Rhyacobates scorpio 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 : 56-60

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.8385656
persistent identifier	https://treatment.plazi.org/id/045E878D-FFEB-2900-3A13-FADC733609C7
treatment provided by	Plazi
scientific name	Rhyacobates scorpio Andersen & Chen, 1995
status

Treatment

Rhyacobates scorpio Andersen & Chen, 1995 View in CoL

Figs 2D View Fig , 3O View Fig , 4L View Fig , 5N View Fig , 7E View Fig , 8K View Fig , 32–33 View Fig View Fig

Rhyacobates scorpio Andersen & Chen, 1995: 62–63 View in CoL , figs 1, 28–32 (original description).

Diagnosis

Body length of apterous females 9.22–11.95, of apterous males 8.01–8.10. Female: pronotum mainly black with a median brownish-yellow spot; mesonotum and metanotum mainly black with a median brownish-yellow stripe ( Figs 2D View Fig , 3O View Fig , 32A View Fig , 33A View Fig ); abdominal segments I–VI straight, with long, blackish setae on mesal margins of the connexivum; abdominal segment VII elongate, abruptly bent dorsad at an angle of about 90° ( Figs 5N View Fig , 33C View Fig ), dorsally with an angular process terminating each connexivum ( Fig. 33D–F View Fig ), posterior margin of sternum VII angularly produced in the middle ( Fig. 33G View Fig ). Male: middle trochanter with 3–5 spines; middle femur with spines but not in distinct row ( Fig. 33J View Fig ); length of middle tibia ca 1.2–1.4 times length of hind tibia; proctiger relatively large, with broadly rounded lobes laterally ( Figs 7E View Fig , 33K View Fig ); paramere relatively slender, strongly curved at basal fourth, distal part tapering towards hook-shaped apex ( Figs 8K View Fig , 33L View Fig ).

Material examined

Holotype ( Fig. 32A–C View Fig )

CHINA • ♀ (apterous); Sichuan Province, Song Ch′i Hsien ; Jul. 1938; D.C. Graham leg.; USNM .

Paratypes ( Fig. 32D–G View Fig )

CHINA – Sichuan Province • 2 ♁♁, 1 ♀ (apterous); E-mei Mountain, Jie-yin Temple; 14 Jul. 1957; Le-yi Zheng leg.; NKUM • 1 ♀ (apterous); Song Ch′i, Kuanhsien; Aug. 1938; D.C. Graham leg.; USNM • 1 ♀ (apterous); Wenchuan City; Aug. 1938; D.C. Graham leg.; USNM .

Non-type specimens

CHINA – Sichuan Province • 1 ♁, 1 ♀ (apterous); E-mei-shan City, E-mei Mountain, Qingyin Attic ; 29°34′29.7″ N, 103°24′38.3″ E; 19 Aug. 2013; Zhen Ye leg.; NKUM GoogleMaps • 5 ♁♁, 11 ♀♀ (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 • 2 ♁♁, 10 ♀♀ (apterous); Ya-an City, Bi-xia Mountain ; 30°4′8.9″ N, 102°59′34.6″ E; 30 Jul. 2016; Chen-guang Zheng leg.; NKUM GoogleMaps .

Supplemental description

Apterous female

MEASUREMENTS. Body length 9.22–11.95, width 3.31–3.81, head width 1.83, interocular width 0.84, eye length (dorsal view) 0.78; relative lengths of antennal segments I–IV: 4.85: 1.51:1.83:1.29; pronotum: length 1.02,width 2.08;mesonotum: length2.97, width 3.81; metanotum:length 1.25,width 3.28;abdomen length (ventral view) 5.06; abdominal sternum VII: length 1.53, width 1.58; abdominal mediotergite I: length 0.63, width 1.63; relative lengths of leg segments (femur:tibia: tarsal segment I:tarsal segment II): fore leg: 5.15: 4.59:2.23:1.32, middle leg: 14.15:8.52: 5.32: 0.59, hind leg: 14.31:7.92:0.21:0.28.

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 2D View Fig , 3O View Fig , 32A View Fig , 33A View Fig ). Connexivum dorsally brownish-yellow. Abdominal tergum I with a median yellow marking. Mesosternum chiefly blackish with two median yellowish spots, divided by a blackish line ( Fig. 33B View Fig ). Abdominal venter light yellow.

ABDOMEN. Abdomen relatively short, gradually tapering towards apex ( Fig. 33C View Fig ). Connexiva on abdominal segments I–VI erect, not meeting each other above mediotergites, reflexed upon abdominal mediotergite VII ( Fig. 33A View Fig ). Abdominal segment VII elongate, completely enclosing genital segments, nearly as long as two preceding abdominal segments together, abruptly turning dorsad at a maximum angle of about 90°, dorsally with an angular process terminating each connexivum ( Fig. 33D–F View Fig ), posterior margin of sternum VII angularly produced in the middle ( Fig. 33G View Fig ).

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; posterior margin broadly rounded and brownish; abdominal segment VII only weakly turned dorsad.

MEASUREMENTS. Body length 11.31, width 3.58, head width 1.64, interocular width 0.84, eye length (dorsal view) 0.73; relative lengths of antennal segments I–IV: 4.63:1.34: 1.62: 1.22; pronotum: length 4.61, width 2.81; mesonotum width 3.58; metanotum: length 0.85, width 3.23; abdomen length (ventral view) 4.68; abdominal sternum VII: length 2.15, width 1.63; abdominal mediotergite I: length 0.66, width 1.17; relative lengths of leg segments (femur:tibia: tarsal segment I:tarsal segment II): fore leg: 4.68:4.28:1.98: 1.15, middle leg: 12.70: 7.26: 3.76:0.58, hind leg: 13.56:6.78: 0.18: 0.29.

Apterous male

MEASUREMENTS. Body length 8.01–8.10, width 1.60–2.81, head width 1.66, interocular width 0.83, eye length (dorsal view) 0.64; relative lengths of antennal segments I–IV: 4.62: 1.48: 1.70: 1.18; pronotum: length 0.91, width 1.83; mesonotum: length 2.38, width 2.81; metanotum: length 0.91, width 2.41; abdomen length (ventral view) 3.72; abdominal sternum VII: length 0.54, width 1.34; abdominal mediotergite I: length 0.41, width 1.06; relative lengths of leg segments (femur: tibia: tarsal segment I: tarsal segment II): fore leg: 5.16:4.40: 1.44: 0.70, middle leg: 13.02:7.44: 3.78: 0.59, hind leg: 13.35: 6.13: 0.19: 0.29.

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 4L View Fig , 33H View Fig ). Connexivum dorsally blackish. Mesosternum chiefly blackish with median brownish spots or totally blackish ( Fig. 33I View Fig ). Abdominal venter dark-yellow.

LEG. Middle trochanter with 3–5 spines on distal part; middle femur with spines but not in distinct row ( Fig. 33J View Fig ).

GENITALIA. Abdominal segment VIII ventro-laterally impressed. Pygophore large, ovate. Proctiger relatively large, with broadly rounded lobes laterally ( Figs 7E View Fig , 33K View Fig ). Paramere relatively long and slender, strongly curved at basal fourth, distal part tapering towards hook-shaped apex ( Figs 8K View Fig , 33L View Fig ).

Dealated macropterous male

MEASUREMENTS. Body length 8.35, width 2.78, head width 1.57, interocular width 0.78, eye length (dorsal view) 0.61; relative lengths of antennal segments I–IV: 4.52: 1.43: 1.61:1.18; pronotum: length 3.20, width 2.51; mesonotum width 2.78; metanotum width 2.46; abdomen length (ventral view) 2.90; abdominal sternum VII: length 0.51, width 1.33; abdominal mediotergite I: length 0.44, width 1.09; relative lengths of leg segments (femur:tibia: tarsal segment I: tarsal segment II): fore leg: 4.85: 4.05: 1.38: 0.95, middle leg: 13.01: 7.55:3.98: 0.54, hind leg: 13.45:6.19: 0.15: 0.23.

Distribution

China: Sichuan ( Andersen & Chen 1995).

Comparative notes

The female of R. scorpio can be distinguished from that of all other species of Rhyacobates by the unique shape of its abdomen ( Figs 5N View Fig , 33C View Fig ): abdominal segments I–VI are straight, with long, blackish setae on the lateral margins of the connexivum; abdominal segment VII is elongate, and abruptly turns dorsad at a maximum angle of about 90°, dorsally with an angular process terminating each connexivum ( Fig. 33D–F View Fig ), ventrally with a median process ( Fig. 33G View Fig ).