Gerris (s. str.) nepalensis Distant, 1910

Polhemus, J. T., 2012, The water skater genus Gerris Fabricius (Hemiptera: Heteroptera: Gerridae) in Vietnam, with the description of a new species, Zootaxa 3382, pp. 20-28 : 25

Gerris (s. str.) nepalensis Distant, 1910

Gerris nepalensis Distant, 1910: 142 (type locality: Nepal); Paiva, 1918: 23 (record Myanmar); Lundblad, 1933: 267–270, Fig. 9 (record China); Andersen & Chen, 1993: 157–158, Figs. 3, 4, 21–23; Andersen, 1993: 2485, 2490, Figs. 5C, 10D, 11B, 14A–D, 26.

Gerris amembo Esaki & Miyamoto in Miyamoto, 1958: 125–127, pl. 16e, 16f, 19, 29–34 (type locality: Kyushu, Chikugo, Japan) (synonymized with G. nepalensis by Kanyukova, 1982: 82).

Material examined. VIETNAM: Ninh Binh Prov.: 25 males, 22 females (apterous), Gia Vien, Van Long Wetland Nature Reserve , coll. Tran A.D., 7 Jun. 2003, TAD0347 ( NHMW, ZMHU, ZRC) .

CHINA: 1 male (macropterous), “China, Chenfu Wu., 1959-186” ( NHMW) ; 1 male (macropterous), Guangxi Prov., Bez. Liuzhou, Shanmenjiang forest farm, 10km NE Liuzhou, 150–200m, coll. H. Schillhammer (18a), 11 Nov. 1993 ( NHMW) .

JAPAN: 1 female (macropterous), “Japan 1874” ( NHMW) .

THAILAND: 1 female (macropterous), Ubon Ratchathani, Piboon, Kaensapurn, coll. Yupa Hanboonsong (16), 7 Jul. 1996 ( NHMW) .

Remarks. The structural characteristics of G. nepalensis have been well described and illustrated by Lundblad (1933), Miyamoto (1958), Kanyukova (1982), Andersen & Chen (1993), and Andersen (1993). Diagnostic characterstics of this species are as follows: pronotum black with pale yellow stripe on anterior part; sternum 7 of male simple, without teeth; sternum 8 of female without transverse depression; ventral surface of male abdominal segment 8 with two lateral impressions covered with silvery hairs; female connexival corners produced into slender processes (see Andersen 1993; Andersen & Chen 1993).

Distribution. This species is widespread from South Asia ( Nepal, India, Bangladesh) to East Asia ( Japan, China) and Southeast Asia ( Thailand, Vietnam) (Andersen 1993; Andersen & Chen 1993). In Vietnam, its distribution seems to be restricted to the northern part.