Taxonomic review of Rhyacobates Esaki, 1923, with descriptions of three new species (Hemiptera: Heteroptera: Gerridae) Author Leng, Zhaoqi 89B546A1-5B53-4C03-9098-FBB36BC9EC85 Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, 300071, China. zhaoqileng0712@gmail.com Author Tran, Anh Duc 3CB36F17-D917-4600-B888-C33B1C04259F Faculty of Biology, VNU University of Science, Vietnam National University, Hanoi, Nguyen Trai, Thanh Xuan, Hanoi, Vietnam. tran.anhduc@hus.edu.vn Author Ye, Zhen B095C7FB-E95B-4D0D-A61F-09B0B223571F Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, 300071, China. yezhen1987331@nankai.edu.cn text European Journal of Taxonomy 2023 2023-09-28 893 1 1 73 https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2285/9863 journal article 274285 10.5852/ejt.2023.893.2285 e441bc9d-bb44-4ee6-b29f-a6724b96592b 2118-9773 8385630 D9DA4879-BC1D-4947-96E8-7D574DE334BA Rhyacobates edentatus Andersen & Chen, 1995 Figs 3J , 4G , 5I , 6I , 8G , 27–28 Rhyacobates edentatus Andersen & Chen, 1995: 63–64 , figs 33–36 (original description). Fig. 26. Photographs of Rhyacobates constrictus Tran & Nguyen, 2016 . A–B . Holotype, apterous female (ZVNU). A . Body, lateral view. B . Habitus, dorsal view. C . Allotype, apterous male (ZVNU), habitus, dorsal view. Scale bar = 3 mm. Diagnosis Body length of apterous females 7.21–9.64, of apterous males 5.70–6.62. Female: pronotum mainly black with a median brownish-yellow spot; mesonotum and metanotum mainly black with a median brownish-yellow stripe ( Figs 3J , 28A ); posterior part of abdomen curved dorsad to oblique position, both sides of abdominal segment VII dorsally folded mesad, almost meeting each other over mediotergite ( Fig. 28D–F ), posterior margin of sternum VII truncate or with obtuse angle ( Fig. 28E ). Male: middle trochanter without spines; middle femur with scattered small spines, not arranged in distinct row ( Fig. 28I ); length of middle tibia ca 1.9–2.0 times length of hind tibia; proctiger with angular lobes laterally ( Figs 6I , 28J ); paramere relatively slender, curved at basal third, distal part tapering towards hook-shaped apex ( Figs 8G , 28K ). Material examined Holotype ( Fig. 27A–B ) CHINA • ♀ (apterous); Guangdong Province , Lian County , Yao-an Village ; 30 Jul. 1962 ; Le-yi Zheng and Han-hua Cheng leg.; NKUM . Paratypes ( Fig. 27C–D ) CHINA • 3 ♁♁, 1 ♀ (apterous); same collection data as for holotype; NKUM . Non-type specimens CHINA – Chongqing City • 7 ♁♁, 8 ♀♀ (apterous); Nan-chuan Region , Jin-fo Mountain ; 29°3′25.6″ N , 107°5′55.1″ E ; 598 m a.s.l. ; 19 Jul. 2022 ; Qiao Mu et al. leg.; NKUM . – Guangdong Province • 13 ♁♁, 10 ♀♀ (apterous); Qing-yuan City , Guang-dong-di-yi Mountain ; 24°47′42.1″ N , 112°54′47.5″ E ; 696 m a.s.l. ; 21 Jul. 2019 ; Si-ying Fu leg.; NKUM • 1 ♁, 2 ♀♀ (apterous); Shao-guan City , Nan-ling ; 24°54′58.4″ N , 113°2′47.6″ E ; 513 m a.s.l. ; 5 Jun. 2016 ; Ya-hui Zhen leg.; NKUM . – Guangxi Province • 1 ♁, 1 ♀ (apterous); Gui-lin City , Long-sheng County , Hua-ping National Nature Reserve ; 25°41′11.5″ N , 109°56′59.1″ E ; 540–800 m a.s.l. ; 18 Jul. 2009 ; Zhong-hua Fan leg.; NKUM • 2 ♁♁, 3 ♀♀ (apterous); Laibin City , Jin-xiu County , Da-yao Mountain ; 24°8′40.2″ N , 110°4′49.1″ E ; 565 m a.s.l. ; 25 Jul. 2019 ; Zhen Ye leg.; NKUM . – Guizhou Province • 1 ♀ (apterous); Zun-yi City , Kuan-kuo-shui National Nature Reserve ; 28°5′9.4″ N , 107°14′47.5″ E ; Jul. 2012 ; Tong-yin Xie leg.; NKUM . – Fujian Province • 1 ♁, 2 ♀♀ (apterous); Nan-ping City , Wu-yi Mountain ; 27°38′53.1″ N , 117°58′20.1″ E ; 18 Jul. 2018 ; Si-ying Fu , Kun Jiang and Xin Yang leg.; NKUM . – Hubei Province • 64 ♁♁, 55 ♀♀ (apterous); Huang-gang City , Ying-shan County , Jiu-gong Mountain ; 29°22′08.6″ N , 114°34′36.5″ E ; 700 m a.s.l. ; 3 Aug. 2010 ; Wen-jun Bu et al. leg.; NKUM • 13 ♁♁, 16 ♀♀ (apterous); Huang-gang City , Ying-shan County , Jiu-gong Mountain ; 29°23′59.7″ N , 114°39′24.5″ E ; 130 m a.s.l. ; 11 Jul. 2022 ; Zhao-qi Leng and Zhen Ye leg.; NKUM . – Hunan Province • 4 ♁♁, 5 ♀♀ (apterous); Shao-yang City , Dong-kou County , Luo-xi ; 27°2′19.4″ N , 110°13′48.6″ E ; 500 m a.s.l. ; 27 Jul. 2016 ; Yan-chen Li and Chen-guang Zheng leg.; NKUM . – Jiangxi Province • 2 ♁♁, 2 ♀♀ (apterous); Lu-shan City , Gu-ling County ; 9 Aug. 1934 ; O. Piel leg.; IZAS . – Sichuan Province • 4 ♁♁, 3 ♀♀ (apterous); Lu-zhou City , Huang-jing ; 28°14′57.3″ N , 105°44′39.5″ E ; 886 m a.s.l. ; 7 Aug. 2016 ; Chen-guang Zheng leg.; NKUM • 1 ♀ (apterous); Le-shan City , Mu-chuan County , Hei-xiong Valley ; 28°52′26.8″ N , 103°57′31.1″ E ; 1090 m a.s.l. ; 2 Aug. 2017 ; Chen-guang Zheng leg.; NKUM . Fig. 27. Photographs of Rhyacobates edentatus Andersen & Chen, 1995 and relevant labels. A–B . Holotype, apterous female (NKUM). A . Habitus, dorsal view. B . Labels. C–D . Paratype, apterous male (NKUM). C . Habitus, dorsal view. D . Labels. Scale bar: A, C = 3 mm. Supplemental description Apterous female MEASUREMENTS . Body length 7.21–9.64, width 3.03–3.53, head width 1.63, interocular width 0.66, eye length (dorsal view) 0.62; relative lengths of antennal segments I–IV: 4.18: 1.31: 1.35: 1.05; pronotum: length 0.81, width 1.71; mesonotum: length 2.57, width 3.30; metanotum: length 0.86, width 3.09; abdomen length (ventral view) 2.70; abdominal sternum VII: length 0.84, width 1.48; abdominal mediotergite I: length 0.49, width 1.29; relative lengths of leg segments (femur: tibia: tarsal segment I: tarsal segment II): fore leg: 4.17:3.66: 2.17: 0.95, middle leg: 12.27:7.72: 4.48: 0.48, hind leg: 12.78: 6.41: 0.21: 0.27. COLORATION . Median black spot of head posteriorly bifurcate. Pronotum mainly black with a median brownish-yellow spot. Mesonotum and metanotum mainly black with a median brownish-yellow stripe ( Figs 3J , 28A ). Connexivum dorsally brownish-yellow. Abdominal tergum I yellow or with a yellow marking. Mesosternum chiefly blackish with a median subtriangular yellowish spot ( Fig. 28B ). Abdominal venter light yellow. ABDOMEN . Abdomen relatively short, with posterior part curved dorsad to oblique position ( Figs 5I , 28C ). Connexiva erect anteriorly, reflexed above terminal mediotergites ( Figs 3J , 28A ), or never converging. Abdominal segment VII elongate ( Fig. 28C ), nearly as long as two preceding abdominal segments together ventrally, completely enclosing genital segments ( Fig. 28D ). Both sides of abdominal segment VII folded mesad on dorsal side, almost meeting each other over mediotergite ( Fig. 28D–F ), posterior margin of sternum VII truncate or with obtuse angle ( Fig. 28E ). Apterous male MEASUREMENTS . Body length 5.70–6.60, width 1.70–1.90, head width 1.26, interocular width 0.50, eye length (dorsal view) 0.49; relative lengths of antennal segments I–IV: 2.90: 0.95: 1.01: 0.75; pronotum: length 0.65, width 1.35; mesonotum: length 1.85, width 1.94; metanotum: length 0.55, width 1.78; abdomen length (ventral view) 2.21; abdominal sternum VII: length 0.42, width 0.91; abdominal mediotergite I: length 0.29, width 0.66; relative lengths of leg segments (femur: tibia: tarsal segment I: tarsal segment II): fore leg: 3.12: 2.41: 0.89: 0.58, middle leg: 8.77: 7.09: 3.31: 0.34, hind leg: 9.48:3.50: 0.14: 0.19. Fig. 28. Morphological features of Rhyacobates edentatus Andersen & Chen, 1995 . A . Body of female, dorsal view. B . Body of female, excluding head and prothorax, ventral view. C . Body of female, lateral view. D . Abdominal end of female, dorsal view. E . Abdominal end of female, ventral view. F . Abdominal end of female, caudal view. G . Body of male, dorsal view. H . Body of male, excluding head and prothorax, ventral view. I . Basal part of right middle leg of male, ventral view. J . Proctiger of male, dorsal view. K . Left paramere, lateral aspect, two different views. Scale bars: A–I = 1 mm; J–K = 0.2 mm. COLORATION . Median black spot of head posteriorly bifurcate. Pronotum mainly black with a median brownish-yellow spot. Mesonotum mainly black with a median brownish-yellow stripe. Metanotum chiefly blackish, without yellow markings ( Figs 4G , 28G ). Connexivum dorsally blackish. Mesosternum chiefly blackish with a median subtriangular yellowish spot, narrower than that of female ( Fig. 28H ). Abdominal venter light yellow. LEG . Middle trochanter without spines; middle femur with scattered small spines, not arranged in distinct row ( Fig. 28I ). GENITALIA . Abdominal segment VIII ventro-laterally impressed. Pygophore large, ovate. Proctiger with angular lobes laterally ( Figs 6I , 28J ). Paramere relatively slender, curved at basal third, distal part tapering towards hook-shaped apex ( Figs 8G , 28K ). Distribution China : Fujian , Guizhou , Hunan , Hubei , Sichuan , Yunnan (first records); Guangdong , Guangxi ( Andersen & Chen 1995 ). Comparative notes Rhyacobates edentatus can be distinguished from the other species of Rhyacobates by the combination of following features of the female: the posterior part of the abdomen is curved dorsad to an oblique position, both sides of abdominal segment VII are dorsally folded mesad, almost meeting each other over the mediotergite ( Fig. 28D–F ), and the posterior margin of sternum VII is obtusely angled or truncate, and without posterior processes ( Fig. 28E ).