The genus Metrocoris Mayr, 1865 (Gerromorpha: Gerridae) in Vietnam, with descriptions of five new species Author A. D., Tran Author Polhemus, D. A. text Raffles Bulletin of Zoology 2017 2017-05-24 65 109 149 journal article 6572 10.5281/zenodo.4502634 fde5f083-514d-400b-b886-e792390afd86 2345-7600 4502634 E9197A2F-EE46-4E5E-93C5-37E4CEC1A240 Metrocoris quynhi Tran & Zettel, 2005 ( Figs. 10, 11 , 35 , 66–70 ) Metrocoris quynhi Tran & Zettel, 2005: 45–48 , Figs. 10–17 , 25, 28, 29 ( type locality: Sa Pa , Lao Cai , Vietnam ). Material examined. Holotype and paratypes : see Tran & Zettel (2005) . Others – VIETNAM : Lao Cai Prov. : 1 female (apt), Sa Pa , Hoang Lien N’Park , Nui Xe , upstream of Suoi Vang , coll. Tran A.D. , 4 July 2004 , TAD0416 ( ZRC ) ; 5 males , 25 females (apt), 4 males , 6 females (mpt), Sa Pa , Hoang Lien N’Park , Nui Xe , Suoi Vang , coll. Tran A.D. , 4 July 2004 , TAD0417 ( ZRC ) ; 2 males , 1 female (apt), 1 immature , crest of pass N. of Mt. Fan Si Pan , 18 km NW. of Sa Pa on Lai Chau road, 1980 m asl , 22°21′10″N , 103°45′57″E , water temp. 16°C, 8 April 2000 , 09:00–11:00 hrs., CL 4400, coll. D.A. Polhemus , J.T. Polhemus & P. Nguyen ( USNM ) ; 2 males , 5 females (apt), Sa Pa , Nui Xe , Tram Ton area , small feeder of Vang stream, near waterfall, coll. Dinh N.H. et al., 23 April 2011 , DNH11.05 ( ZMHU ) ; 1 male , 1 female (apt), Sa Pa , Nui Xe , Tram Ton area , Vang stream, coll. Dinh N.H. et al., 23 April 2011 , DNH11.06 ( ZMHU ) ; 2 males , 6 females (apt), Sa Pa , Nui Xe , Tram Ton area , feeder stream of Vang stream, coll. Dinh N.H. et al., 23 April 2011 , DNH11.07 ( ZMHU ) ; 3 males , 1 female (apt), Sa Pa , Nui Xe , Tram Ton area , northward feeder stream of Vang stream, coll. Dinh N.H. et al., 23 April 2011 , DNH11.09 ( ZMHU ) ; 1 female (apt), Sa Pa , Trung Chai , km 119 Nat. Road #4D, Mong Sen stream, coll. Dinh N.H. et al., 25 April 2011 , DNH11.15 ( ZMHU ) ; 1 male (apt), Sa Pa , Nam Cang , Nam Cang stream, coll. Dinh N.H. et al., 23 October 2012 , DNH12.08 ( ZMHU ) ; 5 males , 2 females (apt), 6 males , 5 females (mpt), Sa Pa , Nui Xe , Tram Ton area , Vang stream and its feeders, coll. Tran A.D. , 30 May 2013 , TAD1319 ( ZMHU ) ; 3 males , 3 females (apt), Sa Pa , Nui Xe , Tram Ton area , Vang stream, coll. Tran A.D. et al., 25 October 2013 , TAD1356 ( ZMHU ) ; 12 males , 17 females (apt), Sa Pa , Nui Xe , Tram Ton area , feeder stream of Vang stream, coll. Tran A.D. et al., 25 October 2013 , TAD1357 ( ZMHU ) ; 5 males , 5 females (apt), Sa Pa , stream from waterfall by roadside from Nui Xe to Sa Pa town , ca. 13 km from Sa Pa , coll. Tran A.D. et al., 25 October 2013 , TAD1358 ( ZMHU ) . Lai Chau Prov. : 1 male , 1 female (apt), Tam Duong , stream at San Xa Ho bridge, km 85 Nat. Road #4D, coll. Tran A.D. , 31 May 2013 , TAD1323 ( ZMHU ) . Figs. 66–73. Morphological features of Metrocoris species. 66–70: M. quynhi (65–70 reproduced from Tran & Zettel, 2005 ). 66: right fore leg of male. 67: pygophore, lateral view. 68: male genital capsule, dorsal view. 69: left paramere. 70: female sternum 7, in situ. 71–73: M. obscurus . 71: right fore leg of male. 72: left paramere. 73: sternum 7 of female, ventral view (66, 71 same scale; 67, 68 same scale; 69, 72 same scale; 70, 73 same scale). Diagnosis. Male: fore femur incrassate (ratio length/width 3.22–3.67), distal one-third constricted, but without distinct ventral indentation, with bipartite apical tooth, of which the distal part is the elevated rim of the ventral surface; inner face of fore tibia with subbasal tooth-like elevation ( Fig. 66 ). Male genitalia: abdominal segment 8 large (see Tran & Zettel, 2005 : Fig. 11 ); pygophore, on dorsal view, prolonged and subapically constricted, with apical margin straight, and with straight, slender dorsolateral process ( Figs. 67, 68 ); proctiger long, with narrow distal part ( Fig. 68 ); paramere hook-shaped, apically pointed ( Figs. 35 , 69 ); endosoma: dorsal sclerite long and recurved proximally, apical accessory sclerite indistinct, lateral sclerite straight, ventral sclerite long (see Tran & Zettel, 2005 : Figs. 15, 16 ). Abdomen of female: sternum 7 ( Fig. 70 ) with large medial lobe; lateral parts with longitudinal ridge from anterior end of incision to hind margin, and with small, mediad directed, wing-shaped lobes covering most-lateral parts of medial lobe; medial lobe subtrapezoidal, with distinctly notched hind margin, slanted dorsocaudad; on dorsal view, tergum 7 small, hidden under tergum 6. Size: apterous males: length 6.3–7.0 ( holotype 6.6), width 3.03–3.25 ( holotype 3.10), macropterous males: length 6.4–6.5, width 3.00–3.30; apterous females: length 5.4–5.8 ( allotype 5.45), width 3.30–3.40 ( allotype 3.40), macropterous females: length 5.0–5.5, width 3.01–3.30. Remarks. Metrocoris quynhi belongs to the M. anderseni species group (sensu Chen & Nieser, 1993 ) and is the first species of this group found in Vietnam . The morphological characteristics of the M. anderseni group and a detailed comparison of Metrocoris quynhi to other members of this group has already been provided by Tran & Zettel (2005: 44–45) . Distribution. Vietnam : Lao Cai , Lai Chau (first record) ( Fig. 139 ).