Rhyacobates recurvus 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 recurvus

description: Rhyacobates recurvus Andersen & Chen, 1995
Figs 3N, 4K, 5M, 7D, 8J, 14, 31
Rhyacobates recurvus Andersen & Chen, 1995: 59, figs 16–17 (original description).
Diagnosis
Body length of apterous females 7.06–8.71, of apterous males 5.42–5.91. Female: pronotum mainly black with a median brownish-yellow spot; mesonotum and metanotum mainly black with a median brownish-yellow stripe (Figs 3N, 31A); abdomen relatively short, with posterior part distinctly curved dorsad to oblique or nearly vertical position (Figs 8J, 31C); abdominal mediosternite VII tapering caudad, posterior margin with a median process; apex of the process pointed and hook-shaped (Fig. 31D, F). Male: middle trochanter with one spine; middle femur with scattered small spines, not arranged in distinct row (Fig. 31I); length of middle tibia ca 1.6 times length of hind tibia; proctiger laterally with rounded lobes (Figs 7D, 31J); paramere relatively slender, strongly curved at basal fourth, middle part thickened, distal part tapering towards narrowly rounded apex (Figs 8J, 31J).
Material examined
Non-type specimens
CHINA – Hubei Province • 7 ♁♁, 5 ♀♀ (apterous); Huang-gang City, Ying-shan County, Jiu-gong Mountain; 29°3′25.6″ N, 107°5′55.1″ E; 130 m a.s.l.; 11 Jul. 2022; Zhao-qi Leng and Zhen Ye leg.; NKUM. – Jiangxi Province • 1 ♁, 2 ♀♀ (apterous); Nan-chang City; 2 Jun. 1919; IZAS. – Zhejiang Province • 3 ♀♀ (apterous); Jin-hua City, Pan-an County, Da-pan Mountain; 28°58′30.1″ N, 120°31′36.4″ E; 29 Jul. 2015; Wen-bo Yi leg.; NKUM.
Supplemental description
Apterous female
MEASUREMENTS. Body length 7.06–8.71, width 2.63–2.90, head width 1.42, interocular width 0.53, eye length (dorsal view) 0.60; relative lengths of antennal segments I–IV: 3.95: 1.05:0.93:0.78; pronotum: length 0.74, width 1.52;mesonotum: length2.44, width 2.63; metanotum:length 0.69, width 2.34; abdomen length (ventral view) 1.96; abdominal sternum VII: length 0.90, width 1.12; abdominal mediotergite I: length 0.28, width 1.09; relative lengths of leg segments (femur:tibia: tarsal segment I:tarsal segment II): fore leg: 4.10: 3.65:1.67:0.83, middle leg: 12.02:6.95: 2.91: 0.38, hind leg: 12.35:5.05:0.16:0.18.
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 3N, 31A). Abdominal tergum I with yellowish spots on each side or completely yellow. Connexivum dorsally brownish-yellow. Mesosternum chiefly blackish with a median subtriangular yellowish spot (Fig. 31B). Abdominal venter light yellow.
ABDOMEN. Abdomen relatively short, with posterior part distinctly curved dorsad to oblique or nearly vertical position (Figs 5M, 31C). Connexiva erect on abdominal segments I–II, converging along dorsal midline of segments III–VI, reflexed above terminal terga (Fig. 31A). Abdominal segment VII elongate, ventral margin longer than dorsal margin in lateral view (Figs 5M, 31C), nearly as long as three preceding abdominal segments together, not completely enclosing genital segments (Fig. 31D); laterosternites of connexivum VII expanded dorsad, folded mesad (Fig. 31A), meeting in middle of abdominal dorsum or overlapping each other (Fig. 31E). Abdominal sternum VII tapering caudad, posterior margin with a median process; apex of the process pointed and hook-shaped (Fig. 31D, F).
Apterous male
MEASUREMENTS. Body length 5.42–5.91, width 1.73–2.01, head width 1.23, interocular width 0.41, eye length (dorsal view) 0.49; relative lengths of antennal segments I–IV: 2.93: 0.93: 0.97: 0.73; pronotum: length 0.64, width 1.27; mesonotum: length 1.78, width 1.83; metanotum: length 0.63, width 1.73; abdomen length (ventral view) 1.91; abdominal sternum VII: length 0.42, width 0.79; abdominal mediotergite I: length 0.21, width 0.56; relative lengths of leg segments (femur: tibia: tarsal segment I: tarsal segment II): fore leg: 3.08: 2.64: 0.88: 0.54, middle leg: 9.64: 4.87: 2.17: 0.32, hind leg: 10.06: 3.10: 0.13: 0.16.
COLORATION. Median black spot of head posteriorly bifurcate. Mesonotum mainly black with a median brownish-yellow stripe. Metanotum chiefly blackish, without yellow markings (Figs 4K, 31G). Connexivum dorsally blackish. Mesosternum chiefly blackish with a median subtriangular yellowish spot, narrower than that of female (Fig. 31H). Abdominal venter light yellow.
LEG. Middle trochanter with one spine; middle femur with scattered small spines, not arranged in distinct row (Fig. 31I).
GENITALIA. Abdominal segment VIII ventro-laterally impressed. Pygophore large, ovate. Proctiger with rounded lobes laterally (Figs 7D, 31J). Paramere relatively slender, strongly curved at basal fourth, middle part thickened, distal part tapering towards narrowly rounded apex (Figs 8J, 31J).
Distribution
China: Hubei, Zhejiang (first records); Jiangxi (Andersen & Chen 1995).
Comparative notes
Rhyacobates recurvus is most similar to R. turgidus sp. nov.; see comparative notes under R. turgidus.
Remarks
Andersen & Chen (1995) described this species based on a single female specimen from Jiangxi, China. In this study, we have collected both males and females from Hubei and Zhejiang, China; thus, we can provide a description of the apterous male and additional distribution information.
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 54-56, DOI: 10.5852/ejt.2023.893.2285, http://zenodo.org/record/8385630