Hair-like Setae Research Articles

Phyllodiaptomusparachristineae, a new species of copepod (Copepoda, Calanoida, Diaptomidae) from the floodplain of the lower Mekong River Basin in Thailand and Cambodia.

Phyllodiaptomus (Phyllodiaptomus) parachristineaesp. nov., a new diaptomid copepod, was collected from 30 sites in the lower Mekong River Basin floodplain in northeastern Thailand and nine sites in Cambodia. The new species is the 13th species of the genus to have been recorded across Asia. It has a wide range of habitats, occurring in small to large, temporary to permanent water bodies, and it can be found at any time of the year. The morphology of the new species is most similar to that of the males of P. (P.) christineae, having a comb on the antepenultimate segment on the right antennule, symmetrical caudal rami, a narrow hyaline lamella on the left P5 basis, a distal accessory spine on the right P5Exp-2, and a single-lobed Enp on the right P5. On the other hand, the males of the new species have second and third urosomites without hair-like setae on the ventral margin, a rounded distal margin of the P5 intersclerite plate, a semi-circular lamella on the right P5 basis, a strong principal lateral spine inserted at the proximal 1/3 of the right P5Exp-2, and a two-segmented left P5Enp. Morphological differences among species in the subgenus Phyllodiaptomus (Phyllodiaptomus) as well as the distribution and habitats of the 13 species and two subspecies of Phyllodiaptomus in Asia are discussed.

Synopsis of the genus Greeffiella (Nematoda: Desmoscolecida), with the description of two new species from the Sea of Japan and the Black Sea

The genus Greeffiella Cobb, 1922 includes twelve species inhabiting all oceans of the world. Updated brief and illustrated diagnoses, an identification key and data on the geographical and bathymetrical distribution of all Greeffiella species are given. Two new species are described and illustrated: G. japonica sp. nov. from the Sea of Japan and G. pontica sp. nov. from the Black Sea. The genus is recorded from the Sea of Japan for the first time, and G. japonica sp. nov. completes the list of the free-living nematode species inhabiting the shelf of the Far Eastern seas of Russia. This species is characterised by 70 annules dorsally and 62 ones ventrally, the ocelli located on the annules 19 and 29, somatic setae 11‒25 μm long, six pairs of subdorsal tubular setae on the body, the vulva surrounded by dense fine hair-like setae, located between the annulus 37 and 38, the tubular anus, and the terminal tube 10 μm long. Greeffiella pontica sp. nov. mentioned by the authors in 2021 as Greeffiella sp. was collected in the northwestern shelf of Crimea (the Black Sea) at a depth of 56 m and is characterised by the following characters: 67‒70 annules dorsally and 67‒68 ones ventrally, the absence of ocelli, somatic setae 12‒42 μm long, seven pairs of subdorsal tubular setae on the body, the vulva surrounded by short sparse setae, not visible anus, and the presence of three thin terminal tubes 13 μm long.

The Real Characters of Heptagenia ngi Hsu (1936) from China Representing a New Genus (Ephemeroptera: Heptageniidae)

A very common and early named mayfly species from China, Heptagenia ngi Hsu, 1936, has no exact descriptions of its imago nor nymph, so its generic status is not clear. Based on detailed re-descriptions and pictures of all its stages from fresh materials, it is transferred into a new genus Maculogenia Zhou, gen. nov. Its nymph has conspicuous pale-dark colored body, slightly concave posterior margin of head, scattered simple setae on ventral maxillae, spines and very fine hair-like setae on caudal filaments. Similarly, its imago also has remarkable dark stripes and dots on the pale body, small median titillators and short first segment of foretarsi, apically expanded penes without any spines. It is similar to the genera Electrogena, Thamnodontus, and Parafronurus but they can be differentiated easily by above selected key structures.

A Review of the Genus Serratella Edmunds, 1959 in China with Description of a New Species (Ephemeroptera: Ephemerellidae).

Species in the genus Serratella Edmunds, 1959 from China have never been compared and photographed systematically. Six valid Chinese Serratella species are recognized and revised in this paper. Among them, the imagos of S. brevicauda Jacobus et al., 2009 are unknown; the nymph of this species has a stout, strong body, with remarkably short caudal filaments and maxillary palpi. In contrast, only the imago stage of Serratella fusongensis (Su and You, 1988) (=Serratella longipennis Zhou et al., 1997, syn. nov.) is known; it has relatively long penes with small dorsal projections. The nymphs of S. setigera Bajkova, 1967 have small abdominal tergal spines but distinct, stout, blunt bristles on the spines, and the apexes of the male penes are round and shallowly divided. The fourth species, S. acutiformis sp. nov., which was collected from Western China, has sharp penial apexes (imagos) and large abdominal spines (nymphs). Unlike the former four species, S. ignita (Poda, 1761) and S. zapekinae Bajkova, 1967 has sub-quadrate penes without prominent dorsal projections. The nymph of S. ignita has lateral hair-like setae on the caudal filaments, while the nymph of S. zapekinae lacks such setae but has pairs of tubercles on the head and pronotum. Some characters used in the generic delineation of the genera Ephemerella Walsh, 1862 and Serratella, such as nymphal maxillary palpi and hair-like setae on caudal filaments as well as features of the imaginal penes and forelegs, are varied in Chinese species. However, all species in this paper have bifurcate ventral lamellae of gill VI. Our work highlights a need for further comparative systematic study of the genera Serratella, Ephemerella, and another related genus Torleya Lestage, 1917.

A new genus and four new species of Gyponini (Insecta: Hemiptera: Cicadellidae) with long ovipositors from Amazonas, Brazil.

A new leafhopper genus of the tribe Gyponini, Domahovana gen. nov., is proposed and described based on four newly described species from Amazonas State, Northern Brazil: Domahovana icamiabas sp. nov. (type species) and Domahovana mani sp. nov. from Reserva Biolgica do Cuieiras, Manaus and Domahovana naia sp. nov. and Domahovana yamurikuma sp. nov. from Comunidade Lago Grande no Seringal do Recreio, Rio Gregrio, Ipixuna. The new genus can be distinguished from other Gyponini mainly by the combination of the following morphological features: body medium-sized; head short with distinct foliaceous transition between crown and face; forewing with m-cu1 crossvein absent and m-cu2 crossvein basad of r-m1 crossvein for a long distance; male pygofer long and without process; subgenital plate subtriangular, ventrally covered by long hair-like setae; style long and narrow, with a ventromesal tooth; aedeagus atrium with single or paired short ventral processes, shaft short, with dorsal apodeme well developed and expanded laterally; and ovipositor extremely long, narrow and straight, with other terminalia also elongate, a unique feature among female Gyponini. A key to the four known species of Domahovana is provided.

A new species of Epeorus (Caucasiron) (Ephemeroptera, Heptageniidae) from Azerbaijan and Iran.

A new species, Epeorus (Caucasiron) hyrcanicussp. nov., is described based on larval morphology and molecular data (COI) containing sequences from all Caucasian Caucasiron species described to date. The species is distributed in the Hyrcanian forest of southeastern Azerbaijan and northwestern Iran. Based on our wide-range sampling, the new species is likely endemic to this area. The most pronounced larval morphological diagnostic characters are the coloration pattern of abdominal sterna (a pair of oblique stripes and stripe-like medio-lateral maculae) and terga (triangular medial maculae), poorly developed projection of the costal margin of gill plates III, presence of hair-like setae on the surface of abdominal terga, and relatively wide shape of gill plates VII (in natural position from ventral view). The diagnostic characters are compared to related species, and primary information to habitat is provided.

Morphometric Analysis of Coptotermes spp. Soldier Caste (Blattodea: Rhinotermitidae) in Indonesia and Evidence of Coptotermes gestroi Extreme Head-Capsule Shapes.

Simple SummaryThe morphological characteristics of the soldier caste in termites provide valuable taxonomic information at the species level. Head-shape variation in soldiers was often used as an indicative characteristic in some genera. While species with egg-shaped and waterdrop-shaped head capsule (HC), Coptotermes gestroi and C. curvignathus, respectively, are familiar in Indonesia, neither a measurement nor head index may avoid the subjectivity of shape interpretation. We conducted linear and geometric morphometrics analyses of soldiers’ HC of Coptotermes spp. obtained from various locations in Indonesia. Although subtle differences were observed, the posterior parts of the HC laterally expanded in a gradual manner in C. gestroi, C. sepangensis, and C. curvignathus in that order. Furthermore, three extreme head-shape variations of C. gestroi were found to exist in nature. Overall, we explicitly vocalized the complexity of utilizing HC morphometric measurement and shape for species determination in Coptotermes spp.Linear and geometric morphometrics approaches were conducted to analyze the head capsule (HC) shape of collected soldier caste specimens of Coptotermes from various locations in Indonesia. The soldiers’ morphology was observed and measured. The results of the principal component analysis of the group of all species showed two important groups of variables, i.e., the body size and setae characteristics of the pronotum and head. The multicollinearity of the morphometric variables showed the importance of body measurements as well as important alternative characteristics such as the pronotum setae (PrS) and HC setae. Four trends of HC shape were observed across the species. Interestingly, three extreme shapes were depicted by geometric morphometrics of the C. gestroi HC. The phylogenetic tree inferred from 12S and 16S mitochondrial gene fragments showed high confidence for C. gestroi populations. The lateral expansion of the posterior part of the HC across the species was in accordance with the increasing of the number of hairlike setae on the pronotum and HC. These differences among species might be associated with mandible-force-related defensive labor and sensitivity to environmental stressors.

A new genus of Euthyplociinae from Ecuador (Ephemeroptera: Euthyplociidae).

Three unusual nymphs of Euthyplociidae, subfamily Euthyplociinae, are described from Ecuador. A new genus and new species are established to accommodate these individuals. The morphologically unique specimens are defined by the following characters: short, stout tusks lacking spine-like setae but densely covered with long, hair-like setae; head almost as long as wide; long, quadrate clypeus with acute apicolateral projections; apex of 3rd segment of labial palp acute; apex of 3rd segment of maxillary palp acute and narrow. The hind wing is small, similar to that of Mesoplocia. An ongoing study of the phylogeny of the family recovers Dasyplocia gen. nov. as closely related to Euthyplocia and Mesoplocia.

Cryphalus eriobotryae sp. nov. (Coleoptera: Curculionidae: Scolytinae), a New Insect Pest of Loquat Eriobotrya japonica in China.

A previously unknown bark beetle species, Cryphalus eriobotryae sp. nov. Johnson, 2019 has emerged as a lethal pest of loquat (Eriobotrya japonica) in China. The description of new species has been provided. The new species is distinguished from the other Cryphalus by the weakly aciculate frons, by the antennae, with unevenly spaced procurved sutures, by the short pronotal disc, with hair-like setae, and by the widely spaced mesocoxae. The survey of plantation records from around Suzhou suggests that this beetle was introduced from another area not long before 2017. In the surveyed loquat plantation in 2018, 20–90% of trees showed signs of infestation, and 5% were killed in 2018, resulting in the death of over 1000 trees. Outbreaks of the apparently loquat-specific Cryphalus eriobotryae can be diagnosed by hundreds of cankers on the trunk, and wilted foliage. This pest is of concern as a loquat plantation pest and as a pest of fruit production and ornamental trees within Suzhou, and globally.

A new Epeorus (Caucasiron) (Ephemeroptera: Heptageniidae) species from Turkey based on molecular and morphological evidence.

Epeorus (Caucasiron) turcicus sp. nov. is described based on larvae from NE Turkey. The new species can be distinguished from other Caucasiron by a unique combination of several diagnostic characters: the presence of a rounded hypodermal medial femur spot, colouration of abdominal terga and sterna, narrow gill plate VII, fine hair-like setae on the surface of abdominal terga, and absence of postero-lateral projections on tergum X. In addition to morphological analysis, two single-locus analytical approaches are employed for delimiting the new species using COI sequences (Automatic Barcode Gap Discovery, ABGD; and General Mixed Yule Coalescent Model, GMYC). Both approaches unambiguously recognized E. (C.) turcicus sp. nov. as a distinct species. Our molecular dataset contains all Caucasiron species occurring in the Caucasus and the delimitation of individual species mostly follows the morphologically defined species. This study confirms the suitability of the GMYC approach for species delimitation within Caucasiron.

The last instar larva and pupa of Ora depressa (Coleoptera: Scirtidae), a marsh beetle with underwater pupation

Abstract In this contribution we describe and illustrate for the first time, detailed morphology and chaetotaxy of the last instar larva and the pupa of Ora depressa (Fabricius, 1801), and provide diagnostic characters and information on its biology. The last instar larva of O. depressa exhibits the characters traditionally recognized as diagnostic of the genus, i.e. the tip of the mandible obtuse, and the fourth maxillary palpomere long, almost as long as third palpomere. Ora depressa is characterized by a broadly elliptical body, which is widest at the metanotum, being brownish testaceous in color with several brown spots, having the dorsal surface mostly covered with numerous grooved scale-like setae and also several ungrooved scale-like setae, hair-like setae, club-like setae and pore-like sensilla distributed in a specific pattern, and the femur and tibiotarsus bearing a row of natatorial setae. The last instar larva of Ora depressa can be distinguished from those of the other known species of the genus by lobes of clypeolabrum being as long as wide and socket bristles with 2–6 inner teeth. The pupa of O. depressa differs from those of the other known species of the genus in the absence of pronotal horns and by the place where pupation occurs. Ora depressa pupates underwater, hanging from water’s surface with the aid of the laterally expanded pronotum which bears hydrophobic setation along the lateral margins.

Adhesion and friction in hunting spiders: The effect of contact splitting on their attachment ability

Adhesive foot pads (claw tufts) of spiders consist of hair-like setae representing a two-leveled hierarchical structure, which provides strong attachment to a wide variety of surfaces. Several previous studies on adhesive foot pads concentrated on the function of the terminal contact elements (spatulae) for adhesion and friction, whereas the role of the higher hierarchical level (setae) remained largely unknown. In the present paper, we examined the influence of both setal width and the density of the setal array on attachment and on the ability to adapt to rough substrate surfaces in three hunting spider species that differ in the configuration of the adhesive foot pads: Zoropsis spinimana (Zoropsidae), Cupiennius salei (Ctenidae) and Anyphaena accentuata (Anyphaenidae). We found that spiders with denser and smaller setal tips gained higher vertical pull-off strength (adhesion per total contacting pad area) and traction force (friction) on smooth surfaces. Traction force experiments on surfaces with different roughness revealed a strong friction reduction on substrates with a mean asperity size of 1μm. This supports previous studies that demonstrated the existence of a critical roughness that is equivalent to or smaller than the dimension of spatulae. There was no significant difference in traction forces between smooth surfaces and surfaces with asperities comparable to the dimensions of setal tips (9 and 12μm). This suggests that the setal level is less decisive for the adaptability to the substrate geometry than the spatula level, especially at small length scales of surface roughness.

Notes on the genus Navicordulia Machado & Costa, 1995 (Odonata: Anisoptera: Corduliidae s. str.): description of a new species, phylogenetic affinities and aspects of biogeography.

Based on a single male specimen, a remarkable new species of the genus Navicordulia is described from the Massif du Mitaraka in French Guiana (Tumuc-Humac Mountains). Another new species of this genus is also reported from the same locality but is not described. This is the first record of the genus from French Guiana, hitherto being unknown within a radius of more than 1000 km. Apparent rarity or absence of records is probably due to its secretive habits. Navicordulia tumucurakensis sp. nov. presents unique characters not present in other species of the genus including: almost no excavation of the anal angle, proximal sternal pilose ridge of abdominal segment 7 transformed into two large lateral oreillets disconnected from the median carina, additional distal sternal pilose ridge transformed into a medial knob, epiproct not extending beyond the distal half of the cerci, very long cerci surpassing those of described species, cerci lacking ventro-medial carina and tubercle and exhibiting a distal ventral brush of hair-like setae. It is a forest species inhabiting hilly landscapes at low altitude, unlike other closely related intertropical species which are encountered in more elevated areas above 850 m. It is most closely related to N. longistyla, a typical cerrado species from the central Brazilian plateau or possibly to N. nitens from the central south Venezuelan Guaiquinima Tepui. Based on unique derived male abdominal structures and also on the female ovipositor and related structures, the South American genus Navicordulia and the Southeast Asian/Melanesian genus Metaphya are considered current adelphotaxa. This disrupted geographic distribution could be explained by a common ancestor having had a Gondwanian dispersal until the Late Cretaceous or Paleocene.

A New, Peculiar Genus and Species of Thyretina (Erebidae: Arctiinae, Syntomini) and a Review of African Syntomini Bearing a Pointed Abdominal Tuft

The genus Tervurenia gen. nov. is designated as new and its single species T. eloumdeni spec. nov. is described from western and central Africa (Afrotropical region). The genus is separable from its closely related genera by the simultaneous occurrence in males of pectinate antenna, extremely reduced, lobate hindwings, and the tuft of elongate scales on the tip of the abdomen. The systematic position of the new genus within the tribe Syntomini is discussed on the basis of morphological characters. A key for the identification of the genera of African Thyretina bearing a pointed abdominal tuft is also provided. Wing pattern and male genitalia of the new species are depicted and a hypothesis about the function of the pointed abdomen with elongated hair-like setae is discussed.

Redescription of the larva of Gynacantha cylindrata Karsch (Insecta: Odonata: Aeshnidae).

The ultimate stadium larva of Gynacantha cylindrata Karsch, 1891 is described and illustrated based on fifteen male and female exuviae from Bundibugyo, Uganda. The larva resembles those of the few described African species of the genus but shows a denser coverage of spine-like setae on body surface and abundance of hair-like setae on mouthparts. The female gonapophyses appear to be the longest described in the genus up to now and similar to those of G. villosa, a species included in the same group of African species.

Three new species of Leptohyphes Eaton (Ephemeroptera: Leptohyphidae) from Colombia

Three new species of Leptohyphes Eaton 1882 (Ephemerotera: Leptohyphidae) are described, diagnosed and illustrated from nymphs collected in Colombia. Geographical ranges and ecological notes relating important environmental variables are given for each species. Leptohyphes andina sp. nov. is characterized by: forefemur length / maximum width 1.8-1.9, fore and hind margin of middle and hind femora with strong spines on elevated sockets, femoral surface covered by small pale spots, apex of femora with anterior margin roundly projected distally, tarsal claw only with 3-4 marginal denticles, pronotum with triangular lateral projection, hind wing pads present in female, gill formula 3/5/5/5/2, gill V with ventral extension on dorsal lamella. Leptohyphes quimbaya sp. nov. presents the following characters: body covered by hair-like setae, with paired short and blunt tubercles on abdominal terga V-IX, femora wide (forefemur length/ maximum width 1.6), fore and hind margin of femora with tiny spines, tarsal claws with 2-3 marginal denticles, pronotum with triangular (but apically blunt) lateral projection, hind wing pads present in females, gill formula 3/7/7/5/2, gill V without ventral extension on dorsal lamella. Leptohyphes calarca sp. nov. is distinguished by: pilose body, slender femora (forefemur length / maximum width 2.3), foremargin of middle and hind femora without spines, tarsal claws with 5 marginal denticles and 1 submarginal subapical denticle, pronotum strongly projected laterally, fore wingbuds blackish, hind wing pads present in females, gill formula 3/4/4/3/1, gill V with ventral extension on dorsal lamella.

Phylogenetic utility, and variability in structure and content, of complete mitochondrial genomes among genetic lineages of the Hawaiian anchialine shrimp Halocaridina rubra Holthuis 1963 (Atyidae:Decapoda)

The Atyidae are caridean shrimp possessing hair-like setae on their claws and are important contributors to ecological services in tropical and temperate fresh and brackish water ecosystems. Complete mitochondrial genomes have only been reported from five of the 449 species in the family, thus limiting understanding of mitochondrial genome evolution and the phylogenetic utility of complete mitochondrial sequences in the Atyidae. Here, comparative analyses of complete mitochondrial genomes from eight genetic lineages of Halocaridina rubra, an atyid endemic to the anchialine ecosystem of the Hawaiian Archipelago, are presented. Although gene number, order, and orientation were syntenic among genomes, three regions were identified and further quantified where conservation was substantially lower: (1) high length and sequence variability in the tRNA-Lys and tRNA-Asp intergenic region; (2) a 317-bp insertion between the NAD6 and CytB genes confined to a single lineage and representing a partial duplication of CytB; and (3) the putative control region. Phylogenetic analyses utilizing complete mitochondrial sequences provided new insights into relationships among the H. rubra genetic lineages, with the topology of one clade correlating to the geologic sequence of the islands. However, deeper nodes in the phylogeny lacked bootstrap support. Overall, our results from H. rubra suggest intra-specific mitochondrial genomic diversity could be underestimated across the Metazoa since the vast majority of complete genomes are from just a single individual of a species.

Redescription of Ecdyonurus (Ecdyonurus) russevi Braasch & Soldán, 1985 (Ephemeroptera: Heptageniidae).

This study is focussed on the redescription of Ecdyonurus (Ecdyonurus) russevi Braasch & Soldán on the basis of the type material (holotype and paratypes) and topotypes collected in the Strandzha Mts. (Bulgaria). Female imago and subimago, larva and egg of the species are described for the first time and the male imago is redescribed in detail. The features distinguishing the species from other representatives of the genus Ecdyonurus are presented. Ecdyonurus russevi differs by the combination of several characters in the colour pattern of abdominal terga and wings, colour of lateral portion of male eyes and male genitalia structure in adults; some overlap has been observed in the number of groups of setae, bristles and hair-like setae on maxillae and labial palps, shape of pronotal projection and colour of tarsi in larvae; and insignificant number of knob-terminated coiled threads on exochorion, with only a few such attachment elements on one pole in eggs. Biology and present distribution of the species are discussed.

Dorsolateral cuticular outgrowths in second stadium larvae ofGomphus flavipes(Odonata: Gomphidae)

Second and third stadium larvae of Gomphus flavipes have dorsolateral cuticular outgrowths in the form of small basal tubercles bearing fan-shaped setae. These sensilla are aligned in two rows on each side of the thorax and abdomen. European species of Gomphus, Onychogomphus and Ophiogomphus that we examined lack these structures, having instead, at most, short hairlike setae in double rows. The fan-shaped setae of G. flavipes are present only in second and third stadia, apparently being lost later in larval development. We speculate that this loss might be due to changes in microhabitat or might be some kind of phylogenetic constraint.

Uptake and Retention of Microplastics by the Shore Crab Carcinus maenas

Microplastics, plastics particles <5 mm in length, are a widespread pollutant of the marine environment. Oral ingestion of microplastics has been reported for a wide range of marine biota, but uptake into the body by other routes has received less attention. Here, we test the hypothesis that the shore crab (Carcinus maenas) can take up microplastics through inspiration across the gills as well as ingestion of pre-exposed food (common mussel Mytilus edulis). We used fluorescently labeled polystyrene microspheres (8-10 μm) to show that ingested microspheres were retained within the body tissues of the crabs for up to 14 days following ingestion and up to 21 days following inspiration across the gill, with uptake significantly higher into the posterior versus anterior gills. Multiphoton imaging suggested that most microspheres were retained in the foregut after dietary exposure due to adherence to the hairlike setae and were found on the external surface of gills following aqueous exposure. Results were used to construct a simple conceptual model of particle flow for the gills and the gut. These results identify ventilation as a route of uptake of microplastics into a common marine nonfilter feeding species.