Accessory Setae Research Articles

Description of one species of freshwater amphipod Hyalella (Crustacea, Peracarida, Hyalellidae) from the northwest region of the state of Rio Grande do Sul, Southern Brazil.

In this study, a new species of Hyalella is described from southern region of Brazil. Hyalella jaboticabensis n. sp. was recorded in the municipality of Jaboticaba, northwest region of state of the Rio Grande do Sul, southern Brazil. This species is characterized by showing smooth body surface, epimeral plates not acuminated, inner face of the gnathopod 1 with nine or ten serrate setae and some simple setae (six to eight), inner ramus of uropod 1 of males with one short curved seta, peduncle of the uropod 3 with six cuspidate setae with an accessory seta and two or three cuspidate setae on the rami, telson as long as wide (square) with six to eight short and long cuspidate setae with an accessory seta. This new description increases the Brazilian known diversity of species of Hyalella to 42 (25 to southern Brazilian region) and 108 species in the Americas. It is noting that it is crucial to know the complete diversity of Hyalella genus, and to consider conservation measures to protect species like H. jaboticabensis n. sp., endemic to two single small streams.

Two new species of Hyalella Smith, 1874 (Malacostraca: Amphipoda: Hyalellidae) from the state of Santa Catarina, Brazil.

The genus Hyalella Smith, 1874 occurs exclusively in the Americas. In Brazil, the states of Santa Catarina and Rio Grande do Sul have the largest number of records with 20 species. This paper presents two new species for the state of Santa Catarina, Brazil. The serrate setae with accessory seta, a new type of seta, is registered for the genus and observed on gnathopods 1 and 2. Additionally, microtrichs are reported on articles, a detail that has not been mentioned in previous studies. Hyalella carsone sp. nov. is characterized by gnathopod 1 with comb-scales from the basis to the carpus, gnathopod 2 dactylus with proximal margin strongly serrated and the presence of serrate setae on the articles of gnathopods 1 and 2. Hyalella wangarie sp. nov. is characterized by gnathopod 2 palm not sinuous with margin inconspicuously serrated, peduncle and inner ramus of the pleopod with simple setae, presence of curved seta on uropod 1 of male and gnathopod 1 palm on female slightly serrated. In this work we expand the number of species from Brazil and increase the morphological knowledge of the genus Hyalella.

New species of genus Dinogamasus Kramer (Mesostigmata, Laelapidae) associated with large carpenter bees (Hymenoptera: Apidae) in Egypt, with new concepts of the genus

The Laelapid family of cosmopolitan mites includes both free-living predators and associated species to arthropods, mammals, or birds. A new species of laelapid mite, Dinogamasus pubescensae n. sp. Abo-Shnaf and Kamel associated with Xylocopa pubescens Spinola (Hymenoptera: Apidae), is described and illustrated. This is a third report of the genus Dinogamasus from Egypt. The new species can be distinguished from its congeners by the combination of the following characters: dorsal cheliceral seta present; hypertrichous idiosoma and opisthogaster; sternum without accessory setae, st2 longest, st4 present, endopodal and metapodal plates present, genital shield shorter than anal shield, anal shield rectangular. The genus diagnoses are discussed in terms of new notions. Modification of Lundqvist’s key (1999) is made to facilitate identification of D. pubescensae n. sp. Abo-Shnaf and Kamel from other species.

Two new species of the genus Macrosiphoniella Del Guercio, 1911 (Hemiptera, Aphidomorpha: Aphididae) inhabits yarrow in Kazakhstan

Two new aphid species of the nominotypical subgenus of the genus Macrosiphoniella (Aphidinae) are described from Kazakhstan. Both species inhabits yarrow (Achillea millefolium L.). Macrosiphoniella kazakhstanica sp. n. most similar to M. silvestrii Roberti, 1954 but differs latter in the number of secondary rhinaria in apterous and alate viviparous females (5–10 and 24–26 vs 14–25 and 48–68), proportion of the processus terminalis to the base of the VI antennal segment (3.7–4.9 vs 2.8–3.6), proportion of antennal segment III to processus terminalis (0.82–0.98 vs 1.11–1.36), as well as the absence of dorsal sclerites at base of setae and color of all tibiae (brown in M. silvestrii and pale in the middle in new species). Macrosiphoniella sarmatica sp. n. is similar to M. terraealbae Kadyrbekov, 2000 but differs from latter in the ratios of the length of the processus terminalis to the length of the base of the 7th antennal segment (3.15–3.75 vs 2.7–3.1), length of the frontal setae to diameter of third antennal segment (1.6–1.7 vs 2.2–2.6), the number of accessory setae on the ultimate rostral segment (6 vs 7–8) and the number of setae on the cauda (10–13 vs 12–19).

A new species of Metopolophium Mordvilko, 1914 (Hemiptera: Aphididae: Aphidinae) on Rosa beggeriana from Iran

A new species of the genus Metopolophium Mordvilko, 1914 (Hemiptera: Aphididae: Aphidinae: Macrosiphini) is described and illustrated. Apterous and alate viviparous females, oviparous females, and apterous males of Metopolophium rogeri sp. nov. on Rosa beggeriana (Rosaceae) are collected from Kerman Province, Iran. The new species is morphologically most similar to M. alpinum Hille Ris Lambers, 1966, but is characterized by the low ratio of processus terminalis to basal segment of antennal segment VI, high ratio of siphunculus to cauda length and the presence of many more accessory setae on the ultimate rostral segment. This holocyclic aphid is monoecious and not attended by ants. The biometric data are given, and the key to the aphids associated with Rosa species in Blackman and Eastop (2021) is modified to accommodate the new species.

A new species of Eulachnus Del Guercio from China (Hemiptera: Aphididae: Lachninae).

We describe apterous and alate viviparous females of a new species of the Lachninae genus Eulachnus (Eulachnini) from China. The new species, Eulachnus blackmani sp. nov., can be easily separated from other Asian representatives of this genus: the ultimate rostral segments are without accessory setae; the spinal scleroites are larger than the pleural and marginal ones; there are a few very long setae on the distal part of the tibiae and on the hind tarsus. The new species is morphologically most similar to the European E. nigricola (Paek), and hence unusual within the Asian Eulachnus fauna.

A new species of Acaudinum Brner (Hemiptera; Aphididae; Aphidinae) from Kazakhstan.

The new species Acaudinum (Acaudinum) rogeri sp.n. is described from Kazakhstan from Serratula coronata L. The new species is close to A. (Acaudinum) longisetosum Holman, 1970 and A. (Acaudinum) roumanicum Holman, 1991. It differs from both species in the proportion of the length of the last rostral segment to the length of the second segment of the hind tarsus (1.471.71 versus 1.221.55), the number of accessory setae on the last segment of the rostrum (46 versus 25). Fewer setae on the anterior margin of the genital plate (810 and 1024). It also differs from A. longisetosum in the ratio of siphunculi length to body length (0.130.20 versus 0.200.30), in having fewer setae on the cauda (1012 and 1317), and 8th abdominal tergite (46 in comparison with 59). From A. roumanicum with a longer second segment of the hind tarsus (0.140.19 mm and 0.120.15 mm). From A. centaureae (Koch, 1854) it is distinguished by setae on trochanters, femora, and ventral side of the body which is long and thin, and a fodder plant belonging to another genus of Asteraceae family. A comprehensive key to distinguish apterous viviparous females based on existing keys is provided.

Hyalella luciae (Crustacea, Amphipoda, Hyalellidae)a new species of freshwater amphipod from Southern Brazil.

Currently, the freshwater amphipod Hyalella Smith, 1874 includes 91 valid species distributed only in the Americas. This study describes the fifth species for the Vrzea River basin, located in the northwestern region of the state of Rio Grande do Sul, Southern Brazil. Among its most prominent features are the presence of the curve seta on the inner ramus of uropod 1 of the males, sternal gills on segments 2-7, propodus ventral face of the gnathopod 1 with nine serrate setae and several small simple and triangular setae, peduncle of uropod 3 with 11-12 distal cuspidate setae with accessory setae, and telson with fifteen cuspidate setae with accessory setae distributed on distal margin. This study presents a detailed comparison of the species we are describing with those already discovered. The diversity of freshwater amphipods in southern Brazil is intriguing. Further investigations should open the way to elucidate the evolutionary history of these crustaceans, uncovering the potential and patterns of diversification of the genus Hyalella.

A new species of freshwater amphipod (Crustacea, Peracarida, Hyalellidae) from Southern Brazil

The freshwater amphipod of the genus Hyalella is typical from continental American waters and shows high levels of endemicity and Brazil has the second largest diversity. A new species is described here, Hyalella longipropodus n. sp. that occurs in a spring of southern Brazil in the municipality of Palmeira das Misses, in the northwestern region of state of Rio Grande do Sul, southern Brasil. Hyalella longipropodus n. sp. shows the following character states: antenna 2 more than half body length, gnathopod 2 propodus elongated, uropod 1 inner ramus of male without apical curved setae, uropod 3 peduncle with seven strong distal setae with accessory setae, ramus of uropod 3 with ten cuspidate setae with accessory setae. Hyalella longipropodus n. sp. occurs in sympatry with H. gauchensis, but these differ especially in the size and shape of gnathopod 2, the presence of curved setae on uropod 1 in H. gauchensis and the absence in H. longipropodus n. sp., antenna length (longer in H. longipropodus n. sp.) and number of cuspidate setae on uropods 1, 2, and 3. Besides the morphological differences, H. longipropodus n. sp. presented genetic differences always above 19% for the COI gene and 29 % for the 16S rRNA gene, when compared with other species found in the northwestern region of the state of Rio Grande do Sul, showing that it is really a species not yet described by science.

Three new species of Hyalella (Crustacea: Amphipoda: Hyalellidae) from the Southern Brazilian Coastal Plain.

In this study, three new species of Hyalella (Crustacea: Amphipoda: Hyalellidae) are described based on specimens collected in wetlands located in three freshwater ecoregions (Southeastern Mata Atlântica, Tramandaí-Mampituba and Laguna dos Patos) of the southern Brazilian Coastal Plain (states of Rio Grande do Sul and Santa Catarina). Hyalella minuana n. sp. was recorded in the southernmost region of the state of Rio Grande do Sul. This species is characterized by presenting smooth body surface, epimeral plates not acuminated, nine serrate setae on the inner face of gnathopod 1, and peduncle of uropod 3 with four cuspidate setae with accessory seta and without plumose seta on the margin of the telson. Hyalella lagoana n. sp. was recorded in the northern region of Rio Grande do Sul and southern region of Santa Catarina. This species shows body surface smooth, epimeral plates not acuminated, nine serrate setae on the inner face of gnathopod 1, peduncle of uropod 3 with five cuspidate setae with accessory seta, and telson with six cuspidate setae with accessory seta without plumose seta on the margins. Hyalella sambaqui n. sp. was recorded in the state of Santa Catarina. This species is characterized by presenting smooth body surface, epimeral plates not acuminated, six serrate setae on the inner face of gnathopod 1, peduncle of uropod 3 with three cuspidate setae with accessory seta, and telson with three cuspidate setae with accessory seta and four plumose setae on the margin of the telson. The new records elevates the known diversity of species of Hyalella in the Brazilian territory to 33 species (19 in the southern Brazilian region) and to 83 species in the Americas.

A new species of Zeuxo (Crustacea: Peracarida: Tanaidacea) from Japan, with remarks on carapace pigmentation as a potentially useful taxonomic character

ABSTRACT We describe Zeuxo ezoensis sp. nov. from Hokkaido, Japan. This species closely resembles Z. phytalensis, Z. shitipingensis and Z. turkensis in having the pleopodal endopod with one inner plumose seta, maxillipedal palp article 4 with one outer simple seta, the left mandible with a wide, denticulate lacinia mobilis and one bifurcate accessory seta, and the right mandible with a peg-like lacinia mobilis and two accessory setae. It differs from them in having (1) antennal article 6 longer than wide, (2) the distal region of the maxillipedal endite with four spiniform setae and two circumplumose setae, (3) maxillipedal palp article 2 with one outer simple seta, (4) the chelipedal carpus with three or four dorsodistal simple setae, (5) the chelipedal dactylus with one inner simple seta, (6) the pereopod-1 basis with one or two ventrodistal simple setae, (7) the pereopod-1 carpus with one ventrodistal simple seta, and (8) the uropod with four or five articles (basal article plus three or four ramus articles). Partial nucleotide sequences for the cytochrome c oxidase subunit I (COI) gene (655 nt) from Z. ezoensis specimens from four localities in Hokkaido showed Kimura 2-parameter (K2P) divergences of 0–0.5% and 0.6–1.5% within and between populations, respectively. Based on the COI data, we examined the phylogenetic position of Z. ezoensis within Zeuxo. Six specimens used for morphological observations and 10 specimens used for COI sequencing showed a similar dorsal pigmentation pattern on carapace. We briefly discuss the validity of using this pattern as a diagnostic character in Zeuxo taxonomy. http://zoobank.org/urn:lsid:zoobank.org:pub:6CB565DB-DAFF-41EF-A06D-EAAE2F619C31

Description of the Males of Androlaelaps misionalis and Androlaelaps ulysespardinasi (Acari: Parasitiformes: Laelapidae) Parasitic of Sigmondontine Rodents From Northeastern Argentina.

Laelapinae mites are common ectoparasites of small mammals, mainly sigmodontine rodents, but males are not frequent in natural populations. In this study, the morphology of the unknown males of Androlaelaps misionalis Lareschi, 2010 and Androlaelaps ulysespardinasi Lareschi, 2011 are described. The males of these species differ from the male of Androlaelaps rotundus (da Fonseca, 1936), a close species, because of the size and shape of their dorsal shield and the length of paranal and sternal st1 and st2 setae. The males of A. misionalis and A. ulysespardinasi differ in their size, in the distance of j6 setae in the dorsal shield, length of hypostomal seta hyp3, number of accessory setae in holoventral shield, length of postanal and sternal st3 setae, number of opisthogastric setae in unarmed integument lateral to level of coxae IV, and shape of tip of movable digit in the chelicera.

How orb-weavers find and grasp silk lines

Spiders are effectively blind with respect to the lines in their own webs. Species in four orb-weaving families solved the problem of finding lines by tapping with their anterior legs, like a blind man with his cane, and then “following” these anterior legs with more posterior legs, which grasp lines that the anterior legs are already holding. Following behavior occurs during several stages of orb construction, and probably economizes on searching time and effort. The movements of following legs are finely adjusted to the morphological details of the grasping structures on their tarsi (the middle claw and its associated serrate accessory setae): the small searching movements made by following legs have consistent orientations: legs I and II move prolaterally, while legs III and IV moved retrolaterally. These orientations are appropriate to bring the asymmetrically placed middle claw and accessory setae into contact with the line. Spiders solved the additional problem of grasping lines that are more or less parallel to the long axis of the leg by using a previously unrecognized movement; they rotate the distal portion of the leg on its longitudinal axis, orienting the middle claw so that it is more or less perpendicular to the line. As an orb-weaver moves across her web, she probably constantly adjusts the rotation of each leg to align its middle claw perpendicular to the lines that it grasps.

Molecular Phylogeny of Acerentomidae (Protura), with Description ofAcerentuloides bernardisp. nov. from North America

The closely related genera Acerentulus Berlese, 1908 and Acerentuloides Ewing, 1921 are represented in the USA by only 3 species: Acerentulus confinis (Berlese, 1908), Acerentulus christensoni (Ewing, 1940), and Acerentuloides americanus (Ewing, 1924). Study of proturan material from North America yielded a new species belonging to Acerentuloides. The new species is characterized by the absence of seta sd4 on the head, presence of a minute apical median seta on abdominal legs II and III, unique shape of maxillary gland with distal row of clustered globules, presence of setae modified as short, thickened sensilla (sd5 on head, β1 and δ4 on foretarsus, setae P4 on metanotum and A2 on thoracic sterna, and accessory setae on tergites and sternites I–VI), absence of seta P1a on abdominal tergites I–VI, foretarsal sensillum b longer than c, and presence of psl pores only on tergite VI. Molecular sequences for several Acerentomidae, including A. confinis, were used to develop hypotheses about species relationships within Acerentomidae.

Two new species of ectinosomatid copepods (Harpacticoida: Ectinosomatidae) from the Caribbean coast of Colombia

Biological samples from the lagoonal system Laguna Navío Quebrado, Caribbean Colombian coast, yielded 2 undescribed species of harpacticoid copepods of the family Ectinosomatidae. The first species, Halectinosoma arangureni sp. nov., is most closely related to H. langi Wells, 1967, H. curticorne (Boeck, 1873) and H. abyssicola (Bodin, 1968), but diverges from these congeners in: 1) the length-width ratio of the maxillipedal basis; 2) the outer caudal seta(II)/caudal ramus length ratio; 3) details of the mandible palp and blade; 4) the length of the inner exopodal seta of P5; 5) the accessory seta on the male P5 exopod, and 6) a T-shaped incision on the male third urosomite. The second species, Pseudobradya gascae sp. nov. closely resembles P. robusta Sars, 1910 and P. barroisi (Richard, 1893), but diverges from these species by: 1) the number of antennular segments in the female; 2) the absence of a seta on the antennary EXP2; 3) proportions of the maxilliped; 4) the relative length of P1EXP; 5) caudal seta III/caudal ramus length ratio, and 6) the unusually long middle seta of P5EXP. Both genera are recorded for the first time in Colombia.

A new species of Acyrthosiphon (Hemiptera, Aphididae) from France and Spain.

A new species in one of the largest genera of Macrosiphini (Hemiptera, Aphididae), Acyrthosiphon pilosum sp. n., is described from apterous and alate viviparous females and oviparous females from French and Spanish Mediterranean localities, living on species of Ononis (Fabaceae), mainly O. natrix. The new species is characterized by the presence of many accessory setae on the ultimate rostral segment, and usually five setae on the first tarsal segments, a combination that is not present in any other known Acyrthosiphon species; in addition marginal tubercles are present on prothorax and several of abdominal segments 2-5.

Description of a new species of the genus Peltidium Philippi, 1839 from southern Korea (Copepoda, Harpacticoida) – with a review of the genus

Peltidium byungwooi sp. nov. is described in morphological detail from samples collected from the macroalgal beds on rocky bottoms using a light trap from Yeoseodo Island, Korea. Our studies revealed the following morphological diagnostic characters: body strongly chitinized and dorsoventrally flattened; antennule 7-segmented; antenna with allobasis, exopod 2-segmented, bearing one and three setae, respectively; allobasis of maxilla bilobed, drawn out into a small claw with two accessory setae; endopod represented by a small protuberance bearing one seta; swimming legs P2–P4 exp-3 with two outer spines; P2 enp-1 without inner seta; P3 enp-3 with two inner setae; inner endopodal lobe of female P5 with very short outer seta (about 5.4 times shorter than inner one, 3.6 times in male); male P2 enp-3 bearing modified inner distal spine with blunt tip. Phylogenetic, zoogeographic, biological, and ecological characteristics of the family Peltidiidae are reviewed for the genus Peltidium.http://zoobank.org/urn:lsid:zoobank.org:pub:765492B8-73DF-4650-BDFA-71C73BBD7600

Revision of the GenusAndinentulus(Protura: Acerentomidae: Berberentulinae), with a Key to South and Central American Acerentomidae Species

AbstractThe species Acerentulus rapoportiCondé, 1963 is redescribed, transferred to genus AndinentulusTuxen, 1984, and synonymized with Andinentulus ebbeiTuxen, 1984 on the basis of type series. Andinentulus rapoporti (Condé, 1963) comb. nov. is characterized by very long and sword-shaped foretarsal sensillum a' sensillum b that is half the length of sensillum c, presence of additional seta d6 on the head, absence of seta P1a on abdominal tergites I–VI, and short oblong accessory setae on tergites I–VI. The differences between the genus Andinentulus and morphologically similar genera, which have three setae on the abdominal legs, are discussed. A key to South and Central American Acerentomidae species and their distribution in America is provided. The mitochondrial cytochrome oxidase subunit I sequence (barcode) is provided for several specimens of the species and compared with other proturan barcodes with a phylogenetic analysis.

Review of Tuxenentulus and Fjellbergella Species (Protura: Acerentomidae, Acerentominae)

Abstract Two new species of Tuxenentulus Rusek, 1974 and FjellbergellaNosek, 1978 are described: Tuxenentulus solncevae n. sp. from the Russian Far East and Fjellbergella uteorum n. sp. from Colorado. T. solncevae n. sp. is characterized by short and broad foretarsal sensilla c and e, presence of cephalic seta d6 on head, presence of seta Pla on abdominal tergites I–VI, and sensilliform accessory setae on segments I–VI. F. uteorum n. sp. (Colorado) possesses 19 posterior setae on abdominal tergite VII, including median seta Pc, and 14 setae on tergite IX. A key to known world Tuxenentulus and Fjellbergella spp. is provided.

A new species of the genus Pleuroxus Baird (Cladocera: Anomopoda: Chydoridae) from Jeju Island, South Korea.

A new species of the genus Pleuroxus Baird (Cladocera: Anomopoda: Chydoridae) is described from Jeju Island, South Korea. P. jejuensis sp. nov. is the closest relative of the aduncus-like species from southern hemisphere instead of P. aduncus s. str. It shares with P. wittsteini Studer, 1878 in: (1) brown colour; (2) absence of denticles on postero-ventral portion of valve; (3) unusually short postpore distance; (4) grouped postanal teeth. P. jejuensis sp. nov. differs from P. wittsteini in: (1) smaller postpore distance; (2) submarginal setules on inner side of the posterior valve margin; (3) prominent postero-dorsal angle of the postabdomen; (4) only two postanal teeth in each group; (5) longer proximalmost basal spine of the postabdominal claw; (6) very short accessory seta on limb I. The wittsteini-like chydorines seem to be remnants of an old, pan-continental species group.