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 bilobatoides Chen & Nieser, 1993 ( Figs. 1, 2 , 5, 6 , 33 , 47–51 ) Metrocoris bilobatoides Chen & Nieser, 1993: 20–21 , Figs. 48, 52–53 , 60–62 ( type locality: Tam Dao , Vinh Phuc , Vietnam ). Material examined. VIETNAM : Ha Giang Prov. : 2 males , 1 female (apt) , 1 male (mpt), Vi Xuyen , Xin Chai commune, Da stream by the road from Thanh Thuy to Lao Chai , coll. Tran A.D. et al., 09 May 2014 , TAD1405 ( ZMHU ) ; 3 males , 1 female (mpt), Bac Quang, km 13 road 177, Tan Lap commune, waterfall & stream, ca. 86 km to Coc Pai town , coll. Tran A.D. et al., 10 May 2014 , TAD1410 ( ZMHU ) ; 1 male (apt), 1 male , 1 female (mpt), Hoang Su Phi , Nam Ty commune, bridge at km 34 road 177, waterfall & stream, ca. 65 km to Coc Pai , coll. Tran A.D. et al., 10 May 2014 , TAD1411 ( ZMHU ) ; 3 males , 3 females (apt), 4 males , 1 female (mpt), Xin Man , Nam Dan commune, Thac Tien - Deo Gio , stream 100 m below waterfall, coll. Tran A.D. et al., 11 May 2014 , TAD1413 ( ZMHU ) ; 1 female (apt), Xin Man , Nam Dan commune, Thac Tien - Deo Gio , waterfall & stream, coll. Tran A.D. et al., 11 May 2014 , TAD1414 ( ZMHU ) . Lao Cai Prov. : 1 female (apt), Sa Pa , Nui Xe , small waterflow near the Forest Ranger Station , coll. Tran A.D. , 2 June 2003 , TAD0339 ( ZRC ) ; 1 male (mpt), Sa Pa , Hoang Lien N’Park , Sin Chai , coll. Tran A.D. , 1 June 2003 , TAD0337 ( ZRC ) ; 3 males , 2 females (apt), Sa Pa , Hoang Lien N’Park , Sin Chai , coll. Tran A.D. , 3 July 2004 , TAD0415 ( ZRC ) ; 4 males , 5 females (apt), Cat Cat , 1200 m asl , 5 km SW. of Sa Pa , 22°19.720′N 103°50.023′E , coll. L. Peregovits & T. Vásárhelyi , 12 March 1998 , No. 1 ( MTMB ) ; 22 males , 32 females (apt), 2 males , 3 females (mpt), rocky river and tributary 7 km NE. of Sa Pa on Lào Cai road, 1220 m asl , 22°22′19″N , 103°52′16″E , water temp. 17°C, 7 April 2000 , 0830–1000 hrs., CL 4395, coll. D.A. Polhemus , J.T. Polhemus & P. Nguyen ( USNM , BPBM ) ; 2 females (apt), rocky streamlet with cascades, 16 km NW. of Sa Pa on Lai Chau road, 1890 m asl , 22°21′28″N , 103°46′37″E , water temp. 17°C, 8 April 2000 , 1315–1330 hrs., CL 4402, D.A. Polhemus , J.T. Polhemus & P. Nguyen ( USNM , BPBM ) ; 26 males , 20 females (apt), 1 female (mpt), rocky stream 12 km NW. of Sa Pa on Lai Chau road, 1815 m asl , 22°22′22″N , 103°47′35″E , water temp. 18.5°C, 8 April 2000 , 1530–1645 hrs., CL 4404, coll. D.A. Polhemus , J.T. Polhemus & P. Nguyen ( USNM , BPBM ) ; 1 male (apt), cascading stream 20 km NE. of Sa Pa on Lào Cai road, 565 m asl , 22°26′20″N , 103°55′36″E , water temp. 19°C, 9 April 2000 , 1215–1430 hrs., CL 4406, coll. D.A. Polhemus , J.T. Polhemus & P. Nguyen ( USNM , BPBM ) ; 2 males , 1 female (apt), Sapa area , small stream crossing road from Quy Hô to Ta Giang Phinh , 9 May 1995 , coll. D. Currie , B. Hubley & J. Swann , ROM 956023, hemock forest, second growth ( USNM ) ; 1 male (apt), Sa Pa , Cat Cat , Muong Hoa stream, coll. Dinh N.H. et al., 22 April 2011 , DNH11.01 ( ZMHU ) ; 1 male , 1 female (apt), 1 male , 1 female (mpt), Sa Pa , Sin Chai , Muong Hoa stream, coll. Dinh N.H. et al., 22 April 2011 , DNH11.03 ( ZMHU ) ; 1 male (apt), Sa Pa , Sin Chai , feeder stream of Muong Hoa stream, coll. Dinh N.H. et al., 22 April 2011 , DNH11.04 ( ZMHU ) ; 1 male (apt), Sa Pa , O Quy Ho pass, stream and waterfall, ca. 9 km from Sa Pa town , coll. Dinh N.H. et al., 23 April 2011 , DNH11.11 ( ZMHU ) ; 1 male , 1 female (mpt), Sa Pa , Ban Den , Ta Van , Muong Hoa stream, coll. Dinh N.H. et al., 24 April 2011 , DNH11.13 ( ZMHU ) ; 1 male , 2 females (apt), Sa Pa , Ban Ho , Nam Pu stream 2, coll. Dinh N.H. et al., 22 October 2012 , DNH12.02 ( ZMHU ) ; 1 male , 1 female (apt), Sa Pa , Seo Trung Ho stream, coll. Dinh N.H. et al., 22 October 2012 , DNH12.05 ( ZMHU ) ; 1 male , 2 females (apt), Sa Pa , Thanh Phu , near junction of Nam Cang and Muong Hoa streams, coll. Dinh N.H. et al., 23 October 2012 , DNH12.06 ( ZMHU ) ; 1 female (apt), Sa Pa , Nam Sai , Seo Nam Sai stream 1, coll. Dinh N.H. et al., 24 October 2012 , DNH12.09 ( ZMHU ) ; 3 females (apt), Sa Pa , Ban Ho , Nam Pu stream (feeder stream of Muong Hoa stream), site 1, at lower section, coll. Tran A.D. et al., 26 October 2013 , TAD1361 ( ZMHU ) ; 7 males , 7 females (apt), Sa Pa , Sin Chai , Sin Chai stream, site 1, coll. Tran A.D. et al., 27 October 2013 , TAD1363 ( ZMHU ) ; 2 males , 4 females (apt), Sa Pa , Sin Chai , Sin Chai stream, site 2, feeder stream, coll. Tran A.D. et al., 27 October 2013 , TAD1364 ( ZMHU ) ; 1 female (apt), 1 male (mpt), Sa Pa , Sin Chai , Muong Hoa stream ( Cát stream), coll. Tran A.D. et al., 27 October 2013 , TAD1365 ( ZMHU ) ; 2 females (apt), Sa Pa , Cat Cat , Ho stream (feeder stream of Muong Hoa stream), coll. Tran A.D. et al., 27 October 2013 , TAD1366 ( ZMHU ) ; 2 males , 4 females (apt), Sa Pa , Cat Cat , Muong Hoa stream ( Cát stream), coll. Ngo Q.H. et al., 27 October 2013 , TAD1367 ( ZMHU ) ; 2 males (apt), 1 female (mpt), Sa Pa , Trung Chai , km119 Nat. Road #4D, coll. Ngo Q.H. et al., 28 October 2013 , TAD1370 ( ZMHU ) . Vinh Phuc Prov. : 5 males , 2 females (apt), Tam Dao , 1200 m asl , coll. Vásárhelyi , 14 October 1986 , No. 50 ( MTMB , NHMW ) ; 2 males (mpt), Vinh Phu , Tam Dao , 1200 m asl , coll. M. Josifov , 8 April 1978 ( NHMW ) ; 1 male (apt), Tam Dao , forest stream, 1000–1100 m asl , coll. Papácek , 17 May 1995 ( NHMW ) ; 12 males , 10 females (apt), 13 males , 10 females (mpt), Vinh Phu , Tam Dao , coll. L. Dembicky , 9–18 May 1996 ( NHMW ) ; 1 female (apt), 2 females (mpt), 21°27′N 105°39′E , 70 km NW. Hanoi , Tam Dao , 900–1200 m asl , coll. Pacholátko & Dembicky , 9–19 May 1996 ( NHMW ) ; 2 males , 1 female (apt), Tam Dao , 1200 m asl , coll. Vásárhelyi , 12 October 1986 , No. 26 ( MTMB ) ; 3 males (apt), Tam Dao , 1200 m asl , on light, coll. Vásárhelyi , 13 October 1986 , No. 37 ( MTMB ) ; 7 males , 11 females (apt), 3 males (mpt), Tam Dao N’Park , Suoi Mo (upstream of Thac Bac waterfall), coll. Tran A.D. , 16 June 2003 , TAD0350 ( ZRC ) ; 8 males , 7 females (apt), 2 females (mpt), Tam Dao N’Park , Thac Bac stream (near Doi Che ), coll. Tran A.D. , 17 June 2003 , TAD0351 ( ZRC ) ; 7 males , 6 females (apt), 3 males , 4 females (mpt), Tam Dao N’Park , Suoi Bua Lon ( Bua Lon stream), coll. Tran A.D. , 19 June 2003 , TAD0356 ( ZRC ) ; 2 males , 3 females (apt), 1 male (mpt), stream at Tam Dao , NW. of Hanoi , 940 m asl , vic. 21°27′53″N , 105°38′45″E ,water temp. 17°C, 18 March 2000 , CL 4359, coll. J.T. Polhemus & P. Nguyen ( USNM ) ; 1 male , 1 female (apt), waterfall below Tam Dao , NW. of Hanoi , 870 m asl , 21°27′11″N , 105°38′35″E , water temp. 17°C, 18 March 2000 , CL 4360, coll. J.T. Polhemus & P. Nguyen ( USNM , BPBM ) . Ninh Binh Prov. : 1 male , 1 female (apt), Cuc Phuong , 400 m asl , coll. Vásárhelyi , 17 October 1986 , No. 68 ( MTMB ) . Figs. 32–43. Parameres of Metrocoris species. 32: M. stranguloides , specimen from Vietnam, Gia Lai Prov., 60 km N. of An Khe (CL 4309). 33: M. bilobatoides , specimen from Vietnam, Lao Cai Prov., 12 km NW. of Sa Pa (CL 4404). 34: M. johnpolhemi , new species , specimen from Vietnam, Lai Chau Prov., Nam Ceung stream (CL 4409). 35: M. quynhi , specimen from Vietnam, Lao Cai Prov., 18 km NW. of Sa Pa (CL 4400). 36: M. obscurus , specimen from Vietnam, Lao Cai Prov., 4 km NE. of Sa Pa (CL 4407). 37: M. acutus , specimen from Vietnam, Hai Hung Prov., 22 km N. of Chi Linh (CL 4375). 38: M. nigrofascioides , specimen from Vietnam, Binh Dinh Prov., An Khe Pass (CL 4291). 39: M. sicilis , new species , specimen from Vietnam, Hanoi, Ba Vi N’Park (CL 4393). 40: M. triangulatus , specimen from Vietnam, Gia Lai Prov., N. of Tram Lap (ROM-961066). 41: M. ciliatus , paratype, from Vietnam, Lai Chau Prov., Muong Te (TAD1329). 42: M. nigriventris , new species , paratype, from Vietnam, Lao Cai Prov., 20 km NE. of Sa Pa (CL 4406). 43: M. monticola , new species , paratype, from Vietnam, Lao Cai Prov., Sa Pa, Sin Chai (TAD1363). Figs. 44–55. Morphological features of Metrocoris species. 44–46: M. stranguloides . 44, 45: right fore legs of male. 46: sternum 7 of female, ventral view. 47–51: M. bilobatoides . 47, 48: right fore leg of male, same scale. 49, 50: tergum 7 of female, dorsal view (49: specimen from Tam Dao; 50: specimen from Lao Cai). 51: sternum 7 of female, ventral view. 52–55: M. vietnamensis (52–55 reproduced and modified from Tran & Zettel, 2005 ). 52, 53: right fore legs of male. 54: left paramere. 55: sternum 7 of female, in situ (44, 45, 47, 48, 52, 53 same scale; 46, 49–51, 55 same scale). Diagnosis. Male: fore femur moderately incrassate (variations existed, ratio length/width about 3.60–4.75), indentation on ventral surface with small tooth on proximal edge, and a stout sub-apical tooth (in more slender fore femur, indentation usually smaller, Figs. 47, 48 ). Male genitalia large: segment 8, pygophore and proctiger elongate; paramere prominent, falciform with pointed apex ( Fig. 33 ), endosoma as in Chen & Nieser (1993 : Fig. 62 ). Female: tergum 7 sub-triangular, sometimes apex medially produced ( Figs. 49, 50 ); sternum 7 large, posterior part constricted and produced two separate lobes, sometimes curved dorsad, completely enclosing genitalia, the notch between two lobes narrow, angular ( Fig. 51 ). Size: apterous males: length 5.3–5.8, width 2.38–2.81, macropterous males: length 6.6–7.6, width 2.29–2.64 (mpt); apterous females: length 4.8–5.6, width 2.57–2.87, macropterous females: length 6.3–6.8, width 2.62–2.77. Remarks. The specimens from Lao Cai Prov. present some structural variations in regard to tergum 7 of the female. In the female specimens from this locality, tergum 7 has its apex distinctly produced ( Fig. 50 ), while female specimens from the type locality have the apex only slightly produced ( Fig. 49 ). Other characters (endosoma, fore leg, parameres of the male, sternum 7 of the female) indicate that these populations are conspecific, with the variations in tergum 7 representing intra-specific variation. For further notes, see Remarks for M. johnpolhemi , new species . Distribution. Vietnam : Lao Cai , Ha Giang (first record), Vinh Phuc , Ninh Binh ( Fig. 138 ).