Ranatra parmata Mayr, 1865

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 : 33-34

Ranatra parmata Mayr, 1865

( Figs. 13, 14 )

Ranatra parmata Mayr, 1865: 446

Material examined. — SINGAPORE: 1 female, Sime Road , 20 Jan.1995, coll. D. H. Murphy & P. K. L. Ng ( ZRC) ; 1 female, Lorong Banir , 24 May 1994, NS141B, coll. unk. ( ZRC) ; 1 male, Bukit Kallang , 6 May 1994, NS129B, coll. unk. ( ZRC) . MALAYSIA, Johor: 1 female, swamp forest stream 15 km. W. of Sedili Besar, 20 m ., 16 Oct.1986, CL 2218, coll. D. A. & J. T. Polhemus ( JTPC) . Selangor: 1 male, North Selangor peat swamp forest, stream at 34 km. marker on road to Tanjung Malim , 17 Jun.1991, ZRC 6-15706, LHK 154, H. K. Lua ( ZRC) Perak: 1 female, Sungai Chebu , 6 Mar.1963, coll. unk. ( ZRC) ; 1 male, 2 females, small shaded stream in disturbed primary forest, 34 km. E. of Grik , 20 Aug.1985, CL 2079, coll. D. A. & J. T. Polhemus ( JTPC) .

Extralimital material examined. — INDONESIA, Sumatera Utara Prov.: 2 males, Kab. Tapanuli Utara, Kec. Parlilitan, small rushing stream in rock bed, 3 km. E. of Parlilitan, 900 m ., 10 Nov.1985, CL 2191, coll. D. A. & J. T. Polhemus ( JTPC) . Kalimantan Timur Prov.: 3 males, 2 females, Borneo , small waterfall 4 km. NE of Kota Bangun, 27Aug.1985, CL 2095, D. A. & J. T. Polhemus ( JTPC) . Nusa Tenggara Barat Prov.: 1 male, 2 females, Lombok, Aik Jut River , 1 km. N. of Sesaot, 30 km. NE of Mataram, 350 m ., 23 Oct.1985, CL 2178, coll. D. A. & J. T. Polhemus ( JTPC) ; 8 males, 6 females, Sumbawa, Kab. Bima, Bela River , 12 km. N. of Kuta, 28 km. SW of Bima, 100 m ., 19 Oct.1985, CL 2172, coll. D. A. & J. T. Polhemus ( JTPC) . Nusa Tenggara Timur Prov.: 3 males, 1 female, Sumba, Kambahapang River , 59 km. SW of Waingapu, 530 m ., water temp. 25°C., 14 Sep.1991, CL 2599, coll. D. A. & J. T. Polhemus ( JTPC) . LAOS, Bokeo Prov.: 1 male, Tonpheng [Ton Pheung Dist.], 31 Mar.1966, coll. native collector ( BPBM) ; 1 female, same data as preceding but 15 Apr.1966 ( BPBM) . ANDAMAN ISLANDS: 1 male, Doligung, S /AND 11, 8 Dec.1976, F. Starmuhlner ( JTPC) .

Diagnosis. — Male body length 30–33 mm, length of respiratory siphon 10–12 mm; female body length 34–37 mm, length of respiratory siphon 10–13 mm. Colouration brown, with legs often bearing alternating annulations of light and dark brown. Head with frons strongly tuberculate between the eyes. Vental prothorax with a broad, shallow longitudinal sulcus, closed distally, anterior third of this sulcus bearing weak longitudinal carina. Fore femur with single large tooth near midpoint of margin contacting infolded tibia; middle femur slightly shorter than hind femur; hind femur reaching halfway along abdominal sternite VI in both sexes. Male paramere with a deep, narrow incision subapically, separating a distal hook from a large, rounded subapical lobe with small tubercle, apex of distal hook curving back so as to contact subapical lobe or nearly so ( Figs. 13, 14 ).

Distribution. — Originally described from Java ( Mayr, 1865), and subsequently recorded from Sumbawa, Sumba, Nias, Thailand, Laos, the Andaman Islands and Langkawi Island in the Peninsular Malaysian state of Kedah ( Lansbury, 1972; J. Polhemus & Starmühlner, 1990; Zettel & Tran, 2009). The material reported below includes the first published records for Sumatra, Lombok, Singapore, and the Peninsular Malaysian states of Johor, Selangor, and Perak.

Discussion. — A moderate-sized Ranatra species , immediately recognisable by the tuberculate frons, relatively short respiratory siphon in relation to the body length, and the distinctive shape of the male paramere ( Figs. 13, 14 ). The Singapore and Peninsular Malaysian specimens show variation in size but uniformity in male paramere structure, with the subapical lobe of the male paramere more acute than shown in Lansbury (1972). These specimens will, however, run to R. parmata in Lansbury’s (1972) key based on the posteriorly obscure longitudinal carina on the prosternum. Given this mix of character states, the Singaporean and Malaysian populations may represent a distinct taxon, but a full review of species concepts in the R. gracilis group (to which N. parmata belongs) is beyond the scope of the current paper, so all specimens from the region under study that run to R. parmata in the current key are retained under that name for the present.

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.