Rhyacobates anderseni Tran & Yang, 2006

Tran, A. D. & Nguyen, X. Q., 2016, Three new species of the water strider genus Rhyacobates Esaki, 1923 (Hemiptera: Gerridae) from Vietnam, Zootaxa 4121 (5), pp. 501-516 : 512-513

Rhyacobates anderseni Tran & Yang, 2006

Rhyacobates anderseni Tran & Yang, 2006: 14 –16, Figs. 7–16 , 27 (type locality: Vu Quang, Ha Tinh Prov., Vietnam).

Material examined. For holotype and paratypes, see Tran & Yang (2006).

Size. Males, length 6.0–6.1 (allotype 6.0), width 1.83–1.85 (allotype 1.83) (apterous), length 6.1–6.2, width 1.85–1.88 (macropterous); females, length 6.8–7.0 (holotype 6.8), width 2.52–2.57 (holotype 2.52) (apterous).

Remarks. The followings are diagnostic characteristics of R. anderseni : the mesonotum of the male has a slender yellow stripe on the posterior half; the mesonotum of the female has a broader yellow median marking on the posterior three-fifths; the abdomen of the male is relatively short; in lateral view, abdominal segment 8 of the male has a concave ventral surface; the male proctiger has round angular projections on each side (see Tran & Yang 2006: Fig. 12 ); the male paramere is falciform, slightly broad, long, and not conspicuously setose (see Tran & Yang 2006: Figs. 13 , 14 ); the metanotum of the female has a pointed median process on the posterior margin (see Tran & Yang 2006: Fig. 7 ); the abdomen of the female is short (length about 0.2 times body length), sternum 7 is long, almost enclosing the genital segments with its connexival margin raised slightly upwards, with a pair of long posterior projections pointing outwards and downwards (see Tran & Yang 2006: Figs. 8, 9 ), and its posterior margin is almost straight, bearing two short lateral processes (see Tran & Yang 2006: Fig. 10 ). For detailed comparisons of Rhyacobates anderseni with its congeners and other ptilomerine genera (Andersenius and Pleciobates ), refer to Tran & Yang (2006: 16).

Habitats. See Tran & Yang (2006: 16).

Distribution. Vietnam: Ha Tinh. China: Yunnan.

Figures

FIGURES 1 – 10. Morphological features of Rhyacobates angustus sp. n. (1) right fore leg of female. (2) basal part of right middle leg of male, ventral view. (3) proctiger of male. (4, 5) left paramere, from different views. (6) endosomal sclerites. (7) body of female, lateral view. (8) abdomen of female, dorsal view, (9, 10) apex of abdomen of female, ventral and lateral views.

FIGURES 11 – 13. (11) Habitat of type locality of Rhyacobates zetteli sp. n. (12, 13) Habitus of R. zetteli sp. n. (12) apterous male. (13) apterous female (photographed by Tran Anh Duc).

FIGURES 14 – 23. Morphological features of Rhyacobates zetteli sp. n. (14) right fore leg of female. (15) basal part of right middle leg of male, ventral view. (16) proctiger. (17, 18) left paramere, two different views. (19) endosomal sclerites. (20) body of female, lateral view. (21 – 23) apex of abdomen of female, dorsal, ventral, and lateral views respectively.

FIGURES 27 – 39. Morphological features of Rhyacobates constrictus sp. n. (27) right fore leg of female. (28) basal part of right middle leg of male, ventral view. (29) proctiger. (30 – 32) left paramere from three different views. (33) endosomal sclerites. (34) body of female, lateral view. (35) apex of abdomen of female, lateral view. (36) abdomen of female holotype, dorsal view. (37) apex of abdomen of female holotype, ventral view. (38, 39) apex of abdomen of female paratype, dorsal and ventral view.