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 obscurus Chen & Nieser, 1993 ( Figs. 12, 13 , 36 , 71–73 ) Metrocoris obscurus Chen & Nieser, 1993: 27–29 , Figs. 70, 71 , 76 , 84 ( type locality: Bumgahtauang-Hpungan , Myanmar ). Material examined. VIETNAM , Lao Cai Prov. : 2 males , 5 females (apt), stream in open valley, 4 km NE. of Sa Pa on Lao Cai road, 1250 m asl , 22°21′10″N , 103°52′12″E , water temp. 24°C, 9 April 2000 , 1630–1700 hrs., CL 4407, coll. D.A. Polhemus , J.T. Polhemus & P. Nguyen ( USNM ) ; Cao Bang Prov. : 1 male , 3 females (apt), Bao Lac, Dinh Phung commune, near Tung Muu, stream by the Nat’ road 34, coll. Tran A.D. et al., 20 December 2013 , TAD1378 ( ZMHU ) . Diagnosis. Male: fore femur incrassate (ratio length/width 3.22–3.67), ventral margin sinuate on distal half (widest at ca. distal half), with a single apical tooth; inner surface of tibia without sub-basal elevation ( Fig. 71 ). Male genitalia: abdominal segment 8 large, ventral side about as long as wide; pygophore long, with apical margin broadly rounded, dorsolateral process of pygophore short and directed dorsad; proctiger long, with narrow distal half; paramere sharply bent on distal one-third, with broadly rounded tumescence subapically on outer margin ( Fig. 72 ); endosoma as in Chen & Nieser (1993 : Fig. 84 ). Female: body dorsoventrally compressed; sternum 7 large, length along midline about same as length of preceding abdominal sterna combined; posterior sternum 7 with two small and finger-like lobes, separated by wide, shallow, transverse notch ( Fig. 73 ). Size: apterous males: length 6.2–6.9, width 3.05–3.45; apterous females: length 5.9–6.1, width 3.35–3.48. Remarks. Metrocoris obscurus belongs to the M. obscurus species group (sensu Chen & Nieser, 1993 ) and is the only taxon in this species group. The specimens from Vietnam are slightly larger than the type specimens from Myanmar and China (see Chen & Nieser, 1993 ). Distribution. Vietnam (first record): Lao Cai , Cao Bang ( Fig. 139 ). Extralimital records: Myanmar : Bumgahtauang-Hpungan; China : Yunnan .