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The Crato Formation (Lower Cretaceous, Brazil) is a Konservat-Lagerstätte preserving a great number of exceptionally well-preserved insects. Here, we sought to explore the preservational modes of two abundant aquatic and terrestrial groups of this unit, mayflies and crickets. To better understand how exceptional is their preservation, we also present detailed data on the modes of preservation of mayflies from the renowned Solnhofen limestones (Upper Jurassic, Germany). For the Crato Formation, out of 234 fossil mayflies and crickets, ten specimens were additionally analyzed using scanning electron microscopy coupled to energy dispersive X-ray spectroscopy (SEM-EDS), energy and micro-energy dispersive X-ray fluorescence (EDXRF and μEDXRF), and μRaman spectroscopy. For the Solnhofen limestones, 85 adult mayflies were analyzed, and five of them were subjected to SEM-EDS and μEDXRF analyses. The Crato specimens preserve several external and internal microfeatures. The areas with the highest fidelity of preservation are characterized by smaller and more closely-packed crystals when compared to less-preserved parts. We also recovered microscopic features that suggest the presence of microbial mats during the fossilization process. All the analyzed Crato specimens are preserved by replacement of tissues with iron oxides after pyritization. Sulfur occurs scattered in some regions of the crickets, but is associated with low iron counts, which may indicate the presence of sulfates post-dating pyrite oxidation. Additionally, the orthopterans have calcium phosphate preserving some of their structures. Differing from Crato insects, Solnhofen mayflies are overall poorly preserved as mere imprints, and their micron-scale morphology is obliterated by coarse mineral growth, whereas tissues are obliterated by calcite crystals alone or in combination with globular material. There is an elevated concentration of Si, K, Ca, Ti, Mn, and Fe in comparison to the host rock, which may be related to a yet unknown mineral phase(s). Although the paleoenvironments of the Crato Formation and the Solnhofen limestones are different, there are similarities in the style of preservation of their vertebrates and in some of their paleoenvironmental conditions such as anoxic hypersaline bottom waters and deposition of laminated limestones. However, the same does not apply to the preservation of insects, specifically mayflies, which are poorly preserved in the Solnhofen limestones. [ABSTRACT FROM AUTHOR]

BACKGROUND: The rise of insecticide resistance against malaria vectors in sub-Saharan Africa has resulted in the need to consider other methods of vector control. The potential use of biological methods, including larvivorous fish, Bacillus thuringiensis israelensis (Bti) and plant shading, is sustainable and environmentally friendly options. This study examined the survivorship of Anopheles arabiensis and Anopheles funestus larvae and habitat productivity in four permanent habitat types in Homa Bay county, western Kenya. METHODS: Predator densities were studied in a laboratory setup while habitat productivity and larval survivorship was studied in field setup. RESULTS: Fish were observed as the most efficient predator (75.8% larval reduction rate) followed by water boatman (69%), and dragonfly nymph (69.5%) in predation rates. Lower predation rates were observed in backswimmers (31%), water beetles (14.9%), water spiders (12.2%), mayflies (7.3%), and tadpoles (6.9%). Increase in predator density in the field setup resulted in decreased Culex larval density. Larval and pupa age-specific distribution was determined and their survivorship curves constructed. Combined larvae (Stage I-IV) to pupa mortality was over 97% for An. arabiensis and 100% for An. funestus. The highest larval stage survival rate was from larval stages I to II and the lowest from larval stage IV to pupa. Stage-specific life tables indicated high mortality rates at every developmental stage, especially at the larval stage II and III. CONCLUSION: Determination of the efficiency of various larval predators and habitat productivity will help with the correct identification of productive habitats and selection of complementary vector control methods through environmental management and/or predator introduction (for instance fish) in the habitats.

Mountainous regions are biodiversity hotspots with a high rate of endemism. However, these areas are witnessing accelerated warming, that threaten biodiversity and potentially causes habitat shrinkage for many species. Our study focuses on one such species, Andesiops peruvianus, a native mayfly of the mountains regions of South America. Our objectives were to analyze the genetic diversity of the 16 S gene in several populations, to assess their climate niche and potential distribution under future climate change scenarios. For genetic analysis samples were collected and sequenced from different sites across the South America (Argentina, Bolivia, Ecuador, and Colombia) and combine with the GenBank database. We identified 17 unique haplotypes based on 16 S gene, grouping them into two mains lineages: northern (Colombia and Ecuador) and southern (Bolivia and Argentina). Niche analysis showed a significant divergence between the northern and the southern lineages, suggesting distinct ecological niches. As future climatic changes were examined, both groups were observed to potentially lose about half of their suitable habitats. Habitat loss is the greatest at lower altitudes, but with some gain at higher altitudes. Isothermality and Annual Mean Temperature played a crucial role in defining habitats suitable for A. peruvianus. These features, coupled with their low thermal tolerance, might render the species particularly vulnerable to the impacts of climate change. Implications for insect conservation: This study highlights the need for targeted conservation strategies that protect and restore habitats along the altitudinal gradient to facilitate gene flow and enhance the resilience of A. peruvianus and other species to climate change. [ABSTRACT FROM AUTHOR]

Mayflies (Ephemeroptera) are among the crucial water and habitat quality bioindicators. However, despite their intensive long‐term use in various studies, more reliable mayfly DNA barcode data have been produced in a negligible number of countries, and only ~40% of European species had been barcoded with less than 50% of families covered. Despite being carried out in a small area, our study presents the second‐most species‐rich DNA reference library of mayflies from Europe and the first comprehensive view from an important biodiversity hotspot such as the Western Carpathians. Within 1153 sequences, 76 morphologically determined species were recorded and added to the Barcode of Life Data System (BOLD) database. All obtained sequences were assigned to 97 BINs, 11 of which were unique and three represented species never barcoded before. Sequences of 16 species with high intraspecific variability were divided into 40 BINs, confirming the presence of cryptic lineages. Due to the low interspecific divergence and the non‐existing barcoding gap, sequences of six species were assigned to three shared BINs. Delimitation analyses resulted in 79 and 107 putative species respectively. Bayesian and maximum‐likelihood phylogenies confirmed the monophyly of almost all species and complexes of cryptic taxa and proved that DNA barcoding distinguishes almost all studied mayfly species. We have shown that it is still sufficient to thoroughly investigate the fauna of a small but geographically important area to enrich global databases greatly. In particular, the insights gained here transcend the local context and may have broader implications for advancing barcoding efforts. [ABSTRACT FROM AUTHOR]

Three new fossil mayfly (Ephemeroptera) larvae from the Redmond Formation (Cenomanian) of Newfoundland and Labrador, Canada, are described: Alatuscapillus icarus gen. et sp. nov. (family Oligoneuriidae), Cruscolli sheppardae gen. et sp. nov. (family Heptageniidae), and Protoligoneuria borealis sp. nov. (family Hexagenitidae). This discovery marks the first juvenile insect nymphs to be described from this formation and helps fill gaps in our understanding of the global and temporal distribution of mayflies during the Cretaceous period. Of these, C. sheppardae marks the oldest occurrence of the family Heptageniidae in the fossil record, while A. icarus and P. borealis mark the first fossil occurrences of the families Oligoneuriidae and Hexagenitidae in North America. The anatomy, preservation, and behaviour of these new mayfly species inferred from modern taxa consolidate the hypothesis that the Redmond Formation's palaeoenvironment was lacustrine in nature. [ABSTRACT FROM AUTHOR]

The Crato Formation (Lower Cretaceous, Brazil) is a Konservat-Lagerstätte preserving a great number of exceptionally well-preserved insects. Here, we sought to explore the preservational modes of two abundant aquatic and terrestrial groups of this unit, mayflies and crickets. To better understand how exceptional is their preservation, we also present detailed data on the modes of preservation of mayflies from the renowned Solnhofen limestones (Upper Jurassic, Germany). For the Crato Formation, out of 234 fossil mayflies and crickets, ten specimens were additionally analyzed using scanning electron microscopy coupled to energy dispersive X-ray spectroscopy (SEM-EDS), energy and micro-energy dispersive X-ray fluorescence (EDXRF and µEDXRF), and µRaman spectroscopy. For the Solnhofen limestones, 85 adult mayflies were analyzed, and five of them were subjected to SEM-EDS and µEDXRF analyses. The Crato specimens preserve several external and internal microfeatures. The areas with the highest fidelity of preservation are characterized by smaller and more closely-packed crystals when compared to less-preserved parts. We also recovered microscopic features that suggest the presence of microbial mats during the fossilization process. All the analyzed Crato specimens are preserved by replacement of tissues with iron oxides after pyritization. Sulfur occurs scattered in some regions of the crickets, but is associated with low iron counts, which may indicate the presence of sulfates post-dating pyrite oxidation. Additionally, the orthopterans have calcium phosphate preserving some of their structures. Differing from Crato insects, Solnhofen mayflies are overall poorly preserved as mere imprints, and their micron-scale morphology is obliterated by coarse mineral growth, whereas tissues are obliterated by calcite crystals alone or in combination with globular material. There is an elevated concentration of Si, K, Ca, Ti, Mn, and Fe in comparison to the host rock, which may be related to a yet unknown mineral phase(s). Although the paleoenvironments of the Crato Formation and the Solnhofen limestones are different, there are similarities in the style of preservation of their vertebrates and in some of their paleoenvironmental conditions such as anoxic hypersaline bottom waters and deposition of laminated limestones. However, the same does not apply to the preservation of insects, specifically mayflies, which are poorly preserved in the Solnhofen limestones.

Abstract Organisms can respond to environmental gradients from local to landscape features. Aquatic insects are particularly affected by watershed peculiarities due to their dependence on microhabitat conditions. However, these relationships are poorly understood in lotic ecosystems of subtropical grasslands, limiting water resources management and bioassessment proposals. Here, we investigated how local stream environment and variations in landscape types affect the assemblage structure of a bioindicator insect group, face to the spatial proximity of the sampled locations. We sampled immatures of Ephemeroptera, Plecoptera, and Trichoptera in streams along the Brazilian Pampa biome, recording environmental descriptors in different grassland ecosystem types. The structure of aquatic insect assemblages differed across grassland types, with specific dominant genera associated with each landscape. Spatially-structured water physicochemical descriptors explained a significant amount of variation in assemblage data. Our findings suggest that grassland ecosystem type delimitations capture ecological attributes, influencing watershed features important to EPT assemblage structuration. Moreover, we highlight the importance of niche-based process structuring EPT assemblages along grassland ecosystem types of Pampa biome. In addition, we encourage using aquatic insects in bioassessment of lotic waters to assess local and landscape environmental impacts. We strongly recommend considering the grassland ecosystem schedule for water resources management and bioassessment proposals.

We report first record for the mayfly species Waynokiops dentatogriphus Hill, Pfeiffer & Jacobus 2010 from a wadeable stream in Missouri based on aquatic macroinvertebrate community samples collected during September 2021 from a reach of the Meramec River in Dent County in the Ozark Highlands Ecological Section of the state. Select physical and water quality characteristics from the reach are also provided. [ABSTRACT FROM AUTHOR]

Temperature is a key factor that shapes the distribution of organisms. Having knowledge about how species respond to temperature is relevant to devise strategies for addressing the impacts of climate change. Aquatic insects are particularly vulnerable to climate change, yet there is still much to learn about their ecology and distribution. In the Yungas ecoregion of Northwestern Argentina, cold- and warm-adapted species of the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT) are segregated by elevation. We modeled the ecological niche of South American EPT species in this region using available data and projected their potential distribution in geographic space. Species were grouped based on their ecogeographic similarity, and we analyzed their replacement pattern along elevation gradients, focusing on the ecotone where opposing thermal preferences converge. Along this interface, we identified critical points where the combined incidence of cold and warm assemblages maximizes, indicating a significant transition zone. We found that the Montane Cloud Forest holds the interface, with a particularly greater suitability at its lower boundary. The main axis of the interface runs in a N-S direction and falls between 14°C–16°C mean annual isotherms. The probability of a particular location within a basin being classified as part of the interface increases as Kira's warmth index approaches a score around 150. Understanding the interface is critical for defining the thermal limits of species distribution and designing biomonitoring programs. Changes in the location of thermal constants related to mountainous ecotones may cause vertical displacement of aquatic insects and vegetation communities. We have recognized significant temperature thresholds that serve as indicators of suitability for the interface. As global warming is anticipated to shift these indicators, we suggest using them to monitor the imprints of climate change on mountain ecosystems. [ABSTRACT FROM AUTHOR]

The key points of the main evolutionary line of Articulata, leading from polychaetes to insects, are considered. The far-reaching similarity of the most primitive insects, jumping bristletails, with malacostracans, especially syncarids, leaves no doubt about the origin of the former directly from the latter. The similarity of mayfly nymphs to bristletails indicates that the evolution of Pterygota began with amphibiotic Palaeoptera. Myriapods are secondarily simplified descendants of early hexapods, having lost the division of the body into the thorax and abdomen and other ancestral characters due to transition to a cryptic lifestyle. Entognathous hexapods illustrate the initial stages of myriapodization of bristletails. Following Sharov, insect ancestry can be traced back into deep time via crustaceans to trilobitomorphs, Megacheira, and further to the most ancient arthropods, dinocarids—with grasping antennae but without walking legs! Many structural features of arthropods were formed in Polychaeta—the most primitive Articulata. The group most similar to arthropods are scale worms (Aphroditacea). By analogy with myriapods and entognaths, lobopods and non-arthropodan Ecdysozoa should be interpreted as side branches, which emerged from the dinocarid root of Arthropoda and simplified their body plans. Transformations of body plans occurred through heterochronies and heterotopies (including gamoheterotopies). [ABSTRACT FROM AUTHOR]

In temperate and tropical rivers, macroinvertebrates are commonly utilised for biological monitoring. Therefore, it is important to understand their functional feeding guilds and assemblage structure. However, there have been few studies in high‐altitude rivers in East Africa aimed at assessing macroinvertebrate functional guilds. In this study, we examined the macroinvertebrate assemblage characteristics using abundance/diversity metrics and the functional feeding groups (FFGs). We collected physicochemical data and macroinvertebrate samples at seven sites along the Gura River and three sites on the Sagana River. Dissolved oxygen concentration, water temperature, electrical conductivity, pH, turbidity, ammonia, and soluble reactive phosphorus showed significant differences among the sites (p < 0.05). A total of 32 families belonging to 11 orders of macroinvertebrates were collected during the study period. Overall, scrapers were the most abundant FFG, dominated by Heptageniidae (Afronurus). Collector filters and collector gatherers were the second most abundant, while shredders and predators exhibited the least relative abundance. Across all the dominant orders, macroinvertebrate abundance decreased from upstream to downstream sites, with upstream sites exhibiting high diversity and abundance of Ephemeroptera, Diptera, Coleoptera, and Trichoptera taxa. Furthermore, the FFGs in this study differed widely from the River Continuum Concept predictions. Our findings provide crucial understanding of macroinvertebrate assemblage characteristics in high‐altitude rivers. Thus, this study provides additional evidence on the high abundance and diversity of Ephemeroptera and Trichoptera taxa in tropical rivers. [ABSTRACT FROM AUTHOR]

Abstract: Aim Macroinvertebrates are extensively employed as bioindicators for evaluating how stream ecosystems respond to alterations in physical and chemical habitats caused by human activity. Although family-taxonomic level is usually used to identify macroinvertebrates in biomonitoring programs, coarser taxonomic resolution may provide similar information. We aim to evaluate taxonomic sufficiency by comparing macroinvertebrate communities at the order and family levels to differentiate the effects of different land uses. Methods We conducted colonization experiments using artificial substrates in streams representing three land use types: urban (U, n=3), intensive agriculture - dairy production (AD, n=4), and extensive cattle ranching (CR, n=4). Results We obtained similar results using both taxonomic levels, which effectively distinguished the impacts of different land uses. In the sites examined, the majority of indicator groups exhibited only one family per order, with the exception of Ephemeroptera (Leptophlebiidae, Baetidae, and Caenidae). Notably, Baetidae and Caenidae were more prevalent in streams associated with extensive cattle ranching (CR). Conclusions Although this study provides a clear precedent, further investigation of these systems and other land uses (e.g., afforestation) is needed to validate this pattern. Coarser taxonomic assessment holds potential as a cost-effective method for stream monitoring and assessment in Uruguay.

Mountain freshwater communities are generally considered sensible to accelerated climatic changes, though their vulnerabilities have not been well evaluated. Individual species or species groups are expected to respond differently depending on their adaptations, traits, or distributions, but this has not yet been distinguished. This work used available climate change vulnerability scores (ccvs) of European Ephemeroptera, Plecoptera, and Trichoptera (EPT) species (n = 1,402) to (1) compare the vulnerability between species pools of different ecoregions including alpine species and alpine endemics, (2) contrast the vulnerability between the different insect orders, and (3) assess the altitude–vulnerability relationship within the European Alps. We revealed fifty alpine Plecoptera and Trichoptera species that are categorized highly vulnerable to climate change effects (= 31 percent of all highly vulnerable European species) with the highest proportions in species inventories of alpine endemics and high-altitude waters (51 percent of high-altitude species are classified as highly vulnerable). The ccvs analysis specifically for mountain waters shows that a disproportionately high number of alpine species, and particularly alpine endemics, will be affected by climate change and suggests that Ephemeroptera may be better prepared than Plecoptera and Trichoptera. Thus, this trait-based evaluation suggests that mountain stream invertebrate communities are undergoing disproportionate restructurings in response to climate change effects more than lowland communities are.

We present a genome assembly from an individual male Siphlonurus alternatus (the Northern Summer Mayfly; Arthropoda; Insecta; Ephemeroptera; Siphlonuridae). The genome sequence is 455.8 megabases in span. Most of the assembly is scaffolded into 11 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has also been assembled and is 19.36 kilobases in length.

We present a genome assembly from an individual female Ecdyonurus torrentis (the Large Brook Dun; Arthropoda; Insecta; Ephemeroptera; Heptageniidae). The genome sequence is 503.2 megabases in span. Most of the assembly is scaffolded into 11 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has also been assembled and is 15.69 kilobases in length.

Abstract Aim The present study investigated the influence of environmental variables on macrobenthic fauna in the Achenkovil River, Southern Western Ghats, Kerala. The knowledge of aquatic ecosystems in many remote areas is very scanty and no one has yet made an attempt to study the macrobenthic fauna of Achenkovil river. Since, macrobenthos play an important role in the benthic community structure a better knowledge of their ecology and distributional patterns in remote freshwater ecosystems would be of great interest for a better understanding of their functioning. Methods A bimonthly sampling was conducted from February 2019 to January 2020. Water samples for physicochemical analysis were carried to the laboratory in clean polyethylene bottles. The macrobenthic fauna was collected using Van Veen grab (0.025m2). Multivariate statistical technique such as Principal Component Analysis was used to monitor the variation in environmental parameters. The diversity of macrobenthic fauna was studied using Simpson_1-D, Shannon_H, Evenness_e^H/S, and Margalef’s indices. We analyzed the relationship between environmental variables and macrobenthic fauna, using Canonical Correlation Analysis and Pearson correlation. Results A total of 3563 individuals belonging to 9 orders, 32 families, 32 genera, and 32 species were identified. The most dominant order was Ephemeroptera followed by Coleoptera and Trichoptera and the least dominant was Zygoptera. The maximum number of macrobenthic fauna was observed in station 1(S1), (1461 Ind/m2) and the least in station 9 (S9), (37 Ind/m2). Station 1 (S1) is a pristine forest area, so this area is considered the reference site. The macrobenthic fauna in the pristine headwater forests (S1) was much more diverse than in the river mouth (S9) which is a highly impacted region. This region is facing various kinds of anthropogenic stress resulting in pollution and deterioration of water quality. The macrobenthic community structure in the Achenkovil River was significantly associated to the variations in water quality due to various natural as well as anthropogenic stresses. Conclusions It can be concluded that Ephemeroptera, Coleoptera, and Trichoptera were the most dominant groups in the undisturbed habitats in the river during the study period. The predominance of Chironomidae species, especially from the Chironomus genus in the midstream and downstream segments of the river is possibly due to their ability to adapt to various environmental conditions or habitats and their tolerance to the low oxygen content in anoxic conditions of the bottom sediment. The lowest abundance of macrobenthos at all the studied stations was observed at station 9 (S9) during dry seasons. S9 is a highly impacted region, characterized by high temperature, turbidity, TDS, pH, conductivity, nitrate, and phosphate values. For this reason, anthropogenic stress and changing environmental conditions are the main factors affecting the distribution of the macrobenthic fauna of the Achenkovil River basin, Kerala.

The main tributary of the Yamuna, the Tons River, exhibits altitudinal changes in its macroinvertebrate community's diversity, abundance, and composition. Between May 2019 and April 2021, the study was conducted in the upper section of the river. A total of 48 numbers of taxa from 34 families and ten orders were recorded during the investigation. At this elevation of 1150 to 1287 m, the two most predominant orders are Ephemeroptera (32.9%) and Trichoptera (29.5%). During the premonsoon season, they had the lowest macroinvertebrate density (250–290 individuals/m2), and the post-monsoon season had the highest density (600–640 individuals/m2). During the post-monsoon season, the maximum larval forms (60%) of various insect orders were predominant. The findings indicated that lower altitudes (1150–1232 m) have higher macroinvertebrate abundance than higher ones. The diversity of dominance is shallow at site-I (0.0738) and strong at the site-IV during the premonsoon season (0.03837). Taxa richness, as measured by the Margalef index (D), peaked in the spring season (January to March) at 6.9 and reached its lowest point (5.74) in the premonsoon season (April to May). Only 16 taxa were discovered in site-I and site-II, but 39 taxa were discovered at low altitudes (site-IV, 1100 m) (1277–1287 m). The Tons River contains a total of 12 and 13 genera, respectively, that belong to the orders Ephemeroptera and Trichoptera, according to qualitative study of the macroinvertebrates. The current study supports the use of macroinvertebrates as bioindicator species for monitoring biodiversity and assessing the health of ecosystems. [ABSTRACT FROM AUTHOR]

Aquatic insects comprise 10% of all insect diversity, can be found on every continent except Antarctica, and are key components of freshwater ecosystems. However, aquatic insect genome biology lags dramatically behind that of terrestrial insects. If genomic effort was spread evenly, one aquatic insect genome would be sequenced for every ~9 terrestrial insect genomes. Instead, ~24 terrestrial insect genomes have been sequenced for every aquatic insect genome. This discrepancy is even more dramatic if the quality of genomic resources is considered; for instance, while no aquatic insect genome has been assembled to the chromosome level, 29 terrestrial insect genomes spanning four orders have. We argue that a lack of aquatic insect genomes is not due to any underlying difficulty (e.g., small body sizes or unusually large genomes), yet it is severely hampering aquatic insect research at both fundamental and applied scales. By expanding the availability of aquatic insect genomes, we will gain key insight into insect diversification and empower future research for a globally important taxonomic group.

Throughout the humid tropics, increased land disturbance and concomitant road construction increases erosion and sediment delivery to rivers. Building road networks in developing countries is commonly a priority for international development funding based on anticipated socio-economic benefits. Yet the resulting erosion from roads, which recent studies have shown result in at least ten-fold increases in erosion rates, is not fully accounted for. While effects of road-derived sediment on aquatic ecosystems have been documented in temperate climates, little has been published on the effects of road-induced sediment on aquatic ecosystems in developing countries of the tropics. We studied periphyton biomass and macroinvertebrate communities on the deltas of Río San Juan tributaries, comparing north-bank tributaries draining undisturbed rain forest with south-bank tributaries receiving runoff from a partially-built road experiencing rapid erosion. Periphyton biomass, richness and abundance of macroinvertebrates overall, and richness and abundance of Ephemeroptera, Plecoptera and Trichoptera were higher on the north-bank tributary deltas than the south-bank tributary deltas. These findings were consistent with prior studies in temperate climates showing detrimental effects of road-derived fine sediment on aquatic organisms. A Non-Metric Multidimensional Scaling (NMDS) analysis showed the impacted community on the south-bank deltas was influenced by poorly-sorted substrate with greater proportions of fine sediment and higher water temperatures.

Human activities may influence the diversity of aquatic insects in rivers. This study aims to assess the diversity of aquatic insects and their relation with mercury levels and water quality along rivers located near the gold mine in Poboya, Central Sulawesi. The insects were collected at six locations based on human activity levels. At each site, the mercury level of water was measured using atomic absorption spectrophotometry (AAS). In addition, water temperature, acidity, dissolved oxygen, and total dissolved solids were determined. The study recorded 23 species of aquatic insects belonging to 7 orders and 14 families. Mercury levels in the rivers did not exceed the threshold except at two sites and did not affect aquatic insects’ diversity. The diversity of aquatic insects, however, tends to decrease downstream. The diversity of aquatic insects, particularly the Ephemeroptera, Plecoptera, and Trichoptera orders, tended to be higher at the higher dissolved oxygen sites.

Motivation: Aquatic insects comprise 64% of freshwater animal diversity and are widely used as bioindicators to assess water quality impairment and freshwater ecosystem health, as well as to test ecological hypotheses. Despite their importance, a comprehensive, global database of aquatic insect occurrences for mapping freshwater biodiversity in macroecological studies and applied freshwater research is missing. We aim to fill this gap and present the Global EPTO Database, which includes worldwide geo‐referenced aquatic insect occurrence records for four major taxa groups: Ephemeroptera, Plecoptera, Trichoptera and Odonata (EPTO). Main type of variables contained: A total of 8,368,467 occurrence records globally, of which 8,319,689 (99%) are publicly available. The records are attributed to the corresponding drainage basin and sub‐catchment based on the Hydrography90m dataset and are accompanied by the elevation value, the freshwater ecoregion and the protection status of their location. Spatial location and grain: The database covers the global extent, with 86% of the observation records having coordinates with at least four decimal digits (11.1 m precision at the equator) in the World Geodetic System 1984 (WGS84) coordinate reference system. Time period and grain: Sampling years span from 1951 to 2021. Ninety‐nine percent of the records have information on the year of the observation, 95% on the year and month, while 94% have a complete date. In the case of seven sub‐datasets, exact dates can be retrieved upon communication with the data contributors. Major taxa and level of measurement: Ephemeroptera, Plecoptera, Trichoptera and Odonata, standardized at the genus taxonomic level. We provide species names for 7,727,980 (93%) records without further taxonomic verification. Software format: The entire tab‐separated value (.csv) database can be downloaded and visualized at https://glowabio.org/project/epto%5fdatabase/. Fifty individual datasets are also available at https://fred.igb‐berlin.de, while six datasets have restricted access. For the latter, we share metadata and the contact details of the authors. [ABSTRACT FROM AUTHOR]

IntroductionEcogeographical patterns in body size have been described across a wide range of vertebrate species. However, insects have shown inconsistent patterns in studies to date. Aquatic insects, particularly those from remote regions, have barely been explored.MethodsThe Magellanic sub-Antarctic ecoregion offers an ideal natural laboratory with near pristine environments, limiting the potential influence of confounding variables. In this study, we evaluated the influence of elevation on body and wing size and aspect ratio patterns for 10 species of mayfly (Ephemeroptera) and stonefly (Plecoptera) along a steep coastal elevation gradient (~0–600 m a.s.l.).ResultsWe detected significant relationships between altitude and morphological features for the studied species. Additionally, we found that in females, morphological changes were slightly more pronounced than in males, probably due to their role as dispersers. While body size showed an increase along the elevation gradient, there was a notable decrease in some species' wing length over a relatively short geographic distance.DiscussionOur data suggest that morphological plasticity might be promoted in response to the harsh environmental conditions that typify the steep coastal Magellanic sub-Antarctic mountain ranges.

Abstract Background Hox genes are key regulators of appendage development in the insect body plan. The body plan of mayfly (Ephemeroptera) nymphs differs due to the presence of abdominal appendages called gills. Despite mayflies’ phylogenetic position in Paleoptera and novel morphology amongst insects, little is known of their developmental genetics, such as the appendage-regulating Hox genes. To address this issue we present an annotated, early instar transcriptome and embryonic expression profiles for Antennapedia, Ultrabithorax, and Abdominal A proteins in the mayfly Hexagenia limbata, identify putative Hox protein sequences in the mayflies H. limbata, Cloeon dipterum, and Ephemera danica, and describe the genomic organization of the Hox gene cluster in E. danica. Results Transcriptomic sequencing of early instar H. limbata nymphs yielded a high-quality assembly of 83,795 contigs, of which 22,975 were annotated against Folsomia candida, Nilaparvata lugens, Zootermopsis nevadensis and UniRef90 protein databases. Homeodomain protein phylogeny and peptide annotations identified coding sequences for eight of the ten canonical Hox genes (excluding zerknüllt/Hox3 and fushi tarazu) in H. limbata and C. dipterum, and all ten in E. danica. Mayfly Hox protein sequences and embryonic expression patterns of Antp, Ubx, and Abd-A appear highly conserved with those seen in other non-holometabolan insects. Similarly, the genomic organization of the Hox cluster in E. danica resembles that seen in most insects. Conclusions We present evidence that mayfly Hox peptide sequences and the embryonic expression patterns for Antp, Ubx, and Abd-A are extensively conserved with other insects, as is organization of the mayfly Hox gene cluster. The protein data suggest mayfly Antp, Ubx, and Abd-A play appendage promoting and repressing roles during embryogenesis in the thorax and abdomen, respectively, as in other insects. The identified expression of eight Hox genes, including Ubx and abd-A, in early instar nymphs further indicates a post-embryonic role, possibly in gill development. These data provide a basis for H. limbata as a complementary Ephemeridae model to the growing repertoire of mayfly model species and molecular techniques.

Intermittent rivers, common in dry parts of the world, such as the Mediterranean region, are hydrologically harsh habitats characterized by periodical flow cessation. Ephemeroptera are aquatic insects common in both lotic and lentic waterbodies, where they show a high sensitivity to anthropogenic modifications of their habitat. Therefore, they are widely used as bio-indicators of the freshwater's health. However, mayfly assemblages and their ecological requirements in the karst Mediterranean intermittent habitats are still not sufficiently known. Thus, the work presented here includes an analysis of mayfly assemblages and their relationship with environmental variables in the lotic phase of four intermittent rivers in the karst Mediterranean region of Croatia. Considering that the studied intermittent rivers are hydrologically extreme environments, a total of 12 recorded mayfly species could be considered as rather high species richness. Nevertheless, species richness per river was quite low (between three and six), and was highly influenced by river morphology, physico-chemical water properties (especially conductivity, water velocity, and concentrations of dissolved oxygen), and anthropogenic pressures. Our results could contribute to the mayfly species protection in karst Mediterranean intermittent freshwater habitats in the Balkans, as well as to the development of conservation measures for those threatened habitats. [ABSTRACT FROM AUTHOR]

This study was carried out to determine the seasonal distribution of the Ephemeroptera of the Kızılırmak Basin and to evaluate the relations of the identified taxa with the physicochemical variables in their distribution areas, to reveal the ecological water quality through both these parameters and the benthic metrics developed for the Kızılırmak basin. Field studies were carried out in 13 different localities in spring, summer and autumn periods in 2018. A total of 990 individuals were examined and 27 species belonging to seven families were identified. Species diversity according to Shannon-Wiener (H) values was highest at station 8 (1.52) and lowest at station 7 (0.23) in the spring period, highest at station 3 (1.49) lowest at station 7 (0.23) in the summer period, and highest at the 2nd (1.44) and lowest at the 4th (0.14) station in the autumn period. According to the calculated average H values of the stations, the stations 4, 6, 7, 10 and 12 were determined in the polluted water class, while the other stations were determined in the moderate polluted water class. According to cluster analysis; the highest similarities were seen between the station 1 and the stations 2 and 9 (71%). According to the ANOSIM result, in which the differences between the seasonal distributions of the species were evaluated, there was a significant difference between the spring period and the summer and autumn periods. According to the result of MANOVA, which was applied to understand the differences between environmental variables and seasonal groups, there was a significant difference between spring and summer seasons in terms of temperature variable, while dissolved oxygen variable was significantly differed among all season groups. The water quality of the stations was evaluated together with the biotic index based on physico-chemical variables and benthic metrics, and the stations with reference characteristics were determined. Accordingly, in terms of both physicochemical parameter measurements and index values calculated on biological data, it was determined that the stations are mostly in reference feature (high, good and moderate quality water class) away from pollution pressure. [ABSTRACT FROM AUTHOR]

A nationally significant collection of mayflies that has been amassed and curated at Canterbury Museum, Christchurch, New Zealand is described. A project to formally catalogue the backlog of this collection was completed in 2018. This collection has been primarily worked on, added to, and curated by Terry Hitchings since the early 1990s, with his son Tim Hitchings assisting this work since the late 2000s. This paper outlines this process involved in cataloguing the collection and preparing the data for publication to online biorepositories. The dataset was published to the Atlas of Living Australia (ALA) and the Global Biodiversity Information Facility (GBIF) in late 2021. This dataset contains just under 49,000 published specimen records with high quality field collection information. It represents nearly all currently described mayfly species in New Zealand. Areas of collecting focus include most of the South Island of New Zealand, with collecting gaps in South Westland and Marlborough. There are large collecting gaps throughout the North Island of New Zealand. An overview of the trends shown in the dataset is provided. Future work is identified and recommended to enhance and improve this dataset to highlight and promote freshwater ecosystems in New Zealand. [ABSTRACT FROM AUTHOR]

Mountain freshwater communities are generally considered sensible to accelerated climatic changes, though their vulnerabilities have not been well evaluated. Individual species or species groups are expected to respond differently depending on their adaptations, traits, or distributions, but this has not yet been distinguished. This work used available climate change vulnerability scores (ccvs) of European Ephemeroptera, Plecoptera, and Trichoptera (EPT) species (n = 1,402) to (1) compare the vulnerability between species pools of different ecoregions including alpine species and alpine endemics, (2) contrast the vulnerability between the different insect orders, and (3) assess the altitude–vulnerability relationship within the European Alps. We revealed fifty alpine Plecoptera and Trichoptera species that are categorized highly vulnerable to climate change effects (= 31 percent of all highly vulnerable European species) with the highest proportions in species inventories of alpine endemics and high-altitude waters (51 percent of high-altitude species are classified as highly vulnerable). The ccvs analysis specifically for mountain waters shows that a disproportionately high number of alpine species, and particularly alpine endemics, will be affected by climate change and suggests that Ephemeroptera may be better prepared than Plecoptera and Trichoptera. Thus, this trait-based evaluation suggests that mountain stream invertebrate communities are undergoing disproportionate restructurings in response to climate change effects more than lowland communities are. [ABSTRACT FROM AUTHOR]

While there is substantial support for the river continuum concept (RCC) using aquatic macroinvertebrates, nearly all of this support has come from studies using benthic specimen counts or relative biomass as the basis for comparing sites. We instead assessed the RCC using the ash-free dry mass (AFDM) of winged adult Ephemeroptera, Plecoptera, and Trichoptera (EPT) specimens. Insects were sampled at 13 sites along a 100 km 2nd–4th order reach of the Pine River in northern Lower Michigan using ultraviolet lights. Specimens were identified to the genus level and the AFDM of each functional feeding group (FFG) was calculated. Forty-two environmental and river morphological variables were tested for their ability to predict differences in EPT FFG biomass. A determined environmental gradient relating to increasing river size predicted over 80% of FFG biomass differences. Biomass of each individual FFG increased along the determined gradient, except for scrapers which decreased at the most downstream sites. The number of EPT genera also increased along the gradient. Our results were similar to those of previous studies, except that shredders nearly doubled in importance compared to RCC predictions, suggesting a greater ecological impact of shredders on forested streams than is typically reported. [ABSTRACT FROM AUTHOR]

Data are presented on changes in the mayfly community from the small salmon Tigrovaya River under different hydrological conditions and weak anthropogenic effect. About 40 species of the order Ephemeroptera are recorded in the river. The larvae of mayflies are dominant in the benthic community on sediments with fractions of <22 cm; their abundance reaches 176–8601 ind./m2 and biomass 0.38–19.67 g/m2. Minimum values are recorded during the summer flood, the maximum abundance during the ice period, and the maximum biomass in the spring–summer low- water period. Mayfly species belonging to five ecological groups have been detected in the studied section of the Tigrovaya River. Representatives of the families Heptageniidae and Ephemerellidae, mainly of the genera Cinygmula and Drunella, play the leading role in the formation of the mayfly community throughout the year. High quantitative parameters are achieved in some cases due to the nymphs and larvae of early ages. [ABSTRACT FROM AUTHOR]

While there is substantial support for the river continuum concept (RCC) using aquatic macroinvertebrates, nearly all of this support has come from studies using benthic specimen counts or relative biomass as the basis for comparing sites. We instead assessed the RCC using the ash-free dry mass (AFDM) of winged adult Ephemeroptera, Plecoptera, and Trichoptera (EPT) specimens. Insects were sampled at 13 sites along a 100 km 2nd–4th order reach of the Pine River in northern Lower Michigan using ultraviolet lights. Specimens were identified to the genus level and the AFDM of each functional feeding group (FFG) was calculated. Forty-two environmental and river morphological variables were tested for their ability to predict differences in EPT FFG biomass. A determined environmental gradient relating to increasing river size predicted over 80% of FFG biomass differences. Biomass of each individual FFG increased along the determined gradient, except for scrapers which decreased at the most downstream sites. The number of EPT genera also increased along the gradient. Our results were similar to those of previous studies, except that shredders nearly doubled in importance compared to RCC predictions, suggesting a greater ecological impact of shredders on forested streams than is typically reported.

This study was carried out in 20 different localities in the spring, summer and autumn periods in 2019 in order to determine the Ephemeroptera fauna of the Ceyhan Basin and to reveal its relation-shipwithsomephysicochemicalparameters.Asaresult,971specimenswereexaminedand17species belonging to six families were identified. There is no data on the given taxa in the Ceyhan basin so all taxa are new records for the Ceyhan Basin. According to the Shannon-Wiener (H) diver-sityindex,thehighestandlowestdiversityvaluesweredetermined,respectively, inthespringatstations 7th (1.456) and 6th (0.173), in the summer at stations 20th (1.311) and 13th (0.341), and in the autumn at stations 15th (1.102) and 8th (0.457). According to Evenness (E) values, the most homoge-neous stations are the 3rd (0.963), 7th (0.973) and 1st (0.945) stations in the same seasonal order, and the stations with the least homogeneity are the 16th (0.529), 16th (0.659) and 8th (0.527) stations. Ac-cordingtoclusteranalyses,thehighestsimilaritieswereobservedbetweenstations3rdand5thinaddition to stations 9th,14th,17th,18th and 19th with 100% percentage. Based on the physicochemical parameters measured in accordance with the Surface Water Quality Regulation, the water quality classes of the stations were in high quality water (Class I) and less contaminated (Class II) water.Ca-nonical correspondence analysis was applied to reveal the relationships between Ephemeroptera taxa and physicochemical parameters.

A nationally significant collection of mayflies that has been amassed and curated at Canterbury Museum, Christchurch, New Zealand is described. A project to formally catalogue the backlog of this collection was completed in 2018. This collection has been primarily worked on, added to, and curated by Terry Hitchings since the early 1990s, with his son Tim Hitchings assisting this work since the late 2000s. This paper outlines this process involved in cataloguing the collection and preparing the data for publication to online biorepositories. The dataset was published to the Atlas of Living Australia (ALA) and the Global Biodiversity Information Facility (GBIF) in late 2021. This dataset contains just under 49,000 published specimen records with high quality field collection information. It represents nearly all currently described mayfly species in New Zealand. Areas of collecting focus include most of the South Island of New Zealand, with collecting gaps in South Westland and Marlborough. There are large collecting gaps throughout the North Island of New Zealand. An overview of the trends shown in the dataset is provided. Future work is identified and recommended to enhance and improve this dataset to highlight and promote freshwater ecosystems in New Zealand.

The origin of the insect odorant receptor (OR) gene family has been hypothesized to have coincided with the evolution of terrestriality in insects. Missbach et al. (2014) suggested that ORs instead evolved with an ancestral OR co-receptor (Orco) after the origin of terrestriality and the OR/Orco system is an adaptation to winged flight in insects. We investigated genomes of the Collembola, Diplura, Archaeognatha, Zygentoma, Odonata, and Ephemeroptera, and find ORs present in all insect genomes but absent from lineages predating the evolution of insects. Orco is absent only in the ancestrally wingless insect lineage Archaeognatha. Our new genome sequence of the zygentoman firebrat Thermobia domestica reveals a full OR/Orco system. We conclude that ORs evolved before winged flight, perhaps as an adaptation to terrestriality, representing a key evolutionary novelty in the ancestor of all insects, and hence a molecular synapomorphy for the Class Insecta.

Environmental factors strongly contribute to shaping the morphology of organisms. The present study mainly aims to examine how some physical factors in a habitat influence morphological variations in Baetis vernus along the Karaj River. Sampling was conducted using a kick net sampling device with a mesh size of 500 μm at 10 sampling sites (three replicates) by recording 11 environmental variables in autumn (2018) and spring (2019). The species was identified through gender classification (male and female). Graticule was used to measure 42 morphological properties of 30 (male and female) samples identified at each site. Following the statistical analysis of the data, the results showed significant changes in environmental factors such as temperature (autumn), depth (spring), and elevation (autumn and spring) (p

Background: Hox genes are key regulators of appendage development in the insect body plan. The body plan of mayfly (Ephemeroptera) nymphs differs due to the presence of abdominal appendages called gills. Despite mayflies' phylogenetic position in Paleoptera and novel morphology amongst insects, little is known of their developmental genetics, such as the appendage-regulating Hox genes. To address this issue we present an annotated, early instar transcriptome and embryonic expression profiles for Antennapedia, Ultrabithorax, and Abdominal A proteins in the mayfly Hexagenia limbata, identify putative Hox protein sequences in the mayflies H. limbata, Cloeon dipterum, and Ephemera danica, and describe the genomic organization of the Hox gene cluster in E. danica. Results: Transcriptomic sequencing of early instar H. limbata nymphs yielded a high-quality assembly of 83,795 contigs, of which 22,975 were annotated against Folsomia candida, Nilaparvata lugens, Zootermopsis nevadensis and UniRef90 protein databases. Homeodomain protein phylogeny and peptide annotations identified coding sequences for eight of the ten canonical Hox genes (excluding zerknüllt/Hox3 and fushi tarazu) in H. limbata and C. dipterum, and all ten in E. danica. Mayfly Hox protein sequences and embryonic expression patterns of Antp, Ubx, and Abd-A appear highly conserved with those seen in other non-holometabolan insects. Similarly, the genomic organization of the Hox cluster in E. danica resembles that seen in most insects. Conclusions: We present evidence that mayfly Hox peptide sequences and the embryonic expression patterns for Antp, Ubx, and Abd-A are extensively conserved with other insects, as is organization of the mayfly Hox gene cluster. The protein data suggest mayfly Antp, Ubx, and Abd-A play appendage promoting and repressing roles during embryogenesis in the thorax and abdomen, respectively, as in other insects. The identified expression of eight Hox genes, including Ubx and abd-A, in early instar nymphs further indicates a post-embryonic role, possibly in gill development. These data provide a basis for H. limbata as a complementary Ephemeridae model to the growing repertoire of mayfly model species and molecular techniques. [ABSTRACT FROM AUTHOR]

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In the aquatic insects, mayfly nymphs have developed a remarkable diversity of life strategies and feeding habits. However, the early evolution of these strategies and the role of mayfly nymphs in freshwater palaeoecosystems remain largely unknown. We investigated fossil mayfly nymphs from the Grès à Voltzia Formation from the Middle Triassic, France, which represents the oldest known outcrop yielding a diverse mayfly fauna. We focused on three species, namely Mesoplectopteron longipes, Vogesonympha ludovici and Triassoephemera punctata, and investigated both original type material and numerous previously unstudied specimens. As a result, we provide a new interpretation of their morphology, life histories, and systematics: the nymphs of M. longipes, V. ludovici and T. punctata were aquatic and at least the former two species undoubtedly lived in flowing water as passive filter‐feeders. This finding represents the so far earliest occurrence of this feeding strategy in aquatic insects. The most obvious morphological adaptations to this lifestyle are long filtering setae arranged in rows on forelegs, analogous to some modern mayfly nymphs. We place the three investigated species M. longipes, V. ludovici and T. punctata in a newly established, unranked higher taxon, Sinebranchia, representing the sister group to Heptabranchia (Coxoplectoptera + Ephemeroptera). Sinebranchia share a single‐segmented tarsus synapomorphic with Heptabranchia, but retain the plesiomorphic condition of double tarsal claws. Sinebranchia are also characterized by their autapomorphic lack of tracheal gills, probably connected to their life in flowing, well‐oxygenated water. [ABSTRACT FROM AUTHOR]

New methods are required for biomonitoring of poorly known tropical ecosystems, but biological assessments of environmental status are limited by insufficient information on taxonomy, composition and ecology of local communities. The current work applies DNA‐based assessment to establish the impact of various types of anthropogenic disturbances on the freshwater macroinvertebrates in an understudied biodiversity hotspot in South Asia, an area that attracts increasing attention for the loss of aquatic ecosystems.We sampled 16 river systems in the Chittagong Hill Tracts region of Bangladesh and characterised habitat intactness based on a set of 14 environmental parameters associated with habitat quality and human activities. Whole‐community metabarcoding was used to investigate the distribution of hypothetical species‐level clusters (Operational Taxonomic Units, OTUs) across sites of different impacts.We found >900 DNA clusters of insects, decapods and molluscs, dominated by Diptera, which revealed significant variation (p < 0.001) in richness across sites. The presumed sensitive Ephemeroptera‐Plecoptera–Trichoptera (EPT) represented 15.6% of total OTU richness. The type and strength of anthropogenic stressors varied greatly across streams but did not affect total OTU diversity. In contrast, EPT richness decreased by ~50% in response to habitat degradation. Partial‐network analysis revealed 26 OTUs that may serve as potential indicators for either good or poor ecological status. Overall, our results document high diversity, local endemicity and pronounced responses to disturbance in these largely unexplored but threatened habitats.Synthesis and applications. The proposed methodology combines local habitat surveys across sites of various degrees of disturbance with species‐level metabarcoding, as a model for biological evaluation of water bodies in poorly known and inaccessible places across the world. Implemented here for the Indo‐Burmese hotspot, the approach will have great value for applied conservation management as a step towards building a biomonitoring system in this region where currently little is known about the taxonomy, diversity and endemicity in both intact and disturbed ecosystems. [ABSTRACT FROM AUTHOR]

Caenis rivulorum Eaton, 1884 is widely distributed and has been reported from a wide range in the Palearctic region.We report this species from Japan for the first time, from five locations of Hokkaido based on morphology and molecular data.

The objective of this work is to further the knowledge of gut fungi, inhabiting the digestive tract of mandibulated arthropods, traditionally the Trichomycetes (currently Kicksellomycotina), in Argentina. The geographical distribution of these endobionts, especially in aquatic insects, but also other arthropods, is updated as well as host records and site information. Fungal species (Harpellales), which mostly colonize immature stages of aquatic insects, were identified in members of Coleoptera, Diptera, Ephemeroptera, Plecoptera, and Trichoptera from different biogeographical regions, from the far North in Jujuy province to the southernmost point in Tierra del Fuego. The overall goal of this review is to consolidate all the published and unpublished records from the country in order to summarize their geographical distribution.

Based on a recent field survey in Iraqi Kurdistan and a critical evaluation of previously published data, 37 mayfly species are listed as occurring in Iraq. We collected and identified nine species as new for the country and corrected some previously published records. For several species scarcely treated in the literature, we provide information allowing their identification in the larval stage to promote the acquisition of reliable faunistic data from Iraq in the future.