Ranatra rafflesi Tran & D. Polhemus, 2012

Polhemus, Dan A. & Polhemus, John T., 2013, Guide To The Aquatic Heteroptera Of Singapore And Peninsular Malaysia. X. Infraorder Nepomorpha-Famlies Belostomatidae And Nepidae, Raffles Bulletin of Zoology 61 (1), pp. 25-45 : 38-39

Ranatra rafflesi Tran & D. Polhemus, 2012

( Figs. 22, 23 , 26 , 28 )

Ranatra rafflesi Tran & D. Polhemus, 2012: 104

Material examined. — SINGAPORE: 3 males, 2 females, Upper Selatar Reservoir , 27–28 May 2008, A. D. Tran and A. Lok, TAD0830 (holotype and paratypes, ZRC and BPBM) . INDONESIA, Riau Islands Prov. : 5 males, Batam [Riau Archipelago, Batam Is.], coll. C. M.Yang et al., 29 Jan.1992, NUS.6.15699–15703 (paratypes, ZRC) ; 1 male, 2 females, Riau Archipelago, Pulau Bintan North, coll. H. K. Lua, 26 Jun.1995, LHK259 (paratypes, ZRC) .

Diagnosis. — Male body length 21–24 mm, length of respiratory siphon 19–23 mm; female body length 25–29 mm, length of respiratory siphon 20–24 mm. Colouration dark brown, legs paler, with yellowish patches on fore femora. Head with vertex slightly raised above the eyes into a low, conical tumescence. Ventral prothorax with a prominent medial longitudinal carina present along entire length. Fore femur long and slender with two sharply angulate teeth distal of the midpoint on the margin adjacent to the infolded tibia, consisting of a relatively large tooth on outer face and a smaller tooth on inner face ( Fig. 28 ); middle and hind femora equal in length; hind tibia very slightly longer than middle tibia; hind femora in both sexes exceeding posterior apex of operculum. Male paramere with a broad, rounded incision subapically, isolating an apically expanded distal hook from a small, angulate subapical lobe ( Figs. 22, 23 ).

Distribution. — Known from Singapore and the adjacent Indonesian islands of Bintan and Batam.

Discussion. — Ranatra rafflesi may be separated from the superficially similar R. longipes and R. thai by the more open curve and flared apex of the distal hook on the male paramere (compare Figs. 23, 24 to Figs. 19–22 ), the more acute dorsal margin of the sclerotized distal section of the male phallotheca when viewed laterally (compare Figs. 25, 26 ), and the larger, more truncate tooth on the fore femur (compare Figs. 27, 28 ). Ranatra rafflesi may also be separated from the superficially similar R. malayana from Sulawesi and R. natunaensis from Natuna Island (west of Borneo) by its longer hind femora, which exceed the tip of the abdomen (excluding the respiratory siphon) in males and reach its posterior apex in females.

Figures

Figs. 19–24. Ranatra species, male left parameres, outer view with detail of distal hook. 19, 20, R. longipes, specimen from Singapore, Nee Soon. 21, 22, R. thai, specimen from Thailand, Chiang Mai Prov. (CL 2201). 23, 24, R. rafflesi, specimen from Singapore, Selatar Reservoir.

Figs. 25, 26. Ranatra species, male phallotheca, right lateral view. 25, R. longipes, specimen from Singapore, Nee Soon.26, R. rafflesi, specimen from Singapore, Selatar Reservoir.

Figs. 27–29. Ranatra species, forelegs. 27, R. longipes longipes, specimen from Singapore, Nee Soon.28, R. rafflesi, specimen from Singapore, Selatar Reservoir. 29, R. varipes, specimen from Laos, Khammouane Prov.