Three new species of the water strider genus Rhyacobates Esaki, 1923 (Hemiptera: Gerridae) from Vietnam Author Tran, A. D. Author Nguyen, X. Q. text Zootaxa 2016 4121 5 501 516 journal article 38884 10.11646/zootaxa.4121.5.1 50bb9c19-8df5-4fbf-a78b-f8ba2d6355bc 1175-5326 271684 BCADF85B-CB84-4694-963A-AF9F0E3F40D4 Rhyacobates abdominalis Andersen & Chen, 1995 Rhyacobates abdominalis Andersen & Chen, 1995 : 58 –59, Figs. 12–15 ( type locality: Ruyang Nat. Res., Guangdong Prov., China ); Tran & Yang, 2006 : 19 (record Vietnam ). Material examined. Paratypes : 1 male , 1 female (apterous), “ China : Guangdong Prov., Ruyang Nat. Res., Lao Peng Keng stream, 1100m , 14.8.1990 , coll. P.P. Chen, C9012” ( NHMW ). For formerly examined specimens (from Vietnam ), see Tran & Yang (2006) . Size. Males, length 6.8–7.0, width 2.10–2.20 (apterous), length 6.4–6.6, width 2.06–2.11 (macropterous, dealated); females, length 9.9–10.0, width 3.50 (apterous), length 9.4–9.6, width 3.14–3.30 (macropterous, dealated). Remarks. Rhyacobates abdominalis can be recognised by the following diagnostic characters: abdominal segment 8 of the male is ventrolaterally impressed; the proctiger of the male has a small angular projection on each side; the male paramere is slender with a broad basal part and hook-shaped apex (see Andersen & Chen 1995 : Fig. 15 ); the abdomen of the female is distinctly curved dorsad, abdominal segment 7 possesses a short projection on each connexivum, and the posterior margin of sternum 7 has a sharp, small median process (see Andersen & Chen 1995 : Figs. 12–14 ). The specimens of R. abdominalis from Vietnam were not significantly different compared to the paratypes from China , except for the larger size and less pointed median process of sternum 7 in the female. They were collected from the same habitat as Rhyacobates gongvo . For description notes of Vietnamese specimens, see Tran & Yang (2006: 19) . Habitats. See Tran & Yang (2006: 18, 19) . Distribution. Vietnam : Lao Cai. China : Guangdong.