Rhyacobates malaisei Andersen & Chen 1995
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 malaisei

description: Rhyacobates malaisei Andersen & Chen, 1995
Figs 3M, 4J, 5L, 7C, 8I, 30
Rhyacobates malaisei Andersen & Chen, 1995: 59–61, figs 18–61 (original description).
Diagnosis
Body length of apterous females 7.00–9.82, of apterous males 6.00–6.81. Female: pronotum mainly black with a median subtriangular brownish-yellow spot; mesonotum mainly black with a median brownish-yellow stripe; metanotum completely black, without median yellow stripe; connexiva erect on abdominal segments I–VI, parallel to each other above mediotergites, curved mesad over mediotergite VII (Fig. 30A), meeting in middle of abdominal dorsum (Fig. 30D) or overlapping each other (Fig. 30E); abdominal segment VII dorsally with a long process terminating each connexivum (Fig. 30F), posterior margin of the long process with dense setae; abdominal segment VII laterally with a pair of small, pointed processes (Fig. 30G); posterior margin of sternum VII truncate or slightly sunken, without median process (Fig. 30F). Male: median black spot of head posteriorly bifurcate and extending to the hind margin of head; pronotum mainly black with a median subtriangular brownish-yellow spot; middle trochanter without spines; middle femur with scattered small spines, not arranged in distinct row (Fig. 30J); length of middle tibia ca 2.0–2.1 times length of hind tibia; proctiger widened, with angular lateral lobes produced into small process directing postero-ventrad (Figs 7C, 30K); paramere relatively slender and evenly curved, apex slightly spatulate (Figs 8I, 30L).
Material examined
Non-type specimens
CHINA – Yunnan Province • 1 ♁, 4 ♀♀ (apterous); An-ning City, Qing-long County; 25°0′58.1″ N, 102°19′35.2″ E; 790 m a.s.l.; 28 Jun. 2016; Hua-xi Liu leg.; NKUM • 7 ♁♁, 8 ♀♀ (apterous); Da-li City; Yang-bi County; 25°42′25.3″ N, 99°56′49.8″ E; 1500 m a.s.l.; 20 Aug. 2006; Xu Zhang leg.; NKUM • 2 ♁♁ (apterous); Kun-ming City; Mu-yang River; 23°4′4.7″ N, 113°12′15.0″ E; 2041 m a.s.l.; 3 Oct. 2022; Xun Hao leg.; NKUM.
Supplemental description
Apterous female
MEASUREMENTS. Body length 7.00–9.82, width 2.10–2.88, head width 1.48, interocular width 0.75, eye length (dorsal view) 0.53; relative lengths of antennal segments I–IV: 3.88: 1.03: 1.35: 0.91; pronotum: length 0.80, width 1.68; mesonotum: length 2.53, width 2.88; metanotum: length 0.78, width 2.44; abdomen length (ventral view) 4.83; abdominal sternum VII: length 1.96, width 1.51; abdominal mediotergite I: length 0.46, width 1.38; relative lengths of leg segments (femur: tibia: tarsal segment I: tarsal segment II): fore leg: 3.85: 3.15: 1.52:0.85, middle leg: 10.85: 5.91: 2.53:0.34, hind leg: 10.91:3.47: 0.19: 0.20.
COLORATION. Median black spot of head posteriorly bifurcate. Pronotum mainly black with a median subtriangular brownish-yellow spot. Mesonotum mainly black with a median brownish-yellow stripe. Metanotum chiefly black, without yellow markings (Figs 3M, 30A). Connexivum dorsally blackish. Venter of female chiefly blackish with a median yellowish spot (Fig. 30B). Abdominal venter light yellow.
ABDOMEN. Abdomen elongate, nearly straight, moderately curved dorsad towards end (Fig. 30C). Connexiva erect on abdominal segments I–VI, parallel to each other above mediotergites, reflexed over abdominal mediotergite VII (Fig. 30A), meeting in middle of abdominal dorsum (Fig. 30D) or overlapping each other (Fig. 30E). Abdominal segment VII elongate, nearly as long as two preceding abdominal segments together ventrally (Figs 5L, 30C), completely enclosing genital segments (Fig. 30D–E). Abdominal segment VII dorsally with a long process terminating each connexivum (Fig. 30F), posterior margin of the long process with dense setae. Abdominal segment VII laterally with a pair of small, pointed processes (Fig. 30G), posterior margin of sternum VII truncate or slightly sunken, without median process (Fig. 30F).
Apterous male
MEASUREMENTS. Body length 6.00–6.81, width 1.70–1.98, head width 1.21, interocular width 0.54, eye length (dorsal view) 0.48; relative lengths of antennal segments I–IV: 3.58: 0.89: 1.23:0.72; pronotum: length 0.69, width 1.32; mesonotum: length 1.91, width 1.98; metanotum: length 0.42, width 1.73; abdomen length (ventral view) 2.57; abdominal sternum VII: length 0.43, width 0.66; abdominal mediotergite I: length 0.25, width 0.62; relative lengths of leg segments (femur: tibia: tarsal segment I: tarsal segment II): fore leg: 3.54:3.01: 1.03: 0.54, middle leg: 10.11: 5.03:2.75: 0.31, hind leg: 10.56:2.56: 0.13: 0.16.
C OLORATION. Median black spot of head posteriorly bifurcate and extending to the hind margin of head. Pronotum mainly black with a median brownish-yellow spot, which is subtriangular-shaped. Pronotum mainly black with a median brownish-yellow spot. Mesonotum mainly black with a median brownish-yellow stripe. Metanotum chiefly black, without yellow markings (Figs 4J, 30H). Connexivum dorsally blackish. Mesosternum mainly blackish with a median brownish small spot (Fig. 30I). Abdominal venter dark-brownish.
ABDOMEN. Abdominal mediotergite I not swollen, fully covered with silvery pubescence.
LEG. Middle trochanter without spines; middle femur with scattered small spines, not arranged in distinct row (Fig. 30J).
GENITALIA. Abdominal segment VIII ventro-laterally impressed. Pygophore large, ovate. Proctiger widened, with angular lateral lobes produced into small process directed postero-ventrad (Figs 7C, 30K). Paramere relatively slender and evenly curved, apex slightly spatulate (Figs 8I, 30L).
Distribution
China: Yunnan; Thailand: Chiang Mai; Myanmar: Bumgahtuang-Hpungan (Andersen & Chen 1995).
Comparative notes
Rhyacobates malaisei is most similar to R. gongvo; see comparative notes under R. gongvo.
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 51-52, DOI: 10.5852/ejt.2023.893.2285, http://zenodo.org/record/8385630