taxonID	type	description	language	source
03D587CD4724FFCA21E2FB8C6392A9CD.taxon	materials_examined	Material examined. – Stream near road linking Padang Gaong Rd to Makam Mahsuri Rd: 1 male (macropterous), HZL 9.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCA21E2FB8C6392A9CD.taxon	distribution	Distribution. – From northeastern India and southern China to Java, Borneo, and the Philippines (Lansbury, 1973). Lansbury (1973) records this species from “ Telaga Pabila ” a place which we were unable to locate, but may be in Malaysia. Otherwise, this is the first record from Malaysia.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCA22A2FD856095AF4A.taxon	materials_examined	Material examined. – Stream near road linking Padang Gaong Rd to Makam Mahsuri Rd: 1 female (macropterous), HZL 9.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCA22A2FD856095AF4A.taxon	distribution	Distribution. – From India to Japan and Australia (Andersen & Weir, 2004).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCA2273FC2360D7A8A0.taxon	materials_examined	Material examined. – Temurun Waterfalls: 6 males, 5 females (macropterous), HZL 2.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCA2273FC2360D7A8A0.taxon	distribution	Distribution. – Thailand (Nieser, 2000). First record from Malaysia.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCA2252FB196735A9B9.taxon	materials_examined	Material examined. – Telaga Tujuh – Air Telaga: 1 female (macropterous), HE 2.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCA2252FB196735A9B9.taxon	distribution	Distribution. – From India and Sri Lanka to Sumatra, Java and Bali (Nieser, 2002).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCA2256F9F666FCAB10.taxon	materials_examined	Material examined. – (all brachypterous): Telaga Tujuh – Air Telaga: 8 males, 4 females, HZL 1 a. Temurun Waterfalls: 15 males, 2 females, HZL 2.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCA2256F9F666FCAB10.taxon	distribution	Distribution. – Johor in Western Malaysia and Singapore (Nieser, 2002). First record from Kedah, which to our knowledge is the northernmost recorded distribution.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCA21E9F9E56205AB8A.taxon	materials_examined	Material examined. – Stream near road linking Padang Gaong Rd to Makam Mahsuri Rd: 1 male, 1 female (macropterous), HZL 9.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCA21E9F9E56205AB8A.taxon	discussion	Remarks. – Because of the different paramere compared with the nominate form (see Lansbury, 1972), this taxon should have the status of a distinct species.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCA21E9F9E56205AB8A.taxon	distribution	Distribution. – Thailand (Lansbury, 1972). Chen et al. (2005) list the Malay Peninsula with a question mark. First record from Malaysia.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCA22DCFF4C609BADED.taxon	materials_examined	Material examined. – (all macropterous): Air Tejun: 1 male, 1 female, HZL 10; 2 females, TAD 0623.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCA22DCFF4C609BADED.taxon	distribution	Distribution. – From northern Thailand to the Lesser Sunda Islands (Lansbury, 1972). Northern records possibly belong to R. lansburyi Chen, Nieser & Ho, 2004 described from Yunnan and Chiang Mai (see Chen et al., 2004). First record from Malaysia.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCB2275F8A96295ACF7.taxon	materials_examined	Material examined. – (all macropterous): Telaga Tujuh – Air Telaga: 41 males, 29 females, HZL 1 a; 1 male, 1 female, HZL 1 b; 6 males, 7 females, TAD 0613.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4724FFCB2275F8A96295ACF7.taxon	distribution	Distribution. – Thailand, Vietnam, and Singapore (Nieser, 2002). First record from Malaysia.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCB21F1FBC36206A900.taxon	materials_examined	Material examined. – Datai Resort, pool: 1 female (macropterous), HE 3.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCB21F1FBC36206A900.taxon	distribution	Distribution. – From India and Sri Lanka to Java and Sulawesi (Nieser, 2004).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCB21E6FAB9611AAA19.taxon	materials_examined	Material examined. – Telaga Tujuh – Air Telaga: 1 female (macropterous), HE 2.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCB21E6FAB9611AAA19.taxon	distribution	Distribution. – From India to Iriomote (off Japan), Taiwan, the Philippines, and Singapore (Nieser, 2004).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCB21E0F9966274AB97.taxon	materials_examined	Material examined. – Temurun Waterfalls: 1 male (macropterous), KV 3. Datai Resort, pool: 1 female (macropterous), HE 3.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCB21E0F9966274AB97.taxon	distribution	Distribution. – From the Andaman Islands and Vietnam through Malesian region to Australia, Tahiti, Guadalcanal, and Okinawa (Nieser, 2004); with several records from West Malaysia and Singapore (Kovac & Yang, 1995; Nieser, 2004).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCB22AAFF4C60B0ADCA.taxon	materials_examined	Material examined. – (all macropterous): Temurun Waterfalls: 10 males, 5 females, HZL 2; 2 males, 1 female, TAD 0614, 3 males, 1 female, KV 3. Air Tejun: 2 males, 2 females, L 10 HZ; 1 male, TAD 0623.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCB22AAFF4C60B0ADCA.taxon	distribution	Distribution. – Thailand, Vietnam, and West Malaysia (Nieser, 1998).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCB22A2FC59609CA8F0.taxon	materials_examined	Material examined. – Telaga Tujuh – Air Telaga: 6 males, 1 female (brachypterous), KV 6; 2 males (brachypterous), 5 males, 10 females (macropterous), HZL 1 a; 1 male, 1 female (brachypterous), 5 males, 4 females (macropterous), HZL 1 b; 1 female (brachypterous), TAD 0613.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCB22A2FC59609CA8F0.taxon	distribution	Distribution. – West Malaysia, Sumatra, and Borneo (Papá ek & Zettel, 2000), southern Thailand (Sites & Polhemus 2002).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCB217DFECC63C9AE29.taxon	materials_examined	Material examined. – (all macropterous): Telaga Tujuh – Air Telaga: 1 male, 2 females, TAD 0613; 11 females, HZL 1 a. Swamp on way to Telaga Tujuh: 1 male, HZL 8.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCB217DFECC63C9AE29.taxon	distribution	Distribution. – Widespread from Iran to Australia (Nieser, 2002).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCB22B0FDA36622AF20.taxon	materials_examined	Material examined. – Swamp next to road to Telaga Tujuh: 1 female (macropterous), HZL 8.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCB22B0FDA36622AF20.taxon	distribution	Distribution. – From India to Sulawesi, New Caledonia; several records from West Malaysia (Nieser, 2004).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCD228CFAC9609BAE77.taxon	description	(Figs. 2, 6 - 12)	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCD228CFAC9609BAE77.taxon	materials_examined	Material examined. – Holotype (macropterous male) and paratypes (1 hindwing-micropterous female, 3 macropterous males, 2 macropterous females), HZL 9, labeled “ MALAYSIA, Kedah \ C-Langkawi, S slopes \ of Gn. Raya, lowland \ stream, 22.11.2006 \ leg. H. Zettel (HZL 9) ”, holotypes and paratypes in NHMW, 1 paratype male in ZRC.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCD228CFAC9609BAE77.taxon	description	Description of macropterous male. – Habitus: see Figure 2. Body size: length 1.9 – 2.0 mm, width 1.35 – 1.40 mm. Colour: Yellow with extended dark brown markings on dorsum, especially on head (Figs. 2, 6). Venter mostly brownish. Legs and antennae yellow; rostrum light brown. Cephalonotum with lateral margins behind eyes slightly concave in dorsal view; sharp margin of pronotal part ending in short distance from posterolateral corner and there forming a small, rather blunt angulation; head with densely set small punctures, with very narrow interspaces, almost dull; disk of pronotum set with numerous very fine micropunctures, and with scattered, unequally distributed and somewhat larger punctures becoming denser towards sides. Mesoscutellum 0.9 times as long as wide, with puncturation of similar size, but slightly denser than on disk of pronotum, micropunctures medially obliterated. Hemelytron with slightly stronger puncturation, interspaces shagreened and dull. Genal plate stout; pronotal plate (Fig. 7) with shallow incision, anteriorly relatively wide. Inner corner of propleural plate broadly convex. Eye index: 2.1 – 2.2. Fourth rostral segment 2.3 times as long as segment 3. Ventral carinae (Fig. 8): Prosternal carina with posterior corner approximately rectangular, with posterior edge slightly concave; apices of meso- and metasternal carina thin-laminate, that on mesosternum strongly reduced; carina of sternite 3 with few small denticles, the proximal one variably enlarged. Abdominal segments strongly asymmetrical. Aedeagus (Fig. 9) moderately slender, apically rather stout and slightly bent to right side; with narrow apical plate posteriorly extended into short spine. Right paramere (Fig. 10) shorter than left paramere, slender-lanceolate, curved, apex minutely pointed. Left paramere (Fig. 11) moderately slender, distally evenly narrowed and slightly curved, apex narrowly rounded. Description of macropterous female. – Body size: length 2.1 – 2.2 mm, width 1.46 – 1.49 mm. Eye index: 2.1. Most characteristics similar to that of male, except the following. Abdomen symmetrical. Sternite 6 with concave hind margin. Subgenital plate (Fig. 12) with broad mediodistal lobe with broadly convex hind margin; inner ridge strongly concave, almost semicircular. Ventral laterotergites 8 slender. Hindwing-micropterous female: body size: length 2.1 mm, width 1.42 mm; eye index: 2.6; pronotum with posterolateral corners less elevated and with angulation of lateral margin more blunt; hemelytron without embolar and claval sutures; other characteristics as in brachypterous female. Hindwing-micropterous male: unknown.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCD228CFAC9609BAE77.taxon	etymology	Etymology. – Named after the island of type locality. The species epithet is a Latinized adjective.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCD228CFAC9609BAE77.taxon	discussion	Remarks. – This species belongs to the Hydrotrephes martini group as defined by Zettel (2000 a). Hitherto, this species group contained eight described species, distributed on the islands of Borneo (five species), Sumatra, Siberut, and Nias (one species each) (Zettel, 2004 a; Papá ek & Zettel, 2005). Hydrotrephes langkawicus, new species is one of the smallest species of the genus; in the H. martini group only H. nitidus Zettel, 2004, a strongly shiny species with deeply emarginate prosternal carina, is of similar size. The genital structures of the male of H. langkawicus are characteristic. Further, the combination of the weakly emarginate prosternal carina, the reduced lamina on the mesosternal carina, and the lobate subgenital plate of the female is unique.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4725FFCD228CFAC9609BAE77.taxon	distribution	Distribution. – Only known from the type locality on Langkawi Island.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4723FFCD22A7FD0C670AA84E.taxon	materials_examined	Material examined. – Swamp next to road to Telaga Tujuh: 1 female (apterous), HZL 8. Stream near road linking Padang Gaong Rd to Makam Mahsuri Rd: 2 females (apterous), HZL 9.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4723FFCD22A7FD0C670AA84E.taxon	distribution	Distribution. – Widespread in Australasia from southern China to Australia, and in the southeastern Palaearctic (Japan) (Polhemus & Polhemus, 2001); recorded from several localities in West Malaysia (Yang et al., 1999; Polhemus & Polhemus, 2001).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFCE21A6FB796392A9B9.taxon	materials_examined	Material examined. – Swamp next to road to Telaga Tujuh: 1 male (brachypterous), 2 females (macropterous), HZL 8.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFCE21A6FB796392A9B9.taxon	distribution	Distribution. – Thailand and Vietnam (Yang & Zettel, 2005). Vitheepradit et al. (2005) recorded H. annamana already from the most-southern part of Thailand (Satun, Songkhla) close to the Malaysian border. First record from Malaysia.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFCE21E0F9F6613BAAD7.taxon	materials_examined	Material examined. – (all brachypterous): Air Tejun: 1 male, 1 female, HZL 10. 1 male, 1 female, TAD 0623.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFCE21E0F9F6613BAAD7.taxon	distribution	Distribution. – Southern China, West Malaysia, Sumatra, Java, and Borneo (Yang & Zettel, 2005).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFCE21A3F8EC617EABED.taxon	materials_examined	Material examined. – Temurun Waterfalls: 1 male (macropterous), HZL 2.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFCE21A3F8EC617EABED.taxon	distribution	Distribution. – Thailand and West Malaysia (Vitheepradit et al., 2005; Yang & Zettel, 2005).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFCE22A5FF4C67D2AE00.taxon	materials_examined	Material examined. – Swamp on way to Telaga Tujuh: 2 males, (macropterous), HZL 8; 2 males (macropterous), 1 female (brachypterous), TAD 0621. Telaga Tujuh – Air Telaga: 1 female (macropterous), TAD 0613. Stream near road linking Padang Gaong Rd to Makam Mahsuri Rd: 1 male, 1 female (macropterous), TAD 0622.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFCE22A5FF4C67D2AE00.taxon	distribution	Distribution. – Widespread from southern China to Australia (Yang & Zettel, 2005).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFCE2002FF4C63A9AE0A.taxon	materials_examined	Material examined. – Swamp next to road to Telaga Tujuh: 4 males, 1 female (apterous), 3 males (macropterous), HZL 8; 1 male (apterous), 1 female (brachypterous), 1 male (macropterous), TAD 6021.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFCE2002FF4C63A9AE0A.taxon	distribution	Distribution. – Except for some remote oceanic islands in all warm regions of the Old World (Polhemus & Polhemus, 2001); recorded earlier from West Malaysia by Yang et al. (1999).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFC022B3FD7961D2AA37.taxon	description	(Figs. 3, 13 – 16)	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFC022B3FD7961D2AA37.taxon	materials_examined	Material examined. – Holotype (apterous female) and paratypes (4 apterous females, 3 apterous males, 1 macropterous-dealate male), HZL 10, labeled “ MALAYSIA, Kedah \ C-Langkawi, Air Tejun, \ nr Kampung Buku, small \ stream, 22.11.2006 \ leg. H. Zettel (HZL 10) ”, holotypes and paratypes in NHMW, 1 paratype female and 1 paratype male in ZRC. – Further paratypes from Malaysia: 1 apterous female, 1 apterous male “ MAL, Terengganu, Sekaya, \ Sg. Brang. HK Lua, \ 21 - OCT- 1998, \ LHK 040 ” (ZRC).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFC022B3FD7961D2AA37.taxon	description	Description of apterous female. – Measurements: Body length 1.31 – 1.42 mm (holotype 1.42 mm). Body width 0.74 – 0.80 mm (holotype 0.79 mm). Relative lengths of antennomeres 1 – 4 (holotype): 0.9: 1.0: 1.8: 1.4. Relative lengths of leg segments (relative to mesofemur length = 100; holotype): profemur 45, protibia 44, protarsus 4 + 14, mesofemur 100, mesotibia 81, mesotarsus 36 + 23, metafemur 71, metatibia 56, metatarsus 9 + 14. Body tear-shaped, sides of abdomen not strongly convergent (Fig. 3). Dorsal aspect black except some indistinct dark orange marks along dorsal eye margin and mesonotum yellowish white except narrow lateral margins. In lateral aspect pro-, meso-, and metapleura yellowish white except narrow or broad stripe along dorsal margin of meso- and metapleura black, mesacetabula with or without dark mark, and metacetabula with narrow or broad dark stripe distally. Ventral aspect black, except prosternum and mesosternum yellowish white with or without infuscated acetabula. Antenna and legs black, except metatrochanter, profemur except apex, and basal half of metafemur whitish; coxae variably infuscated. Median pronotal length 0.35 times eye length. Dorsum of thorax with very short, decumbent pilosity. In lateral aspect, head and mesonotum with scattered black erect setae, those on mesonotum much shorter than those on head. Posterior corners of meso-metanotum slightly acute, apex without conspicuous long setae. Structures of abdomen (Figs. 3, 13, 14) relatively simple: in dorsal view (Fig. 13), connexiva nearly evenly converging, slightly more on segments 5 and 6. Laterotergites directed more or less dorsad, slightly laterodorsad anteriorly and weakly mediodorsad posteriorly, so that all tergites completely, and all sternites partly visible in dorsal view. Each sternite laterally with 1 – 2 long, black setae beneath dorsal margin; sternite 7 additionally with relatively long pilosity at connexival corners. Laterotergites 2 – 4 and 7 and tergites 1 – 7 with short pilosity; laterotergites 5 - 6 with conspicuous, mesad directed setae; tergite 7 with some long black setae on its lateral portions. Suture between tergites 1, 2, and 3 weakly impressed, medially hardly curved cephalad; all other sutures well developed and nearly straight. Tergites without median elevations, and dull. Hind margin of tergite 7 slightly convex; tergite 8 medially with shallow impression, with hind margin bearing few long, black setae. In lateral view (Fig. 14), few long setae surpassing connexival margin; connexival corners acute, with black pilosity. Gonocoxa plate-like; proctiger small, directed ventrocaudad. Description of apterous male. – Measurements: Body length 1.06 – 1.11 mm. Body width 0.62 – 0.66 mm. Colour similar to that of female, except yellowish marks on meso- and metanotum separated by narrow black line and pronotum medially with small orange mark in one specimen. Dorsum of thorax and abdomen shinier than in female. Median pronotal length 0.4 times eye length. Black setae laterally on mesothorax and sternites similar with those of female, longest setae on sternites ca. 0.10 mm long. Dorsum of body with very short pubescence, but head and tergite 7 with some longer setae in addition. Suture between tergites 1 and 2 weak, other sutures between tergites well developed. Tergite 5 circa 8 times as wide as long at midline. Paramere (Fig. 15, 16) moderately curved at basal third, strongly twisted, relatively broad, subapically weakly widened (in caudal view), apex very acute. Description of macropterous male. – Body length 1.18 mm, body width 0.67 mm. Colour similar as in apterous morph, but posterior half of pronotum with half-ovate yellowish mark, and metafemora yellowish white in proximal three-fifths. Pronotum very large, at midline about 2.0 times as long as eye, covering meso- and metanotum, with distinct humeri. Wings of dealate specimen broken off at base, approximately at level of posterior apex of pronotum. All tergites almost flat, tergite 1 not longer than tergite 2. Macropterous female: unknown.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFC022B3FD7961D2AA37.taxon	etymology	Etymology. – This species is dedicated to Tohru Naruse, who accompanied the authors for field work in Langkawi.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFC022B3FD7961D2AA37.taxon	discussion	Remarks. – This species belongs to the S. esakii group as defined by Lansbury & Zettel (1997). Within this group, two species complexes are recognized. The S. esakii complex includes S. esakii Lansbury & Zettel, 1997 from Borneo, S. palawanensis Lansbury & Zettel, 1997 from Palawan (Philippines), and some other undescribed Bornean species. It can be distinguished by wide tergites of the apterous female that are completely visible in dorsal view as the laterotergites are directed laterad or laterodorsad, by tufts of hairs on sternite 2 of the female, and by a slender distal section of the parameres of the males (see Lansbury & Zettel, 1997). The second complex, the S. aberrans complex, contains S. aberrans Lansbury & Zettel, 1997 from Borneo, S. setosa Zettel & Tran, 2005 from Vietnam, S. narusei, and several other undescribed species from Borneo and southeast Asia. Species of this complex can be recognized by the laterotergites of the apterous female which are flapped over the tergites to a varying degree (at least slightly on segments 6 or 7), by a row of long setae on the sternites of the female (situated parallel with and beneath the connexival margin), by the absence of hair tufts on the female’s sternite 2, and by the subapically slightly widened paramere of the male (male of S. aberrans unknown). Additionally, the species have a similar colour pattern (but some variation in the extent of the yellow base of the metafemur) and agree in the general structures of meso-metanotum and abdomen. For comparison, the authors used the type series of S. setosa and the holotype (female) of S. aberrans. Beside the specimens from Langkawi, only two specimens from Terengganu match the diagnostic characters of S. narusei and were included in the type series. Numerous specimens were studied from other parts of peninsular Malaysia (Johore), from Singapore, from the Indonesian islands of Batam and Bintan, and from Sarawak on Borneo (all in ZRC), but it was concluded that they either belong to additional undescribed species or that at least the differences are too big to include them in the type series of S. narusei without a more detailed revision of the whole complex. Strongylovelia narusei differs from S. aberrans and S. setosa (and from most other material studied, except one population from Johore which is eventually conspecific with S. narusei) in a rather conspicuous long pilosity on laterotergites 5 and 6 of the apterous female, and from S. setosa in the more slender apex of the paramere of the male. The ratio of antennomeres 2 and 3 of females is 1.9 – 2.0 in S. aberrans, 1.7 – 1.8 in S. setosa and S. narusei. The posterior corners of the meso-metanotum of apterous females bear a dense group of long black setae in S. narusei, which is absent or inconspicuous in other species. An important characteristic to separate species of the S. aberrans complex might be the presence or absence of long setae on tergite 7 of apterous females, which either occur in small numbers on its lateral areas or in a more or less transverse row close to the tergite’s hind margin. Unfortunately, these setae tend to break off, so that in some cases either only their base is visible or they cannot be seen at all. Such setae could be observed on the lateral parts of tergite 7 of S. narusei and S. aberrans, but not in S. setosa. The apterous female of S. setosa differs also from both species in a deeper, more elongate depression of the tergite 8.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD4720FFC022B3FD7961D2AA37.taxon	distribution	Distribution. – Malaysia: Langkawi, Terengganu.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472EFFC0201EF98C615AA407.taxon	materials_examined	Material examined. – (all apterous): Pantai Datai: 1 male, 2 females, KV 5. Pebble beach near Sungei Lengara: 2 males, 2 females, HZL 3 a; 3 males, 2 females, TAD 0615. Jalan Tanjung Rhu, rocky shore: 9 males, 5 females, HZL 7 b; 3 males, 5 females, TAD 0620.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472EFFC0201EF98C615AA407.taxon	distribution	Distribution. – West coast of the Malay Peninsula, with records from southern Thailand (Phang Nga, Phuket) and West Malaysia (Negeri Sembilan, Pulau Angsa) (Andersen, 1989). One male from Vietnam was preliminarily identified as this species (Zettel & Tran, 2006).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472EFFC0226EFF4C67BDAE60.taxon	materials_examined	Material examined. – (all apterous): Pantai Rhu: 16 males, 29 females, KV 4. Jalan Tanjung Rhu, rocky shore: 1 female, HZL 7 b; 1 male, 1 female, TAD 0620. Former record from Langkawi: 1 male (paratype) Langkawi Is., 6. IV. 1934, leg. R. Brown, in Coll. J. T. Polhemus (ANDERSEN 1992).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472EFFC0226EFF4C67BDAE60.taxon	distribution	Distribution. – Widely distributed along the coasts of the Sunda Shelf area; recorded from southern Thailand, Malaysia (peninsular, P. Tioman, Sarawak), Indonesia (Pulau Batam, Java), and Vietnam (Andersen, 1992; Yang et al., 1999; Zettel & Tran, 2006).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472EFFC0228DF943671BABF7.taxon	materials_examined	Material examined. – Telaga Tujuh – Air Telaga: 1 male (apterous), 2 females (macropterous), HZ 1 a; 1 male, 1 female (macropterous), TAD 0613. Jalan Tanjung Rhu, fish pond: 1 male, 1 female (apterous), 2 females (macropterous), HZL 7 a. Swamp on way to Telaga Tujuh: 4 males, 2 females (apterous), 2 males, 6 females (macropterous), HZL 8.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472EFFC0228DF943671BABF7.taxon	distribution	Distribution. – From India to Japan and Australia (Andersen & Weir, 2004).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472EFFC022A0FD5967CBAFD9.taxon	materials_examined	Material examined. – Jalan Tanjung Rhu, mangroves: 1 female (apterous), HZL 6.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472EFFC022A0FD5967CBAFD9.taxon	distribution	Distribution. – Described from southern Thailand, Borneo (Sarawak), and southern Philippines (Andersen, 2000), but records from Borneo and Philippines belong to undescribed, closely-related species (unpublished data). Confirmed record from Malaysia.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472EFFC022BFFBD66709A917.taxon	materials_examined	Material examined. – Jalan Tanjung Rhu, mangroves: 12 males, 21 females (apterous), HZL 6.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472EFFC022BFFBD66709A917.taxon	distribution	Distribution. – Described from Singapore (Andersen, 2000) and recorded from Vietnam (Zettel & Tran, 2006). First record from Malaysia.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472EFFC022B4FAAC67F0AA6A.taxon	materials_examined	Material examined. – Pantai Rhu: 2 females (apterous), KV 4. Former record for Langkawi: 1 male, 3 females (paratypes), same locality data (Andersen, 2000).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472EFFC022B4FAAC67F0AA6A.taxon	distribution	Distribution. – West Malaysia, Singapore, Borneo, and Philippines (Andersen, 2000).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472FFFC221A5FF4C60C9A437.taxon	description	(Figs. 3, 4, 17 - 23)	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472FFFC221A5FF4C60C9A437.taxon	materials_examined	Material examined. – Holotype (macropterous male) and paratypes (2 apterous females, 1 macropterous male, 5 macropterous females), HZL 1 b, labeled “ MALAYSIA, Kedah \ W-Langkawi, Telaga Tujuh \ stream, 20.11.2006 \ leg. H. Zettel (HZL 1 b) ”, holotype and paratypes in NHMW, 1 paratype macropterous female in ZRC. – Further paratypes from Malaysia: 1 male (macropterous), 1 female (macropterous) “ MAL- Selangor, Ulu \ Gombak; \ 06 - MAY- 1996 \ HK Lua et al. \ LHK 0305 ” (ZRCS). – Further paratypes from Singapore: 7 males, 5 females (apterous) “ SIN- Bt. Timah NR \ HK Lua et al. \ 08 - DEC- 1995 \ NS 0209 ” (ZRCS, NHMW); 2 females (apterous) “ ZRC Chestnut Drive \ NS 128 A \ 5 th May 1994 ” (ZRCS); 3 males (apterous) “ SIN- Chestnut Dr., \ Seletar Reservoir, \ 26 - MAY- 1994 \ HK Lua et al. \ NS 0142 C ” (ZRCS, NHMW); 3 females (apterous) “ SIN, Chestnut Dr., \ Seletar Reservoir, \ “ Ua 2 ” side stream; HK Lua et al. \ 26 - V- 1994, NS 142 G ” (ZRCS); 2 females (apterous) “ Nature Reserves Survey \ Chestnut Dr., NS 142 C \ 26 May 1994 ” (ZRCS); 1 male (apterous), 1 female (apterous) “ Nature Reserves Survey \ Chestnut Dr., NS 138 B \ Singapore \ 19 May 1994 ” (ZRCS); 1 male, 1 female (apterous) “ stm # H, Mac Ritchie \ Forest, 2.2.1994 \\ NS 124 F ” (ZRCS); 1 female (apterous) “ Nature Reserves Survey \ MacRitchie, NS 161 D \ Singapore \ 13 June 1994 ” (ZRCS); 2 females (apterous) “ Nature Reserves Survey \ MacRitchie, NS 161 B \ Singapore, 17 June 1994 ” (ZRCS); 1 male (apterous), 1 female (apterous) “ Nature Reserves Survey \ Nee Soon Swamp Forest \ NS 158 B, Singapore \ 13 June 1994 ” (ZRCS); 1 female (apterous) “ SIN- Nee Soon \ swamp forest; \ 12 - JUN- 1995 \ HK Lua et al. \ NS 0187 A ” (ZRCS); 1 female (apterous) “ SIN- Nee Soon \ KL Yeo \ 06 - MAY- 1992 \ YKL 0794 A ” (ZRCS); 1 male, 2 females (apterous) “ ZRC Nee Soon Swamp Forest \ NS 126 A upstream # 23 \ 28 April 1994 ” (ZRCS).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472FFFC221A5FF4C60C9A437.taxon	description	Description of macropterous male. – Body length 1.28 – 1.32 mm (holotype: 1.31). Pronotal width 0.56 – 0.58 mm (holotype: 0.58). Length of second antennomere of holotype 0.11 mm. Length of metatibia of holotype 0.42 mm. Colour (Fig. 3): Head and pronotum brownish, humeri, anterior and posterior margin of pronotum yellowish orange to different extend. Sides and venter mainly dark brown, connexival margins, segments 7 and 8, and genitalia yellow or light orange. Antennae brown, except base yellow. Legs yellow, but apices of femora and tibiae, and all tarsi brownish. Fore wings pale brown, base and two weakly delimited spots whitish. Pilosity: Generally short, except lateral hind margin of sternite 7 set with long setae. Dorsum without large black impressions. Head width ca. 1.2 times head length. Relative lengths of antennomeres 1 – 4 (holotype): 1.0: 1.0: 1.2: 2.5. Relative lengths of leg segments (relative to metatibia length = 100; holotype): profemur 66, protibia 54, protarsus 32, mesofemur 74, mesotibia 66, mesotarsus 11 + 28, metafemur 85, metatibia 100, metatarsus 12 + 30. Profemur slender. Protibia straight, distally widened, apically with long slender process set in blunt angle with tibia axis and bearing apically a minute grasping comb (Fig. 17). Mesotibia with short process bearing minute grasping comb (Fig. 18). Abdomen slender (Fig. 20). Sternite 6 without modifications. Sternite 7 anteromedially slightly swollen, posteriorly with strong, transverse impression, distinctly concave in lateral view (Fig. 19); hind margin medially slightly emarginated. Segment 8 and genital capsule small. Pygophore and proctiger slightly asymmetrical. Left paramere reduced. Right paramere (Fig. 21) elongate, curved, distally slender. Description of macropterous female. – Body length 1.37 – 1.49 mm. Pronotal width 0.60 – 0.67 mm. Colour as in male, except sternite 7 ventrally brown; in some specimens, dorsum more infuscated. Pilosity: generally short, but laterotergites 2 with few longer setae, sternite 7 at connexival corner with tuft of long setae and laterotergites 8 and complete posterior edge of tergite 8 with dense brush of long setae. Legs simple. Abdomen slender, anteriorly without modifications. Tergite 8 forming a sharp edge, dorsal and posterior face forming a right angle; posterior face ca. 2.5 times as wide as long. Proctiger forming a prominent, ventrocaudad directed knob. Most of gonocoxa 1 concealed by sternite 7. Description of apterous male. – Body length 1.16 – 1.23 mm. Pronotal width 0.45 – 0.48 mm. Colour: Similar to macropterous morph. Head usually orange. Pronotum brown with broad orange margin anteriorly, posterior margin rarely with narrow yellow margin. Tergites and laterotergites variably brownly infuscated. Most commonly, laterotergites, tergite 7, segment 8, and medial areas of tergites 1 – 3 orange, tergites 4 – 5 brown, in other specimens tergites 3 – 6 to 1 – 6 brown and laterotergites 4 – 5 also browly infuscated. Tergites 1 – 3 (– 4) more or less frosted. Pilosity as in macropterous morph. Legs, abdomen, and genitalia as in macropterous morph. Pronotum much smaller, but long compared with some other species of the genus, medianly ca. 0.8 times as long as head and almost completely covering metanotum, hind margin convex. Sides of abdomen anteriorly subparallel, laterotergites moderately raised throughout. Tergite 7 much larger than preceding tergites, ca. 0.8 times as long as wide and slightly longer than tergites 5 and 6 combined. Description of apterous female. – Body length 1.17 – 1.31 mm. Pronotal width 0.48 – 0.57 mm. Colour dorsally similar to that of apterous male, but in some specimens dark parts more pronounced and giving a more distinct pattern. Tergites (1 –) 2 – 3 frosted, 4 – 8 not frosted. Venter and sides as in macropterous female. Pronotum as in apterous male. Abdomen (Figs. 22, 23) usually very narrow, with sides anteriorly constricted, narrowest at segment 3, slightly convex at segments 5 - 6 and then again narrowed at segment 7. In such specimens laterotergites almost vertical throughout. In specimens with more swollen abdomen (probably filled with eggs), laterotergites directed more laterad or even totally flat, giving the abdomen a broader appearance. Tergite 7 ca. 0.7 times as long as broad at anterior margin and ca. 1.5 times as long as tergite 6; its sides strongly convergent posteriad. Tergite 8 almost as long as tergite 7, slightly longer than wide, and shallowly concave. Terminalia as in macropterous morph.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472FFFC221A5FF4C60C9A437.taxon	etymology	Etymology. – From Latin minutissimus; referring to the species’ extremely small size.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472FFFC221A5FF4C60C9A437.taxon	discussion	Remarks. – The presence of a mesotibial comb of the male (Fig. 18) and the asymmetrical genitalia of the male with a long right (Fig. 21) and a reduced left paramere place M. minutissima in the subgenus Picaultia Distant, 1913. The new species is one of the smallest in the genus and has a slender body (Figs. 4, 5). Apterous specimens have the dorsum usually orange to light brownish with variably infuscated pronotum and abdomen. The male can be recognized by the concave outline of sternite 7 in lateral view (Fig. 19), by the small genital capsule (Fig. 20), and by the shape of the slender and curved right paramere (Fig. 21). The female can be easily distinguished from other Picaultia species by characteristics of the abdomen: The tergite 8 possesses a dense brush of equally long setae all along its posterior edge which are more than half as long as the tergite length (Fig. 22); in the apterous female, tergite 1 is usually completely frosted, tergites 2 – 3 discretely, but completely frosted and tergites 4 – 8 usually not frosted at all.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472FFFC221A5FF4C60C9A437.taxon	distribution	Distribution. – Malaysia (Langkawi, Selangor) and Singapore.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC3228EFB5B6607A9F1.taxon	materials_examined	Material examined. – Sungei Lengara: 1 male (macropterous), HZL 3 b. Swamp on way to Telaga Tujuh: 1 male, 1 female (macropterous), HZL 8; 2 males (macropterous), 1 female (apterous), TAD 0621.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC3228EFB5B6607A9F1.taxon	distribution	Distribution. – The typical subspecies from India to Japan, Philippines, Borneo, and Sumatra; other subspecies eastwards to Australia and Vanuatu (Andersen, 1975).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC32287F9CE600DABDB.taxon	materials_examined	Material examined. – (all macropterous): Sungei Lengara: 2 males, 1 female, HZL 3 b. Telaga Tujuh – Air Telaga: 1 male (macropterous), KV 6; 2 males, HZ 1 a; 1 female, TAD 0613. Temurun Waterfalls: 1 female, HZL 2. Stream near road linking Padang Gaong Rd to Makam Mahsuri Rd: 1 male, 2 females, HZL 9; 1 male, TAD 0622. Jalan Tanjung Rhu, mangroves: 1 male, TAD 0619. Swamp on way to Telaga Tujuh: 1 male, 2 females, TAD 0621.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC32287F9CE600DABDB.taxon	distribution	Distribution. – From India to southern China, Philippines, Sulawesi, and the Lesser Sunda Islands (Chen et al., 2005).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC322A5FE2760AEAEC4.taxon	materials_examined	Material examined. – Temurun Waterfalls: 1 male (macropterous), HZL 2.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC322A5FE2760AEAEC4.taxon	distribution	Distribution. – Thailand, Singapore, Sumatra, Borneo (Andersen, 1995, Chen & Zettel, 1998). First record from West Malaysia.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC322BEFCFD67E5A862.taxon	materials_examined	Material examined. – Swamp on way to Telaga Tujuh: 1 male, 1 female (macropterous), 1 female (apterous), HZL 8.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC322BEFCFD67E5A862.taxon	distribution	Distribution. – Widespread in the southeastern Palaearctic and Oriental Region, eastwards to New Guinea and the Solomon Islands (Andersen, 1995); records from the Philippines partly refer to N. philippinensis Zettel, 2004 and all material east of the Wallace Line should be re-examined for conspecificity (Zettel, 2004 b).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC321FEFE056208AF5A.taxon	materials_examined	Material examined. – Dati rain forest: 4 males, 1 female (macropterous), HE 1; Temurun Waterfalls: 2 males, 1 female (apterous), KV 3; 5 males, 7 females (macropterous), TAD 0614; 10 males, 10 females, HZL 2. Gunung Raja: 36 males, 25 females (macropterous), HZL 4 a; 1 male (apterous), 2 males, 4 females (macropterous), TAD 0617. Durian Perangin: 2 females (macropterous), TAD 0618.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC321FEFE056208AF5A.taxon	distribution	Distribution. – Southwestern China, Thailand, and West Malaysia (Zettel, 2001).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC32195FADC616EAACD.taxon	materials_examined	Material examined. – Gunung Raya: 1 male (macropterous), HZL 4 a. Telaga Tujuh – Air Telaga: 1 female (macropterous), HZL 1 a; 1 female (apterous), HZL 1 b. Durian Perangin: 1 female (macropterous), KV 2; 1 female (macropterous), HZL 5. Air Tejun: 8 males, 12 females (apterous), 2 males, 1 female (macropterous), HZL 6; 5 males, 10 females (apterous), 1 male (macropterous), TAD 0623.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC32195FADC616EAACD.taxon	distribution	Distribution. – Described from Singapore (Yang & Polhemus, 1994) and later recorded from the Malay Peninsula and some Indonesian islands (Anambas, Natuna, Bintan, Java) by Tran & Yang (2004).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC321CCFC536174A8E7.taxon	materials_examined	Material examined. – Telaga Tujuh – Air Telaga: 2 females (macropterous), HZL 1 a; 1 male, 1 female (macropterous), HZL 1 b. Temurun Waterfalls: 1 female (apterous), KV 3. Durian Perangin: 6 males, 3 females (macropterous), HZL 5. Stream near road linking Padang Gaong Rd to Makam Mahsuri Rd: 1 female (apterous), HZL 9.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC321CCFC536174A8E7.taxon	distribution	Distribution. – From India to southeastern China and Lombok in Indonesia (Zettel, 2000 b).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC321CAF8A567F1AD8F.taxon	materials_examined	Material examined. – Telaga Tujuh – Air Telaga: 2 females (m a c r o p t e r o u s), K V 6; 1 f e m a l e (a p t e r o u s), 2 f e m a l e s (macropterous), HZ 1 b; 1 male, 1 female (apterous), 1 male, 1 female (macropterous), TAD 0613. Temurun Waterfalls: 3 males, 1 female (macropterous), HZL 2. Air Tejun: 1 male (macropterous), 1 female (apterous), HZL 10; 1 male, 2 females (apterous), TAD 0623.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472DFFC321CAF8A567F1AD8F.taxon	distribution	Distribution. – Southwestern China, Thailand, Vietnam, and West Malaysia (Andersen, 1995, Zettel & Chen, 1996; both sub Limnometra matsudai).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC4201FFDE6623DAF07.taxon	materials_examined	Material examined. – Air Tejun: 1 male, 1 female (apterous), HZL 10; 3 males, 2 females (apterous), TAD 0623.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC4201FFDE6623DAF07.taxon	distribution	Distribution. – West Malaysia and Sumatra (Polhemus & Andersen, 1984).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC422C6FE0660B6AEE0.taxon	materials_examined	Material examined. – (all apterous): Pantai Rhu: 7 males, 5 females, KV 4. Jalan Tanjung Rhu, mangroves: 5 males, 3 females, HZL 6.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC422C6FE0660B6AEE0.taxon	distribution	Distribution. – From India to the Malay Peninsula (Chen et al., 2005).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC421C8FB056263AA0D.taxon	materials_examined	Material examined. – Stream near road linking Padang Gaong Rd to Makam Mahsuri Rd: 3 males, 4 females (apterous), HZL 9; 2 males, 2 females (apterous), TAD 0622.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC421C8FB056263AA0D.taxon	distribution	Distribution. – West Malaysia, Singapore, and Sumatra (Polhemus, 1994), populations from southern Thailand need revision.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC42269FCD96710A819.taxon	materials_examined	Material examined. – (all apterous): Pantai Rhu: 1 male, 2 females, KV 4. Pantai Datai: 1 female, KV 5.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC42269FCD96710A819.taxon	distribution	Distribution. – From the Malay Peninsula (west coast) to the Philippines and Halmahera in Indonesia (Andersen & Cheng, 2004, Zettel, 2005).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC42270FB9667A6A9C7.taxon	materials_examined	Material examined. – (all apterous): Jalan Tanjung Rhu, rocky shore: 5 males, 3 females, HZL 7 b, 3 males, 3 females, TAD 0620. Former record from Langkawi: 1 male, “ Langkawi Is., 4. IV. 1934, leg. R. Birch ”, in the Natural History Museum, London (HERRING 1961).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC42270FB9667A6A9C7.taxon	distribution	Distribution. – Indo-West Pacific, from the Red Sea to Australia (Andersen & Cheng, 2004).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC4227DF9FC6609AADD.taxon	materials_examined	Material examined. – (all apterous): Pantai Kok: 1 female, KV 1. Pantai Datai: 40 males, 34 females, KV 5.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC4227DF9FC6609AADD.taxon	distribution	Distribution. – From the Nicobar Islands and southern Thailand until Vanuatu (Andersen & Cheng, 2004).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC42274F8D56084ABFA.taxon	materials_examined	Material examined. – Pantai Rhu: 3 males, 4 females (apterous), KV 4.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC42274F8D56084ABFA.taxon	distribution	Distribution. – Malay Peninsula and Sri Lanka (Andersen & Cheng, 2004).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC42192FF4C61DBADC9.taxon	materials_examined	Material examined. – Jalan Tanjung Rhu, mangroves: 1 male, 1 female (macropterous), HZL 6; 2 males, 1 female (apterous), TAD 0619.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC42192FF4C61DBADC9.taxon	distribution	Distribution. – Sri Lanka, eastern India, Myanmar, and southern Thailand (Andersen, 1975; Hecher & Zettel, 1996; Buzzetti et al., 2006). First record from Malaysia.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC421F7FCBC61EEA8AD.taxon	materials_examined	Material examined. – Datai environment: 1 female (macropterous), HP 1; Telaga Tujuh – Air Telaga: 1 male, 1 female (apterous), HZL 1 a; 1 male (apterous), HZL 1 b; 4 males, 3 females (apterous), TAD 0613. Temurun Waterfalls: 1 female (apterous), HZL 2; 3 males, 5 females (apterous), 3 males, 5 females (apterous) 2 males (macropterous), TAD 0614. Durian Perangin: 1 male (macropterous), TAD 0618.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC421F7FCBC61EEA8AD.taxon	distribution	Distribution. – Thailand, Vietnam, and West Malaysia (Andersen, 1980; Polhemus & Andersen, 1984).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC421CDF9A56231ABF7.taxon	materials_examined	Material examined. – Temurun Waterfalls: 2 males (apterous), HZL 2, 2 males, 1 female (apterous), HE 4. Durian Perangin: 1 male, 1 female (apterous), 1 male, 1 female (macropterous), HZL 5. Stream near road linking Padang Gaong Rd to Makam Mahsuri Rd: 2 females (apterous), HZL 9. Telaga Tujuh – Air Telaga: 1 male (apterous), 1 male (macropterous), HZL 1 a; 1 male (apterous), TAD 0613. Gunung Raya: 2 males (apterous), TAD 0617. Air Tejun: 1 female (apterous), 1 female (macropterous), HZL 10. Material examined. – From Myanmar and southern China to the Malay Peninsula; in West Malaysia a common species (Polhemus, 2001).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC42272FF4C67D9ADA9.taxon	materials_examined	Material examined. – (all apterous): Datei environment: 1 female, HP 1; Air Tejun: 3 males, 2 females, HZL 10; 5 males, 4 females, TAD 0623.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472AFFC42272FF4C67D9ADA9.taxon	distribution	Distribution. – Southern Thailand, West Malaysia, and Sumatra (Chen & Nieser, 2002).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472BFFC52199FF4C61B1AEDA.taxon	materials_examined	Material examined. – Datai rain forest: 1 male, 2 females (apterous), HE 1; Telaga Tujuh – Air Telaga: 1 male, 4 females (apterous), 2 females (macropterous), HZ 1 b; 2 males, 2 females (apterous), TAD 0613. Sungei Lengara: 1 male (apterous), HZL 3 b. Air Tejun: 1 male, 3 females (apterous), HZL 10; 3 males, 2 females (macropterous), KV 6; 1 female (apterous), TAD 0623. Durian Perangis: 1 male (apterous), 2 males, 5 females (macropterous), KV 2. Gunung Raya: 2 males, 3 females (macropterous), TAD 0617.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472BFFC52199FF4C61B1AEDA.taxon	discussion	Remarks. – See M. squamifer.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472BFFC52199FF4C61B1AEDA.taxon	distribution	Distribution. – Originally described from Myanmar and Thailand (Chen & Nieser, 1993), later recorded from Vietnam (Zettel & Chen, 1996) and West Malaysia (Yang & Kovac, 1995; Yang et al., 1999; Cheng et al., 2001).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472BFFC621D0FCD36293ACF7.taxon	materials_examined	Material examined. – Datai environment: 1 male (apterous), HP 1; Datai rain forest: 1 male, 1 female (apterous), 1 male (macropterous), HE 1; Telaga Tujuh – Air Telaga: 1 male, 2 females (apterous), HZ 1 a. Temurun Waterfalls: 3 males (macropterous), 3 female (apterous), HZL 2. Gunung Raya: 1 male (macropterous), HZL 4 a. Durian Perangin: 1 male, 1 female (apterous), L 5 HZ. Air Tejun: 1 male (apterous), HZL 10.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472BFFC621D0FCD36293ACF7.taxon	discussion	Remarks. – Identification of the species of the Metrocoris nigrofasciatus group is difficult. Identity of M. squamifer specimens from Langkawi has been confirmed by comparison with Malaysian specimens in NHMW identified by Dr. Ping- ping Chen. Using the key characters in Chen & Nieser (1993), male specimens might be identified as M. nigrofasciatus Distant, 1903 due to the fact that the subapical tooth on the fore femur is of variable shape and often reduced in small apterous and in all macropterous specimens. Distinction of these two species should be based on genitalia, especially on the shape of the paramere. The paramere of M. squamifer has a distinct ventral angle – although rarely so strongly pronounced as in the figure by Chen & Nieser (1993) – but the parameres of M. nigrofasciatus and M. nigrofascioides are evenly rounded. Although sorting males of M. squamifer and M. nigrofascioides is easy by the absence or presence of a notch on the fore femur, females can be distinguished only by colour, M. squamifer being on average lighter than M. nigrofascioides. The key character for females of M. squamifer given in Chen & Nieser (1993) is the colour pattern of tergite 8, but it could not conclusively separate the Langkawi specimens because apterous females from Langkawi have a black base of tergite 8. However, if tergite 8 is partly retracted into tergite 7, in some M. squamifer females a colour pattern appears which corresponds with the key character. Usually the yellow colour on tergite 8 is reduced to a small circular spot in M. nigrofascioides, but more extended in M. squamifer. For separation of females, authors used the extension of the mesopleural stripe (reaching further posteriad in M. nigrofascioides than in M. squamifer), and the result agreed well with the identification of males from the same samples. Macropterous females are generally lighter than apterous females of the same species, and this morph of M. nigrofascioides was assigned to the males from the same sample.	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
03D587CD472BFFC621D0FCD36293ACF7.taxon	distribution	Distribution. – Southern Thailand, West Malaysia, Sumatra, and Java (Chen & Nieser, 1993).	en	Zettel, Herbert, Tran, A. D. (2009): First Inventory Of The Water Bugs (Heteroptera: Nepomorpha: Gerromorpha) Of Langkawi Island, Kedah, Malaysia. Raffles Bulletin of Zoology 57 (2): 279-295, DOI: 10.5281/zenodo.5342032
