Rheumatogonus vietnamensis Zettel & Chen, 1996

Jehamalar, E. Eyarin & Chandra, Kailash, 2020, A new species of Tenagogonus Stål (Hemiptera: Heteroptera: Gerridae) and first records of eight species of aquatic and semi-aquatic Heteroptera from India, Zootaxa 4718 (1), pp. 95-107 : 104-105

Rheumatogonus vietnamensis Zettel & Chen, 1996

( Figs. 1 L–M)

1996. Rheumatogonus vietnamensis Zettel & Chen : Entomologische Abhandlungen, Staatliches Museum für Tierkunde Dresden, 57 (6), 171.

Material examined. INDIA, MEGHALAYA, East Khasi Hills District, 1 apt. ♂, 1 apt. ♀, Shella Bazar, a stream near Shella River , 23 m , 25.18094° N, 91.63533° E, 6.iii.2016, Coll. E.E. Jehamalar. Reg. No. 9373/H15.

Diagnosis. Rheumatogonus vietnamensis can be identified by the indistinct anterolateral patch of medium sized setae on the mesosternum (only visible in alcohol), absence of prominent setae on the mesal margin of the connexivum of the female; presence of a basolateral triangular process of the ventral sclerite and the distinct accessory lateral sclerite of the male endosoma.

Distribution. India (Meghalaya, Fig. 4B ), Cambodia, Thailand, Vietnam, Laos, Indonesia (Natuna Island) ( Chen & Nieser 2002, Tran & Yang 2004, Zettel et al. 2017).

Remarks. Abdominal tergum VII of the female is erected posteriorly giving a hump-like appearance in lateral view; this character is not mentioned in the original description of the species. Only a pair of specimens was available for the present study, so the characters should be studied thoroughly.

Figures

FIGURES 1A–M. A, Ranatra libera, male, dorsal view; B, apical part of the paramere of R. libera, lateral view; C, Hydrometra jaczewskii, male, dorsal view; D, same, abdominal tip, lateral view; E, H. longicapitis, female, lateral view; F, Strongylovelia balteiformis, apterous male, dorsal view; G, S. hainanensis, apterous female, dorsal view; H, same, lateral view; I, Tenagogonus kuiterti, apterous male, dorsal view; J–K. Gerris lobatus, brachypterous male: J, abdominal tip, lateral view; K, habitus, dorsal view; L, Rheumatogonus vietnamensis, apterous male, dorsal view; M, same, apterous female, dorsal view.

FIGURES 4A–C. A, Map of India showing location of state of Meghalaya; B, Distribution in Meghalaya of Ranatra libera in blue squares; Hydrometra jaczewskii in green triangles; H. longicapitis in red square; Gerris lobatus in pink circle; Rheumatogonus vietnamensis in black circle; C, Distribution in Meghalaya of Strongylovelia balteiformis in red circles; S. hainanensis in pink square; Tenagogonus aruli sp. nov. in green squares; T. kuiterti in blue circles.