Metrocoris ciliatus den Boer, 1965

A. D., Tran & Polhemus, D. A., 2017, The genus Metrocoris Mayr, 1865 (Gerromorpha: Gerridae) in Vietnam, with descriptions of five new species, Raffles Bulletin of Zoology 65, pp. 109-149 : 128

Metrocoris ciliatus den Boer, 1965

( Figs. 41 , 80–83 )

Metrocoris ciliatus den Boer, 1965: 23–26 , Figs. 36, 41–43 , 45 (type locality: Dawna Hills, Myanmar); Chen & Nieser, 1993: 54–57 (redescription, records from Thailand).

Material examined. VIETNAM: Lai Chau Prov.: 1 male (mpt), Muong Te, Muong Mo stream, by the road from Muong Te town to Lai Ha, ca. 33 km from Muong Te town , coll. Tran A.D. et al., 3 June 2013, TAD1329 ( ZMHU) .

CHINA: Yunnan Prov.: 5 males, 5 females (apt) , 6 males, 7 females (mpt), Xishuangbanna, Mengyang, Mengang River : forest stream, coll. Cheng L. et al., 18–31 May 2000, LC019 ( ZRC) ; 1 male, 2 females (apt), 1 male (mpt), ZRC.6.22062, Xishuangbanna, Jinghong, Banna N’Park , 850 m asl, small forest stream, coll. Yang C.M. & P. Chew, 28 May–12 June 2002, YCM0327 ( ZRC) .

Diagnosis. Both sexes: fore femur slender (ratio length/width: males ca. 8.5, females ca. 8.0), sub-apically constricted, ventral surface with sub-apical elevation ( Fig. 80 ). Male: pro-, meso- and metanotum, pleura, and abdominal tergum 1 with scattered black setae; genitalia small, abdominal segment 8 slightly shorter than wide on ventral, pygophore and proctiger simple; paramere falciform, short, with curvature at distal half, apex blunt ( Figs. 41 , 81, 82 ); endosoma as in Fig. 83 . Female: thoracic segments without black setae; sternum 7 about as long as sterna 4–6 together, posterior margin broadly rounded (modified from Chen & Nieser, 1993).

Size (after Chen & Nieser, 1993): apterous males: length 4.8, width 2.5; apterous females: length 5.0, width 2.7 (specimen from Vietnam, macropterous male: length 6.64, width 2.53).

Remarks. This is the first record of this taxon in Vietnam. For comparative notes, see Remarks under M. inthanon .

Distribution. Vietnam (first record): Lai Chau ( Fig. 140 ). Extralimital records: Myanmar: Dawna Hills; Thailand: Chiang Mai; China: Yunnan.

Figures

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. 80–90. Morphological features of Metrocoris species. 80–83: M. ciliatus, macropterous male. 80: right fore leg. 81, 82: left paramere, two different views. 83: endosomal sclerites, lateral view. 84, 85: M. inthanon. 84: right fore leg of male. 85: apex of abdomen, female, ventral view. 86–90: M. triangulatus. 86–89: male holotype. 86: A, right fore leg. 87: left paramere. 88, 89: endosomal sclerites, lateral and dorsal views. 90: abdomen of female, ventral view (80, 84, 86 same scale; 81–83 same scale; 85, 90 same scale).

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).

Fig. 140. Distribution records in Vietnam of Metrocoris ciliatus, M. inthanon, Metrocoris sicilis, new species, and M. triangulatus.