Rhyacobates anderseni Tran & Yang, 2006

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 : 34-36

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.8385640
persistent identifier	https://treatment.plazi.org/id/045E878D-FFFD-291F-3A05-FCCC714B0E96
treatment provided by	Plazi
scientific name	Rhyacobates anderseni Tran & Yang, 2006
status

Treatment

Rhyacobates anderseni Tran & Yang, 2006 View in CoL

Figs 3F View Fig , 4E View Fig , 5E View Fig , 6E View Fig , 8E View Fig , 23 View Fig

Rhyacobates anderseni Tran & Yang, 2006: 14–16 View in CoL , figs 7–16, 27 (original description).

Rhyacobates anderseni View in CoL – Tran & Nguyen 2016: 513 View Cited Treatment (with remarks).

Diagnosis

Body length of females 6.79–7.30, of males 6.00–6.20. Both sexes: mesonotum mainly black with a median brownish-yellow stripe (broader in female, narrower in male); metanotum chiefly blackish, without yellow markings ( Figs 3F View Fig , 23A View Fig ). Female: hind margin of metanotum with a pointed median process extending over abdominal tergum I ( Fig. 23C–D View Fig ); pronotum mainly black with a median brownish-yellow spot; posterior margin of abdominal segment VII with four processes, dorsally with a long process terminating each connexivum ( Fig. 23F–G View Fig ), laterally with a pair of pointed processes ( Fig. 23F, H View Fig ), ventrally almost truncate, without median process ( Fig. 23H View Fig ). Male: middle trochanter without spines; middle femur with scattered small spines, not arranged in distinct row ( Fig. 23K View Fig ); length of middle tibia ca 1.8–1.9 times length of hind tibia; proctiger with rounded lobes laterally ( Figs 6E View Fig , 23L View Fig ); paramere relatively stout and evenly curved, middle part thickened, distal part tapering towards rounded apex ( Figs 8E View Fig , 23M View Fig ).

Material examined

Type specimens

See Tran & Yang (2006).

Non-type specimens

CHINA • 5 ♁♁, 3 ♀♀ (apterous); Yunnan Province, Jing-hong City, Cai-yang River ; 22°33′4.1″ N, 101°5′14.6″ E; 879 m a.s.l.; 30 Jul. 2016; Zhen Ye leg.; NKUM GoogleMaps .

VIETNAM • 1 ♁ (apterous), 1 ♁ (macropterous); Hà Tĩnh Province, Vũ Quang National Park, Khe Nam Châm stream, site #1, upstream; 18°17′31.5″ N, 105°21′18.7″ E; 21 Apr. 2022; A.D. Tran et al. leg.; TAD2208; ZVNU GoogleMaps • 1 ♀ (macropterous); same collection data as for preceding; NKUM GoogleMaps .

GPS data of previous records: see Tran & Yang (2006).

Supplemental description

Apterous female

MEASUREMENTS. Body length 6.79–7.30, width 2.00–2.60, head width 1.32, interocular width 0.58, eye length (dorsal view) 0.59; relative lengths of antennal segments I–IV: 3:0.86: 1.21: 0.74; pronotum: length 0.73, width 1.47; mesonotum: length 2.36, width 2.54; metanotum: length 0.88, width 1.98; abdomen length (ventral view) 2.88; abdominal sternum VII: length 1.23, width 1.18; abdominal mediotergite I: length 0.15, width 0.96; relative lengths of leg segments (femur:tibia: tarsal segment I:tarsal segment II): fore leg: 3.03: 2.35:1.17:0.83, middle leg: 8.75: 5.35:2.63:0.45, hind leg: 8.85:3.08:0.15: 0.21.

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 3F View Fig , 23A View Fig ). Connexivum dorsally blackish. Venter of female chiefly blackish with a median yellowish spot ( Fig. 23B View Fig ). Abdominal venter light yellow.

ABDOMEN. Hind margin of metanotum produced as a median protuberance over abdominal tergum I ( Fig. 23C–D View Fig ). Abdomen relatively short, nearly straight, moderately curved dorsad posteriorly ( Figs 5E View Fig , 23E View Fig ). Connexivum on abdominal segments I–VI dorsally blackish, forming a straight line in dorsal view ( Figs 3F View Fig , 23A View Fig ). Abdominal segment VII elongate, nearly as long as three preceding abdominal segments together ( Fig. 23E View Fig ), completely enclosing genital segments ( Figs 3F View Fig , 23G View Fig ). Posterior margin of abdominal segment VII with four processes, dorsally with a long, slender process terminating each connexivum ( Fig. 23G View Fig ), laterally with a pair of pointed processes ( Fig. 23F, H View Fig ), ventrally almost truncate, without a median process ( Fig. 23H View Fig ).

Apterous male

MEASUREMENTS. Body length 6.00–6.20, width 1.70–1.90, head width 1.21, interocular width 0.55, eye length (dorsal view) 0.53; relative lengths of antennal segments I–IV: 2.84: 0.89:1.14:0.78; pronotum: length 0.68, width 1.31; mesonotum: length2.13,width 1.85; metanotum:length 0.64, width 1.65;abdomen length (ventral view) 1.94; abdominal sternum VII: length 0.38, width 0.59; abdominal mediotergite I: length 0.19, width 0.68; relative lengths of leg segments (femur:tibia: tarsal segment I:tarsal segment II): fore leg: 3.04: 2.44:0.89:0.54, middle leg: 8.80: 4.86:2.38:0.36, hind leg: 8.75:2.62:0.11: 0.15.

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 4E View Fig , 23I View Fig ). Connexivum dorsally blackish. Metasternum anteriorly blackish and posteriorly light yellow ( Fig. 23J View Fig ). Abdominal venter anteriorly blackish and posteriorly light yellow or completely light yellow.

LEG. Middle trochanter without spines; middle femur with scattered small spines, not arranged in distinct row ( Fig. 23K View Fig ).

GENITALIA. Abdominal segment VIII ventro-laterally impressed. Pygophore large, ovate. Proctiger with rounded lobes laterally ( Figs 6E View Fig , 23L View Fig ). Paramere relatively stout and evenly curved, middle part thickened, distal part tapering towards rounded apex ( Figs 8E View Fig , 23M View Fig ).

Distribution

China: Yunnan; Vietnam: Hà Tĩnh ( Tran & Yang 2006).

Comparative notes

Rhyacobates anderseni is distinct from all congeners in having a median process on the posterior margin of the metanotum in the female ( Fig. 23D View Fig ), which is present in three other ptilomerine genera, i.e., Andersenius , Pleciobates and Jucundus Distant, 1910 . However, this species matches all other characteristics of Rhyacobates defined by Andersen & Chen (1995), as discussed by Tran & Yang (2006: 16). Future phylogenetic studies using molecular data may help to resolve the taxonomic position of this species.