Family Heptageniidae Research Articles

New Late Cretaceous (Cenomanian) fossil mayfly nymphs (Oligoneuriidae, Heptageniidae, Hexagenitidae) from the Redmond Formation, Labrador, Canada

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.

A new Cinygmula McDunnough, 1933 species with distinct imaginal frontal fold from eastern Chinese Himalaya (Ephemeroptera: Heptageniidae).

In the family Heptageniidae (Ephemeroptera), Cinygmula hutchinsoni (Traver, 1939) from central Asia is the only species known to possess pointed claws and a distinct frontal fold. Here, a second similar species with the same combination of characters is described. Cinygmula longissima sp. nov. is found in the eastern Himalaya of China, shows stouter imaginal penes, darker wingbases, and narrower nymphal gills than the previous one. This discovery indicates that this species of Heptageniidae are not limited to central Asia but live in high-altitude alpine habitats.

Description of Some Aquatic Insect Genera in Greater Zab River Branches, North of Iraq

Aquatic insects samples were collected from 6 sites along the Greater Zab River in the northern Iraq from Duhok and Erbil governorates over 12 months during September 2016 to August2017, which belong to seven orders (Ephemeroptera, Plecoptera, Trichoptera, Odonatan, Diptera, Coleoptera, and Megaloptera). Clustering mitochondrial DNA cytochrome c oxidase and 16S rDNA genes, morphological keys, and matches in the Barcode of Life Database, we identified 24 species return to 7 orders and 12 families, as indicated in the results. The reported species were: Ephemeroptera 5 members of the family Heptageniidae (Maccaffertium meririvulanum, Raptoheptagenia cruentata, Ecdyonurus dispar, Anepeorus rusticus, Stenonema femoratum), 1 Ephemerellidae (Seratella ignita), 1 Arthropleidae (Arthroplea bipunctata), 6 Baetidae (Baetis alpinus, Baetis braaschi, Baetis noa, Baetis harrisoni, Iswaeon anoka, Heterocloeon amplum), 1 member for each of Diptera, Coleoptera, Megaloptera and Odonatan orders, while Plecoptera 2 members Leuctridae (Leuctra hippopoides, Leuctra inermis) and Tricoptera 4 members 3 Hydropsychidae (Leptonema albovirens, Hydropsyche simulans, Arctopsyche irrorate), 1 Hydroptilidae (Ochrotrichia tenuata). Most of these recorded species and genera were mentioned for the first time and represent new records in Iraq. Presence and distribution of identified species varied between studied sites, as a result of differences in biogeographical and physical conditions.

The First Described Nymphs and Detailed Imagoes of the Species Thalerosphyrus cingulatus Navás Revealing a New Mayfly Genus from Eastern China (Ephemeroptera: Heptageniidae, Ecdyonurinae).

Simple SummaryThe reduction or loss of crossveins on colorful wings can be found in several lineages of mayflies, especially those with small to tiny bodies. However, in the family Heptageniidae, whose nymphs have very flat bodies and usually crawl on the surface of rocks to pebbles, this situation is very rare. Surprisingly, about 90 years ago, a Spanish entomologist Longinos Navás briefly described and illustrated a Chinese mayfly, Thalerosphyrus cingulatus, with few crossvein rows which is further heavily pigmented with yellowish to brown stains. Unfortunately, this interesting species and its outstanding morphology have never been re-checked or confirmed until now. In 2021, tens of specimens of this mayfly were re-found and its mating flight behavior was recorded. Therefore, the original characters of this species are re-described and photographed in detail. The results show both its imagoes and nymphs have a long series of combined characteristics of several related genera, and it represents a new clade and owns a new phylogenetic position of the subfamily Ecdyonurinae. To reflect its uniqueness, a new genus, Regulaneuria Zhou, gen. nov., is established herein. The similar venations are found in several families of the order Ephemeroptera. This means the reduction of crossveins can happen repeatedly and convergently in mayflies but our finding here is the extreme one of the family Heptageniidae.The nymph and detailed imaginal morphology of the Chinese mayfly Thalerosphyrus cingulatus have not been reported since it was named by Navás in 1933. Here based on newly collected nymphal and associated imaginal materials of this species from eastern China, we find both nymphs and adults have several extraordinary characters. In adults, forewings have less crossveins in costal and subcostal sections, others crossveins arranged into five regular rows; tibiae and tarsi of midlegs and hindlegs subequal in length; male compound eyes widely separated and penes simple and fused. The nymphs have greatly extended lateral pronotum, round supracoxal spurs and extended dorsal lamellae of gills, especially those of the gills VII; maxillae have two independent distal dentisetae. These combined characters represent a new generic taxon. Therefore, Regulaneuria Zhou, gen. nov. is established here to include the species Regulaneuria cingulata (Navás, 1933) comb. nov. The forewing venation of the species R. cingulata is unique in the family Heptageniidae but similar to some counterparts of Leptophlebiidae and Baetidae.

Morphological and Molecular Identification of Three Genera of the Family Heptageniidae (Ephemeroptera) from Ava Sheen Branch/ Greater Zab Tributary, North of Iraq

The aquatic Heptageniidae family of Ava-sheen branch (Greater Zab Tributary) in Duhok Governorate/ Iraq was studied. Samples were collected using Surber stream sampler to study their diagnostic morphological characteristics and molecular phylogenetic profile using a nuclear gene 16s ribosomal RNA. The morphological and molecular identification supported that the three species, Epeorus longimanus, Heptagenia elegantula and Ephemerella cornutus belong to Heptageniidae family, while the molecular results also confirmed the monophyletic origin of these three genera.

The mitochondrial genomes of palaeopteran insects and insights into the early insect relationships

Phylogenetic relationships of basal insects remain a matter of discussion. In particular, the relationships among Ephemeroptera, Odonata and Neoptera are the focus of debate. In this study, we used a next-generation sequencing approach to reconstruct new mitochondrial genomes (mitogenomes) from 18 species of basal insects, including six representatives of Ephemeroptera and 11 of Odonata, plus one species belonging to Zygentoma. We then compared the structures of the newly sequenced mitogenomes. A tRNA gene cluster of IMQM was found in three ephemeropteran species, which may serve as a potential synapomorphy for the family Heptageniidae. Combined with published insect mitogenome sequences, we constructed a data matrix with all 37 mitochondrial genes of 85 taxa, which had a sampling concentrating on the palaeopteran lineages. Phylogenetic analyses were performed based on various data coding schemes, using maximum likelihood and Bayesian inferences under different models of sequence evolution. Our results generally recovered Zygentoma as a monophyletic group, which formed a sister group to Pterygota. This confirmed the relatively primitive position of Zygentoma to Ephemeroptera, Odonata and Neoptera. Analyses using site-heterogeneous CAT-GTR model strongly supported the Palaeoptera clade, with the monophyletic Ephemeroptera being sister to the monophyletic Odonata. In addition, a sister group relationship between Palaeoptera and Neoptera was supported by the current mitogenomic data.

<strong>Deciphering genital anatomy of rare, delicate and precious specimens: first study of two type specimens of mayflies using micro-computed X-ray tomography (Ephemeroptera; Heptageniidae)</strong>

The use of non-invasive techniques to study a wide array of zoological specimens has been increasing considerably during the 21st century. Among these techniques, micro-computed X-ray tomography (μ-CT) is gaining much attention. This method may allow access to hardly visible and internal structures of valuable specimens (e.g. type specimens) through virtual dissections. We studied two type specimens of Ephemeroptera belonging to the family Heptageniidae using μ-CT; the male lectotype of Epeorella borneonia Ulmer, 1939 (pinned specimen) and the male holotype of Rhithrogeniella ornata Ulmer, 1939 (specimen in ethanol). These specimens are the only male adults known in their respective genera; hence a detailed description of their genitalia could reveal important taxonomic and phylogenetic information. We present here the first-ever μ-CT study of mayfly type specimens, and confirm that male genitalia of R. ornata lack titillators, whereas those of E. borneonia possess a pair of titillators which were concealed within the penis lobes.

Intermediate hosts of the trematode Collyriclum faba (Plagiochiida: Collyriclidae) identified by an integrated morphological and genetic approach

BackgroundThe cutaneous monostome trematode Collyriclum faba (Bremser in Schmalz, 1831) is a bird parasite with a hitherto unknown life cycle and highly focal occurrence across the Holarctic and Neotropic ecozones.MethodsRepresentative specimens of benthic organisms were sampled at multiple sites and dates within the known foci of C. faba occurrence in Slovakia. A combined approach involving detailed morphological examination and sequencing of two independent DNA loci was used for their analysis.ResultsWe elucidated the complete life cycle of C. faba, which we determined to include the aquatic gastropod mollusk Bythinella austriaca (Frauenfeld, 1857) as the first intermediate host, the mayflies of the family Heptageniidae, Ecdyonurus venosus (Fabricius, 1775) and Rhithrogena picteti Sowa, 1971 x iridina (Kolenati, 1839), as the second intermediate hosts, and birds (primarily but not exclusively passeriform birds) as the definitive hosts. Bythinella austriaca occurs focally in the springs of tributaries of the Danube in the Alpine-Carpathian region. The restricted distribution of B. austriaca explains the highly focal distribution of C. faba noticed previously in spite of the broad distribution of its second intermediate and definitive host species. Utilization of both larval and adult Ephemeroptera spp. as the second intermediate hosts explains the known spectrum of the definitive host species, with the highest prevalence in species feeding on larvae of Ephemeroptera, such as Cinclus cinclus (Linnaeus, 1758) and Motacilla cinerea Tunstall, 1771, or adults of Ephemeroptera, such as Sylvia atricapilla (Linnaeus, 1758) and Regulus regulus (Linnaeus, 1758). In this study, we also determine the prevalence and DNA sequences of other immature trematode specimens found in the examined benthic organisms (particularly the families Microphallidae, Troglotrematidae and Nanophyetidae and Euryhelmis zelleri Grabda-Kazubska, 1980, Heterophyidae), and describe cercariae of C. faba.ConclusionsWe determined the full life cycle of the Central European populations of C. faba. We speculate that other species of Bythinella and the closely related genus Amnicola may serve as first intermediate hosts in other parts of the distribution range of C. faba. Similarly, other Ephemeroptera of the family Heptageniidae may serve as the second intermediate hosts of C. faba in the Americas.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-015-0646-3) contains supplementary material, which is available to authorized users.

Distributional Patterns of Benthic Macro-invertebrate Fauna in the Glacier Fed Rivers of Indian Himalaya

Large-scale distributional pattern for the benthic macro-invertebrate fauna was determined in the glacier fed Himalayan and Trans-Himalayan rivers and streams of India at the elevation range of 2000-3000 m asl. In Trans-Himalaya the family Heptageniidae (Ephemeroptera) alone (Chandra and Bhaga) or in combination with Chironomidae (Diptera) in similar proportions (Chenab) or Diptera alone (Miyar) dominated the assemblages. Its influence seems to extend to Rupin drainage in the Himalaya where Chironomidae alone dominated the assemblages. Except for this Himalayan river. Various families of Trichoptera attained highest abundance in other rivers of the Himalaya. Thus, Leptoceridae in combination with Limnephilidae (Alaknanada at Tapovan) and Heptageniidae and Baetidae (Alaknanada at Mana) is the only instance of similarity in abundant taxa by virtue of same river. The Mandakini was partially similar to Alaknanda by virtue of abundant Limnephilidae. The Bhagirathi was characterized by abundance of Philopotamidae. Thus, assemblages exhibit greater variability in the Himalayan rivers than Trans-Himalayan rivers and are hence entirely different, as also evident from the cluster analysis. This present hypothesis is not applicable to explain the macro-invertebrate assemblages in Himalayan and Trans-Himalayan region.DOI: http://dx.doi.org/10.3126/on.v11i1.8242 Our Nature Vol.11(1) 2013: 36-44

New species of the family Heptageniidae (Ephemeroptera) from Borneo and the Philippines

Afronurus webbi sp. n. (♂), A. sarawakensis sp. n. (♂) and Epeorus boonsoongi sp. n. (larva) are described, and details and new records are provided for Atopopus tarsalis (♂, larvae), Atopopus sp. A and Thalerosphyrus sp. A (♀) from Borneo (East Malaysia). Afronurus freitagi sp. n. (♂-La), A. lantuyanensis sp. n. (♂), A. leytenensis sp. n. (♂), A. mindanaoensis sp. n. (♂) and A. panayensis sp. n. (♂) are described from the Philippines. Afronurus philippinensis Flowers & Pescador, 1984, A. sibuyanensis Mol, 1987 are reported from new localities and Asionurus sp. A for the first time from the Philippines. The taxonomic position of several controversial species like Ecdyonurus illotus Navás, 1933, Epeorella borneonia Ulmer, 1939, Thalerosphyrus torridus (Walker, 1853), T. sumatranus (Ulmer, 1939) and some zoogeographic viewpoints are discussed. Compsoneuria (Palawaneuria) cabayuganensis Braasch & Freitag, 2008 is considered as species incertae sedis. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Life cycle studies of Heptageniidae (Insecta: Ephemeroptera) in Kumbbakarai Stream of Western Ghats,Tamil Nadu, India

Life cycle studies of Epeorus sp., Afronurus kumbbakkaraiensis and Thalerosphyrus flowersi of the family Heptageniidae were conducted in the Kumbbakarai stream of Western Ghats, southern India. Epeorus sp. may have more than one univoltine brood since part of the eggs hatch in northeast monsoon period and the rest in the following summer. Life cycle of Afronurus kumbbakkaraiensis and Thalerosphyrus flowersi is basically multivoltine with asynchronous, overlapping genera. However, this study reveals the possible influence of summer in numerical reduction of Afronurus kumbbakkaraiensis and Thalerosphyrus flowersi.

Effects of insecticide exposure on feeding inhibition in mayflies and oligochaetes

The present study examined the effects of pulse exposures of the insecticide imidacloprid on the mayfly, Epeorus longinmanus Eaton (Family Heptageniidae), and on an aquatic oligochaete, Lumbriculus variegatus Miller (Family Lumbriculidae). Pulse exposures of imidacloprid are particularly relevant for examination, because this insecticide is relatively soluble (510 mg/L) and is most likely to be at effect concentrations during runoff events. Experiments examined the recovery of organisms after a 24-h pulse exposure to imidacloprid over an environmentally realistic range of concentrations (0, 0.1, 0.5, 1, 5, and 10 microg/L). Effects on feeding were measured by quantifying the algal biomass consumed by mayflies or foodstuffs egested by oligochaetes. Imidacloprid was highly toxic, with low 24-h median lethal concentrations (LC50s) in early mayfly instars (24-h LC50, 2.1 +/- 0.8 microg/L) and larger, later mayfly instars (24-h LC50, 2.1 +/- 0.5 microg/L; 96-h LC50, 0.65 +/- 0.15 microg/L). Short (24-h) pulses of imidacloprid in excess of 1 microg/L caused feeding inhibition, whereas recovery (4 d) varied, depending on the number of days after contaminant exposure. In contrast to mayflies, oligochaetes were relatively insensitive to imidacloprid during the short (24-h) pulse; however, immobility of oligochaetes was observed during a 4-d, continuous-exposure experiment, with 96-h median effective concentrations of 6.2 +/- 1.4 microg/L. Overall, imidacloprid reduced the survivorship, feeding, and egestion of mayflies and oligochaetes at concentrations greater than 0.5 but less than 10 microg/L. Inhibited feeding and egestion indicate physiological and behavioral responses to this insecticide.

Comparative morphological and Electrophoretic studies onAfronurus zebratus(Hagen, 1864) comb. n. and other European Heptageniidae (Ephemeroptera), including a key to the European genera of Heptageniidae

Specimens of Baetis fallax (Hagen, 1864) and B. zebrata (Hagen, 1864) were collected on the Island of Corsica. Imagines were obtained by breeding and were investigated morphologically and biochemically. Our results show that B. fallax belongs to the genus Electrogena Zurwerra & Tomka, 1985 (= E. pseudograndiae Zurwerra & Tomka, 1986, syn. n.), but that B. zebrata belongs to the genus Afronurus Lestage, 1924. The genus Afronurus is new to Europe. Using isoenzyme electrophoresis we could show that the genera Afronurus, Electrogena and Ecdyonurus Eaton, 1868, are mutually separated at a low level of the genetic identity index that is characteristic of the genera of this family (Zurwerra et al., 1987). A key for the larval and imaginal stages of the European genera of the family Heptageniidae is presented.

Comparative mouthpart morphology and evolution of the carnivorous heptageniidae (Ephemeroptera)1

Mouthparts of the carnivorous mayfly larvae in the family Heptageniidae are detailed and compared to each otheras well as to generalized, non‐carnivorous heptageniid mouthparts. The three carnivorous forms are presently classified in the genera Anepeorus, Spinadis, and Pseudiron, although proper application of these names to larval stages is tentative. Autapomorphies in each of the carnivores are numerous. General loss of setae and development of impaling structures are not used as phyletic data since they are subject to convergence in carnivores in general; however, synapomorphies involving maxillary crown spinal plates, the superlinguae, and labial palpi suggest a common carnivorous ancestor for the group and strongly suggest that Spinadis and Pseudiron are sister groups. General facies support this. Behavioral studies indicate that, contrary to previous reports and drawings, the legs of live Pseudiron larvae orient forward and the femoral setal row is posterior, just as in other heptageniids.

Predator‐Prey Interactions between Stoneflies and Mayflies: Behavioral Observations

Field experiments were conducted at two streams to determine the mechanisms by which mayfly prey detect and avoid stonefly predators, and to quantify the effect of stonefly predators upon mayfly behavior, distribution, and activity levels. Direct observations of the interactions between stoneflies and mayflies were made at Otter Creek, Sauk County, Wisconsin, USA and the East River, Gunnison County, Colorado, USA using plexiglass boxes with screen ends and an artificial substrate. Ephemerella subvaria and Stenonema fuscum, Otter Creek, avoided the stonefly predator Acroneuria lycorias given only noncontact chemical stimuli. Ephemerella infrequens and Baetis bicaudatus, East River, Responded to long—range chemical stimuli from Megarcys signata and Kogotus modestus, East River. Baetis phoebus and Heptagenia hebe, Otter Creek, and Cinygmula sp., East River, did not respond to stonefly predators given long—range chemical cues along. Differences among responses of different mayflies may be due to differential predation pressure or effectiveness of predator evasion tactics. None of the species of mayflies tested responded to the presence of stonefly predators given only visual stimuli. The Ephemerella species assumed a "scorpion"—like display posture upon encounter with the stoneflies. This posture may increase the apparent size of the mayflies which are then rejected by the tactile predators. The Baetis species characteristically swam or drifted in response to contact with the stonefly predators. Predator evasion could partially explain the high incidence of this genus of mayflies reported in stream drift. The remaining mayflies, of the family Heptageniidae, showed an effective crawling evasion upon contact with stonefly predators. Ephemerella infrequens and B. bicaudatus differentially responded to contact with three different stonefly predators in the East River. Both species of mayflies evaded contact with Pteronarcella badia, a large omnivorous stonefly which morphologically resembles M. signata, significantly less frequently than they evaded M. signata and K. modestus upon contact. The mechanism by which this differentiation occurs could be chemotactile. Cinygmula sp. avoided all stoneflies equally regardless of size or relative threat of consumption. Tactile stimuli are probably responsible for this behavior.