Species Of Plecoptera Research Articles

Diversity and Ecological Distribution of Plecoptera of Minas Gerais, Brazil.

The order Plecoptera constitutes a relatively small group of aquatic insects, encompassing 17 extant families and comprising over 4400 valid species. In Brazil, the number of valid extant species is 207, located in two families: Perlidae (149) and Gripopterygidae (58). Despite extensive research on the southeastern region of Brazil, there is a notable scarcity of comprehensive studies consolidating geographical records and species richness of Plecoptera in the state of Minas Gerais. This study seeks to increase and refine our understanding of Plecoptera within Minas Gerais, focusing on its diversity and distribution. The initial phase involved a thorough review of articles documenting Plecoptera species in the state. Subsequently, biological material from the Museum of Entomology at the Federal University of Viçosa collection was meticulously identified, and its geographical records were incorporated. Utilizing this dataset, we compiled an updated list of Plecoptera species documented in Minas Gerais. Geographical coordinates of collection points were then mapped and graphically represented to elucidate the geographic and altitudinal distribution of these species. A total of 42 Plecoptera species were identified within the state of Minas Gerais, adding many occurrence records and documenting the first record of Gripopteryx pinima for the state. Despite these advancements, knowledge gaps persist, particularly in the mesoregions of Triângulo/Alto Paranaíba, Oeste de Minas, Vale do Mucuri, and Campo das Vertentes. This endeavor serves as an initial foundation to stimulate further collections and investments in undersampled areas, fostering future monitoring and conservation initiatives for aquatic environments.

Amphibitic stoneflies (Plecoptera) are integrators of ecosystem processes in alluvial aquifers of gravel‐bed river floodplains

AbstractOver 50 years ago nymphs of the Plecoptera species, Paraperla frontalis Banks, 1906 (Plecoptera: Chloroperlidae), were shown to exist in a shallow floodplain aquifer of the Tobacco River, a gravel‐bed river in western Montana and later they were documented throughout the main stems of the Flathead River system. Nymphs are almost never found in surface waters, until they emerge on the river shorelines. As teneral adults, they mate and subsequently deposit fertilized eggs into the river. This novel life cycle is termed “amphibitic.” Over the years we and others have found P. wilsoni Ricker, 1965 (Plecoptera: Chloroperlidae), Kathroperla perdita Banks, 1920 (Plecoptera: Kathroperlidae), and five species of Isocapnia Banks, 1938 (Plecoptera: Capniidae), including long‐winged and brachypterous adults and wingless dwarfs (male and female), occupying amphibitic niches in the alluvial aquifers of rivers in Washington, Idaho, Colorado, Alaska and British Columbia. These stoneflies are remarkably tolerant of hypoxia which allows them to exist as abundant consumers in aquifer food webs subsidized by ancient methane. Indeed, stonefly tissues contain carbon that is up to 7000 years old, underscoring the existence of a strong interaction involving the uptake of labile carbon derived from methanogenic and methanotrophic process in aquifers. Details of life cycles, trophic relationships, distribution and abundance have been documented by a suite of studies on the Nyack Floodplain of the Middle Flathead River, Montana. In this paper we review the ecophysiology and ecology of these unique stoneflies in the context of their functional role in gravel‐bed river ecosystems.This article is categorized under: Water and Life > Nature of Freshwater Ecosystems Water and Life > Conservation, Management, and Awareness

DNA barcoding reference libraries of Italian Plecoptera: a gap analysis

Plecoptera is a small order of aquatic insects that is considered one of the most endangered groups of insects due to increasingly altered freshwater ecosystems. Plecoptera nymphs can be challenging to identify at the species level because diagnostic characters for most species are lacking, while adults can be difficult to collect routinely given their short life span. Species identification by DNA barcoding is increasingly used as an alternative to morphological identification, but gaps and inaccuracies in reference databases needed for taxonomic assignment can undermine the utility of barcoding in real case studies. Here we aim to: i) quantify the number of Italian species of Plecoptera with barcodes from specimens collected worldwide and from Italy; ii) perform a regional assessment of DNA barcoding coverage; iii) calculate the intraspecific distance among available sequences to evaluate the potential presence of errors and cryptic species. As reference databases, we used both a non-curated database (BOLD) and a curated database (MIDORI2) to test the effect of sequence selection on the availability of reference sequences. We found that 67.6% and 51.8% of the Italian Plecoptera species were represented in BOLD and MIDORI2. Most of the available sequences were obtained from specimens collected outside Italy, with only 21.8% and 13.5% of the Italian species having sequences from specimens collected in Italy. Endemisms were poorly represented, and intraspecific distances for some species were high, which suggest cryptic diversity or erroneous assignments. Our results support the growing need to increase international cooperation among barcode initiatives and to promote the integration between molecular biologists and zoologists to exploit the full potential of DNA barcoding to protect biodiversity.

Orophilic and crenophilic stoneflies (Insecta: Plecoptera) of the Italian region: new species, nomenclatural changes, updated and annotated checklist

An updated checklist of 191 Plecoptera species currently known from the Italian region is presented. Four new species are described: Protonemura marilouae sp. nov. from Calabria and Sicily, P. olahi sp. nov. from the central Apennines (Abruzzi), Leuctra stronensis sp. nov. from the Pennine Alps and L. trecimensis sp. nov. from the Dolomites. The males of Protonemura hirpina Consiglio, 1958b, and Leuctra silana Aubert, 1953b, are re-described, and their females are described for the first time. Four taxa are raised from subspecies to species rank: Protonemura padana Vinçon & Ravizza, 2005, Leuctra aubertorum Ravizza & Ravizza Dematteis, 1994a, L. orsiera Ravizza & Vinçon, 2003 and L. incudensis Vinçon & Ravizza, 2000b. Nemoura banatica Kis, 1965 is restored as a valid species, removed from synonymy with N. marginata Pictet, 1836, and its male is re-described. Protonemura beatensis robusta Berthélemy, 1963 is declared to be a junior synonym of P. salfii (Aubert, 1954c). Taxonomical notes on problematic species are added. The present checklist is the result of the compilation of published and unpublished data collected by the first three authors between 1974 and 2023. Distribution, altitudinal range and flight period of all species are summarized in table I. The altitudinal limits of nearly all orophilic Plecoptera species of the Italian Alps and Apennines are shown to have shifted to higher altitudes over a period of 30 or more years. An exhaustive bibliography of the original species descriptions of the Italian Plecoptera fauna is provided.

Aquatic insects (Ephemeroptera, Plecoptera, Trichoptera and Diptera: Tipuloidea) from the upper Neretva in Bosnia-Herzegovina

Within the upper Neretva catchment in Bosnia several hydropower plants are projected. Between 28.6. and 1.7.2022 a baseline survey was initiated to screen the area regarding the diversity of aquatic insects and its linked conservation value. In total, 59 Trichoptera species, ten Plecoptera species, 19 Ephemeroptera and 16 Diptera (Tipuloidea) species were collected, of which Baeoura sp. is new to science. 35 species are endemics of the Balkans, most species are rheobiontic and need high water current. The most abundant taxa are species of the trichopteran genus Agapetus (A. slavorum and A. ochripes) – surface grazers sensitive to water fluctuations and therefore vulnerable to hydropower-induced water level changes. With estimated 40,000 attracted specimens per night, light traps were extraordinarily successful. The extremely high diversity, as well as the enormous abundance of aquatic insects, underline the importance of the upper Neretva as an unimpacted riverine system embedded in dense natural and near-natural forest.

Sequencing Analysis of COI Genes Isolated from Vietnam’s Endemic Insect Species (Insecta: Plecoptera) for DNA Barcoding Database

The Insecta are the most diverse group of animals on the planet. The diversity of Plecoptera aquatic insect order is used as an environmental and ecological indicator. The study of endemic species is important for confirming the national biodiversity and contributing to the determination of national sovereignty. Despite Vietnam being a biodiversity hotspot, the number of known insect species remains limited. As a result, DNA barcoding has been used as a cutting-edge technique to efficiently and rapidly classify biological species. The Cytochrome c oxidase subunit I (COI) gene is widely regarded as a standard barcode for animal classification. In this study, we amplified and sequenced a portion of the COI gene fragment with a molecular weight of 710 bp for eight insect species belonging to the order Plecoptera, endemic to Vietnam. When compared to the previously published sequences of other Plecoptera species, the results of COI gene sequence analysis showed a high divergence of at least 9.9%. Molecular analysis of the studied species accurately demonstrated their endemism and morphological similarities. This study contributes to the development of a DNA barcoding database for endemic insects in Vietnam.

Preface: Proceedings of the XVIth International Conference on Ephemeroptera and XXth International Symposium on Plecoptera

Because of uncertainty about hosting an international, in-person conference in mid-2021, our meeting was postponed until summer 2022. Uncertainty continued into 2022. We could not wait longer, so The Joint Meeting of the XVI International Conference on Ephemeroptera and XX International Symposium on Plecoptera was a virtual affair hosted from the University of Illinois Urbana Champaign, U.S.A. The conference occurred daily, 0600–0900 hrs Chicago time, 26–29 July 2022. Despite the virtual venue, 41 oral (video) and 26 poster presentations were given by a total of 133 authors, representing 28 countries. At least 196 unique persons attended the 12 hrs of conference. It was a surprisingly successful meeting. The meeting program and links to all presentations are available from Plecoptera Species File. There were no Lifetime Achievement Awards bestowed upon our members during this meeting. A proposal for a meeting in 2024 in Turin, Italy was presented and accepted. In the weeks following the conference, we learned of the tragic death of our good friend and colleague Dr. Boris C. Kondratieff. We dedicate this volume to his memory and provide an obituary in this volume.

Cavoperlidae, a new stonefly family (Insecta: Plecoptera) from mid-Cretaceous Kachin amber of northern Myanmar

A new genus and species of Plecoptera, Cavoperla excavata gen. et sp. nov., is described based on a male adult specimen preserved in mid-Cretaceous Kachin amber of northern Myanmar. This stonefly is assigned to the superfamily Pteronarcyoidea, which can be determined by its wing venation and mouthpart morphology. However, it exhibits a distinct set of characteristics that differentiate it from all known extant and extinct families within Pteronarcyoidea. To accommodate this unique taxon, a new extinct family, Cavoperlidae fam. nov., is established. Cavoperlidae fam. nov. shows a close relationship to the extant family Styloperlidae. Diagnostic features of Cavoperlidae fam. nov. include the presence of three well-developed ocelli, the absence of a male abdominal hair brush and the trifurcate setae on the apex of the tibia, and the unarmed basal cercal segments.

The First Complete Mitochondrial Genome of Genus Isocapnia (Plecoptera: Capniidae) and Phylogenetic Assignment of Superfamily Nemouroidea.

Capniidae are a family of stoneflies, also known as snow flies, who emerge in winter. The phylogeny of Capniidae is widely accepted to be based on morphological analysis. Until now, only five Capniidae mitochondrial genomes have been sequenced so far. In addition, sampling is required to determine an accurate phylogenetic association because the generic classification of this family is still controversial and needs to be investigated further. In this study, the first mitogenome of genus Isocapnia was sequenced with a length of 16,200 bp and contained 37 genes, including a control region, two rRNAs, 22 tRNAs, and 13 PCGs, respectively. Twelve PCGs originated with the common start codon ATN (ATG, ATA, or ATT), while nad5 used GTG. Eleven PCGs had TAN (TAA or TAG) as their last codon; however, cox1 and nad5 had T as their final codon due to a shortened termination codon. All tRNA genes demonstrated the cloverleaf structure, which is distinctive for metazoans excluding the tRNASer1 (AGN) that missed the dihydrouridine arm. A Phylogenetic analysis of the superfamily Nemouroidea was constructed using thirteen PCGs from 32 formerly sequenced Plecoptera species. The Bayesian inference and maximum likelihood phylogeny tree structures derived similar results across the thirteen PCGs. Our findings strongly supported Leuctridae + ((Capniidae + Taeniopterygidae) + (Nemouridae + Notonemouridae)). Ultimately, the best well-supported generic phylogenetic relationship within Capniidae is as follows; (Isocapnia + (Capnia + Zwicknia) + (Apteroperla + Mesocapnia)). These findings will enable us to better understand the evolutionary relationships within the superfamily Nemouroidea and the generic classification and mitogenome structure of the family Capniidae.

Molecular Phylogenetic Analysis of Nemoura flexuosa Aubert, 1949 Based on Cytochrome Oxidase C Subunit-I Gene from Türkiye

Plecoptera species are valuable both as freshwater indicators and as key role in the food chain of river ecosystems. Moreover, they constitute an order with a high speciation capacity. Therefore, identification at the species level by morphological analysis leads to reliability problems. Studies on the phylogeny of Nemoura flexuosa which belongs to this order are scarce in the literature. Samples were collected from Kocaeli-Türkiye and then morphological and phylogenetic descriptions of the specimens were made. The Cytochrome Oxidase C Subunit-I gene region in mitochondrial DNA was amplified and sequenced. Molecular analyses revealed that the samples belong to the N. flexuosa species. Phylogenetic analyses were carried out by comparing the gene sequences of N. flexuosa haplotypes in Europe with gene sequences of the same basepair length and with the gene sequence of Amphinemura borealis which was used as an outgroup. The two phylogenetic trees were consistent and the collected specimens were evolutionarily closer to the OK316196.1, OK316261.1, OK316397.1, MZ608304.1, KY261370.1 and JX905853.1 haplotype. The presence of N. flexuosa in Kocaeli and the phylogenetic status of the Türkiye haplotype were reported. Clarifying the phylogenetic status of ecologically important species provides basic information for biosecurity studies for possible future conservation and control programs.

Plecoptera (Insecta) Diversity in Indiana: A Watershed-Based Analysis

Plecoptera, an environmentally sensitive order of aquatic insects commonly used in water quality monitoring is experiencing decline across the globe. This study addresses the landscape factors that impact the species richness of stoneflies using the US Geological Survey Hierarchical Unit Code 8 drainage scale (HUC8) in the state of Indiana. Over 6300 specimen records from regional museums, literature, and recent efforts were assigned to HUC8 drainages. A total of 93 species were recorded from the state. The three richest of 38 HUC8s were the Lower East Fork White (66 species), the Blue-Sinking (58), and the Lower White (51) drainages, all concentrated in the southern unglaciated part of the state. Richness was predicted using nine variables, reduced from 116 and subjected to AICc importance and hierarchical partitioning. AICc importance revealed four variables associated with Plecoptera species richness, topographic wetness index, HUC8 area, % soil hydrolgroup C/D, and % historic wetland ecosystem. Hierarchical partitioning indicated topographic wetness index, HUC8 area, and % cherty red clay surface geology as significantly important to predicting species richness. This analysis highlights the importance of hydrology and glacial history in species richness of Plecoptera. The accumulated data are primed to be used for monograph production, niche modeling, and conservation status assessment for an entire assemblage in a large geographic area.

English

Freshwater ecosystems are the major source of water, being used for domestic, agricultural and industrial purposes. Water bodies are subjected to anthropogenic activities leading to degradation of the water quality. The aim of this study is to assess the health status of Isiokpo River. Aquatic insects were sampled from March to August 2017. Physico-chemical parameters were examined using standard laboratory procedures. A total of 21 taxa comprising of 543 individual insects were recovered. Stations 1, 2 and 3 recorded 53.41, 21.36 and 25.23% of the insect population respectively. A total of six Ephemeroptera, Plecoptera and Trichoptera (EPT) species were recorded in the study. The %EPT was 28.57, 33.33 and 30.77% in station 1, 2 and 3 respectively. There were significant differences in the distribution of dissolved oxygen, phosphate, nitrates transparency, flow velocity, and total dissolved solids across the various stations (p<0.05). The reduced level of dissolved oxygen in station 3 as well the dominance of Chironomus sp. are indications of the impact of anthropogenic activities. The study showed that the Isiokpo River is relatively unhealthy. Key words: Aquatic insects, Biomonitoring, Freshwater, Ephemeroptera, Plecoptera, Trichoptera, Water quality.

Impacts of climate change on aquatic insects in temperate alpine regions: Complementary modeling approaches applied to Swiss rivers.

Freshwater biodiversity loss is a major concern, and global warming is already playing a significant role in species extinctions. Our main goal was to predict climate change impacts on aquatic insect species distribution and richness in Swiss running waters according to two climate change scenarios (RCP2.6 and RCP8.5), using different modeling approaches, that is, species distribution models (SDMs), stacked‐SDMs (S‐SDMs) and a macroecological model (MEM). We analyzed 10,808 reaches, used as spatial units for model predictions, for a total river network length of 20,610 km. Results were assessed at both the countrywide and the biogeographic regional scales. We used incidence data of 41 species of Ephemeroptera, Plecoptera and Trichoptera (EPT) from 259 sites distributed across Switzerland. We integrated a coupled model for hydrology and glacier retreat to simulate monthly time‐step discharge from which we derived hydrological variables. These, along with thermal, land‐cover, topographic and spatially explicit data, served as predictors for our ecological models. Predictions of occurrence probabilities and EPT richness were compared among the different regions, periods and scenarios. A Shiny web application was developed to interactively explore all the models’ details, to ensure transparency and promote the sharing of information. MEM and S‐SDMs approaches consistently showed that overall, climate change is likely to reduce EPT richness. Decrease could be around 10% in the least conservative scenario, depending on the region. Global warming was shown to represent a threat to species from high elevation, but in terms of species richness, running waters from lowlands and medium elevation seemed more vulnerable. Finally, our results suggested that the effects of anthropogenic activities could overweight natural factors in shaping the future of river biodiversity.

Estimates of resource transfer via winged adult insects from the hyporheic zone in a gravel-bed river.

Hyporheic zone (HZ) locates below the riverbed providing habitat for macroinvertebrates from where the winged adult insects (i.e., hyporheic insects, HIs) emerge and bring out aquatic resources to the riparian zone. This study estimated mean daily flux as dry biomass (BM), carbon (C), and nitrogen (N) deriving from the dominant HI species Alloperla ishikariana (Plecoptera, Chloroperlidae) for a 4th‐order gravel‐bed river during the early‐summer to summer periods. We hypothesized that HIs were an important contributor in total aquatic resources to the riparian zone. In 2017 and 2018, we set parallelly (May to August) and perpendicularly (June to October) oriented Malaise traps to catch the lateral and longitudinal directional dispersing winged adults of A. ishikariana, and other Ephemeroptera, Plecoptera, Trichoptera, and Diptera from the river and estimated the directional fluxes of them. We further split the directional fluxes as moving away or back to the channel (for lateral) and from down‐ to upstream or up‐ to downstream (for longitudinal). Alloperla ishikariana was similar to other Plecoptera species and differed clearly from Ephemeroptera and Trichoptera in directional characteristics of resources flux, suggesting that the extent and directions of HZ‐derived resource transfer depend on taxon‐specific flight behaviors of HIs. Contributions of A. ishikariana to the riparian zone in total aquatic C and N transfer seasonally varied and were lower in May (5%–6%) and August (2%–4%) and the highest in July (52%–70%). These conservative estimates largely increased (9% in May) after the supplementary inclusion of Diptera (Chironomidae and Tipulidae), part of which were considered HIs. We demonstrated that HZ could seasonally contribute a significant portion of aquatic resources to the riparian zone and highlighted the potential importance of HZ in nutrient balance in the river‐riparian ecosystem.

COMPOSITION OF PLECOPTERA (INSECTA) FAUNA IN RIVERS AT DIFFERENT ALTITUDES OF HIGH MOUNTAIN IN PENINSULAR MALAYSIA

The composition of Plecoptera species in rivers at different altitudes in Malaysia is not well understood. Therefore, a study on the diversity of stonefly (Plecoptera) was carried out at Gunung Jerai, Kedah, and Gunung Ledang, Johor. The data were collected from three streams for each Gunung Ledang and Gunung Jerai making a total of six streams; Tupah, Bt Hampar, and Teroi rivers from Gunung Jerai while, Ulu Jementah, Jeram Tinggi, and Anak Air Puteh rivers from Gunung Ledang. Plecoptera nymphs were collected using the kick-net sampling technique. All rivers from both mountains recorded five genera out of three families but Kamimuria was found only in Gunung Jerai while Phanoperla was found in a river at Gunung Ledang. Anak Air Puteh River (975 m a.s.l.) recorded the greatest diversity of plecopterans genus (4) while Tupah River (200 m a.s.l.), reported the most diverse plecopterans at Gunung Jerai (4). Based on correlation analysis, the plecopterans composition is influenced by water temperature, pH, altitudes, COD, and BOD (p&lt;0.05). Low pH values (acidic) at the highest region for both mountains (Teroi and Anak Air Puteh rivers) allowed an acid-tolerant plecopterans (Nemouridae) to thrive in those rivers. The decreasing diversity of Plecoptera taxa from low to high altitudes were affected by the water physicochemical parameters that vary in altitudes, and probably due to the type of vegetative structures.

Stable isotope ratios of emergent adult aquatic insects can be used as indicators of water pollution in the hyporheic food web

Bio-assessment protocols for the subsurface domain of river channels (i.e. hyporheic zone) are scarce despite of the known importance of its ecological function in river ecosystems. The larvae of the Alloperla ishikariana Plecoptera species inhabit the hyporheic zone. Therefore, we examined whether emergent adult A. ishikariana could serve as proxy indicators of the effects of pollution in the hyporheic food web. The study site comprised a 15-km stretch of a gravel bed river in Hokkaido, Japan, from which all invertebrates were collected from the riverbed at a depth of 30–50 cm, and emergent A. ishikariana adults were sampled in riparian zones. Water quality changed gradually along the river owing to the effects of a wastewater treatment plant and surrounding land uses. Nitrogen and carbon stable isotope ratios (SIRs) of epilithic biofilms, hyporheic particulate organic matter (POM), benthic POM, and invertebrates were used to determine the major basal carbon sources, the effects of water pollution on the hyporheic zone, and the trophic positions of dominant invertebrates. Generalized linear (mixed) models were used for statistical testing and modeling. Amphipoda and the larvae of A. ishikariana were considered as top predators and secondary consumers in the hyporheic food web, respectively. The observed similarity in water quality between the hyporheic and surface water suggested a large degree of hydrological exchange between the two zones, and resulted in positive increases in the nitrogen SIRs of hyporheic invertebrates, including A. ishikariana larvae, in proportion to nitrate levels in the surface water. The nitrogen SIRs of A. ishikariana adults were significantly correlated with the nitrogen SIRs of their larvae within the same location (adjusted R2 = 0.78), indicating that emerged adults can provide information on the longitudinal variability of the effects of synthetic nitrogen. In contrast, the carbon SIRs of adults did not predict those of their larvae, possibly reflecting the diverse feeding habitats of larvae. Overall, we demonstrated that adult aquatic insects emerging from the hyporheic zone can be used as indirect indicators of pollution-associated nutrient assimilation as well as the spatial heterogeneity of dietary carbon resources in hyporheic food web.

Checklist of Plecoptera (Insecta) from the State of Espírito Santo, Brazil

We present here a commented list of the species of Plecoptera currently reported from the State of Espirito Santo, Brazil, based on literature, emendations and on a new record. A total of 39 species are cataloged, as well as their distribution area and additional comments. The present study represents an important contribution to the knowledge of the fauna of Plecoptera in Brazil, leading Espirito Santo to the second state with the largest number of stonefly species recorded from the country.

Combining ddPCR and environmental DNA to improve detection capabilities of a critically endangered freshwater invertebrate

Isogenus nubecula is a critically endangered Plecoptera species. Considered extinct in the UK, I. nubecula was recently rediscovered (in one location of the River Dee, Wales), after 22 years of absence. In a similar way to many other species of Perlodidae, I. nubecula could be utilised as a bio-indicator, for assessing water quality and health status of a given freshwater system. However, conventional monitoring of invertebrates via kick-sampling, is invasive and expensive (time consuming). Further, such methods require a high level of taxonomic expertise. Here, we compared the traditional kick-sampling method with the use of eDNA detection using qPCR and ddPCR-analyses. In spring 2018, we sampled eDNA from twelve locations on the River Dee. I. nubecula was detected using kick-sampling in five of these locations, three locations using both eDNA detection and kick-sampling and one location using eDNA detection alone – resulting in a total of six known and distinct populations of this critically endangered species. Interestingly, despite the eDNA assay being validated in vitro and in silico, and results indicating high sensitivity, qPCR analysis of the eDNA samples proved to be ineffective. In contrast, ddPCR analyses resulted in a clear detection of I. nubecula at four locations suggesting that inhibition most likely explains the large discrepancy between the obtained qPCR and ddPCR results. It is therefore important to explore inhibition effects on any new eDNA assay. We also highlight that ddPCR may well be the best option for the detection of aquatic organisms which are either rare or likely to shed low levels of eDNA into their environment.

Effects of Stream Temperature and Substrate Type on Emergence Patterns of Plecoptera and Trichoptera From Northeastern United States Headwater Streams.

The timing and spatial distribution of aquatic insect emergence is linked to the abiotic and biotic environment in streams. Studies of aquatic insect emergence are needed to generate baseline data to identify potential shifts in phenology and habitat-related emergence with global change. The purpose of this study was to 1) compare the timing of Plecoptera (stonefly) species emergence between two streams with different thermal regimes and 2) characterize the distribution of emerging Plecoptera and Trichoptera (caddisflies) from wood, rock, gravel, and sand substrates in five forested, headwater streams. Emergence timing and duration varied among Plecoptera species, with Ostrocerca albidipennis (Walker) (Plecoptera: Nemouridae) emerging only in May and four species in the genus Leuctra (Plecoptera: Leuctridae) collectively emerging throughout the summer (May to September). We observed earlier emergence of Amphinemura nigritta (Provancher) (Plecoptera: Nemouridae) and a longer total emergence period for Leuctra ferruginea (Walker) (Plecoptera: Leuctridae) in the stream with ~1.5°C warmer temperatures, which suggested that some insects may experience phenological shifts in streams with subtle differences in temperature. The abundance of plecopteran and trichopteran taxa emerging from wood was generally greater than for gravel or sand, and sand was the least preferred emergence substrate. The results suggest that human actions that decrease large wood and increase fine sedimentation may decrease habitat quality for many insect larvae and limit preferred emergence substrates.

Searching for urban pollution signature and sensitive macroinvertebrate traits and ecological preferences in a river in the Eastern Cape of South Africa

Abstract Urbanisation of riverine landscapes is a major threat to river ecosystems because of the ecological consequences of the so called urban stream syndrome. Taxonomically, certain macroinvertebrate metrics such as the diversity of species of Ephemeroptera, Plecoptera and Trichoptera (EPT) are known to be sensitive to urban pollution, whereas chironomids and oligochaetes are relatively tolerant. Trait correlates of such taxonomic metrics are yet to be established even though traits are less constrained by geographical differences. Using the Swartkops as a case study of a river receiving urban pollution, the pattern of trait distribution in relation to a gradient of urban pollution was examined, and urban pollution signature and sensitive traits identified. Macroinvertebrates and physico-chemical analysis were undertaken over a period of three years between August 2009 and September 2012 at one control site and three impacted downstream sites. Seven traits resolved into 32 trait attributes including body size, respiration, body shape, mobility, biotope preference, preferred food, and feeding habits were fuzzy coded and analysed using RLQ and fourth-corner analyses. Of the 32 trait and ecological attributes, four, including large body size (>20 to 40 mm), animal materials as preferred food, predation and a preference for vegetation biotope, which were associated with the impacted sites, and were also significantly positively correlated with at least one physico-chemical indicator of increasing urban pollution were deemed signature traits. Three traits, swimming, fine particulate organic matter and grazing, associated with the control site, which showed significant negative correlations with at least one physico-chemical indicator of increasing urban pollution were identified as sensitive traits. The results indicate that urban pollution differentially influenced macroinvertebrate traits, with the identification of pollution signature and sensitive traits seen as an important step towards the development of trait-based indices for riverine monitoring of urban pollution effects.