Research Article |
Corresponding author: Yanli Yue ( 14332@sicau.edu.cn ) Academic editor: Claudia Hemp
© 2023 Jun-Jie Gu, Chengjie Zheng, Su-Rong Jiang, Yanli Yue.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Gu J-J, Zheng C, Jiang S-R, Yue Y (2023) Phylogeny of genus Sichuana Shen & Yin, 2020 (Orthoptera, Tettigoniidae, Tettigoniinae) with four new species from Sichuan, China. Deutsche Entomologische Zeitschrift 70(2): 337-355. https://doi.org/10.3897/dez.70.105870
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Four new species of Sichuana Shen & Yin, 2020 are described based on morphological comparison and molecular analysis: S. planicercata sp. nov., S. curvicercata sp. nov., S. longilamina sp. nov. and S. magnicerca sp. nov. Specimens showed some intraspecific variation of male tegmina and subgenital plates. The genes COI and 16S were used to analyze the genetic distance between species and COI was used to analyze the phylogenetic relationship of Sichuana.
Drymadusini, genetic distance, revision, variation, veins
The genus Sichuana Shen & Yin, 2020 (Tettigoniinae, Drymadusini) is endemic to Sichuan, China (
After morphological comparison, we revised the diagnosis of Sichuana and described four new species: S. planicercata sp. nov., S. curvicercata sp. nov., S. longilamina sp. nov. and S. magnicerca sp. nov. We analyzed the genetic distances among species using the mitochondrial genes COI and 16S and did a phylogenetic analysis of the genus based on COI.
The specimens were collected in western Sichuan, China. They (including holotypes) are deposited in the collection of the Department of Plant Protection of Sichuan Agricultural University (
Photographs were taken using a SZX16 microscope system (Olympus, Tokyo, Japan), or a Cannon D550 with a 50 mm lens, composing by cellSens Dimension 3.2 software. The images were digitally stacked composites of approximately 20 focal planes using Helicon Focus 6 (http://www.heliconsoft.com accessed on 12 May 2022).
Wing venation nomenclature is based on the interpretation of
Genomic DNA was extracted from the muscles of one hind leg using a CWBIO Universal Genomic DNA Kit by the manufacturer’s instructions. The molecular markers selected for this paper were mitochondrial cytochromec o xidase subunit I gene (COI) and the mitochondrial large-subunit rRNA gene (16S).The primers used are shown in Table
Target genes | Sequences |
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COI | COBL TYTCAACAAAYCAY AARGATATTGG COBU TAAACTTCWGGRTGWCCAAARAATCA |
16S | 16Sa CGCCTGTTTATCAAAAACAT |
16Sb CTCCGGTTTGAACTCAGATCA |
Taxon | COI | 16S | Reference |
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Sichuana magnicerca sp. nov. 1 | OQ799533 | OQ801125 | this study |
S. magnicerca sp. nov. 2 | OQ799537 | OQ801126 | this study |
S. magnicerca sp. nov. 3 | OQ799534 | OQ801127 | this study |
S. magnicerca sp. nov. 4 | OQ799532 | OQ801128 | this study |
S. magnicerca sp. nov. 5 | – | OQ801129 | this study |
S. longilamina sp. nov. | OQ799531 | OQ801133 | this study |
S. feicui | OQ799536 | OQ801124 | this study |
S. planicercata sp. nov. 1 | OQ799525 | OQ801130 | this study |
S. planicercata sp. nov. 2 | OQ799526 | OQ801131 | this study |
S. planicercata sp. nov. 3 | OQ799527 | OQ801132 | this study |
S. planicercata sp. nov.4 | OQ799528 | – | this study |
S. curvicercata sp. nov.1 | OQ799529 | OQ801121 | this study |
S. curvicercata sp. nov.2 | OQ799530 | OQ801122 | this study |
S. curvicercata sp. nov. 3 | – | OQ801123 | this study |
S. cryptospina 1 | MT161464 | – |
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S. cryptospina 2 | MT161465 | – |
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Mongolodectes huangxinleii | MT161460 | – |
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Atlanticus fengyangensis | MG787210 | – |
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The COI and 16S sequences isolated from all samples were used for phylogenetic assay (Table
COI and 16S were used for this analysis (Table
COI was used for this analysis (Table
The satellite maps were sourced from the National Platform for Common Geospatial Information Services (https://www.tianditu.gov.cn/) and edited with ArcGIS 10.8 (
A. Distribution of Sichuana species in Sichuan Province, China; B, C. Enlarged version of Sichuana species distribution; B. S. planicercata sp. nov. and S. curvicercata sp. nov.; C. S. longilamina sp. nov. and S. magnicerca sp. nov. (circles, squares and triangles represent the three clades on the phylogenetic tree).
Orthoptera: Tettigoniidae: Tettigoniinae: Drymadusini
Differs from all other Drymadusini genera in China by its male cercus being strongly incurved at or after its middle with acute apex, with a basal inner tooth (Figs
A–D. Body of Sichuana planicercata sp. nov. A, B. Male holotype; C, D. Female paratype; A, C. Dorsal view; B, D. Lateral view; E. Male terminal abdomen with artificially unfurled cerci in dorsal view for showing inner tooth; F. Male terminal abdomen in dorsal view; G. Female terminal abdomen in dorsal view; H. Male terminal abdomen in lateral view; I. Male left tegmen in lateral view.
Sichuana cryptospina Shen & Yin, 2020.
Holotype : ♂, Xiaojin County, Ngawa Tibetan and Qiang Autonomous Prefecture, Sichuan Province, China, (30°59'31"N, 102°21'39"E, alt., ca. 2700 m), coll. Cheng-Jie Zheng and Yuan Wei, VIII-2022. Paratypes:10♂ 5♀, same data as in holotype.
Differs from all other Sichuana species by its male tenth abdominal tergite with a pair of very short round projections at posterior margin (Fig.
The specific epithet is derived from a combination of the Latin ‘plani’ meaning flat, and ‘cercus’, describing the male cerci not bent ventrally or dorsally. Chinese name: 平尾川螽.
(mm). Body (head to tip of abdomen): 32.4–33.86♂, 34.22–35.83♀; pronotum: 8.26–8.98♂, 7.86–8.46♀; tegmen: 15.39–16.21♂, 7.96–9.35♀; mirror of right tegmen (from fore to hind): 4.23–4.42♂; hind wing: 6.12–6.90♂, 5.43–5.76♀; protibia: 8.86–9.36♂, 8.85–10.31♀; profemur: 7.68–8.04♂, 7.92–8.53♀; mesotibia: 9.18–10.58♂, 9.96–11.28♀; mesofemur: 8.47–9.01♂, 8.48–9.42♀; metatibia: 21.09–22.71♂, 22.39–23.24♀; metafemur: 21.61–22.71♂; 22.98–23.76♀; ovipositor: 20.82–21.43.
Male. Body, large. Frons flat, slightly oblique. Frontal fastigium and clypeofrontal sulcus black. Face light-colored. Occiput convex. Vertical fastigium broad, slightly wider than scape. Median ocellus visible. Compound eyes broadly round and bulging outwards, surrounded by black coloration that extends backward to form a band. Antennae inserted at the inner sides of the compound eyes, scapus robust, much thicker than pedicel, flagellum tapers toward the apex, covered with short setae (Fig.
Pronotum
saddle-shaped, smooth, nearly equal to profemur in length. Disc of prozona with a broadly obtuse concavity in the middle of each side, anterior margin of pronotum slightly concave and posterior margin blunt, median carina faintly indicated in prozona, absent in metazona, lateral carina distinct in metazona, faintly indicated in prozona. Lateral lobe of pronotal length greater than depth, with a light-colored stripe along the lateral margin, sometimes not obvious, humeral sinus obvious (Fig.
Tegmen
approximately equal to, or slightly shorter than, twice length of pronotum, with clear longitudinal and cross veins. Tegmen folded downward along the M+CuA, flat dorsal field with a transverse lacuna in the middle. Tegmen almost the same width as the metazona disc from base to middle, then gradually narrowing in dorsal view. Lateral field of the tegmen slightly broadened (Fig.
Legs. Prothoracic leg: genicular lobes of pro- and mesothoracic leg usually unarmed on both sides, sometimes armed with 1–2 spinules; dorsal procoxa with a long spine; profemur with 0–2 external black spinules and 1–4 internal black spinules ventrally; protibia with a slit-like tympanum on both sides; protibia with 2–3 external spurs dorsally, with 4–5 spurs on each side ventrally; protibia with an external apical spur dorsally and a pair of apical spurs ventrally. Mesothoracic leg: mesofemur with 1–4 external black spinules and 0–2 internal black spinules ventrally; mesotibia with 2–4 external spurs and 3–4 internal spurs dorsally, with 5–6 spurs on each side ventrally; mesotibia with an internal apical spur dorsally and with a pair of apical spurs ventrally. Metathoracic leg: metafemur with sparse black spinules on each side ventrally; metatibia with a row of spines of different sizes on each side dorsally, with a row of sparse tiny spurs on each side ventrally, progressively denser toward apex; metatibia with a pair of apical spurs dorsally, with two pairs of apical spurs ventrally, one pair distinctly larger.
The apical area of the tenth abdominal tergite with a wide and pileous lacuna in the middle, covered with many tiny granular protrusions; posterior margin of tenth abdominal tergite with a shallow notch at the middle of the posterior margin, sides of which form a pair of very short round projections (Fig.
Female. Generally similar to male, but body slightly larger. Tegmen slightly longer or shorter than pronotum, extending to the third abdominal tergum (Fig.
S. planicercata sp. nov., can be assigned to Sichuana Shen & Yin, 2020 by its median carina faintly indicated in the prozona and absent in the metazona; lateral carina distinct in metazona, faintly indicated in prozona; prosternum with a pair of spines; male tegmina mesopterous, far exceeding pronotum; male cerci conical, strongly incurved at middle, apex acute, and with an inner tooth placed in basal area.
S. planicercata sp. nov. is similar to S. curvicercata sp. nov., but differs distinctly by: male cerci not bending ventrally or dorsally, while those of S. curvicercata sp. nov. are curved ventrally with apex pointing dorsally; a hook-like inner tooth that tapers and curves from base to apex, extending far above the top of cerci in lateral view, while S. curvicercata sp. nov. having almost the same thickness overall and suddenly sharp and incurved at apex, slightly above the top of the cerci in lateral view; the posterior margin of the male tenth abdominal tergite has a shallow notch at the middle of the posterior margin, and its sides form a pair of very short round projections, while that of S. curvicercata sp. nov. is without protrusion, only a wide and shallow notch at the middle (Figs
S. planicercata sp. nov. differs from S. feicui He, 2020 and S. cryptospina Shen & Yin, 2020 by the following character states: the lateral field of the male tegmina is only slightly broadened; in the male tegmina, M+CuA is separated to M and CuA after the origin of the handle; the male cerci are strongly incurved after their middle; a hook-like inner tooth is far above the top of the cerci in lateral view; and the pair of projections at the posterior margin of the male’s tenth abdominal tergite is very short and inconspicuous. These two species also differ from S. planicercata sp. nov. in the shape of the inner teeth, the denticles on the titillator, the morphology of the female tenth abdominal tergite, the shape of the stridulatory file, and the number of stridulatory teeth.
Holotype
: ♂, Yonghong village, Dawei town, Xiaojin County, Ngawa Tibetan and Qiang Autonomous Prefecture, Sichuan Province, China (30°58'6"N, 102°38'16"E, alt., ca. 2800 m), coll. Cheng-Jie Zhengand Yuan Wei, VIII-2022. Paratypes: 10♂ 1♀, same data as in holotype (Fig.
Differs from all other Sichuana species by male tenth abdominal tergite without projections at posterior margin (Fig.
A–D. Body of Sichuana curvicercata sp. nov. A, B. Male holotype; C, D. Female paratype; A, C. Dorsal view; B, D. Lateral view; E. Male terminal abdomen with artificially unfurled cerci in dorsal view for showing inner tooth; F. Male terminal abdomen in dorsal view; G. Female terminal abdomen in dorsal view; H. Male terminal abdomen in lateral view; I. Male left tegmen in lateral view.
The specific epithet is derived from a combination of the Latin ‘curvi’ meaning curved and ‘cercus’, describing the male cerci curved ventrally with the apex pointing dorsally. Chinese name: 弯尾川螽.
(mm). Body (head to tip of abdomen): 25.36–26.77♂, 27.28♀; pronotum: 6.98–7.26♂, 7.44♀; tegmen: 11.70–12.42♂, 7.08♀; mirror of right tegmen (from fore to hind): 3.88–3.96♂; hind wing: 4.39–4.62♂, 4.79♀; protibia: 6.24–7.23♂, 7.6♀; profemur: 6.45–6.86♂, 7.28♀; mesotibia: 7.24–7.72♂, 9.32♀; mesofemur: 6.26–7.10♂, 8.16♀; metatibia: 16.33–17.19♂, 19.92♀; metafemur: 17.56–17.8♂; 20.96♀; ovipositor: 17.64.
Male. Body size medium. Frons flat, slightly oblique. Frontal fastigium and clypeofrontal sulcus black. Face light-colored. Occiput convex. Vertical fastigium broad, slightly wider than scape. Median ocellus visible. Compound eyes broadly round and bulging outwards, surrounded by black coloration that extends backward to form a black band. Filiform antennae inserted at the inner side of the compound eyes, scapus robust, much thicker than pedicel, flagellum taper toward the apex, covered with short setae (Fig.
Pronotum
saddle-shaped, smooth, nearly equal to profemur in length. Disc of prozona with a broadly obtuse concavity in the middle of each side, anterior margin of pronotum slightly concave and posterior margin blunt, median carina faintly indicated in prozona, absent in metazona, lateral carina distinct in metazona, faintly indicated in prozona. Lateral lobe of pronotal length greater than depth, with a light-colored stripe along the lateral margin, sometimes not obvious, humeral sinus obvious (Fig.
Tegmen
approximately equal to or slightly shorter than twice length of pronotum, with clear longitudinal and cross veins. Tegmen folded downward along M+CuA, dorsal field flat, with a transverse lacuna in the middle. Tegmen almost the same width with disc of metazona from basic until middle, and then gradually narrowing in dorsal view. Lateral field of tegmen slightly broadened (Fig.
Legs. Prothoracic leg: genicular lobes armed with 1–2 internal spinules and externally unarmed. Dorsal side of procoxa with a long spine. Profemur with 2–4 internal black spinules ventrally; protibia with a slit-like auditory tympanum on both sides; protibia with 0–3 external spurs dorsally, with 4–5 spurs on each side ventrally; protibia with an external apical spur dorsally and with a pair of apical spurs ventrally. Mesothoracic leg: genicular lobes armed with 0–2 spinules on each side. Mesofemur with 2–4 external black spinules and 0–2 internal black spinules ventrally; mesotibia with 2–4 external spurs and 3–4 internal spurs dorsally, with 5–6 spurs on each side ventrally; mesotibia with an internal apical spur ventrally and a pair of apical spurs dorsally. Metathoracic leg: genicular lobes unarmed; metafemur with sparse black spinules on each side ventrally; metatibia with a row of spines of different sizes on each side dorsally, with a row of sparse tiny spurs on each side ventrally, progressively denser toward apex; metatibia with a pair of apical spurs dorsally and two pairs ventrally, one of which is distinctly larger.
The apical area of the tenth abdominal tergite with a wide and pileous lacuna in the middle, covered with many tiny granular protrusions. The tenth abdominal tergite with a wide and shallow notch in the middle of the posterior margin (Fig.
Female. Generally similar to male, but body slightly larger. Tegmen shorter than pronotum, extending to the third abdominal tergum (Fig.
S. curvicercata sp. nov. is similar to S. planicercata sp. nov., but is distinct by: male cerci gradually curved ventrally with the apex pointing dorsally, while those of S. planicercata sp. nov. do not bend ventrally or dorsally; the inner tooth is nearly straight and almost fo same thickness overall and is suddenly sharp and incurved at apex, while that of S. planicercata sp. nov. is tapering and curving from base to apex and is far above the top of the cerci in lateral view; the posterior margin of the male tenth abdominal tergite only with a wide and shallow notch in the middle of the posterior margin, while that of S. planicercata sp. nov. has a pair of very short and inconspicuous projections (Figs
S. curvicercata sp. nov. differs from S. feicui He, 2020 and S. cryptospina Shen & Yin, 2020 by: the lateral field of the male tegmina is slightly broadened; in male tegmina, M+CuA separate to M and CuA after the origin of the handle; the posterior margin of the male tenth abdominal tergite is without projections; male cerci are curved ventrally with the apex pointing dorsally. Furthermore, S. curvicercata sp. nov. differs from S. feicui by its male cerci strongly incurved at the middle. These two species also differ from S. curvicercata sp. nov. in the shape of the inner teeth, the denticles on the titillator, the morphology of the female tenth abdominal tergite, the shape of the stridulatory file, and the number of stridulatory teeth.
Holotype : ♂, Guergou, Li County, Ngawa Tibetan and Qiang Autonomous Prefecture, Sichuan Province, China, (31°30'29"N, 102°58'35"E, alt., ca. 2400 m), coll. Cheng-Jie Zhengand Yuan Wei, VIII-2022. Paratypes: 1♀, same data as in holotype.
Differs from all other Sichuana species by notch of tenth abdominal tergite of male trapezoidal (Fig.
A–D. Body of Sichuana longilamina sp. nov. A, B. Male holotype; C, D. Female paratype; A, C. Dorsal view; B, D. Lateral view; E. Male terminal abdomen with artificially unfurled cerci in dorsal view for showing inner tooth; F. Male terminal abdomen in dorsal view; G. Female terminal abdomen in dorsal view; H. Male terminal abdomen in lateral view; I. Male left tegmen in lateral view.
The specific epithet is derived from a combination of the Latin ‘longus’ meaning long and ‘lamina’ meaning plate, to describe its male subgenital plate which is distinctly longer than the cerci. Chinese name:长板川螽.
(mm). Body (head to tip of abdomen): 27.7♂, 31.38♀; pronotum: 8.36♂, 8.6♀; tegmen: 17.42♂, 8.76♀; mirror of right tegmen (from fore to hind): 4.34♂; hind wing: 7.82♂, 5.54♀; protibia: 7.58♂, 10♀; profemur: 7.4♂, 8.5♀; mesotibia: 9.42♂, 10.94♀; mesofemur: 8.52♂, 9.62♀; metatibia: 21.12♂, 26.28♀; metafemur: 20.98♂; 25.64♀; ovipositor: 23.34.
Male. Body size medium. Frons flat, slightly oblique. Frontal fastigium and clypeofrontal sulcus black. Face light-colored. Occiput convex. Vertical fastigium broad, slightly wider than scape. Median ocellus visible. Compound eye broadly round and bulging outwards, surrounded by black coloration extending backward to form a band. Filiform antennae inserted on the inner sides of the compound eyes, scapus robust, much thicker than pedicel, flagellum tapers toward the apex, covered with short setae (Fig.
Pronotum
saddle-shaped, smooth, nearly equal to profemur in length. Disc of prozona with a broadly obtuse concavity in the middle of each side, anterior margin of pronotum slightly concave and posterior margin blunt, median carina faintly indicated in prozona, absent in metazona, lateral carina distinct in metazona, faintly indicated in prozona. Lateral lobe of pronotal length greater than depth, with a light-colored stripe along the lateral margin, sometimes not obvious, humeral sinus obvious (Fig.
Tegmen
slightly shorter than twice the length of pronotum, with clear longitudinal and cross veins. Tegmen folded downward along the M+CuA, the dorsal field flat, with a transverse lacuna in the middle. Tegmen almost the same width as disc of metazona from base to the middle, then gradually narrowing in dorsal view. Lateral field of the tegmen distinctly broadened (Fig.
Legs. Prothoracic leg: genicular lobes armed with 1–2 internal spinules and externally unarmed. Dorsal procoxa with a long spine. Profemur with 2–4 internal black spinules ventrally; protibia with a slit-like auditory tympanum on both sides; protibia with 2 external spurs dorsally, with 5 spurs on each side ventrally; protibia with an external apical spur dorsally and with a pair of apical spurs ventrally. Mesothoracic leg: genicular lobes armed with 0–1 external spinule and 1 internal spinule; mesofemur with 2–3 external black spinules and 0–2 internal black spinules ventrally; mesotibia with 2 external spurs and 3 internal spurs dorsally, with 5 spurs on each side ventrally; mesotibia with an internal apical spur dorsally and with a pair of apical spurs ventrally. Metathoracic leg: genicular lobes unarmed; metafemur with sparse black spinules on each side ventrally; metatibia with a row of spines of different sizes on each side dorsally, with a row of sparse tiny spurs on each side ventrally, progressively denser toward the apex; metatibia with a pair of apical spurs dorsally, with two pairs of apical spurs ventrally, one pair distinctly larger.
The apical area of the tenth abdominal tergite with a wide lacuna in the middle covered with many tiny granular protrusions. The posterior margin of the tenth abdominal tergite with a trapezoidal notch at the middle, its sides forming a pair of round, blunt lobes (Fig.
Female. Generally similar to male, but body slightly larger. Tegmen shorter than pronotum, extending to the third abdominal tergum (Fig.
S. longilamina sp. nov. differs from S. feicui He, 2020, S. cryptospina Shen & Yin, 2020, S. planicercata sp. nov. and S. curvicercata sp. nov. by the following: pair of cone-shaped spines on prosternum more slender; pair of lobes on mesosternum acutely triangular, height greater than width (Fig.
These four species also differ from S. longilamina sp. nov. in the shape of the inner teeth, the denticles on the titillators, the morphology of the tenth abdominal tergite, the shape of the stridulatory file, and the number of stridulatory teeth.
Holotype : ♂, Zagunao town, Li County, Ngawa Tibetan and Qiang Autonomous Prefecture, Sichuan Province, China, (31°27'33"N, 103°10'52"E, alt., ca. 2000 m), coll. Cheng-Jie Zheng and Yuan Wei, VIII-2022. Paratypes: 8♂ 11♀, same data as in holotype.
Differs from all other Sichuana species by notch of male tenth abdominal tergite U-shaped; large and long male cercus beyond subgenital plate (Fig.
A–D. Body of Sichuana magnicerca sp. nov. A, B. Male holotype; C, D. Female paratype; A, C. Dorsal view; B, D. Lateral view; E. Male terminal abdomen with artificially unfurled cerci in dorsal view for showing inner tooth; F. Male terminal abdomen in dorsal view; G. Female terminal abdomen in dorsal view; H. Male terminal abdomen in lateral view; I. Male left tegmen in lateral view.
The specific epithet is derived from a combination of the Latin ‘magnus’ meaning huge and ‘cercus’, to describe its male cerci, large and longer than the subgenital plate. Chinese name: 巨钩川螽.
(mm). Body (head to tip of abdomen): 30.78–33.02♂, 35.1–37.34♀; pronotum: 8.16–9.04♂, 8.82–9.7♀; tegmen: 15.84–17.57♂, 8.14–8.92♀; mirror of right tegmen (from fore to hind): 4.39–4.64♂; hind wing: 8.23–8.39♂, 5.28–5.78♀; protibia: 8.12–9.14♂, 9.5–10.58♀; profemur: 7.68–8.34♂, 8.04–8.98♀; mesotibia: 9.42–10.12♂, 10.52–11.74♀; mesofemur: 8.44–9.39♂, 9.1–10.18♀; metatibia: 22.24–24.43♂, 24.36–27.76♀; metafemur: 23.02–24.88♂; 24.48–27.54♀; ovipositor: 21.48–24.39.
Male. Body size medium. Frons flat, slightly oblique. Frontal fastigium and clypeofrontal sulcus black. Face light-colored. Occiput convex. Vertical fastigium broad, slightly wider than scape. Median ocellus visible. Compound eyes broadly round and bulging outwards, surrounded by black coloration that extending backward to form a band. Filiform antennae inserted at inner sides of the compound eyes, scapus robust, much thicker than pedicel, flagellum tapering toward apex, covered with short setae (Fig.
Pronotum
saddle-shaped, smooth, nearly equal to profemur in length. Disc of prozona with a broadly obtuse concavity in the middle of each side, anterior margin of pronotum slightly concave and posterior margin blunt, median carina faintly indicated in prozona, absent in metazona, lateral carina distinct in metazona, faintly indicated in prozona. Lateral lobe of pronotal length greater than depth, with a light-colored stripe along the lateral margin, sometimes not obvious, humeral sinus obvious (Fig.
Tegmen approximately equal to or slightly shorter than twice the length of pronotum, with clear longitudinal and cross veins. Tegmen folded downwards along M+CuA, the dorsal field flat, with a transverse lacuna in middle. Tegmen almost same width as disc of metazona from base to middle, and then gradually narrowing in dorsal view. Lateral field of tegmen distinctly broadened (Fig.
Legs. Prothoracic leg: genicular lobes armed with 1–2 internal spinules, unarmed externally. Dorsal surface of procoxa with a long spine; profemur with 3–5 internal black spinules ventrally; protibia with a slit-like auditory tympanum on both sides; protibia with 2–4 external spurs dorsally, with 5 spurs on each side ventrally; protibia with an external apical spur dorsally and a pair of apical spurs ventrally. Mesothoracic leg: genicular lobes armed with 1–2 spinules on each side; mesofemur with 2–3 external black spinules and 0–2 internal black spinules ventrally; mesotibia with 2–3 external spurs and 3–5 internal spurs dorsally, with 5 spurs on each side ventrally; mesotibia with an internal apical spur dorsally and a pair of apical spurs ventrally. Metathoracic leg: genicular lobes unarmed. Metafemur with sparse black spinules on each side ventrally; metatibia with a row of spines of different sizes on each side dorsally, with a row of sparse tiny spurs on each side ventrally, progressively denser toward the apex; metatibia with a pair of apical spurs dorsally, with two pairs of apical spurs ventrally, one pair of which distinctly larger than the other.
Apical area of the tenth abdominal tergite with a slight pileous lacuna covered with many tiny granular protrusions. Posterior margin of tenth abdominal tergite with U-shaped notch in middle, sides of notch which form a pair of round blunt projections (Fig.
Female. Similar to male, but body slightly larger. Tegmen shorter than pronotum, extending to the third abdominal tergum (Fig, 12B, D). Hindwing micropterous, longer than half of pronotum. Cercus conical and pileous. Tenth abdominal tergite depressed downward in middle, and with a V-shaped notch at middle of posterior margin, its sides forming a pair of round blunt projections (Fig.
S. magnicerca sp. nov. is similar to S. cryptospina Shen & Yin, 2020, but differs distinctly by: male cerci large and long, extending beyond subgenital plate, while those of S. cryptospina are relatively shorter and smaller, not extending beyond subgenital plate; the inner tooth is small and placed at the basal-most part of the cerci, while that of S. cryptospina is relatively larger and longer, and is placed at the sub-basal area of the cerci (Fig.
S. magnicerca sp. nov. differs from S. feicui He, 2020, S. planicercata sp. nov., S. longilamina sp. nov. and S. curvicercata sp. nov. by its large and long male cerci, which extend beyond the subgenital plate. Furthermore, S. magnicerca sp. nov. differs from S. planicercata sp. nov. and S. curvicercata sp. nov. by: tenth abdominal tergite with a pair of round blunt projections on posterior margin; in male tegmina M+CuA branching to M and CuA before origin of handle; and lateral field of male tegmina distinctly broadened. It differs from S. feicui by its male cerci strongly incurved after middle. It differs from S. longilamina sp. nov. by male subgenital plate not extended beyond cerci, and male cerci incurved at an obtuse angle. These four species also differ from S. magnicerca sp. nov. in shape of the inner teeth, denticles on the titillators, morphology of female tenth abdominal tergite, shape of stridulatory file, and the number of stridulatory teeth.
The mean of the sequence divergences for COI among species of Sichuana Shen & Yin, 2020 ranged from a low of 2.208% to a high of 15.688% (Table
Species | COI sequence divergences (%) | |||||
---|---|---|---|---|---|---|
S. planicercata | S. magnicerca | S. longilamina | S. feicui | S. curvicercata | S. cryptospina | |
S. planicercata | 0.586 | |||||
S. magnicerca | 13.620 | 0.847 | ||||
S. longilamina | 13.150 | 10.738 | – | |||
S. feicui | 15.391 | 15.688 | 14.407 | – | ||
S. curvicercata | 2.208 | 10.671 | 13.103 | 14.393 | 0.305 | |
S. cryptospina | 13.563 | 8.760 | 11.000 | 17.214 | 12.686 | 0.152 |
Species | 16S sequence divergences (%) | ||||
---|---|---|---|---|---|
S. planicercata | S. magnicerca | S. longilamina | S. feicui | S. curvicercata | |
S. planicercata | 0.127 | ||||
S. magnicerca | 3.989 | 0.000 | |||
S. longilamina | 3.177 | 2.126 | – | ||
S. feicui | 5.828 | 4.945 | 3.719 | – | |
S. curvicercata | 0.830 | 3.652 | 3.245 | 5.900 | 0.254 |
The results of the ML and BI analyses are almost identical (Fig.
Variation in wing shape and venation is documented in various groups of fossil orthopterans and their relatives (
The male subgenital plate of Sichuana also shows different degrees of variation between individuals. The shape and width of the notch on its posterior margin vary between individuals, especially in S. planicercata sp. nov. (Figs
Genetic distance analysis shows that sequence divergences for COI between most species of Sichuana are greater than 8% (Table
Based on the morphological and molecular analysis above, we described four new species of Sichuana Shen & Yin, 2020, S. planicercata sp. nov., S. curvicercata sp. nov., S. longilamina sp. nov. and S. magnicerca sp. nov., and refined the diagnosis of the genus. This large sample suggests that variation in wing venation and the male subgenital plate is common within species in this genus.
We are grateful to the editor and the reviewers for providing us with valuable suggestions and comments to improve this manuscript. We thank Wei Yuan for his help in the specimen collecting and data analysis. We thank Dr Bruce Archibald from the Beaty Biodiversity Museum, Vancouver, Canada for improving the language. We thank Rong Huang for her help in the DNA extraction. We thank Huilai Zhang for his help in the map editing. This work was supported by the National Natural Science Foundation of China (grant numbers 41872020). We acknowledge the support of the Museum für Naturkunde Berlin.