Ranatra varipes Stål, 1861

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 : 35-36

Ranatra varipes Stål, 1861

( Figs. 17, 18 , 29 )

Ranatra varipes Stål, 1861: 203

Material examined. — SINGAPORE: 1 female, Upper Selatar Reservoir , 13 Oct.1986, CL 2213, coll. D. A. & J. T. Polhemus ( JTPC) ; 1 male, Kranji Reservoir , 19 Jun.2008, coll. A. D. Tran, TAD0839 ( ZRC) ; 1 male, 1 immature, Lower Peirce Reservoir , 15 May 2008, coll. A. D. Tran, TAD0819 ( ZRC) ; 1 female, Bukit Timah Nature Reserve , 13 Dec.1995, coll. T. Wong & H. K. Lua, NS214 ( ZRC) ; 1 male, 1 female, Selatar Reservoir, Mandai Lake Road , 16 May 1994, NS134A, coll unk. ( ZRC) . MALAYSIA, Johor: 2 males, 2 females, Muar, Bukit Pasir , 24 Jun.1998, coll. Y. Y. Goh ( ZRC) ; 1 male, 1 female, Pontian, Pekan Nanas , 14 Mar.1999, DW99-04, coll. Y. Cai & D. Wowor ( ZRC) . Selangor: 1 female, North Selangor peat swamp forest, stream at 50 km mark to Tanjung Malim ( United Palm Bhd. ), 18 Jun.1991, coll. unk. ( ZRC) . Penang: 3 males, 2 females, Penang , 9 Jun.1993, coll. H. H. Tan & S. H. Tan ( ZRC) . Perlis: 1 male, 1 female, Sintok – Pahang , 19 Feb.1997, coll. H. K. Lua, LHK329 ( ZRC) . Perak: 1 male, Sungai Kenderong at Gerik , 17 Feb.1997, coll. H. K. Lua, LHK0324 ( ZRC) .

Extralimital material examined. — THAILAND, Chiang Mai Prov.: 1 female, Fang Dist., ponds at Fang Horticultural Station , 500 m ., 15 Nov.1985, CL 2201, coll. J. T. and D. A. Polhemus ( JTPC) . Nakhon Ratchasima Prov.: 1 male, 1 female, Sakaerat Exp. Sta. , 60 km. S. of Nakhon Ratchasima, 300– 600 m ., 14°30'N, 101°55'E, 2–4 Mar.1971, coll. P. & P. Spangler ( USNM) . VIETNAM, Dong Ngai Prov .: 3 males, 1 female, Nam Cat Tien National Park, Crocodile Lake , 100 m ., water temp. 31°C., 5 May 1998, CL 3071, coll. J. T. Polhemus ( JTPC) . LAOS, Khammouane Prov.: 1 male, Phon Tiou , 11 Jun.1965, coll. N. Wilson ( BPBM) .

Diagnosis. — Male body length 20–25 mm, length of respiratory siphon 16–19 mm; female body length 20–27 mm, length of respiratory siphon 15–19 mm. Colouration medium brown, femora mottled with light and dark brown. Head with vertex rounded, not tuberculate or raised above eyes. Ventral prothorax with a prominent medial longitudinal carina present along entire length. Fore femur short and thick, with a large broad, angular tooth near midpoint of the margin adjacent to the infolded tibia and a much smaller angular tooth slightly distal to the midpoint on this same margin ( Fig. 29 ), with the tibia resting between them when closed; hind femora in both sexes reaching beyond posterior margin of abdominal sternite VI. Male paramere with a narrow and shallow incision subapically, isolating a large, highly expanded, blade-like distal process from a very small, obtusely angulate subapical lobe ( Figs. 17, 18 ).

Distribution. — Originally described from Java, and subsequently recorded from Singapore and Peninsular Malaysia ( Malacca, Perak, Selangor, Penang), Sumatra, Vietnam, Burma, India, and Ceylon ( Lansbury, 1972; Fernando & Cheng, 1974). The material listed below includes the first published records for the peninsular Malaysian states of Johor and Perlis, and the country of Laos.

Discussion. — This species may be easily recognised by its relatively short and stout fore femur, with a broadly angulate tooth located near the center of the posterior face plus a much smaller angulate tooth proximal to the larger tooth ( Fig. 29 ); and by the very large, blade-like distal process on the male paramere ( Figs. 17, 18 ). It is less common in collections from Singapore and Peninsular Malaysia than R. thai , but has been taken syntopically with the latter species at a number of localities.

The life history of R. varipes was studied by Chowanadisai et al. (1983), who noted that the species was an efficient predator of mosquito larvae.

Figures

Figs. 11–18. Ranatra species, male left parameres, outer view with detail of distal hook. 11, 12, R. gracilis, specimen from Laos, Vientiane Prov. 13, 14, R. parmata, specimen from Indonesia, Sumbawa (CL 2172). 15, 16, R. spinifrons, specimen from Malaysia, Selangor. 17, 18, R. varipes, specimen from Laos, Khammouane Prov.

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.