Rhagovelia bisinuata, X.Q. & A.D., 2016

X. Q., Nguyen & A. D., Tran, 2016, Descriptions of two new species of Rhagovelia (Heteroptera: Gerromorpha: Veliidae) from Vietnam, Raffles Bulletin of Zoology 64, pp. 389-396 : 392-394

Rhagovelia bisinuata , new species

( Figs. 3, 4 , 16–24 )

Material examined. Holotype (apterous male) and allotype (apterous female): VIETNAM, Nghe An Prov., Pu Mat N’Park, Khe Kem waterfall & stream, site #1, coll. Ngo Q.H., 20 December 2012, NQH1203 ( ZMHU). Paratypes: VIETNAM: Nghe An Prov.: 2 males, 2 females (apterous), 2 males (macropterous), same locality data as holotype ( ZMHU); 1 male, 5 females (apterous), 10 males, 6 females (macropterous), Pu Mat N’Park, Kem waterfall and stream, coll. Tran A.D. et al., 18 April 2013, TAD1310 ( ZMHU). Lao Cai Prov.: 1 male (apterous), Sa Pa, Ban Ho, Nam Pu stream 1, coll. Dinh N.H. et al., 21 October 2012, DNH12.01 ( ZMHU). Ha Giang Prov.: 1 male, 1 female (macropterous), 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). Vinh Phuc Prov.: 11 males, 3 females (apterous), 2 males, 3 females (macropterous), Tam Dao N’Park, Suoi Bua Lon (Bua Lon stream), coll. Tran A.D., 19 June 2003, TAD0356 ( ZRC). Phu Tho Prov.: 1 male, 4 females (apterous), 1 female (macropterous), Xuan Son N’Park, Lap stream, site 1, at Ngoc waterfall, coll. Tran A.D. et al., 5 June 2013, TAD1331 ( ZMHU); 4 males, 2 females (apterous), Xuan Son N’Park, Lap stream, site 2, first concrete bridge from Ngoc waterfall, coll. Tran A.D. et al., 5 June 2013, TAD1332 ( ZMHU); 2 males, 2 females (apterous), Xuan Son N’Park, Lap stream, site 3, second concrete bridge from Ngoc waterfall, coll. Tran A.D. et al., 5 June 2013, TAD1333 ( ZMHU); 3 males, 4 females (apterous), 1 male (macropterous), Xuan Son N’Park, Kim Thuong, Tan Ong stream, site 2, ca. 2 km from Chin Tang waterfall, coll. Tran A.D. et al., 6 June 2013, TAD1335 ( ZMHU); 3 males, 1 female (apterous), Xuan Son N’Park, Kim Thuong, Tan Ong stream, site 3, ca. 4 km from Chin Tang waterfall, coll. Tran A.D. et al., 6 June 2013, TAD1336 ( ZMHU); 4 males, 2 females (apterous), Xuan Son N’Park, Kim Thuong, Tan Ong stream, site 2, ca. 2 km from Chin Tang waterfall, coll. Tran A.D. et al., 28 August 2013, TAD1341 ( ZMHU); 2 males, 4 females (apterous), Xuan Son N’Park, Lap stream, site 1, at Ngoc waterfall, coll. Tran A.D. et al., 30 August 2013, TAD1352 ( NHMW); 1 male, 3 females (apterous), Xuan Son N’Park, Lap stream, site 2, first concrete bridge from Ngoc waterfall, coll. Tran A.D. et al., 30 August 2013, TAD1353 ( ZMHU); 2 males, 1 female (apterous), Xuan Son N’Park, Lap stream, site 3, second concrete bridge from Ngoc waterfall, coll. Tran A.D. et al., 30 August 2013, TAD1354 ( ZMHU). Ha Tinh Prov.: 32 males, 49 females (apterous), 1 male, 1 female (macropterous), Vu Quang N’Park, Khe Lim waterfall, coll. Tran A.D., 24 April 2003, TAD0304 ( ZRC) .

Description. Size: Apterous males: body length 3.00–3.35 (holotype: 3.15), width 1.26–1.39 (holotype: 1.35); apterous females: length 3.05–3.50 (allotype: 3.35), width 1.39–1.55 (allotype: 1.53); macropterous males: length (without wings) 3.10–3.45, width 1.41–1.46; macropterous females: length (without wings) 3.30–3.45, width 1.50–1.55.

Colour ( Figs. 3, 4 ): body mainly black; antennal segment 1 light yellowish at proximal half, brown at distal half; antennal segments 2–4 brown to dark brown; juga, anteclypeus, and rostrum brown to dark brown; pronotum anteriorly with median transverse orange band (width ca. half of pronotum width, median length about a quarter of pronotum length); all acetabulae apically dark brown; all coxae and trochanters mostly yellowish, except distal half of mesotrochanter brown; profemur light yellowish at least at proximal half, brown to black at distal part; metafemur chiefly dark brown or black, only basal one tenth of metafemur yellowish; mesofemur, all tibiae and tarsi mostly brown to black. In females, posterior margin of sternite 7 and gonocoxa brown.

Pilosity: body with short, appressed golden pubescence; dorsum of head, pro- and mesopleura, with numerous long, erect brown or black setae; antennae with scattered long brown or black setae; mesosternum with long yellowish hairs forming inverted V-shaped patch running towards posterior margin; posterior of metasternum with long yellowish hairs; legs with scattered long brown or black setae; in males, abdominal sternites with numerous long, sub-erect yellowish hairs, particularly more dense on lateral areas of sternites; in males, abdominal segment 8 with long brown hairs posteriorly; in females, only lateral areas of sternites with long, sub-erect yellowish hairs, posterior margin of tergite 8, gonocoxa and all of proctiger with long dense brown hairs directed latero-caudad ( Figs. 4 , 21–23 ).

Apterous male: Head length 0.38, width 0.81, eye length 0.32. Lengths of antennal segments 1–4: 0.72, 0.38, 0.47, 0.45. Juga mostly smooth, without spicules; thoracic sterna and pleura without scattered spicules. Pronotum short, median length 0.23; mesonotum length 0.65, about 2.8 times length of pronotum; metanotum length 0.11. Lengths of leg segments (femur, tibia, tarsus 1+2+3): fore leg: 0.79, 0.92, 0.02+0.02+0.22; middle leg: 1.41, 1.21, 0.07+0.52+0.65; hind leg: 1.06, 1.17, 0.04+0.08+0.27. All coxae and trochanters usually without spicules (as in holotype), or at most very few black spicules on dorso-distal surface of metacoxa and metatrochanter in some specimens. Metatrochanter ( Fig. 16 ) with 2–4 black teeth (four in holotype) ventro-distally. Metafemur ( Fig. 16 ) slender, length about 4.5 times width (width without teeth: 0.23), ventral surface armed with a row of teeth, comprising two portions: the proximal portion with 9–10 short, closely-situated teeth starting from base of metafemur, followed by four teeth gradually increasing in length, of which the longest tooth at basal two-fifths of metafemur; the distal portion with 5–7 teeth (five in holotype), starting from the longest tooth at distal two fifths and 4–6 other short, widely-spaced teeth towards apex of metafemur. Metatibia ( Fig. 16 ) slender and straight, inner side with a row of teeth gradually increasing in length from base to apex of tibia.

Abdominal segments gradually narrowed towards abdominal apex; tergites 1–6 subequal in length (0.15–0.20), tergite 7 clearly longer (0.31) than each of preceding tergite, length 0.8 times width, raised posteriorly in lateral view ( Fig. 18 ); abdominal sternites 2, 3 weakly carinate medially; sternite 7 slightly shining; both ventral and dorsal abdominal segment 8 shining. Genital segments: small and weakly modified; segment 8 small, subcylindrical, dorsal length 0.40, anterior of ventral surface medially keeled; pygophore subovate, posterior margin produced medially forming angular apex; proctiger ( Fig. 19 ) longer than wide, proximal half bearing rounded lateral lobes, distal half setiferous; paramere ( Fig. 20 ) flat and sinuate, apex blunt, the middle of lateral surface set with few long setae.

Apterous female: Hind leg ( Fig. 17 ): metatrochanter without black teeth, metafemur slightly more slender, length about 4.8 times width (width 0.22), ventral surface of metafemur with fewer teeth than in males, the proximal row completely reduced or with fewer teeth, the distal row comprising one longer tooth and 3–4 shorter teeth situated towards apex; metatibia straight, inner side without armature.

Abdomen ( Figs. 21–23 ): laterotergites sloped latero-dorsad; laterotergites 6, 7 covered with dense appressed long brown hairs making connexiva 6, 7 appearing somewhat thick; connexiva unevenly converging posteriorly: connexiva 1, 2, 6, 7 narrow; connexiva 3 and 4 shining, swollen upwards and inwards; tergites 1–4 subequal in length (0.16–0.19), tergites 5–8 longer, length as follows: 0.22, 0.25, 0.31, 0.29; tergite 7 about as long as wide; tergite 8 shorter than wide, with posterior margin straight, and postero-lateral margin with dense tufts of hair ( Fig. 21 ); tergite 8 and sternite 7 shining; in lateral view, posterior end of connexivum rightangled and not produced ( Fig. 22 ); abdominal sternites 2, 3 weakly carinate medially; posterior margin of sternite 7 slightly produced medially ( Fig. 23 ); gonocoxa simple, plate-like, mainly exposed; proctiger small, relatively slender, directed straight caudad. Other structural characteristics similar to males.

Macropterous males: Pronotum large, with prominent humeri. Forewing ( Fig. 24 ) with four closed cells, distal cells small, about half the size of basal cells. Metafemur slightly more slender with median teeth on ventral surface shorter than in apterous males. Other characteristics similar to apterous males.

Macropterous females: Pronotum and forewing similar to those of macropterous males. Other characteristics similar to apterous females.

Etymology. The word bisinuata refers to the sinuate paramere of this species.

Comparative notes. Rhagovelia bisinuata , new species clearly belongs to the R. sarawakensis group, in having pronotum shorter than eye length, forewing with four closed cells. However, it can be easily separated from other species of this group by the combination of the following characteristics: the shape of male proctiger ( Fig. 19 ), the sinuate paramere ( Fig. 20 ), the swollen connexiva 3 and 4 of females ( Figs. 21, 22 ), and the postero-lateral dense tufts of hairs on tergite 8 of females ( Figs. 21–23 ). Among these characteristics, the shape of the paramere and the modification of connexiva 3 and 4 of females have not been observed in other Asian species of Rhagovelia . The structure of metafemur of both sexes of R. bisinuata , new species, is similar to those of R. sondaica Polhemus & Polhemus, 1988 , a common and widespread species in Peninsular Malaysia and Borneo, but the parameres and structure of the female abdomen are distinctly different between these two species.

Figures

Figs. 1–4. Habitus of two new species of Rhagovelia (paratypes). 1, 2, Rhagovelia caudata, new species; 3, 4, Rhagovelia bisinuata, new species; 1, 3, apterous males; 2, 4, apterous females, all of same scale.

Figs. 16–24. Rhagovelia bisinuata, new species. 16, right hind leg of male; 17, right metafemur of female; 18, apex of abdomen of male, lateral view; 19, proctiger of male; 20, left paramere; 21, 22, abdomen of female, dorsal view (21) and lateral view (22); 23, apex of abdomen of female, ventral view; 24, right forewing. (16, 17 same scale; 21–24 same scale).