Rhyacobates edentatus Andersen & Chen, 1995

Leng, Zhaoqi, Tran, Anh Duc & Ye, Zhen, 2023, Taxonomic review of Rhyacobates Esaki, 1923, with descriptions of three new species (Hemiptera: Heteroptera: Gerridae), European Journal of Taxonomy 893 (1), pp. 1-73 : 42-47

publication ID	https://doi.org/ 10.5852/ejt.2023.893.2285
publication LSID	lsid:zoobank.org:pub:D9DA4879-BC1D-4947-96E8-7D574DE334BA
DOI	https://doi.org/10.5281/zenodo.10063665
persistent identifier	https://treatment.plazi.org/id/045E878D-FFF5-2915-39E1-F8E273770B8B
treatment provided by	Plazi
scientific name	Rhyacobates edentatus Andersen & Chen, 1995
status

Treatment

Rhyacobates edentatus Andersen & Chen, 1995 View in CoL

Figs 3J View Fig , 4G View Fig , 5I View Fig , 6I View Fig , 8G View Fig , 27–28 View Fig View Fig

Rhyacobates edentatus Andersen & Chen, 1995: 63–64 View in CoL , figs 33–36 (original description).

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 View Fig , 28A View Fig ); 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 View Fig ), posterior margin of sternum VII truncate or with obtuse angle ( Fig. 28E View Fig ). Male: middle trochanter without spines; middle femur with scattered small spines, not arranged in distinct row ( Fig. 28I View Fig ); length of middle tibia ca 1.9–2.0 times length of hind tibia; proctiger with angular lobes laterally ( Figs 6I View Fig , 28J View Fig ); paramere relatively slender, curved at basal third, distal part tapering towards hook-shaped apex ( Figs 8G View Fig , 28K View Fig ).

Material examined

Holotype ( Fig. 27A–B View Fig )

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 View Fig )

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 GoogleMaps . – 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 GoogleMaps • 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 GoogleMaps • 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 GoogleMaps • 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 GoogleMaps • 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 GoogleMaps • 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 GoogleMaps • 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 GoogleMaps • 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 GoogleMaps • 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 GoogleMaps • 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 GoogleMaps • 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 GoogleMaps .

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 View Fig , 28A View Fig ). Connexivum dorsally brownish-yellow. Abdominal tergum I yellow or with a yellow marking. Mesosternum chiefly blackish with a median subtriangular yellowish spot ( Fig. 28B View Fig ). Abdominal venter light yellow.

ABDOMEN. Abdomen relatively short, with posterior part curved dorsad to oblique position ( Figs 5I View Fig , 28C View Fig ). Connexiva erect anteriorly, reflexed above terminal mediotergites ( Figs 3J View Fig , 28A View Fig ), or never converging. Abdominal segment VII elongate ( Fig. 28C View Fig ), nearly as long as two preceding abdominal segments together ventrally, completely enclosing genital segments ( Fig. 28D View Fig ). Both sides of abdominal segment VII folded mesad on dorsal side, almost meeting each other over mediotergite ( Fig. 28D–F View Fig ), posterior margin of sternum VII truncate or with obtuse angle ( Fig. 28E View Fig ).

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.

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 View Fig , 28G View Fig ). Connexivum dorsally blackish. Mesosternum chiefly blackish with a median subtriangular yellowish spot, narrower than that of female ( Fig. 28H View Fig ). Abdominal venter light yellow.

LEG. Middle trochanter without spines; middle femur with scattered small spines, not arranged in distinct row ( Fig. 28I View Fig ).

GENITALIA. Abdominal segment VIII ventro-laterally impressed. Pygophore large, ovate. Proctiger with angular lobes laterally ( Figs 6I View Fig , 28J View Fig ). Paramere relatively slender, curved at basal third, distal part tapering towards hook-shaped apex ( Figs 8G View Fig , 28K View Fig ).

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 View Fig ), and the posterior margin of sternum VII is obtusely angled or truncate, and without posterior processes ( Fig. 28E View Fig ).