Rhyacobates chinensis Hungerford & Matsuda 1959
Creators: name: Leng, Zhaoqi
name: Tran, Anh Duc
name: Ye, Zhen
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Gerridae
Rhyacobates
Rhyacobates chinensis

description: Rhyacobates chinensis Hungerford & Matsuda, 1959
Figs 2B, 3H, 4F, 5G, 6G, 8F, 11–13, 25
Rhyacobates chinensis Hungerford & Matsuda, 1959: 69 (original description).
Rhyacobates esakii Miyamoto & Lee, 1963: 43 (synonymized with Rhyacobates chinensis).
Rhyacobates chinensis – Andersen & Chen 1995: 57, figs 6–11 (with remarks).
Diagnosis
Body length of apterous females 8.01–9.45, of apterous males 6.20–6.81. Female: pronotum mainly black with a median brownish-yellow spot; mesonotum and metanotum mainly black with a median brownish-yellow stripe (Figs 3H, 25A); posterior margin of abdominal segment VII with five processes, including a short, angular process terminating each connexivum, a pair of pointed processes laterally, which are as long as or longer than connexival process, ventrally with a pointed, median process (Figs 5G, 25G–I). Male: middle trochanter with 3–6 spines; middle femur with spines but not in distinct row (Fig. 25L); length of middle tibia ca 1.5–1.7 times length of hind tibia; proctiger with angular lobes laterally (Figs 6G, 25M); paramere relatively slender and sinuate, basal and middle parts thickened, distal part tapering towards hook-shaped apex (Figs 8F, 25N).
Material examined
Non-type specimens
CHINA – Chongqing City • 13 ♁♁, 15 ♀♀ (apterous); Si-mian Mountain; 28°36′30.4″ N, 106°22′19.2″E; 895 m a.s.l.; 10 Aug. 2016; Yan-fei Li leg.; NKUM. – Hebei Province • 10 ♁♁, 11 ♀♀ (apterous); Cheng-de City, Wei-chang County, Yu-dao-kou; 42°13′8.7″ N, 117°1′33.6″ E; 1200 m a.s.l.; 30 Aug. 2016; Ya-hui Zhen leg.; NKUM • 4 ♁♁, 26 ♀♀ (apterous); Cheng-de City, Xing-long County, Wu-ling Mountain; 29 Aug. 1973; Sheng-li Liu leg.; NKUM. – Henan Province • 15 ♁♁, 31 ♀♀ (apterous); Xin-xiang City, Hui County, Bo-bi Village; 35°34′47.2″ N, 113°35′47.6″ E; 1200 m a.s.l.; 21 Jul. 2016; Ye Zhen leg.; NKUM. – Hubei Province • 2 ♁♁, 2 ♀♀ (apterous); Shi-yan City, Zhu-xi Village; 32°16′36.1″ N, 109°41′59.7″ E; 600 m a.s.l.; 11 Aug. 2015; Zhen Ye leg.; NKUM • 8 ♁♁, 12 ♀♀ (apterous); Jinchun County, Wen-quan Bridge; 30°14′35.2″ N, 115°43′5.2″ E; 56 m a.s.l.; 12 Jul. 2022; Zhao-qi Leng leg.; NKUM • 11 ♁♁, 10 ♀♀ (apterous); Sui-zhou City, Hei-long-tan; 31°47′21.1″ N, 114°5′16.1″ E; 225 m a.s.l.; 14 Jul. 2022; Zhao-qi Leng, Chen Liu and Zi-he Li leg.; NKUM • 27 ♁♁, 29 ♀♀ (apterous); Huang-gang City, Ying-shan County, Tao-hua-chong; 30°58′5.2″ N, 116°1′29.3″ E; 719 m a.s.l.; 13 Jul. 2022; Zhao-qi Leng and Zhen Ye leg.; NKUM. – Hunan Province • 5 ♁♁, 5 ♀♀ (apterous); Zhangjia-jie City, Jin-bian-xi; 14 Oct. 1985; Huan-guang Zou leg.; NKUM. – Liaoning Province • 12 ♁♁, 13 ♀♀ (apterous); Dan-dong City, Kuan-dian County; 41°0′5.7″ N, 125°11′26.1″ E; 222 m a.s.l.; 6 Jul. 2016; Juan-juan Yuan leg.; NKUM. – Neimenggu Province • 7 ♁♁, 4 ♀♀ (apterous); Xi-lin-guo-le League, Zhong-li-fang; Aug. 1974; Zhong-ming Jiang leg.; NKUM. – Shaanxi Province • 1 ♁, 1 ♀ (apterous); Chang-zhi City, Tai-hang Mountain; 35°53′52.3″ N, 113°28′57.9″ E; 1070 m a.s.l.; 9 Aug. 2018; Hua-xi Liu and Xue Dong leg.; NKUM • 8 ♁♁, 9 ♀♀ (apterous); Hua County, Gao-tang Village; 34°24′23.3″ N, 109°39′1.6″ E; 1070 m a.s.l.; 7 Jul. 2014; Huan-huan Yang leg.; NKUM. – Sichuan Province • 2 ♁♁, 3 ♀♀ (apterous); Guang-yuan City, Shui-mo-gou; 32°48′3.4″ N, 106°3′33.7″ E; 1002 m a.s.l.; 19 Jul. 2016; Yan-chen Li leg.; NKUM • 6 ♁♁, 7 ♀♀ (dealated macropterous); Guang-yuan City, Shui-mo-gou; 32°48′3.4″ N, 106°3′33.7″ E; 1002 m a.s.l.; 19 Jul. 2016; Yan-chen Li leg.; NKUM • 2 ♁♁, 3 ♀♀ (apterous); Wan-yuan City, Yu-quan Mountain; 32°9′35.6″ N, 108°8′19.4″ E; 580 m a.s.l.; 25 Aug. 2017; Chen-guang Zheng leg.; NKUM. – Tian-jin City • 2 ♀♀ (apterous); Ji-zhou District, Xia-ying Village; 29 Jul. 1985; Liu leg.; NKUM.
Supplemental description
Apterous female
MEASUREMENTS. Body length 8.01–9.45, width 2.60–3.20, head width 1.42, interocular width 0.74, eye length (dorsal view) 0.65; relative lengths of antennal segments I–IV: 4.31: 1.04:1.18:0.86; pronotum: length 0.74, width 1.66;mesonotum: length2.42, width 3.03; metanotum:length 0.62, width 2.75;abdomen length (ventral view) 4.69; abdominal sternum VII: length 1.82, width 1.75; abdominal mediotergite I: length 0.54, width 1.36; relative lengths of leg segments (femur:tibia: tarsal segment I:tarsal segment II): fore leg: 4.36: 3.84:1.96:0.88, middle leg: 12.51:6.85: 3.32: 0.48, hind leg: 14.21:5.45:0.15:0.25.
C OLORATION. 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 3H, 25A). Connexivum dorsally brownish-yellow. Abdominal tergum I completely yellow or with a median yellow marking. Mesosternum chiefly blackish with a median subtriangular yellowish spot (Fig. 25B). Abdominal venter light yellow.
ABDOMEN. Abdomen relatively short, curved dorsad towards end at different angles. Connexiva convergent along dorsal midline of abdominal segments IV–VI, meeting erectly above terminal mediotergites (Fig. 25A). Abdominal segment VII elongate, nearly as long as three preceding abdominal segments together (Fig. 25E). Posterior margin of abdominal segment VII with five processes, dorsally with a short, angular process terminating each connexivum, laterally with a pair of pointed processes, as long as or longer than connexival process, ventrally with a pointed median process (Fig. 25C–D). Processes of abdominal segment VII variable among populations (Fig. 25G–I).
Dealated macropterous female
Similar to apterous female in general structure and coloration with following exceptions: thorax with a pronotal lobe, anterior part with a subrhombic yellow marking, posterior part elongate, covering most of mesonotum (Fig. 25F); posterior margin broadly rounded and brownish; abdominal segment VII wider than that of apterous form.
MEASUREMENTS. Body length 9.19, width 3.48, head width 1.89, interocular width 0.86, eye length (dorsal view) 0.67; relative lengths of antennal segments I–IV: 4.38:1.64: 1.62: 1.03; pronotum: length 3.43, width 2.89; mesonotum width 3.48; metanotum: length 0.73, width 3.06; abdomen length (ventral view) 4.04; abdominal sternum VII: length 1.89, width 2.03; abdominal mediotergite I: length 0.49, width 1.31; relative lengths of leg segments (femur:tibia: tarsal segment I: tarsal segment II): fore leg: 4.44: 4.08: 2.26: 0.92, middle leg: 13.11:7.72: 3.88: 0.61, hind leg: 13.49:5.88: 0.19: 0.25.
Apterous male
MEASUREMENTS. Body length 6.20–6.81, width 1.80–2.10, head width 1.36, interocular width 0.76, eye length (dorsal view) 0.54; relative lengths of antennal segments I–IV: 3.94: 1.01: 1.04: 0.94; pronotum: length 0.74, width 1.58; mesonotum: length 2.19, width 2.18; metanotum: length 0.68, width 2.03; abdomen length (ventral view) 2.53; abdominal sternum VII: length 0.45, width 1.08; abdominal mediotergite I: length 0.34, width 0.79; relative lengths of leg segments (femur: tibia: tarsal segment I: tarsal segment II): fore leg: 3.84: 3.28: 1.16: 0.58, middle leg: 10.90:6.11: 2.63: 0.41, hind leg: 11.57: 3.52: 0.14: 0.20.
C OLORATION. 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 4F, 25J). Connexivum dorsally blackish. Mesosternum chiefly blackish with a median subtriangular yellowish spot, narrower than that of female (Fig. 25K). Abdominal venter light yellow.
LEG. Middle trochanter with 3–6 spines on distal part; middle femur with spines but not in distinct row (Fig. 25L).
GENITALIA. Abdominal segment VIII ventro-laterally impressed. Pygophore large, ovate. Proctiger with angular lobes laterally (Figs 6G, 25M). Paramere relatively slender and sinuate, middle part thickened, distal part tapering towards hook-shaped apex (Figs 8F, 25N).
Dealated macropterous male
Similar to apterous female in general structure and coloration with following exceptions: thorax with a pronotal lobe, anterior part with a subrhombic yellow marking, posterior part elongate, covering most of mesonotum; posterior margin broadly rounded and brownish.
MEASUREMENTS. Body length 7.48, width 2.64, head width 1.46, interocular width 0.76, eye length (dorsal view) 0.59; relative lengths of antennal segments I–IV: 3.86:1.12: 1.16: 0.90; pronotum: length 2.84, width 2.42; mesonotum width 2.64; metanotum: length 0.59, width 2.35; abdomen length (ventral view) 2.84; abdominal sternum VII: length 0.55, width 1.25; abdominal mediotergite I: length 0.29, width 0.89; relative lengths of leg segments (femur:tibia: tarsal segment I: tarsal segment II): fore leg: 4.06: 3.47: 1.06: 0.67, middle leg: 11.69:6.16: 2.76: 0.44, hind leg: 11.81: 4.16: 0.15: 0.21.
Distribution
China: Chongqing, Liaoning, Shaanxi, Shanxi, Sichuan (first records); Hebei, Henan, Hubei, Hunan, Inner Mongolia, Tianjin; Korea: Nam Te Cheon (Andersen & Chen 1995).
Comparative notes
Rhyacobates chinensis is most similar to R. abdominalis; see comparative notes under R. abdominalis.
description: Published as part of Leng, Zhaoqi, Tran, Anh Duc & Ye, Zhen, 2023, Taxonomic review of Rhyacobates Esaki, 1923, with descriptions of three new species (Hemiptera: Heteroptera: Gerridae), pp. 1-73 in European Journal of Taxonomy 893 (1) on pages 37-42, DOI: 10.5852/ejt.2023.893.2285, http://zenodo.org/record/8385630