Although the nymph and subimaginal genitalia of Chinese caenid species Brachoculis acutalis (Zhou, Sun, and McCafferty, ) have been reported, the imago of this species is unknown. Here the reared imagines and photographed nymphs show that this species has a long series of apomorphies and mixed characters between Brachycercinae and Caeninae. Specifically, in nymph, it has three-segmented maxillary and labial palpi, spiny robust body and triangular prosternum. In imago, it has deep brown body, wing base pigmented grey to brown, two independent intercalaries between CuA and CuP, vestigial projections of terga III-IX, forceps with flat base but tapered apex and egg without cap. These features show this species may represent the prototype of the Caenidae.
A new species of the genus Acroneuria Pictet, 1841 of the tribe Acroneuriini, namely Acroneuria lashihaiensis sp. n., is described and illustrated from Yunnan Province of China. Morphological differences between the new species and known congeners are indicated. A key of Acroneuria is provided for males of the 19 known Asian species.http://zoobank.org/urn:lsid:zoobank.org:pub:1DD2532C-9C6B-4469-BD3A-27A69A8DC684
Our study provides new records and a holistic view on distribution and habitats of Prosopistoma pennigerum (M & uuml;ller, 1785) and P. cf. pennigerum in the European part of Russia. In this region, according to the literature data, P. pennigerum has been reported from Tverskaya Oblast' and the Republic of North Ossetia-Alania. Between 2006 and 2022 the authors collected about 3390 macrozoobenthos samples from the European part of Russia, and the genus Prosopistoma Latreille, 1833 was found in less than 0.5% of the samples, which reflects the scarcity of this mayfly. Herein, we publish first records of P. pennigerum from Smolenskaya Oblast' (Western Dvina) and of P. cf. pennigerum from Krasnodarskiy Kray and Republic of Adygea based on the material from the Kuban' River basin. Further, we provide additional records of P. pennigerum from Tverskaya Oblast' (Volga River). Therefore, at present in the European part of Russia, the genus Prosopistoma is known from catchments of the Caspian Sea (Volga, Terek), the Baltic Sea (Western Dvina) and the Azov Sea (Kuban'). The problems of species identification of the material collected in Southern Russia are briefly discussed.
A new stonefly species, Neoperla tumidospina sp. n., is described from the Guangxi Zhuang Autonomous Region in southern China, placed in the subgenus Neoperla (Formosita), and compared to similar taxa. Neoperla (F.) diehli Sivec, 1985 is recorded from Guangxi for the first time. Neoperla (F.) furcostyla Li and Qin, 2013, described from the Mt. Damingshan, Guangxi, is rediscovered in its type locality 13 years after its description. Colour photographs are provided for these species, as well as data on their habitat areas and distributions.http://zoobank.org/urn:lsid:zoobank.org:pub:DAFC8C5C-1732-4A51-94E9-A7A909315C4E
The movement of organisms within river ecosystems has been understood mainly in terms of three dimensions: longitudinal, lateral, and vertical within the water column. However, little is known about the vertical extent of the aerosphere, which is utilised by adult aquatic insects. In this study, vertical adhesive traps were installed on a 59 m-high bridge spanning a mountain stream to investigate a community consisting of adult mayflies, stoneflies, and caddisflies that utilised the aerial zone directly above the river. The results showed that a single female Stenopsyche marmorata Nav & aacute;s, 1920 was captured at a height of 55 m, however, adult insects were concentrated within the zone up to 25 m above the water surface. These observations make a significant contribution to knowledge regarding the flight altitude of adult Ephemeroptera, Plecoptera, and Trichoptera in river ecosystems. Our findings thus indicate that the functional boundaries of river ecosystems can extend to aerosphere. Our article aims to provide new perspectives for re-evaluating conservation strategies for riverine ecosystems, including in relation to the dispersal ecology of aquatic insects and the fragmentation of 'aerial corridors' by artificial structures such as dams.
The drumming duet (=exchange) of Capnia vidua collarti Aubert, 1950 is described from central France populations. The male and female produce grouped call and answer (exchange) signal patterns. However, although less likely, the possibility that the female answer was a repeated monophasic signal cannot be completely ruled out. The number of male call groups ranges from three to 32 (mean 11), with groups containing two beats (exceptionally one or three), and the female answer is composed of two to seven (mean 3.9) groups always containing two beats. Female answer can overlap partially the male call during the duet or can be produced after the end of the male call. Their grouped exchange pattern is similar to that of Capnia atra Morton, 1896, the only Capnia species whose vibrational signal has been described in Europe. The two species exchanges differ with female C. atra answers never overlapping the male call and the male intergroup intervals being evenly spaced. In this study, the C. vidua collarti vibrational signal is also compared to those of other European Capniidae species.
Fieldwork conducted in 2023 at Zerrouka Lake, Middle Atlas, Morocco, revealed Tinodes specimens distinct from T. waeneri Linnaeus, 1758, justifying the designation of a new subspecies: Tinodes waeneri zerroukensis Ibrahimi, Mabrouki, and Taybi, ssp. n. The new subspecies is characterised by the broad and bifid dorsal and intermediate branches of the paraproctal process, and the acuminate ventral process of the basal plate. With the new subspecies, the genus Tinodes Curtis, 1834 now numbers nine species and one subspecies in Morocco.
The genus Rhyacobates Esaki, 1923 has so far been reported from India based only on larvae identified to genus level. This study reports Rhyacobates malaisei Andersen and Chen, 1995 for the first time from India, based on the adult specimens from the Palmajua and Teesta Rivers, West Bengal. A detailed morphological description, including morphometric data, and illustrations of male genitalia is provided.
Here, we present the first record of the water beetle Lachnodacnum saundersi Orchymont, 1937 from the state of Sergipe, Northeast Region, Brazil. The species is rediscovered almost a century after its description in epiphytic bromelias distributed on the Sao Crist & oacute;vao Campus of the Federal University of Sergipe. Lachnodacnum saundersi can be distinguished from its congener L. luederwaldti Orchymont, 1937 by external morphology, mainly the dorsal sculpture and shape of the preepisternal plate and aedeagus. We also provide illustrations of the species habitat and a map of the sampling site. These findings contribute to our understanding of the fauna associated with bromeliad habitats, their interactions, and their importance in maintaining the biodiversity.
In this study, we characterised the relative growth of Campylocia burmeisteri (Hagen, 1888) nymphs. We analysed 70 multiple-sized specimens sampled in the Intervales State Park streams, Sao Paulo State, Brazil. Nymph relative growth was assessed by multivariate morphometric analysis. The Jolicoeur multivariate allometric coefficient revealed that: (1) overall head structures had negative allometry, except for the eyes and mandible tusks; (2) the pronotum also had negative allometry, while mesothorax length and wing pads had positive allometry; (3) the forelegs had positive allometry to length, while hind legs tended to isometry; and (4) the abdomen allometry was also positive. These morphological adjustments observed during nymph ontogeny may be associated with increased feeding efficiency, habitat use, and preparation for adult life.
While use of the emergent adult stage of aquatic insects as stream bioindicators has lagged well behind that of the benthic stage, adult insects of large and diverse taxa such as Trichoptera have great potential for indicating stream conditions. To explore their associations with stream variables, nearly 500,000 adult caddisfly specimens were collected from 798 ultraviolet blacklight samples throughout the northcentral United States. From an original pool of 11 stream characteristic variables, a non-metric multidimensional scaling ordination determined four that were strongly associated with adult caddisfly assemblages: (1) mean summer stream temperature, (2) stream gradient, (3) base flow as a percentage of total flow, and (4) percentage of intact upstream terrestrial habitat. Association values for 209 common species, 60 common genera, and 17 common families from the region are herein presented based on weighted mean specimen abundance and coefficient of variation for each of the four determined variables. While validation of these presented association values using other datasets is necessary to confirm their general utility, this work represents a first step in using adult caddisflies to indicate both natural and anthropogenic stream conditions.
New data on the distribution of 40 species of Dytiscidae are provided. Most of these records are from the Balkan Peninsula (Bulgaria, Greece, Montenegro, North Macedonia and Romania), northern Africa (Algeria and Libya), the Caucasus Region (Armenia, Azerbaijan and the South European Territory of Russia), Central Asia (Kyrgyzstan, Tajikistan and Uzbekistan) and the Himalaya Region (Bhutan, northern India and Nepal). Two species, Hygrotus rufus (Clark, 1863) and Copelatus bacchusi Wewalka, 1981, known previously only from the Palearctic, are reported for the first time from the Oriental Region. Eight species are reported for the first time from Bhutan. Seven of these species, including three species new for the Palearctic Region, were provided by the insect dealer Jingke Li, but the provenance of the specimens is regarded as questionable. The necessity of publishing new records before accepting them for catalogues, e.g., the Catalogue of Palearctic Dytiscidae, is emphasised. Finally, previously published records of four incorrectly identified species/subspecies are corrected.
Ametropus fragilis Albarda, 1878 is widely distributed in the Holarctic Region and recorded from only a few sites in Croatia. Given the considerable gaps in knowledge about its ecology and genetic diversity, this study analyses its distribution, (micro)habitat preferences, and genetic variation in Croatia. Our results showed that the species occurs in two large lowland rivers in Croatia, preferring microhabitats with fine sediments (such as sand and particulate organic matter) which is in accordance with its known habitat preferences. The COI sequences of A. fragilis from Croatia grouped within the same genetic cluster as the A. fragilis sequence from Slovakia. Despite the low genetic distances within this cluster, each specimen possesses a distinct haplotype. Our findings highlight the high conservation value of large European lowland rivers, which play an essential role in preserving endangered species, such as A. fragilis.
This paper presents a catalogue of Corixidae (water boatmen) and Micronectidae (pygmy water boatmen) species of Iran based on a review of the available literature, study of the museum collections, and recently collected material. The Iranian fauna of Corixidae comprises two subfamilies, seven genera, five subgenera, and 24 species, while the fauna of Micronectidae comprises one subfamily with one genus, three subgenera, nine species, and two subspecies. An illustrated key to the genera and species of the family Corixidae is presented. A complementary description of Sigara (Sigara) daghestanica Jansson, 1983 is provided based on material collected from Guilan Province. Three species - Sigara (Eremocorixa) marginata (Fieber, 1851), S. (Vermicorixa) scripta (Rambur, 1840), and Micronecta (Dichaetonecta) isis Horv & aacute;th, 1899 - and one subspecies - S. (Subsigara) samani samani Hoberlandt, 1952 - are excluded from the Corixoidea fauna of Iran.
Platybaetis M & uuml;ller-Liebenau, 1980 is a small genus of mayflies belonging to the family Baetidae. It is restricted to Southeast Asia and India and consists of ten species known morphologically, as no valid DNA barcoding data are available. In Thailand, two species were reported at all stages: Platybaetis bishopi M & uuml;ller-Liebenau, 1980, which spreads from the western to the southern regions of Thailand, and P. nayokensis Sutthinun, Gattolliat, and Boonsoong, 2018, which has been collected only in the central region of Thailand. Based on material collected in a long-term survey in all regions of Thailand between 2017 and 2023, we propose the first comprehensive DNA barcoding database for the genus Platybaetis in Thailand. Surprisingly, this genus appears to comprise five putative species, based on COI data. Despite being a small genus, it is widely distributed throughout the country, as are most other baetid genera. Our work highlights the need to conduct long-term surveys, particularly in Thailand, a country with high level of the biodiversity. These types of surveys not only facilitate unexpected discoveries but can also play a crucial role in monitoring environmental conditions.
Stream communities are shaped by regional-scale processes, yet the influence of regional conditions on local restoration outcomes remains underexplored. Biophysical stream restoration is a common response to environmental legislation but often reveals a disconnect between scientific understanding and policy objectives. In agricultural watersheds, physical habitat restoration ideally complements other best management practices (BMPs), including chemical and biological interventions. However, these landscapes are often heavily modified, with extensive bank erosion and riparian zone loss. In this study, physical habitat restoration was prioritised due to the absence of water quality guideline exceedances and in anticipation of ongoing BMP implementation. It had two main objectives: (1) to assess long-term trends in regional water quality and benthic macroinvertebrate communities across 14 sites in seven streams spanning a gradient of agricultural disturbance, evaluating the ecological integrity surrounding a previously degraded, restored reach; and (2) to use this regional dataset to evaluate restoration outcomes in Ridge Brook - a heavily impacted watershed restored in 2007 to support endangered and culturally significant fish habitat. Findings highlight the limitations of restoration in the absence of broader regional contexts, offering insights to guide future restoration strategies and policy alignment.
Out of the 51 known Latvian Ephemeroptera species, five mayfly species are proposed for the inclusion in the new edition of the Red Data Book of Latvia, which for the first time will be IUCN criteria based. Arthroplea congener Bengtsson, 1908 is assessed vulnerable (VU) with a low number of localities, fragmented regional population and threats from pollution. Ephoron virgo (Olivier, 1791) is also VU, reported from ten localities and threats from light pollution, eutrophication and damming of rivers. Ephemerella mucronata (Bengtsson, 1909) is assessed as endangered (EN) with a fragmented regional population and declining water quality. Eurylophella karelica Tiensuu, 1935 is assessed as near threatened (NT) facing threats from the agricultural pollution. Prosopistoma pennigerum (O.F. M & uuml;ller, 1785) is assessed as regionally extinct (RE) with the last observations from 1965 and previously known localities and habitats flooded by the hydropower plants (HPPs).
An updated checklist of Thai Ephemeroptera is presented, comprising 150 valid species belonging to 74 genera in 19 families. Knowledge of the systematics of Thailand's mayfly fauna has steadily increased over the past decade. The checklist provided herein offers comprehensive documentation of the diversity of mayflies in Thailand. The families Baetidae (38 species) and Heptageniidae (25 species) are the most diverse and common groups of Thai mayflies. Four genera (Cymbalcloeon Suttinun, Gattolliat, and Boonsoong, 2020, Mekongellina Malzacher, 2019, Sangpradubina Boonsoong and Sartori, 2016 and Thainis Malzacher, 2020) are endemics of Thailand. Since several genera and species are only known as larvae, their imagines need to be found and described. Number of the known species is still lower than the estimated species diversity, and several new species are to be discovered. The DNA barcoding library of Thai mayflies (with 62% known species) has been expanding and could be used as a driving tool for the future research on biodiversity and biomonitoring. The checklist of mayfly fauna will contribute fundamental information to taxonomy, systematics and biomonitoring programmes in Thailand.
This study provides the first checklist of Odonata species inhabiting the permanent lowland wetlands of Madurai District, South India, addressing a critical gap in regional ecological knowledge. Over a two-year period, bimonthly surveys employing both transect and visual encounter methodologies documented a total of 31 species across five families: Coenagrionidae, Libellulidae, Gomphidae, Aeshnidae, and Macromiidae. Notably, locally uncommon species such as Gynacantha dravida Lieftinck, 1960, Pseudagrion rubriceps Selys, 1876 and Trithemis aurora (Burmeister, 1839) were identified, underscoring the biodiversity richness of these wetlands. As the first Odonata checklist for the region, the findings provide crucial baseline data for future ecological assessments, emphasising the need to preserve wetland integrity to ensure odonate conservation. This study highlights the relationship between odonate diversity and external pressures such as invasive plant species, human-induced disturbances, and habitat degradation. It underscores the need for targeted conservation measures to mitigate these threats and support the long-term sustainability of odonate populations in these habitats.
The study of epizoic diatoms living on aquatic insects is an unexplored and challenging field of research, offering interesting perspectives. We analysed the epizoic diatom flora living on the exoskeleton of four sympatric genera of Ephemeroptera (Ecdyonurus Eaton, 1868; Ephemera Linnaeus, 1758; Habroleptoides Schoenemund, 1929; Baetis Leach, 1815) collected in a low order stream in North-West Italy. Epizoic diatom communities were very rich and diverse, although no obligate epibionts were observed. Fifty-one diatom species were found on the investigated Ephemeroptera. Among the most abundant: Fistulifera saprophila (Lange-Bertalot and Bonik) Lange-Bertalot, 1997 dominated the sample collected on Baetis; Navicula gregaria Donkin, 1861 was abundant on Ephemera; Cocconeis fetscheriana Stancheva, 2022 was very abundant on Ecdyonurus, while Achnanthidium minutissimum (K & uuml;tzing) Czarnecki, 1994 dominated on Habroleptoides. The taxonomic and functional differences detected in the four epizoic communities offered useful information on hosts' habits, as well as microhabitat and niche exploitation. Low profile and adnate diatoms, able to colonise fast flowing waters, were mostly present on Ecdyonurus according to the reophilous nature of this macroinvertebrate. Motile diatoms, generally closely related to fine sediments, characterised the flora living on Baetis and Ephemera. Diatom colonisation seem strictly correlated to habitat preferences of mayflies.
