Ranatra longipes longipes 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 : 36

Ranatra longipes longipes Stål, 1861

( Figs. 8 , 19, 20 , 25 , 27 )

Ranatra longipes Stål, 1861: 203

Ranatra longipes longipes: Lansbury, 1972: 332

Material examined. — The following additional records are in addition to those listed in Tran & Polhemus (2012): MALAYSIA, Johor: 1 male, Sungai Kayu , 12 Mar.1998, H. H. Tan & O. S. K. Chia, THH9823 ( ZRC); 1 male, 1 female, Mawai, 27 Mar.1992, ZRC 6.22212, coll. unk. ( ZRC) .

Extralimital material examined. — The following extralimital records are in addition to those listed in Tran & Polhemus (2012): MALAYSIA, Sabah: 2 males, Borneo, Sungai Kinabatangan, puddle nr. Danau Biandum Besar, 11 Apr.1994, coll. H. K. Lua & C. Y. Chang ( ZRC) . Sarawak: 3 females, Borneo, Sibu, Sungai Teku, 15 May 1994, MK94-23, coll. unk. ( ZRC) . INDONESIA, Sumatera Barat Prov. : 10 males, 10 females, Sumatra, Bukittingi, Lawang, 5 Jul.1992, W. G. Ullrich ( USNM) .

Diagnosis. — Male body length 21–26 mm, length of respiratory siphon 16–22 mm; female body length 24–27 mm, length of respiratory siphon 16–22 mm. Colouration medium brown, legs in some specimens weakly annulate with lighter brown. Head with vertex slightly raised above the eyes, sometimes with small incipient tubercle. Ventral prothorax with a prominent medial longitudinal carina present along entire length. Fore femur long and slender with two teeth distal to midpoint on the margin adjacent to the infolded tibia, consisting of a moderate sized tooth on outer face and a smaller tooth on inner face ( Fig. 27 ); middle tibia longer than both middle and hind femora; hind tibia distinctly longer than middle tibia; hind femora in both sexes slightly exceeding operculum. Male paramere with a moderately narrow and deep incision subapically, isolating an apically expanded and weakly toothed distal hook; subapical lobe absent or at best barely suggested ( Figs. 19, 20 ).

Distribution. — The nominate subspecies of R. longipes was described from Java ( Stål, 1861), with subsequent records from Sumatra ( Lundblad, 1933), Borneo ( Lansbury, 1972), Peninsular Malaysia (Fernando & Cheng, 1974), and Sulawesi (Nieser & Chen, 1991); the latter authors also made passing reference to specimens from Bali, but provided no specific data. Lansbury (1972) also described the subspecies R. longipes thai from Thailand (later elevated to full species status by Tran & D. Polhemus, 2012) and R. longipes celebensis from the southwestern peninsula of Celebes. As discussed by Tran & D. Polhemus (2012) most if not all of the Malaysian records of R. longipes longipes north of Johor represent R. thai Lansbury. Based on currently understood distributional patterns, it now appears that R. longipes is a predominantly insular species occurring on the Greater Sunda Islands and immediately adjacent smaller islands eastward to Sulawesi, with the westward limits of its range being reached in the extreme southern Peninsular Malaysia and Singapore. Detailed distribution data for the nominate subspecies were provided by Tran & D. Polhemus (2012), who listed further records from Singapore, Malaysia (Johor and Sabah), and Indonesia (Java, Sumatra, and Borneo).

Discussion. — Ranatra longipes is a relatively slender, delicate species, with males noticeably smaller in size than females. It may be separated from the very similar R. thai by the structure of the distal hook on the male paramere (compare Figs. 19, 20 to 21, 22), and by the longer hind tibia in relation to the middle tibia. The male genitalic figures attributed to this species in Chen et al. (2005, pg. 53, figs. 34, 35) in fact represent R. thai (see below).

Figures

Fig. 8. Ranatra longipes Stål, female, specimen from Indonesia, Java, Bogor.

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.