taxonID	type	description	language	source
03F987C93C3E5441FF38FB7315F7FDF2.taxon	discussion	Remarks. Species of the R. biroi group can be recognised by the combination of the following characteristics: small size, body length not greater than 33.0 mm (males 17.5 – 30.0 mm, females 18.7 – 33.0 mm); siphon length about 0.60 – 1.05 × body length, depending on species; vertex generally higher than eye in lateral view (except R. biroi Lundblad, 1933) and usually with very low tubercle (in some species without tubercle); eye width in dorsal view about 0.9 – 1.5 × interocular width; anterior pronotal length about 1.3 – 1.8 × posterior pronotal length; slender fore femur, with two ventral teeth situated at ca. distal 0.4 of femoral length, without pre-apical tooth; posterior margin of metasternum usually convex (in some species straight or slightly emarginated); operculum of female not extending beyond apex of connexivum (modified from Lansbury, 1972). The R. biroi group shares many characteristics with the R. filiformis group. According to Lansbury (1972), the only discriminating character is eye width (in dorsal view). Species of the R. filiformis group have smaller eyes; eye width is 0.65 – 0.98 times of interocular width. However, this character is not completely discrete. Whereas most species of the R. biroi group have eye width at least equal to interocular width (up to 1.3 times), the eye width of R. nieseri Tran & Nguyen, 2016, ranges between 0.9 and 1.1 times of interocular width. Until further molecular data become available for a phylogenetic approach in the evaluation of this classification, we follow Lansbury’s (1972) classification and treat them as separate groups. Species of the R. biroi group are highly similar to each other, with very few characters to separate them. The most reliable character is the structure of the paramere. Other characters, e. g., the posterior margin of the metasternum, the relative widths of the mesosternum between the middle coxae and of the metasternum between the hind coxae, and the length of the hind femur, are useful to provisionally separate species, but should be used in combination with the parameres. Thus, identification of species is reliable only for male specimens, and females have to be associated with identifiable males.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3D5442FF67FAC4111BF790.taxon	description	(Fig. 1 A)	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3D5442FF67FAC4111BF790.taxon	materials_examined	Material examined. SRI LANKA: 1 male (ZRC _ ENT 00013064), Tabbowa Wewa nr. Puttalam, 8 ° 04 ′ N, 79 ° 56 ′ E, coll. M. M. Bahir, 23 October 1998, MMB 006.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3D5442FF67FAC4111BF790.taxon	diagnosis	Diagnosis. Body length: males 28.0 – 30.0, females 28.5 – 33.0 (also based on description by Lansbury, 1972); siphon length ca. 0.88 – 0.97 × body length; lorum lower than clypeus; vertex higher than eye, evenly rounded, without tubercle; eye width ca. 1.5 × interocular width; space between middle coxae clearly narrower (about 0.75 ×) than space between hind coxae; posterior margin of metasternum convex; hind femur, when folded back parallel to body, reaching midlength of operculum (in both sexes); paramere constricted in distal part, apical hook broadly curved and slender, tip of hook narrowly rounded (Fig. 1 A).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3D5442FF67FAC4111BF790.taxon	distribution	Distribution. India: Patna State, Punjab, Bengal; Sri Lanka (Lansbury, 1972).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3D5442FC45FA561542F78B.taxon	materials_examined	Material examined. No material available.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3D5442FC45FA561542F78B.taxon	diagnosis	Diagnosis (based on description by Lansbury, 1972). Body length: males 29.5, females 30.0 – 33.0; siphon length ca. 0.87 – 1.02 × body length; lorum lower than clypeus; vertex higher than eye, evenly rounded, without tubercle; eye width ca. 1.4 × interocular width; hemelytra slightly surpassing posterior margin of tergum VI; space between middle coxae subequal to space between hind coxae; posterior margin of metasternum convex; hind femur, when folded back parallel to body, slightly surpassing posterior margin of sternum VI (in both sexes); paramere constricted in distal part, apical hook broadly curved and slender, tip of hook narrowly rounded.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3D5442FC45FA561542F78B.taxon	distribution	Distribution. Sri Lanka (Lansbury, 1972).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3C5443FE83FF70120EFA48.taxon	description	(Fig. 1 B)	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3C5443FE83FF70120EFA48.taxon	materials_examined	Material examined. INDONESIA: 4 males, 10 females, Irian Jaya, Fak Fak distr., Lake Yamur, 80 m, April 1998, coll. M. Balke (NHMW). Country uncertain: 1 male, “ Brunner / India / 1868 ”, with label showing “ Ranatra biroi Lundbl., det. O. Lundblad ” (NHMW); 1 female, “ Bruñer [= Brunner] / India / 1868 ” (NHMW).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3C5443FE83FF70120EFA48.taxon	diagnosis	Diagnosis. Body length: males 21.0 – 22.0, females 22.0 – 27.0 (also based on description by Lansbury, 1972); siphon length ca. 0.8 – 1.0 × body length; lorum lower than clypeus; vertex usually lower than eye, thus not visible in lateral view, and without tubercle; eye width ca. 1.3 × interocular width; space between middle coxae about 0.5 × space between hind coxae; posterior margin of metasternum straight; basal part of fore femur about 1.2 × as wide as distal part; hind femur, when folded back parallel to body, reaching mid-length or sometimes posterior quarter of operculum (in both sexes); paramere constricted in distal part, apical hook short, tip of hook expanded, inner margin of hook with pointed tooth.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3C5443FE83FF70120EFA48.taxon	discussion	Remarks. Lansbury (1972) noted that in typical specimens, the vertex was usually lower than the eye in lateral view, but could be more developed in some specimens. The specimens examined in this study have the vertex slightly higher than the eye, and thus the vertex is visible in lateral view. These specimens also present a few minor variations when compared with the description of the species by Lansbury (1972): the hind femur sometimes reaches up to the posterior quarter of the operculum (in Lansbury, 1972, it only reaches just over halfway), and the operculum of the female sometimes reaches the apex of the connexivum (in Lansbury, 1972, it does not reach the apex of the connexivum). Other characters agree well with the description of R. biroi.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3C5443FE83FF70120EFA48.taxon	distribution	Distribution. New Guinea (Lansbury, 1972).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3C5443FF5BFA3A121AF92F.taxon	materials_examined	Material examined. No material available.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3C5444FCF1FE7013A4F7B1.taxon	description	(Fig. 1 C – E)	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3C5444FCF1FE7013A4F7B1.taxon	materials_examined	Material examined. MALAYSIA – Sarawak: 1 male (ZRC _ ENT 00012970), Sarawak, Sg. Stuum Muda, coll. H. H. Tan, 2 September 1996, THH 9694; 2 males, 1 female (ZRC _ ENT 00012971 – 73), Sarawak, Batu Kawa – Matang area, coll. H. H. Tan, 13 January 1996, THH 9601; 1 male (ZRC _ ENT 00012974), Sarawak, Sibu, coll. H. H. Tan & R. Kerle, 3 March 1998, THH 9811; 3 males, 1 female (ZRC _ ENT 00012975 – 78), Sarawak, 10 km from Kuching, coll. H. H. Tan, 4 September 1995, THH 9556; 1 male, 1 female (ZRC _ ENT 00012979 – 80), Sarawak, Kuching to Matang road, coll. H. H. Tan, 14 January 1996, THH 9608; 2 males, 4 females (ZRC _ ENT 00012981 – 83), Sarawak, 8 km towards Gedong, from Serian – Sri Aman road, coll. H. H. Tan, 16 January 1996, THH 9613; 2 males, 1 female (ZRC _ ENT 00012984 – 86), Sarawak 92 - 42; 1 male, 2 females (ZRC _ ENT 00012987 – 88), Sarawak, MK 94 - 55; 1 male, 1 female (ZRC _ ENT 00012989 – 90), Sarawak, blackwater ditch 2 km fr. Kuching, Mantang Batu Kawa Rd from aff. (on way to Kuching) T-junction, coll. K. Lim, 3 July 1992, 92 - 45. INDONESIA – Bintan: 1 male (ZRC. 6.17711), P. Bintan, 47 km to Tg. Pinang, 1 ° 06 ′ 38.1 ″ N, 101 ° 29 ′ 18.0 ″ E, [coll. unknown], 27 April 1994, HH 008; 1 male, 3 females (ZRC. 6.17701), P. Bintan, 1 ° 10 ′ 26.2 ″ N, 104 ° 27 ′ 28.3 ″ E, upstream, [coll. unknown], 27 April 1994, HH 003; 3 males, 4 females (ZRC _ ENT 00012941 – 44), Pulau Bintan, coll. Y. Chia, June 1993, TT 11; 4 males (ZRC _ ENT 00012944 – 48), Pulau Bintan, coll. Y. Chia, June 1993, TT 9; 3 males, 2 females (ZRC _ ENT 00012949 – 52), Pulau Bintan, coll. Y. Chia, June 1993; 1 male (ZRC _ ENT 00012953), Pulau Bintan, north, coll. H. H. Tan, 27 June 1995, THH 9531. INDONESIA – Sumatra: 1 male (ZRC. 6.17685), Sumatra, Jambi, Sg. Alai, [coll. unknown], 21 June 1995, JMB 9511; 1 male, 5 females (ZRC _ ENT 00012954 – 55), Sumatra, east Jambi, coll. H. H. Tan, 22 November 1996, THH 96153; 2 males, 2 females (ZRC _ ENT 00012956 – 58), Sumatra, east Jambi, coll. H. H. Tan, 22 November 1996, THH 96154; 2 males, 1 female (ZRC _ ENT 00012959 – 61), Sumatra, Jambi, Danau, Kamining nr. Kg. Transos, water pH 6.1, coll. M. Kottelat & H. H. Tan, 31 May 1994, MK 94 - 38; 1 male (ZRC _ ENT 00012962), Sumatra Selatan, clear water stream through rubber estate, along road to Sungei Merdak, 7 km into Desa Suka Jaya, coll. H. H. Tan, 11 December 2003, THH 03 - 69; – Banka: 1 male (ZRC _ ENT 00012963), Sumatra, Banka, between Kg. Kurau and Kg. Balilik, 25 km N. of Koba, coll. M. Kottelat et al., 3 March 1993, BANGKA 93 - 95. INDONESIA – Nias: 2 males, Southern Nias, surrounding of Telukdalam, coll. M. A. Jäch, 12 February 1990 (NHMW). INDONESIA – West Kalimantan: 4 males, 4 females (ZRC _ ENT 00013054 – 58, 69 – 71), 2 nymphs, W. Kalimantan, Sg. Sekawi – Danau Sekawi, coll. Y. Y. Goh et al., 14 May 1998, GYY 70 [with paramere of slender form]; 1 male (ZRC _ ENT 00013059), W. Kalimantan, Danau Pantu, coll. Y. Y. Goh et al., 4 May 1998, GYY 51 [with paramere of slender form]; 2 males, 1 female (ZRC _ ENT 00013000 – 02), W. Kalimantan, btw. Sekadau and Sintang, coll. H. K. Lua, H. H. Tan & D. Wowor, 22 April 1998, LHK 0371 / THH 9842; 7 males, 5 females (ZRC _ ENT 00013003 – 010), 2 nymphs, W. Kalimantan, Sintang, Sekadau – Sintang Rd., coll. H. K. Lua, H. H. Tan & D. Wowor, 22 April 1998, LHK 0372 / THH 9843 [with variations in parameres: specimens ZRC _ ENT 00013003 – 04 with paramere of slender form, same as that in GYY 70 sample; others intermediate between holotype and the slender form or same as holotype]; 1 male (ZRC _ ENT 00013011), Kalimantan, Sanggau, along Sekadau – Sintang road, coll. H. K. Lua, H. H. Tan & D. Wowor, 25 April 1998, LHK 0378; 1 male, 3 females (ZRC _ ENT 00013012 – 13), 1 nymph, W. Kalimantan, Pontianak, Sg. Luar nr. Sg. Tayan, coll. H. K. Lua, H. H. Tan & D. Wowor, 26 April 1998, LHK 380 / THH 9854; 9 males, 4 females (ZRC _ ENT 00013014 – 23, 66 – 68), 2 nymphs, Kalimantan, Pontianak, Lobok Raundal nr. Sg. Tayan, coll. H. K. Lua, H. H. Tan & D. Wowor, 26 April 1998, LHK 0381 [parameres: intermediate form between holotype and the slender form as that in GYY 70 sample]; 6 males, 6 females (ZRC _ ENT 00013024 – 30), 1 nymph, Kalimantan, Pontianak, Gg. Semahung, nr Pahuman, coll. H. K. Lua, H. H. Tan & D. Wowor, 27 April 1998, LHK 0383 / THH 9857 [paramere of intermediate form]; 3 males, 1 female (ZRC _ ENT 00013031 – 34), Kalimantan, Pontianak, Sg. Belado, Gg. Kloncet, coll. H. K. Lua, H. H. Tan & D. Wowor, 28 April 1998, LHK 0384; 7 males, 7 females (ZRC _ ENT 00013035 – 42), Kalimantan, Pontianak, Anjungan ‘ D’, coll. H. K. Lua, H. H. Tan & D. Wowor, 28 April 1998, LHK 0385 / THH 9860 [paramere of intermediate form]; 6 males, 4 females (ZRC _ ENT 00013043 – 49), Pontianak, Sg. Kepayan, Pontianak – Anjungan road, coll. H. K. Lua, H. H. Tan & D. Wowor, 29 April 1998, LHK 0386 [some with parameres of intermediate form, others same as holotype]; 1 male (ZRC _ ENT 00013050), W. Kalimantan, Pontianak, Anjungan, Sg. Jelimpo, coll. H. H. Tan & Y. Y. Goh, 28 April 1998, THH 9859 [paramere of intermediate form]; 1 male (ZRC _ ENT 00013051), W. Kalimantan, Desa Tekalong, coll. Y. Y. Goh et al., 8 May 1998, GYY 62 [paramere of intermediate form]; – South Kalimantan: 1 male, 1 female (ZRC _ ENT 00013052 – 53), Kalimantan Selatan, Batulicin basin; stream at Simpang Alok, along road from Batulicin to Mantewe, Desa Gunung Raya, coll. H. H. Tan et al., 14 September 2011, THH 11 - 11 [paramere of intermediate form]; – East Kalimantan: 2 males, 3 females (ZRC _ ENT 00013072 – 76), 1 nymph, Kalimantan Timur, Mahakam basin, Taman Wisata Air Tejun, coll. H. H. Tan & D. Wowor, 11 November 1999, THH 9976 [paramere of intermediate form]; 1 male, 1 female (ZRC _ ENT 00013077 – 78), Kalimantan Timur, Mahakam basin, coll. H. H. Tan & D. Wowor, 11 November 1999, THH 9977.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3C5444FCF1FE7013A4F7B1.taxon	diagnosis	Diagnosis. Body length: males 21.0 – 24.0, females 25.0 – 29.0; siphon length ca. 0.80 – 0.95 × body length; lorum higher than clypeus; vertex higher than eye, with low conical tubercle; eye width ca. 1.0 – 1.1 × interocular width; space between middle coxae about as wide as space between hind coxae; posterior margin of metasternum truncate, only slightly convex; basal part of fore femur about 1.6 × as wide as distal part; hind femur, when folded back parallel to body, slightly surpassing apex of abdomen in males, reaching apex of abdomen in females; paramere tapering along distal third, apical hook evenly curved, tip of hook expanded, ventral margin with a broadly triangular tooth immediately basad of hook (Fig. 1 C – E).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3C5444FCF1FE7013A4F7B1.taxon	discussion	Remarks. This species is closely related to Ranatra natunaensis by having similar paramere structures. Tran & Polhemus (2012) provided comparative notes for these two species. Our examination of numerous further specimens, as listed above, has revealed differences in the paramere structure within samples from the type locality, Singapore, as well as within some samples from other areas. Such variation of the type specimens (from Singapore and from Bintan and Batam of Indonesia) was not reported in the original description by Tran & Polhemus (2012). In the holotype, the width of the apical hook is slightly greater than the width of the middle part (Fig. 1 C). In the “ slender form ” (Fig. 1 E), the middle part and / or the distal constriction before the apical hook is sometimes more slender than that of the holotype, thus the width of the apical hook appears greater than the width of the middle part. The most slender form occurs in samples GYY 70 and GYY 51 from West Kalimantan, Borneo (Fig. 1 E). These samples also exhibit some other differences from the type material of R. rafflesi, such as the space between the middle coxae being very narrow, and the ventral teeth on the fore femur being slightly smaller (so that the width of the femur across the larger tooth is slightly smaller than the maximum width of the femur in the basal half). Several other samples from Kalimantan, as noted in the Material examined section, contain both the most slender form of paramere (like those in samples GYY 70 and GYY 51), the typical form (same as the holotype), and also intermediate forms (Fig. 1 D); however, the shape of the apical hook and the triangular sub-apical tooth of the paramere are consistent among these forms. The distance between the middle coxae is also variable, but always narrower than the distance between the hind coxae. Because these differences occur within localities, we treat them as intra-specific and intrapopulation variations.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C3C5444FCF1FE7013A4F7B1.taxon	distribution	Distribution. Singapore, Borneo (Sarawak), and Indonesia (Bintan, Batam, and Sumatra) (Tran & Polhemus, 2012; Tran & Poggi, 2019). First records from Kalimantan (Borneo) and Nias Island.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C395447FE97FF701126FD32.taxon	description	(Fig. 2)	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C395447FE97FF701126FD32.taxon	materials_examined	Material examined. Holotype (male) “ Philippines: Luzon / Cagayan Province / Gonzaga, Pateng / leg. C. V. Pangantihon ” (PNM). Paratypes: 1 female, same locality data as holotype (CZW); 1 female, Philippines, Cagayan, Peñablanca, Barangay Quibal, Pinacanauan River, 17 ° 42.581 ′ N, 121 ° 48.644 ′ E, 40 m a. s. l., coll. T. Naruse & J. C. E. Mendoza, 25 April 2007, JCEM 07 - 010 (ZRC); 1 male, Philippines, Nueva Ecija, coll. R. Abalos, 13 October 1951 (SEMC).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C395447FE97FF701126FD32.taxon	description	Description. General colouration (Fig. 2 A): mostly light brown to brown; eyes dark brown; all coxae yellowish, fore coxa darker; fore femur mostly yellowish; middle, hind femora and tibiae weakly annulated brown and yellow; fore tarsus yellowish brown, darker at apex; apices of middle and hind femora, middle and hind tarsi dark brown. Hemelytra uniformly textured, yellowish or brown. Measurements: Male (holotype): body length 25.0; length of siphon 18.0; width of head 2.59; interocular width 0.75; width of eye 0.92; pronotal length 6.00, anterior pronotal length 4.58; posterior pronotal length 2.58; anterior pronotal width 1.66; posterior pronotal width 2.28; lengths of leg segments: fore leg: coxa 6.67, femur 9.67, tibia 3.33, tarsus 0.72; middle leg: femur 13.40, tibia 16.50, tarsus 2.20; hind leg: femur 13.30, tibia 16.00, tarsus 2.25. Females: body length 28.0 – 29.0; length of siphon 21.0 – 22.0; width of head 2.80 – 2.90; interocular width 0.88; width of eye 0.96 – 1.01; pronotal length 6.75, anterior pronotal length 5.00; posterior pronotal length 3.17; anterior pronotal width 1.89; posterior pronotal width 2.75; lengths of leg segments: fore leg: coxa 7.50, femur 10.90, tibia 3.75, tarsus 0.72; middle leg: femur 15.40, tibia 17.10, tarsus 2.23; hind leg: femur 15.30, tibia 17.30, tarsus 2.23. Head (Fig. 2 B, C): Vertex raised above eyes but without tubercle; width of eye clearly greater than interocular width; clypeus smooth and flat, higher than lorum and clearly surpassing lorum anteriorly; lorum swollen, with slightly angular dorsal margin, bearing sparse, long, pale setae, similar setae also on vertex. Antenna (Fig. 2 D) with fingerlike projection of second antennal segment about two-thirds the length of third segment. Thorax: Pronotal length shorter than fore coxa (about 0.9 × the length of fore coxa) and about 0.6 × the length of fore femur; anterior lobe about 1.58 – 1.78 × as long as posterior lobe; anterior collar of pronotum slightly raised in lateral view; ratio of posterior width / anterior width 1.37 – 1.46; posterior lobe with humerus broadly rounded, with a sublateral longitudinal groove bordered by a lateral swelling (Fig. 2 B, C). Scutellum with length ca. 1.85 – 2.11 × width, anterior two thirds slightly swollen, followed by two sublateral depressions before posterior third, apex pointed. Prosternum anteriorly with paired broad, shallow longitudinal depressions separated by a median carina; median carina extending to base of a U-shaped depression on posterior section. Mesosternum with concave anterior margin, flat anterior part, middle part grooved along midline, before narrow posterior projection between middle coxae. Metasternum with anterior part weakly grooved along midline, posterior part weakly raised along midline, posterior margin slightly emarginated (Fig. 2 E). Space between middle coxae much narrower (less than 0.5 ×) than space between hind coxae. Hemelytra with membrane slightly surpassing posterior margin of abdominal tergum VI. Legs: Fore femur (Fig. 2 B): in both sexes slender, widest at basal part, ratio of maximum width at basal part / maximum width at distal part in male (holotype) 1.55, in females 1.66 – 1.77; ventral margin with two subtriangular teeth at distal 0.4 of femoral length, larger tooth on outer surface, smaller tooth on mesial surface situated slightly more anteriorly than larger tooth; ratio of width of femur across larger tooth (excluding tuft of setae) / width of femur at basal part 0.77 – 0.86 (holotype 0.81); ratio of width of femur across smaller tooth (excluding setae) / width of femur at basal part 0.65 – 0.75 (holotype 0.75). Middle femur about as long as hind femur; hind femur, when folded back parallel to body, reaching about anterior two-thirds operculum. Middle tibia slightly longer than middle femur; hind tibia longer than hind femur; middle and hind tibiae both bearing dense fringes of long setae on posterior margins along nearly their entire lengths. Abdomen: Operculum of male (Fig. 2 F) about as long as connexivum, medially keeled, apex narrowly rounded. Operculum of female also about as long as connexivum. Respiratory siphon about 0.7 – 0.8 × body length, and about 2.0 × length of sterna III – V combined. Male genitalia: Paramere (Fig. 2 G) dorso-ventrally thickened at middle part, constricted at distal third basad of apical hook; inner margin of hook with a triangular tooth-like elevation; tip of hook expanded; dorsal surface of paramere almost straight, slightly concave at basal two thirds. Phallotheca strongly sclerotised.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C395447FE97FF701126FD32.taxon	etymology	Etymology. This species is named after its type locality, Luzon Island.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C395447FE97FF701126FD32.taxon	discussion	Remarks. In the R. biroi group, four species, namely R. biroi, R. natunaensis, R. rafflesi, and R. luzonensis, new species, are probably closely related based on the presence of a pointed, tooth-like elevation on the inner margin of the paramere apical hook. They are separable using characters in the key above. The paramere of R. luzonensis, new species, appears most similar to that of R. biroi in the distinctly expanded tip of the apical hook and the more obtuse tooth-like elevation on its inner margin. However, other aspects of the paramere show distinct differences between two species: in R. luzonensis, the basal part is dorso-ventrally thicker (it is more slender in R. biroi), the dorsal surface at the distal part has a sulcate area restricted to the area above the apical hook (the sulcate area is located on distal third in R. biroi), and the ventral margin is more gradually tapering towards the sub-apical tooth (it is more abruptly constricted at distal third in R. biroi). In addition, this new species has the following differences from R. biroi: the vertex is visible when viewed laterally, clearly higher than the eyes (in R. biroi, the vertex is lower than the eyes in lateral view), the posterior margin of the metasternum is narrower (more truncate in R. biroi), the median carina of sternum VI of the female is not distinctly raised posteriorly (in R. biroi, it is distinctly raised towards the posterior margin), and the operculum in both sexes reaches the apex of the connexivum (in R. biroi, the operculum usually does not reach the apex of the connexivum).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C395447FE97FF701126FD32.taxon	distribution	Distribution. Philippines: northern Luzon (Cagayan and Nueva Ecija provinces).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C385447FF4CFD13121AFC08.taxon	materials_examined	Material examined. No material available.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C385447FC17FEB315FDFC68.taxon	materials_examined	Material examined. Same as in Tran & Nguyen (2016).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C385447FC17FEB315FDFC68.taxon	diagnosis	Diagnosis. Body length: males 22.0 – 2.5, female 24.0; siphon length ca. 0.7 – 0.8 × body length; lorum swollen, slightly lower than clypeus; vertex higher than eye, with low conical tubercle; eye width ca. 0.9 – 1.1 × interocular width; space between middle coxae about 0.6 × space between hind coxae; posterior margin of metasternum slightly emarginated; hind femur, when folded back parallel to body nearly reaching apex of abdomen (in both sexes); paramere dorso-ventrally constricted in distal third, apical hook evenly curved, tip of hook truncate, expanded, ventral margin with a broad tooth-like elevation immediately basad of hook.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C385447FC17FEB315FDFC68.taxon	distribution	Distribution. Vietnam: Ninh Binh (Tran & Nguyen, 2016).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C385447FF4BFA5A13A9FED2.taxon	materials_examined	Material examined. No material available.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C385447FF4BFA5A13A9FED2.taxon	diagnosis	Diagnosis (based on description by Chen et al., 2004). Body length: males 22.8, females 21.8 – 23.2; siphon length ca. 0.65 – 0.80 × body length; lorum lower than clypeus; vertex higher than eye, with low conical tubercle; eye width ca. 1.1 × interocular width; space between middle coxae about 0.7 × space between hind coxae; posterior margin of metasternum straight or slightly emarginated; hind femur, when folded back parallel to body, surpassing anterior half but not reaching apex of operculum (in both sexes); paramere gradually tapering from distal third towards finger-like apical hook, tip of hook rounded, not expanded, ventral margin with a low and blunt tooth-like elevation immediately basad of hook. Remarks. This species is most similar to R. incisa. For comparative notes, see Chen et al. (2004).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C385447FF4BFA5A13A9FED2.taxon	distribution	Distribution. China: Guangdong and possibly Fujian (see Chen et al., 2004).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C385449FC23FBDA14E0FB52.taxon	description	(Fig. 3)	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C385449FC23FBDA14E0FB52.taxon	materials_examined	Material examined. Holotype (male): “ Philippines: Palawan Prov. / Busuanga Island / 13 road-km WNW Coron / Balulu Falls, leg. H. Zettel ” (PNM). Paratypes: 7 males, 5 females, same locality data as holotype (CZW, NHMW, UPLB, ZRC).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C385449FC23FBDA14E0FB52.taxon	description	Description. General colouration (Fig. 3 A): mostly yellowish brown to brown; eyes dark brown; all coxae yellowish, fore coxa darker; other leg segments mostly yellowish brown, darker at apex. Hemelytra uniformly textured, yellowish or brown. Measurements: Male: body length 22.0 – 23.5 (holotype 23.0); length of siphon 17.0 – 22.0 (holotype 17.0); width of head 2.33 – 2.43 (holotype 2.36); interocular width 0.70 – 0.78 (holotype 0.75); width of eye 0.81 – 0.86 (holotype 0.81); pronotal length 5.79, anterior pronotal length 4.17; posterior pronotal length 2.58; anterior pronotal width 1.55; posterior pronotal width 2.19; lengths of leg segments: fore leg: coxa 5.75, femur 8.50, tibia 3.04, tarsus 0.65; middle leg: femur 13.20, tibia 13.50, tarsus 1.89; hind leg: femur 12.02, tibia 14.30, tarsus 1.94. Females: body length 23.5 – 24.5; length of siphon 15.0 – 21.0; width of head 2.49 – 2.59; interocular width 0.78 – 0.83; width of eye 0.84 – 0.88; pronotal length 5.92, anterior pronotal length 4.25; posterior pronotal length 2.67; anterior pronotal width 1.58; posterior pronotal width 2.25; lengths of leg segments: fore leg: coxa 6.00, femur 8.83, tibia 3.38, tarsus 0.60; middle leg: femur 12.40, tibia 14.25, tarsus 1.99; hind leg: femur 12.25, tibia 14.50, tarsus 1.92. Head (Fig. 3 B, C): Vertex raised above eyes into low, conical tumescence; width of eye slightly greater than interocular width; clypeus smooth and flat, higher than lorum and clearly surpassing lorum anteriorly; lorum with rounded dorsal margin, bearing sparse, long, pale setae, similar setae also on vertex. Antenna (Fig. 3 D) with finger-like projection of second segment about three-quarters the length of third segment. Thorax: Pronotal length slightly shorter than or subequal to fore coxa (0.92 – 1.01 × the length of fore coxa) and about 0.64 – 0.69 × the length of fore femur; anterior lobe about 1.41 – 1.82 × as long as posterior lobe; anterior collar of pronotum slightly raised; ratio of posterior width / anterior width 1.35 – 1.46; posterior lobe with humerus broadly rounded, with a sublateral longitudinal groove bordered by a lateral swelling (Fig. 3 B, C). Scutellum with length ca. 1.5 – 1.9 × width, slightly swollen in anterior two thirds, followed by two sublateral depressions before posterior third, apex pointed. Prosternum anteriorly with paired broad, shallow longitudinal depressions separated by a median carina; median carina extending to base of a broad U-shaped depression on posterior section. Mesosternum with concave anterior margin, flat anterior part, middle part grooved along midline, before a narrow posterior projection between middle coxae. Metasternum with anterior part weakly grooved along midline, posterior part weakly raised along midline, posterior margin straight or slightly emarginated (Fig. 3 E). Space between middle coxae about same as space between hind coxae. Hemelytra with membrane slightly surpassing posterior margin of abdominal tergum VI. Legs: Fore femur (Fig. 3 B) in both sexes slender, widest at basal part, ratio of maximum width at basal part / maximum width at distal part in male 1.45 – 1.61 (holotype 1.45), in females 1.55 – 1.73; ventral margin with two subtriangular teeth at distal 0.4 of femoral length, larger tooth on outer surface, smaller tooth on mesial surface situated slightly nearer to apex of femur than larger tooth; ratio of width of femur across larger tooth (excluding tuft of setae) / width of femur at basal part 0.88 – 0.96 (holotype 0.95); ratio of width of femur across smaller tooth (excluding setae) / width of femur at basal part 0.62 – 0.73 (holotype 0.71). Middle femur slightly longer than hind femur; hind femur, when folded back parallel to body, slightly surpassing apex of operculum. Middle tibia longer than middle femur; hind tibia longer than hind femur; middle and hind tibiae both bearing dense fringes of long setae on posterior margins along nearly their entire lengths. Abdomen: Operculum of male about as long as connexivum, medially keeled, apex narrowly rounded. Operculum of female also about as long as connexivum. Respiratory siphon about 0.6 – 0.9 × body length, and about 1.86 – 2.69 × length of sterna III – V combined, with dense, long, thin setae along ventral margin at ca. basal third. Male genitalia: Paramere (Fig. 3 F) dorso-ventrally constricted at distal quarter, ventral margin with a low, broad elevation before finger-like apical hook, tip of hook evenly rounded. Phallotheca strongly sclerotised.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C385449FC23FBDA14E0FB52.taxon	etymology	Etymology. This species is named after its type locality, Palawan Island.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C385449FC23FBDA14E0FB52.taxon	discussion	Remarks. In the R. biroi group, this new species is most similar to R. nieseri in the general appearance of the parameres and most other morphological features, but it differs from the latter in having the space between the middle coxae about as wide as the space between the hind coxae (in R. nieseri, the space between the middle coxae is distinctly narrower), and the apical hook of the paramere has an evenly rounded tip (truncate in R. nieseri). Ranatra palawanensis, new species, can be separated from a similar subspecies, R. longipes longipes, by the following characteristics: the paramere is dorso-ventrally constricted before the apical hook (whereas in R. longipes longipes, the dorsal margin is mostly straight and the ventral margin before the apical hook is gradually constricted), and the posterior margin of the metasternum is straight or slightly emarginated (it is convex or rounded in R. longipes longipes) (Figs. 3 F, 4 A). Ranatra longipes longipes is widespread in Southeast Asia and reaches northwards of Borneo (see below). Specimens from Luzon reported as “ Ranatra diminuta ” by Polhemus & Reisen (1976) might belong either to R. longipes longipes or to one of the new species; however, the material was not available to us.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C385449FC23FBDA14E0FB52.taxon	distribution	Distribution. Philippines: Palawan.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C36544AFC18FB331489F952.taxon	description	(Fig. 4 A)	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C36544AFC18FB331489F952.taxon	materials_examined	Material examined. SINGAPORE: 1 male, 1 female (ZRC. 6.15400 – 01), Buona Vista Road, fish pond, [coll. unknown], [date unknown]. BRUNEI: 2 males, Brunei, Damuan River, lowland stream, 04 ° 51 ′ N, 114 ° 48 ′ E (GPS), coll. H. Zettel, 14 June 2007 (4) (NHMW). MALAYSIA – West: – Selangor: 1 male, N. Selangor, peat swamp forest, coll. P. K. L. Ng, September 1992 (ZRC). – Johor: 1 male, Johor, Tg. Sedili, S. Selangi, coll. Chia Yi, 22 April 1992, 792 B (ZRC); 1 male, 1 female, Johor, between Pekan Nanas to Pontian, no vegetation, coll. K. L. Yeo, 4 March 1992, # Y 781 B (ZRC); 1 male, 1 female, Johor, 8 km fr. Pontian, Prt Sikom, coll. K. L. Yeo et al., 14 May 1992, 796 c (ZRC); 1 male, Johor, Ayer Baloi, coll. C. M. Yang & K. L. Yeo, 4 March 1992 (ZRC); 1 male, Johor, stream between 35 and 36 milestones along Mersing to Kluang Road, coll. P. K. L. Ng, June 1985 (ZRC). Schödl, 11 February 1991 (12 a) (NHMW); 1 male, West Sumatra, Nature Reserve Harau, 90 km from Padang Panjang, coll. Bujang, 1991 (NHMW); 1 male, West Sumatra, Solok, [coll. unknown], July 1992 (NHMW). INDONESIA – Java: 1 male, 2 females, Java, Bogor, Ciomas, coll. H. H. Tan, 10 July 1996, THH 9667 (ZRC); 3 males, 3 females, Java, Yogyakarta, Kali Progo, coll. T. B. Lim, 28 June 1997, JV 0006 A (ZRC); 2 males, 4 females, Java, Yogyakarta, Kali Progo, coll. T. B. Lim, 29 June 1997, JV 0006 B (ZRC); 1 male, Java, Yogyakarta, Gampulong, coll. T. B. Lim, 29 June 1997, JV 0007 (ZRC); 1 male, 1 female, West Java, Bogor, coll. Hamann, 195 [!] (NHMW). MALAYSIA – Sarawak: 1 male, Sarawak, Miri, coll. H. H. Tan, 26 September 1996, THH 96111 (ZRC); 1 male, 1 female, Sarawak, Marudi, coll. H. H. Tan, 27 September 1996, THH 96114 (ZRC); 1 male, 1 female, Sarawak, MK 94 - 55 (ZRC). – Sabah: 3 males, 2 females, 4 nymphs (ZRC. 6.18700), Sabah, Sg. Kinabatangan, puddle nr. Danau Biandum Besar, coll. H. K. Lua & C. Y. Chang, 12 April 1994, LHK 237; 2 males, 3 females, Sabah, 10 – 12 km before Beaufort on Kota Kinabalu to Beaufort road, peat swamp, blackwater, coll. P. Ng & R. Stuebing, 29 December 1992 (ZRC). INDONESIA – East Kalimantan: 1 male, Kalimantan Timur, Mahakam basin, coll. H. H. Tan & D. Wowor, 2 December 1999, THH 99106 (ZRC); 1 male, 5 females, Kalimantan Timur, Mahakam basin, coll. H. H. Tan & D. Wowor, 10 November 1999, THH 9973 (ZRC); 1 male, 2 females, Kalimantan Timur, Mahakam basin, coll. H. H. Tan & D. Wowor, 11 November 1999, THH 9977 (ZRC). INDONESIA – Sumatra: 2 males, 3 females, Sumatra, Jambi, coll. H. H. Tan, 24 July 1997, THH 9741 (ZRC); 1 male, Sumatra, Jambi, Pijoan, Danau, Setpadang, coll. H. H. Tan, 8 June 1996, THH 9649 (ZRC); 1 male, 1 female, S. Sumatra, Sg. Sentang, coll. H. H. Tan, 27 July 1997, THH 9744 (ZRC); 3 males, 5 females, Sumatra, ca. 80 km south of Medan, coll. H. H. Tan, 15 June 1996, THH 9659 (ZRC); 16 males, 18 females, 1 nymph, Sumatra, Jambie, coll. H. H. Tan, 6 June 1996, THH 9644 (ZRC); 1 male, Sumatra, Jambi, Danau Pinang, lake in forest connected to Sg. Pijoan, coll. M. Kottelat & H. H. Tan, 28 May 1994, MK 94 - 30 (ZRC); 1 male, Sumatra, Lemba Harau, coll. S. INDONESIA – Kundur Island: 1 male, 1 female, 1 nymph, Kundur I., Riaus Is., Parit Gantung Sebesi, Tg. Batu Dist., coll. H. K. Lua & D. Wowor, 12 October 1998, LHK 0397 (ZRC); 2 males, 1 female, Kundur I., Riaus Is., about 7 km from Tg. Batu, coll. H. K. Lua & D. Wowor, 13 October 1998, LHK 0398 (ZRC). INDONESIA – Lombok Island: 1 male, Lombok, Suranadi, coll. M. A. Jäch, 3 February 1988 (14) (NHMW).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C36544AFC18FB331489F952.taxon	diagnosis	Diagnosis. Body length: males 21.5 – 25.5, females 24.0 – 27.0; siphon length ca. 0.65 – 0.85 × body length; lorum about as high as clypeus; vertex higher than eye, with low conical tubercle; eye width ca. 1.2 × interocular width; space between middle coxae about 0.9 × space between hind coxae; posterior margin of metasternum convex; hind femur, when folded back parallel to body, slightly surpassing apex of operculum (in both sexes); paramere slender, apical hook strongly recurved, inner margin of hook with incipient obtuse elevation, tip of hook usually truncated.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C36544AFC18FB331489F952.taxon	discussion	Remarks. Tran & Polhemus (2012) reported that the distribution of R. longipes longipes overlaps with that of R. thai in the southern part of Peninsular Malaysia (Johor) only, and that it does not extend to the northern part of Peninsular Malaysia. Here, we report the first record of this subspecies from Selangor, in western Peninsular Malaysia. This record suggests further overlap between the distribution ranges of R. longipes longipes and R. thai.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C36544AFC18FB331489F952.taxon	distribution	Distribution. Peninsular Malaysia (Johor; first record for Selangor), Singapore, Borneo, Sumatra, Java, Bali, Sulawesi Tenggara (Lansbury, 1972; Nieser & Chen, 1991; Tran & Polhemus, 2012; Polhemus & Polhemus, 2013). First records for Lombok and Kundur (Indonesia).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C35544AFC0CF933154CF828.taxon	materials_examined	Material examined. No material available.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C34544CFE8EFC131142FF72.taxon	materials_examined	Material examined. THAILAND: 1 male, Narathiwat Prov., Ban Sac, coll. H. K. Lua, 23 October 1998, LHK 0402 (ZRC); 2 males, Narathiwat Prov., Sg. Padi, coll. H. K. Lua, 23 October 1998, LHK 0403 (ZRC); 2 males, Nakhon Rachasima Prov., outlet Lam Takong reservoir, coll. H. H. Tan, 16 January 1997, THH 9716 (ZRC); 2 males, Mekong river basin, Huang River tributary, stream on route 2103, 2 km S. of Dan Sai, 17 ° 16 ′ 0.9 ″ N, 101 ° 08 ′ 29.2 ″ E, coll. S. H. Tan & N. Sivasothi, 21 March 1996, TG 11 (ZRC); 2 males, 4 females, Mae Hong Son Prov., 17 road-km N Mae Hong Son, Mok Cham Pae, near Fish Cave, coll. H. Zettel, 11 November 1995 (12 a, 12 b) (NHMW); 1 female, Chiang Mai Prov., Chiang Dao, Ban Yang Thung Pong, c. 500 m a. s. l., coll. H. Zettel, 8 November 1995 (10) (NHMW); 2 females, Khon Kaen Prov., Khon Kaen University, Plastic Pond, coll. H. Zettel, 26 November 1995 (28) (NHMW); 1 male, Chayaphum Prov., Tat Ton NP, Tat Bong, coll. H. Zettel, 27 November 1995 (29) (NHMW); 1 male, 1 female, Chayaphum Prov., Tat Ton NP, Tat Ton, coll. H. Zettel, 27 November 1995 (30) (NHMW); 1 male, Chonburi, Ko Chang, 12 ° 02 ′ N, 102 ° 18 ′ E, coll. F. Seyfert, 26 October – 3 November 2002 (2) (NHMW); 1 male, Sakhon Nakhon, 11 km NE Khan Poon, Huai Ya, coll. W. D. Shepard, 5 March 1994 (NHMW); 1 male, 1 female, Krabi, Ao Nang, coll. M. Madl, 22 November 1991 (2, 3) (NHMW); 8 males, 6 females, Nakhon Ratchasima Prov., Lam Takhong, near Khao Yai NP, stream, 380 m a. s. l., coll. H. Zettel, 8 January 2009 (50) (NHMW). LAOS: 1 female, Champasak Province, Bolaven Plateau, Paksong, 1,250 m a. s. l., coll. P. Schwendinger, 27 December 1996 (NHMW). CAMBODIA: 3 males, 2 females, Kampot Province, O’saray stream, 10 ° 41 ′ 29.3 ″ N, 104 ° 02 ′ 48.8 ″ E, coll. CBC team, 4 March 2019, CA 0116. A 4 (RUPP, NHMW); 1 male, 1 female, Takeo Province, Boeng Cheung Loung Lake, 11 ° 21 ′ 08.1 ″ N, 104 ° 56 ′ 27.3 ″ E, coll. RUPP team, 9 March 2019, CA 0118, HN (RUPP). MALAYSIA – West: – Perak: 1 male (ZRC. 6.18857), Perak, 2 km after Raban before 286 km to K. Bahru, 5 ° 2 ′ 41.2 ″ N, 100 ° 57 ′ 13.1 ″ E, coll. H. H. Tan, 19 November 1995, THH 9591. – Kelantan: 1 male, Kelantan, Sungei Kemia Hulu Besut, 6 km from Kampong Keruah on road to hydroelectric station, coll. P. Ng et al., 20 March 1992, LHK 184 (ZRC); 3 females, Kelantan, tributary of Sungei Hulu Besut, immediately after Kampong Keruah on road to hydroelectric station, coll. H. K. Lua, 20 March 1992, LHK 183 d (ZRC). – Trengganu: 1 male, 1 female, Trengganu, stream at about km 6 on road from Kuala Brang to Kuala Trengganu, coll. P. Ng et al., 19 March 1992, LHK 180 (ZRC); 2 males, Trengganu, coll. P. K. L. Ng et al., 18 – 19 March 1992 (ZRC); 1 male, 2 females, 1 nymph, Trengganu, Rantau Abang, coll. B. Tan & G. Sumita, 16 May 1995, TG 04 (ZRC); 1 male, 1 female, Trengganu, north of Ayer Puteh, about 121 km on road from Kuantan to Kuala Trengganu, coll. P. Ng et al., 19 March 1992, LHK 181 (ZRC); 5 males, 3 females, Trengganu, Rantau Abang, coll. H. H. Tan, 15 May 1995, THH 9518 (ZRC); 1 male, 94 km from K. Trengganu to Kota Bahru, 5 ° 32 ′ 38.5 ″ N, 102 ° 43 ′ 43.9 ″ E, coll. P. K. L. Ng et al., 19 March 1992 (ZRC); 1 male, Trengganu, north of Rantau Abang, swamp at km 56 on road from Kuala Trengganu to Kuantan, coll. P. Ng et al., 18 March 1992, LHK 177 (ZRC); 62 ex. (ZRC. 6.22228), pool at km 94 on road from Kuala Terengganu to Kota Bahru, south of Jerteh, 5 ° 32 ′ 38.5 ″ N, 102 ° 43 ′ 43.9 ″ E, water temp. 26 ° C, pH 6.7, coll. H. K. Lua, 19 March 1992. – Selangor: 1 male, Selangor, lake near Templer Park, coll. C. M. Yang, 15 November 1995, YCM 77 (ZRC); 1 male, 1 female, Selangor, 0.2 km from 45 km Tg. Malim – Sg. Besar Rd, coll. P. K. L. Ng et al., 18 September 1992 (ZRC). – Johor: 2 males, Sg. Selangi, coll. P. Ng et al., 22 April 1992 (ZRC).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C34544CFE8EFC131142FF72.taxon	diagnosis	Diagnosis. Body length: males 21.0 – 24.0, females 22.0 – 26.5; siphon length ca. 0.8 – 1.0 × body length; lorum slightly lower than clypeus; vertex higher than eye, with low conical tubercle; eye width ca. 1.2 × interocular width; space between middle coxae about 0.6 × space between hind coxae; posterior margin of metasternum convex; hind femur, when folded back parallel to body, clearly surpassing apex of operculum (in males) or nearly reaching apex of operculum (in females); paramere slender, apical hook slender, strongly recurved, inner margin of hook without incipient elevation, tip of hook of paramere slightly expanded and rounded.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C34544CFE8EFC131142FF72.taxon	distribution	Distribution. Thailand, Vietnam, Peninsular Malaysia, Cambodia (Lansbury, 1972; Tran & Polhemus, 2012; Polhemus & Polhemus, 2013; Tran & Nguyen, 2016; Zettel et al., 2017).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C33544CFF28FED315D6FC32.taxon	description	(Fig. 4 B, C)	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C33544CFF28FED315D6FC32.taxon	materials_examined	Type material examined. Holotype (male) and paratypes (4 males, 4 females) [note that the number of male / female paratypes is different in Zettel et al. (2017): 5 males, 3 females], “ Cambodia. Krâvanh Mnts, Koh Kong Prov., vic. Tatai, Tatai Riv., 21 – 26.12.2015, 11 ° 35 ′ 27 ″ N, 103 ° 5 ′ 44 ″ E, Martynov A. V. leg. ” (NHMW, CFD, CEI, ZRC). Paratypes (1 male, 2 female), “ Cambodia, Cardamom Mnts. Koh Kong Prov., vic. Chi Phat vill. – trib. Piphot Riv., 17 – 0.12.15, 11 ° 19 ′ 13 ″ N – 23 ′ 12 ″ N, 103 ° 27 ′ 52 ″ E – 32 ′ 34 ″ E, Martynov A. V. leg. ” (NHMW). Additional material examined. INDONESIA – Riau: 1 male, 1 female (ZRC _ ENT 00013061 – 62), Natuna, Pulau Bunguran, Sungei Segeram, Kecamatam Ranai, coll. D. Wowor et al., 18 March 2002, EA-DW 11 [previously det. as “ cf. natunaensis ” in Tran & Yang, 2004]. THAILAND: 1 male (ZRC _ ENT 00013063), Songkla Prov., Nam Tok Khao Chong, coll. H. K. Lua, 26 October 1998, LHK 0410.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C33544CFF28FED315D6FC32.taxon	diagnosis	Diagnosis (adapted from Zettel et al., 2017). Body length: males 19.9 – 22.5, females 22.0 – 23.7; siphon length ca. 0.85 – 0.95 × body length; lorum lower than clypeus; vertex higher than eye, with low conical tubercle; eye width ca. 0.95 – 1.00 × interocular width; space between middle coxae about as wide as space between hind coxae; posterior margin of metasternum slightly convex; hind femur, when folded back parallel to body, surpassing anterior half to reaching posterior third of operculum (in males) or just to anterior third of operculum (in females); paramere (Fig. 4 B, C) relatively broad medially then tapering at distal third, apical hook evenly curved, tip of hook rounded, slightly expanded, ventral margin right before hook with a low, broad elevation.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C33544CFF28FED315D6FC32.taxon	discussion	Remarks. Tran & Yang (2004) examined some specimens collected from Natuna Island and considered that they could be R. natunaensis. In this study, after comparing these specimens with the type specimens of R. cardamomensis, we find no distinct difference between them, except that the hind femora of specimens from Natuna are slightly longer, clearly surpassing the apex of the operculum (in males) or just reaching it (in females). In type specimens of R. cardamomensis, the hind femur of the male reaches to the posterior third or quarter of the operculum, whereas in females it is more variable, from reaching just to midlength or slightly surpassing the apex of the operculum. The parameres are identical (compare Fig. 4 B with Zettel et al., 2017: fig. 13). Thus, these specimens are now confirmed as R. cardamomensis and are first reports of this species outside Cambodia. We have also encountered a male specimen, collected from southern Thailand, which highly resembles the type specimens of R. cardamomensis. It has only a few small differences from the type specimens as follows: the posterior margin of the metasternum is rounded (in type specimens, it is convex but not rounded); the middle femur is slightly shorter, only reaching the anterior third of the operculum (in male type specimens, it reaches its mid-length); the hind femur is slightly longer, just surpassing the apex of the operculum (in male type specimens, it is variable, reaching the posterior third or quarter); and the paramere (Fig. 4 C) is slightly more slender, with its dorsal margin slightly concave before the apical hook, which is slightly more slender (compare with Zettel et al., 2017: fig. 13). However, with only one specimen available, we cannot determine if these differences are reliable for distinguishing it as another species. Thus, we provisionally consider this specimen to be conspecific with R. cardamomensis.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C33544CFF28FED315D6FC32.taxon	distribution	Distribution. Cambodia (Zettel et al., 2017); first records for Indonesia (Natuna Island) and southern Thailand.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C33544CFC6CFC131571F968.taxon	materials_examined	Type material examined. Holotype (male) and paratypes (3 females), “ BURMA: Bago Div. / Bago Yoma, Sein Yai For. / Camp, 1700 m, 29.10.1998, l. Schillhammer (36) ” (NHMW). Additional material. THAILAND: 2 males, Salween Basin, coll. S. H. Tan & N. Sivasothi, 19 March 1996, TG 1 (ZRC).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C33544CFC6CFC131571F968.taxon	diagnosis	Diagnosis. Body length: males 26.0, females 27.0 – 28.0; siphon length ca. 0.95 – 1.05 × body length; lorum higher than clypeus; vertex higher than eye, without tubercle; eye width ca. 1.2 × interocular width; space between middle coxae narrower than space between hind coxae; posterior margin of metasternum convex; hind femur, when folded back parallel to body, slightly surpassing apex of abdomen (in both sexes); paramere relatively broad, apical hook slender, strongly recurved at base, gap between hook and main part of paramere very narrow, tip of hook narrow.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C33544CFC6CFC131571F968.taxon	distribution	Distribution. Myanmar, Thailand (Zettel, 1999; Polhemus & Polhemus, 2012; Tran & Nguyen, 2016).	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C33544CFC17F8DA154CF84F.taxon	materials_examined	Material examined. No material available.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
03F987C93C32544DFFFFFAB311B9F9B2.taxon	etymology	Etymology. The epithet is composed of the Latin adjective ‘ curtus’ (short) and the Latin noun ‘ cauda’ (tail). It refers to the short siphon of this species.	en	Tran, A. D., Zettel, H. (2021): Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species. Raffles Bulletin of Zoology 69: 507-521, DOI: 10.26107/RBZ-2021-0068
