tanypodinae and more broadly to knowledge of Australia’s aquatic insect biodiversity.

A new genus of Chironomidae (Insecta: Diptera) is described based on a single incomplete pupa from Khutel Khara (lower part of the Tsagan Tsab Formation, Lower Cretaceous; Mongolia). The new genus displays a mosaic of Podonominae and Tanypodinae characters. The most distinctive characters of the new taxon are stout strongly darkened anal spurs, strong serration of anal lobes, and peculiar armament at the base of anal lobes, looking as an artichoke-like spinose structure, unique among Chironomidae.

Both sexes of a new fossil genus and species Eoprocladius hoffeinsorum gen. et sp. n. from Eocene Baltic amber are described and illustrated. This is the first report of a chironomid with such a long proboscis within the subfamily Tanypodinae and the tribe Procladiini. Within the family the elongated proboscis with narrow labella and suitable to feed on nectar evolved independently among Eocene and extant adult non-biting midges of the subfamilies Orthocladiinae and Tanypodinae. Djalmabatista maillardi Doitteau & Nel, 2007 from Eocene amber of France is placed in the extant genus Procladius Skuse: Procladius maillardi (Doitteau & Nel, 2007), comb. nov.

The Chickaloon Formation in south-central Alaska contains rich coal deposits dated very close to the Paleocene-Eocene boundary, immediately beneath which occur dispersed nodules of amber along with abundant remains of Metasequoia, dicots, and monocots. The nodules are small (less than 10 mm in length), nearly 10,000 of which were screened, yielding several inclusions of fungi and plant fragments, but mostly terrestrial arthropods: 29 specimens in 10 orders and 13 families. The fungi include resinicolous hyphae and a dark, multiseptate hyphomycete. Plants include wood/bark fragments and fibers, and the microphylls of a bryophyte (probably a moss, Musci). Among the arthropods are arachnids: mites (Acari: Oribatida), Pseudoscorpionida, and the bodies and a silken cocoon of spiders (Araneae). Insecta include Blattodea, Thysanoptera, Hemiptera (Heteroptera and Aphidoidea), Coleoptera (Dermestidae: Megatominae), Trichoptera, Diptera (Chironomidae: Tanypodinae), and Hymenoptera (Formicidae: Formicinae). Nymphal aphids predominate (65% of the arthropod individuals), which were probably feeding on the source tree, likely Metasequoia. There is a bias in preservation toward small arthropods (mean body length 0.75 mm) that are surface-dwelling (nonwinged) stages and taxa. Chickaloon amber contains the most northerly fossil records of pseudoscorpions, thrips, Dermestidae, and Cenozoic ants and mites, so the deposit is contributing unique data on high-latitude paleodiversity of the Paleogene hothouse earth.

Macroinvertebrate community taxonomic and trait structure showed consistent differences between riffles and pools across 12 headwater streams in the Sierra Nevada (California) even as flows varied from wet to dry years and between seasons. Densities of Ephemeroptera, Plecoptera, Trichoptera, Elmidae, Orthocladiinae and Diamesinae midges, and mites were greater in riffles, whereas Tanypodinae, Chironominae, Sialis, and Pisidium were more abundant in pools. Pools had higher densities but estimated biomass was greater in riffles. Collector-gatherer and micropredator abundances were greater in pools whereas grazers, collector-filterers, and macropredators were more abundant in riffles. Stonefly shredders were most abundant in riffles but some caddis shredders were more abundant in pools. Trait state patterns were related to food resource and physical habitat differences between riffles and pools. Of the distinct pool–riffle differences we found among taxa, only about half conformed to expectations from the literature. Pool and riffle assemblages were most dissimilar at intermediate discharge and converged at low and high flows when one or the other habitat dominated. Bioassessment sampling will need to account for these flow-related differences. Benthic invertebrate communities in these mountain streams clearly differ between pools and riffles, but the relative extent of habitats and biological similarity shift with flow regime.

Non-biting midges of the genus Pentaneura are small dipterans with larvae inhabiting in a variety of aquatic systems. Despite the wide geographical and ecological range, the systematics and phylogenetic relationships of the genus remains scarcely understood. Here, the taxonomy of the new world genus Pentaneura Phillip (Diptera: Chironomidae: Tanypodinae) is revised. Except for Pentaneura indecisa (Williston, 1896), diagnoses, descriptions, illustrations and taxonomic keys are provided for all previously described species, P. cinerea (Philippi, 1866), P. elisae Fittkau, 1962, P. inconspicua (Malloch, 1915), P. inoyensis Sublette, 1964 and P. vittaria Sublette and Sasa, 1994. Additionally, three new species are described: P. manueli Silva sp. nov. (Brazil), P. neusae Silva sp. nov. (Costa Rica) and P. waniae Silva sp. nov. (United States). We also present the first phylogenetic analysis of Pentaneura based on morphological data. Cladistic analyses were conducted using 61 morphological traits from 25 species, including genera belonging to the nine currently recognized Tanypodinae tribes (Anatopyniini, Clinotanypodini, Coelopyniini, Fittkauimyiini, Macropelopiini, Natarsiini, Pentaneurini, Procladiini and Tanypodini) and all the species within Pentaneura but P. indecisa. We examine the effects of implied weighting by reanalyzing the data with varying values of concavity constant (k). Our analysis supports the monophyly of Pentaneura based on two synapomorphies, in a wide range of weighting factors. Under these conditions, the genus is recovered sister to Parapentaneura, and these as sister to Hudsonimyia. The proposition of the internal phylogenetic structure in Pentaneura is refrained, as no obvious group-forming character was identified.