Metrocoris stranguloides Chen & Nieser 1993
Creators: name: A. D., Tran
name: Polhemus, D. A.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Gerridae
Metrocoris
Metrocoris stranguloides

description: Metrocoris stranguloides Chen & Nieser, 1993
(Figs. 3, 4, 32, 44–46)
Metrocoris stranguloides Chen & Nieser, 1993: 16–18, Figs, 29, 38, 44–45 (type locality: Hainan Island, China); Zettel & Chen, 1996: 152, 176 (faunistic notes).
Material examined. VIETNAM: Quang Binh Prov.: 1 female (apt), 1 male (mpt), Phong Nha, upstream of Thac Xoi waterfall, coll. Tran A.D., 15 July 2004, DY0407 (ZRC). Da Nang Prov.: 6 males, 3 females (apt), 1 male, 3 females (mpt), Ba Na - Nui Chua, Suoi Cat Lon, 700 m asl, coll. Tran A.D. & Tan H.H., 28 February 2005, THH05-19 (ZRC); 1 male, 1 female (apt), Ba Na - Nui Chua, rocky cascade along road to summit, coll. Tran A.D. & Tan H.H., 28 February 2005, THH05-20 (ZRC); 1 male, 1 female (mpt), Ba Na-Nui Chua, Suoi Nai - Thac Cau Vong, coll. Tran A.D. & Tan H.H., 01 March 2005, THH05-23 (ZRC); 2 males, 1 female (apt), 3 males (mpt), Ba Na - Nui Chua foothills, Suoi Lanh, coll. Tran A.D. & Tan H.H., 01 March 2005, THH05-25 (ZMHU). Quang Ngai Prov.: 18 males, 27 females (apt), 4 males, 1 female (mpt), rocky stream crossing road on E. side of Via Lac Pass, 109 km NE. of Kontum on Hwy. 24, 305 m asl, 14°46′27″N, 108°32′18″E, water temp. 26.5°C, 17 March 2001, CL 4297, coll. D.A. Polhemus, J.T. Polhemus & P. Nguyen (USNM, BPBM). Kon Tum Prov.: 2 males, 5 females (apt.), stream 77 km NE. of Kontum on Hwy. 24, 1195 m asl, 14°38′23″N, 108°23′38″E, water temp. 19°C, 6 March 2001, CL 4283, coll. J.T. Polhemus and P. Nguyen (USNM); 3 males, 6 females (apt), 3 females (mpt), small stream 97 km NE. of Kontum on Hwy. 24, 1065 m asl, 14°42′28″N, 108°27′46″E, water temp. 21°C, 20 March 2001, CL 4303, coll. D.A. Polhemus, J.T. Polhemus & P. Nguyen (USNM, BPBM); 4 males, 12 females (apt), 1 male, 2 females (mpt), stream 96 km NE. of Kontum on Hwy. 24, 1020 m asl, 14°41′58″N, 108°27′33″E, water temp. 22°C, 20 March 2001, CL 4304, coll. D.A. Polhemus, J.T. Polhemus & P. Nguyen (USNM, BPBM). Gia Lai Prov.: 12 males, 11 females (apt), 2 males, 3 females (mpt), 40 km NW. An Khe, Buon Luoi, 14°10′N, 108°30′E, 620–750 m asl, coll. Pacholátko & Dembicky, 28 March–12 April 1995 (NHMW, 5 males, 5 females in ZRC); 12 males, 16 females (apt), 1 female (mpt), Tral Stream, 60 km N. of An Khe, 700 m asl, 14°20′28″N, 108°34′49″E, water temp. 23.5°C, 22 March 2001, CL 4309, coll. D.A. Polhemus, J.T. Polhemus & P. Nguyen (USNM, BPBM); 4 males, 7 females (apt), 1 male, 1 female (mpt), small hill stream in primary forest, 68 km N. of An Khe, 840 m asl, 14°20′52″N, 108°32′57″E, water temp. 21°C, 22 March 2001, CL 4311, coll. D.A. Polhemus, J.T. Polhemus & P. Nguyen (USNM, BPBM); 1 female, 1 male (apt), Nuoc Stream, 47 km N. of An Khe, 580 m asl, 14°14′17″N, 108°36′17″E, water temp. 24°C, 23 March 2001, CL 4312, coll. D.A. Polhemus, J.T. Polhemus & P. Nguyen (USNM, BPBM). Binh Dinh Prov.: 9 males, 4 females (apt), stream in boulders on E. side of An Khe Pass, 16 km E. of An Khe on Hwy. 19, 365 m asl, 13°57′43″N, 108°45′48″E, water temp. 19.5°C, 21 March 2001, CL 4307, coll. D.A. Polhemus, J.T. Polhemus & P. Nguyen (USNM, BPBM). Phu Yen Prov.: 1 male, 5 females (apt), seeps and streamlets on S. side of Ca Pass, 33 km S. of Tuy Hoa on Hwy. 1, 105 m asl, 12°51′47″N, 109°23′53″E, water temp. 25°C, 25 March 2001, CL 4315, coll. D.A. Polhemus, J.T. Polhemus & P. Nguyen (USNM, BPBM). Lam Dong Prov.: 19 males, 10 females (apt), Suoi Vang, 18 km NW. of Da Lat, coll. Vásárhelyi, 17 October 1988, No. 308 (MTMB, NHMW); 69 males, 115 females (apt), 7 males, 13 females (mpt), 12 km N Dalat-LangBian, coll. P. Pacholátko & L. Dembicky, 28–30 April 1994 (NHMW, ZRC); 5 males, 3 females (apt), 2 females (mpt), 12 km N Dalat-Langbian, 12°03′N 108°27′E, 1680–1750 m asl, coll. Pacholátko & Dembicky, 17–21 April 1995 (NHMW, 4 males, 4 females in ZRC); 1 male, 3 females (apt), 1 female (mpt), 16 km N Da Lat-Ankreot, 12°05′N, 108°24′E, 1400 m asl, coll. Pacholátko & Dembicky, 15 April 1995 (NHMW); 5 females (apt), Duc Me, 15 km S. of Bao Loc, 700 m asl, coll. Vásárhelyi, 23 October 1988, No. 371 (MTMB); 1 male, 1 female (apt), Suoi Baco, 12 km S. of Bao Loc, 800 m asl, coll. Vásárhelyi, 25 October 1988, No. 386 (MTMB); 1 male, 1 female (apt), 1 male, 4 females (mpt), Da Lat, a stream running into Dankia lake, coll. Tran A.D., 21 May 2003, TAD0330 (ZRC); 4 males, 3 females (apt), 1 female (mpt), Da Lat, Datanla waterfall, coll. Tran A.D., 22 May 2003, TAD0333a (ZRC); 3 males, 3 females (apt), 1 female (mpt), Dambri Waterfall, N. of Bao Lac, 850 m asl, 11°38′14″N, 107°44′54″E, water temp. 24°C, 7 May 1998, CL 3075, coll. J.T. Polhemus & P. Nguyen (USNM, BPBM); 7 males, 12 females (apt), small steeply dropping stream at Mother Mary Shrine, along Hwy. 20 on S. side of Bao Lac Pass, 18 km W. of Bao Lac, 800 m asl, 11°27′09″N, 107°43′21″E, water temp. 24.5°C, 7 May 1998, CL 3076, coll. J.T. Polhemus & P. Nguyen (DAPC); 3 males, 3 females (apt), stream below Suoi Vàng hydro project (= Gold Stream), 16 km N. of Dalat, 1430 m asl, 11°59′26″N, 108°22′06″E, water temp. 24.5°C, 9 May 1998, CL 3078, coll. J.T. Polhemus & P. Nguyen (DAPC); 10 males, 9 females (apt), 1 female (mpt), small tribs. to stream below Suoi Vàng hydro project (= Gold Stream), 16 km N. of Dalat, 1430 m asl, 11°59′26″N, 108°22′06″E, water temp. 19.5°C, 9 May 1998, CL 3079, coll. J.T. Polhemus & P. Nguyen (DAPC); 1 male (apt), spring fed trib. to stream below Suoi Vàng hydro project (= Gold Stream), 16 km N. of Dalat, 1430 m asl, 11°59′26″N, 108°22′06″E, 9 May 1998, CL 3080, coll. J.T. Polhemus & P. Nguyen (DAPC); 6 males, 8 females (apt), 2 males, 1 female (mpt), Prenn Falls, 13 km S. of Dalat on Hwy. 20, 1160 m asl, 11°52′43″N, 108°28′19″E, water temp. 25.5°C, 10 May 1998, CL 3083, coll. J.T. Polhemus & P. Nguyen (DAPC); 3 males, 1 female (apt), 4 males, 5 females (mpt), small rocky stream at Lang Biang Mtn., 12 km N. of Dalat, 1465 m asl, 12°01′12″N, 108°25′27″E, water temp. 20°C, 11 May 1998, CL 3084, coll. J.T. Polhemus & P. Nguyen (USNM, BPBM); 35 males, 27 females (apt), 3 males, 7 females (mpt), tributary stream to main river at Suoi Vang, 1430 m asl, 11°59′26″N, 108°22′06″E, water temp. 21°C, 11 and 18 May 1998, CL 3085, coll. J.T. Polhemus & P. Nguyen (USNM, BPBM); 3 females (apt), 2 males (mpt), stream and cascade 6 km S. of Dalat on Hwy. 20, 1390 m asl, 11°54′10″N, 108°26′46″E, 20 May 1998, CL 3095, coll. J.T. Polhemus & P. Nguyen (DAPC); 15 males, 24 females (apt), 4 males, 5 females (mpt), stream in pine forest 13 km N. of Dalat on Suoi Vang road, 1495 m asl, 11°59′26″N, 108°23′19″E, water temp. 21.5°C, 28 March 2001, CL 4317, D.A. Polhemus, J.T. Polhemus and P. Nguyen (USNM, BPBM). Ninh Thuan Prov.: 1 male (apt), Nui Chua N’Park, suoi Lo O, coll. Quang N.V., 26 June 2004, NC-03 (ZRC); 19 males, 40 females (apt), 2 males (mpt), first small stream on E. side of Belleview Pass (Ngoan Muc Pass), 66 km NW. of Phan Rang, pools and cascades, 915 m asl, 11°50′25″N, 108°39′21″E, water temp. 24°C, 12 May 1998 and 26 March 2001, CL 3087, coll. D.A. Polhemus, J.T. Polhemus & P. Nguyen (DAPC, USNM, BPBM); 3 males, 1 female (apt), 1 male (mpt), spring fed stream in granite at shrine on E. side of Belleview Pass (Ngoan Muc Pass), 58 km NW. of Phan Rang, 700 m asl, 11°50′41″N, 108°39′57″E, water temp. 724°C, 12 May 1998, CL 3089, coll. D.A. Polhemus, J.T. Polhemus & P. Nguyen (DAPC).
CHINA: Hainan Prov.: 1 female (apt), Hainan (193), 30 km E. Maoyang, 600 m asl, Wuzhi Shan Resort, coll. Jäch, 17–18 January 1996 (NHMW); 1 female (mpt), Wuzhishan, hill stream near Fanxiang, before Shuiman, coll. I-S. Chen et al., 9 September 2005, THH05-67 (ZRC); 13 males, 7 females (apt), 1 female (mpt), Qiongzhong, Baihua waterfall, near Qiongzhong town, coll. I-S. Chen et al., 11 September 2005, THH05-73 (ZRC); 1 male (apt), Qiongzhong, Linmushan forest park, ca. 15 km into track from road, coll. I-S. Chen et al., 11 September 2005, THH05-77 (ZRC); 1 male, 4 females (apt), 1 female (mpt), Baisha, river along road near Yuanmen, to Wuzhishan, coll. I-S. Chen et al., 12 September 2005, THH05-82 (ZRC).
LAOS: Luang Nam Tha Prov.: 3 males, 1 female (apt), 2 females (mpt), 20 km SE. Muang Sing, 950 m asl, coll. Schillhammer (25), 12 June 1996 (NHMW).
Diagnosis. Male: fore femur strongly incrassate with two sub-apical teeth and a median tooth (Figs. 44, 45). Male genitalia large: pygophore sub-ovate (ventral view), slightly raised posteriorly (lateral view); proctiger elongate; paramere long and slender, curved at distal part, but not twisted (Fig. 32); endosoma as in Chen & Nieser (1993: Figs. 44, 45). Female: sternum 7 with broad median lobe, posterior margin of median lobe almost straight (Fig. 46).
Size: apterous males: length 5.5–6.5, width 2.81–3.23, macropterous males: length 7.2–8.3, width 2.71–3.14; apterous females: length 4.8–5.4, width 2.57–3.05, macropterous females: length 6.2–7.4, width 2.67–3.20.
Remarks. Metrocoris stranguloides is the only species of the M. strangulator group known from Vietnam. As defined by Chen & Nieser (1993), the following are characteristics of this group: strongly incrassate fore femur (males), with two sub-apical teeth and a median tooth; large male genitalia with prominent paramere; sternum 7 of female with broad medial lobe. This group contains five species: M. stragulator Breddin (from Java and Sumatra), M. armatus Chen & Nieser (from Thailand), M. malayensis Chen & Nieser (from Thailand and Peninsular Malaysia), M. nieseri Chen & Zettel (from Thailand), and M. stranguloides Chen & Nieser (initially described from Hainan Island and S. Vietnam). Metrocoris stranguloides can be easily distinguished from the other four species in this group by having a long and slender paramere, simply curved on the distal part but not twisted (Chen & Nieser, 1993). Females of this species are also rather different from those of the other four taxa in having a straight hind margin of the median lobe on sternum 7 (females of the other four species have a clearly notched posterior margin on sternum 7).
Distribution. Vietnam: Quang Binh (first record), Da Nang (first record), Ninh Thuan (first record), Gia Lai, Lam Dong, Kon Tum (first record), Quang Ngai (first record) (Fig. 138). Extralimital records: Hainan Island (China), Laos (first record).
description: Published as part of A. D., Tran & Polhemus, D. A., 2017, The genus Metrocoris Mayr, 1865 (Gerromorpha: Gerridae) in Vietnam, with descriptions of five new species, pp. 109-149 in Raffles Bulletin of Zoology 65 on pages 112-116, DOI: 10.5281/zenodo.4502634