LikhitrakarnNatdanaiGolovatchSergei I.PanhaSomsakRevision of the Southeast Asian millipede genus Orthomorpha Bollman, 1893, with the proposal of a new genus (Diplopoda, Polydesmida, Paradoxosomatidae) Zookeys29920112011131116110.3897/zookeys.131.1921 Orthomorpha insularis http://species-id.net/wiki/Orthomorpha_insularis Pocock, 1895Figs 9196Orthomorpha insularisPocock 1895: 817 (D).Orthomorpha clivicolaPocock 1895: 819 (D).Orthomorpha palonensisPocock 1895: 820 (D).Orthomorpha monticolaPocock 1895: 820 (D).Orthomorpha gestriPocock 1895: 820 (D).Orthomorpha gestri – Attems 1936: 205 (M, R); 1937: 94 (M); Jeekel 1963: 265 (M); 1964: 361 (M); 1968: 56 (M).Orthomorpha Gestri – Attems 1898: 328 (D); 1914: 238 (M).Orthomorpha monticola – Attems 1898: 328 (D); 1914: 238 (M); 1936: 205 (M, R); 1937: 94 (M); Jeekel 1963: 265 (M); 1964: 361 (M, D); 1968: 56 (M).Orthomorpha palonensis – Attems 1898: 328 (D); 1914: 238 (M); 1936: 205 (M, R); 1937: 94 (M); Jeekel 1963: 265 (M); 1964: 361 (M); 1968: 56 (M).Orthomorpha clivicola – Attems 1898: 328 (D); 1914: 238 (M); 1936: 204 (M, R); 1937: 93 (M); Jeekel 1963: 265 (M); 1964: 361 (M); 1968: 56 (M).Orthomorpha insularis – Attems 1898: 328 (D); 1914: 238 (M); Jeekel 1963: 265 (M); 1964: 361 (M, D); 1968: 56 (M); 1970: 293 (D); Hoffman 1977: 700 (M); Golovatch 1998: 42 (D).Orthomorpha karschi insularisAttems 1936: 199 (D).Orthomorpha karschii insularis –Attems 1937: 71 (D).Orthomorpha karschii intercedensAttems 1937: 71 (D).Orthomorpha intercedens – Jeekel 1963: 265 (M); 1964: 361 (M); 1968: 56 (M); 1970: 293 (D); Enghoff 2005: 97 (M, R); Decker 2010: 31 (R).Material examined.

2 ♀ (CUMZ), Thailand, Mae Hong Son Prov., Mueang Mae Hong Son Distr., Tham Woa Temple, 19°53'33"N, 98°08'40"E, 19.07.2008, leg. R. Chanabun. 2 ♂, 1 ♀ (CUMZ), Chiang Mai Prov., Mueang Chiang Mai Distr., Doi Suthep National Park, ca 1290 m, 18°48'09"N, 98°54'12"E, 23.04.2009, leg. N. Likhitrakarn. 2 ♂ (CUMZ), same locality, 28.11.2009, leg. N. Likhitrakarn. 1 ♀ (ZMUC), 1 ♀ (ZMUM), 2 ♂, 1 ♀, 2 juv. (CUMZ), same Prov., Chiang Dao Distr., Palong Temple, ca 470 m, 19°24'13"N, 98°55'16"E, 28.09.2010, leg. N. Likhitrakarn. 1 ♂ (CUMZ), Phayao Prov., Phu Sang Distr., Phu Sang National Park, 20°06'02"N, 100°37'56"E, 24.10.2008, leg. C. Sutcharit. 1 ♂, 1 ♀ (CUMZ), Tak Prov., Mae Sot Distr., Doi Mu Soe, 17°18'70"N, 99°33'50"E, 5.10.2008, leg. C. Sutcharit. 1 ♂, same Prov., Tha Song Yang Distr., at Mae Usu Cave, ca 140 m, 17°18'16"N, 98°09'21"E, 30.05.2009, leg. N. Likhitrakarn. 1 ♂ (CUMZ), same Prov., Umphang Distr., near Umphang City, ca 490 m 16°02'20"N, 98°52'0"E, 06.07.2009, leg. N. Likhitrakarn. 2 ♂, 1 ♀ (CUMZ), Kanchanaburi Prov., Thong Pha Phum Distr., Krienkravia Waterfall, ca 260 m, 14°58'55"N, 98°37'53"E, 10.07.2009, leg. C. Sutcharit. 2 ♀ (CUMZ), same locality, 08.05.2010, leg. N. Likhitrakarn. 1 ♀ (CUMZ), same locality, 19.12.2010, leg. N. Likhitrakarn. 1 ♂ (ZMUC), 1 ♂ (ZMUM), 3 ♂, 2 ♀ (CUMZ), same Distr., Thong Pha Phum, 15.08.2007, leg. S. Panha. 1 ♀, 11 juv. (CUMZ), same Prov., Sai Yok Distr., Daowadueng Cave National Park, ca 210 m, 14°28'12"N, 98°49'58"E, 11.07.2009, leg. C. Sutcharit.

Descriptive notes.

Length 33–41.5 mm (♂) to 34–51 mm (♀), width of midbody pro- and metazona 3.1–4.0 and 4.9–5.7 mm (♂), 3.2–4.5 and 5.2–7.0 mm (♀), respectively.

Coloration of live animals (Figs 91A & 92A) blackish brown with rather poorly contrasting light orange-brown to light brown paraterga and epiproct, rear halves to nearly entire metaterga sometimes a little more infuscate, brownish; coloration upon long-term preservation in alcohol basically same, but paraterga, epiproct, most of metatergal surface, as well as frontodorsal parts of prozona contrasting pallid, yellowish or light grey-brown (Figs 91B-H, K-M & 92B-H). A light centrocaudal spot to a broad caudal band on the collum seems to be characteristic of this species, despite its size variation from small and vague to large and clear in alcohol-preserved material (Figs 91B & C, 92B & C).

Antennae rather long, clavate (antennomere 6 broadest), extending behind body segment 3 (♂) or 2 (♀) dorsally.

Collum with caudal corner of paraterga ranging from obtusangular (Fig. 92A & B), via subrectangular (Fig. 91B & C), to evidently acutangular. Calluses of paraterga always very broad and their caudal corners mostly extending only to hind tergal margin, but sometimes, even within a single population, calluses slightly narrower, not reaching rear tergal margin, forming instead a subrectangular turn mesally (Figs 91B-E & 92B-E), extending increasingly beyond rear margin in hind body portion to only several caudal segments, with caudal tip remaining from acute and pointed thoughout (♂ from Phu Sang National Park, Fig. 91K) to mostly narrowly rounded (♂ from Paplong Temple, Fig. 91L & M). Metatergal sulcus visible on segments 5–18 (♂, ♀). Pleurosternal carinae expressed as complete high crests with a sharp caudal tooth on segments 2–4, thereafter increasingly well divided into a front bulge and a caudal tooth on segments 5–7, both increasingly strongly reduced in size until segment 15 or 16 (♂, ♀).

Midbody legs ca 1.1–1.4 (♂) to 0.9–1.3 times (♀) as long as body height.

Tip of gonopod trifid, with terminal lobule longest, middle spiniform prong sometimes being shorter than usual (Figs 93–96).

Orthomorpha insularis Pocock, 1895, ♂ from Doi Suthep National Park (A–J, M), ♂ from Phu Song National Park (K), ♂ from Palong Temple (L). A habitus, live coloration B, C anterior part of body, dorsal and lateral views, respectively D, E, K-M segments 10 and 11, dorsal, lateral, dorsal, dorsal and dorsal views, respectively F, G, H posterior part of body, dorsal, ventral and lateral views, respectively I, J sternal cones between coxae 4, subcaudal and sublateral views, respectively.

Orthomorpha insularis Pocock, 1895, ♂ from Krienkravia Waterfall. A habitus, live coloration B, C anterior part of body, dorsal and lateral views, respectively D, E segments 10 and 11, dorsal and lateral views, respectively F, G, H posterior part of body, dorsal, ventral and lateral views, respectively I, J sternal cones between coxae 4, subcaudal and sublateral views, respectively.

Orthomorpha insularis Pocock, 1895, ♂ from Doi Suthep National Park. A, B right gonopod, mesal and lateral views, respectively C-F distal part of right gonopod, mesal, lateral, suboral and subcaudal views, respectively. Scale bar: 0.2 mm.

Orthomorpha insularis Pocock, 1895, ♂ from Doi Suthep National Park. A, B right gonopod, lateral and mesal views, respectively.Scale bar: 0.2 mm.

Orthomorpha insularis Pocock, 1895, ♂ from Thong Pha Phum. A, B right gonopod, mesal and lateral views, respectively C-F distal part of right gonopod, mesal, lateral, suboral and subcaudal views, respectively. Scale bar: 0.2 mm.

Orthomorpha insularis Pocock, 1895, ♂ from Krienkravia Waterfall. A, B right gonopod, lateral and mesal views, respectively.Scale bar: 0.2 mm.

Remarks.

Jeekel (1970), when redescribing Orthomorpha insularis Pocock, 1895, from material from Myanmar, also emphasized clear variation in the width of the calluses and of the outlines of some paraterga. This has allowed him to synonymize several other nominate congeners, revised from type material from Myanmar, with Orthomorpha insularis (see catalogue section above). The above abundant material from Thailand confirms a profound variation range in size, coloration, shapes of the collum and following paraterga etc. This variation is deemed to be only individual, as our examination of larger series shows. No complete redescription is provided here, because that of Jeekel (1970) is detailed enough.

This species appears to be widespread over much of Thailand, as well as in the adjacent parts of Myanmar (Map 4). Enghoff (2005), Decker (2010) and Likhitrakarn et al. (2010a), in their faunistic accounts on Thai millipedes, mistakenly referred to Orthomorpha intercedens, which is long known to be only a junior synonym of Orthomorpha insularis (see Jeekel 1970).

Distribution of two widespread species of Orthomorpha. Filled square: Orthomorpha lauta Golovatch, 1998; Filled triangle: Orthomorpha insularis Pocock, 1895.

PocockRI (1895) The Myriapoda of Burma, Pt. IV. Report upon the Polydesmoidea collected by Sig. L. Fea, Mr. E. W. Oates and others. Annali del Museo Civico di Storia Naturale di Genova, Serie 2, 14: 787–834.AttemsC (1936) Diplopoda of India.Memoirs of the Indian Museum 11 (4): 133-323.AttemsC (1937) Myriapoda 3. Polydesmoidea I. Fam. Strongylosomidae. Das Tierreich 68: i-xxii, 1–300.JeekelCAW (1963) Paradoxosomatidae from Borneo (Diplopoda, Polydesmida).Tijdschrift voor Entomologie 106: 205-283.JeekelCAW (1964) A new species of Orthomorpha Bollman from Thailand observed in migration, with taxonomic notes on the genus (Diplopoda).Tijdschrift voor Entomologie 107: 355-364JeekelCAW (1968) On the classification and geographical distribution of the family Paradoxosomatidae (Diplopoda, Polydesmida).Academisch Proefschrift, Rotterdam, 162 pp.AttemsC (1898) System der Polydesmiden. I. Theil.Denkschriften der Kaiserlichen Akademie der Wissenschaften zu Wien, mathematisch-naturwissenschaftliche Classe 67: 221-482.AttemsC (1914) Die indo-australischen Myriopoden. Archiv für Naturgeschichte 80A: 1–398.JeekelCAW (1970) A revision of the Burmese Paradoxosomatidae (Diplopoda, Polydesmida) in the Museo Civico di Storia Naturale at Genoa (Part II).Tijdschrift voor Entomologie 113: 289-301.HoffmanRL (1977) Diplopoda from Malayan caves, collected by M. Pierre Strinati.Revue suisse de Zoologie 84 (3): 699-719.GolovatchSI (1998) On several new or poorly-known Oriental Paradoxosomatidae (Diplopoda Polydesmida), VI. Arthropoda Selecta 6(3–4): 35–46. [for 1997]JeekelCAW (1965) A revision of the Burmese Paradoxosomatidae (Diplopoda, Polydesmida) in the Museo Civico di Storia Naturale at Genoa (Part I). Tijdschrift voor Entomologie.108: 95-144.EnghoffH (2005) The millipedes of Thailand (Diplopoda).Steenstrupia 29 (1): 87-103.DeckerP (2010) Contributions to the myriapod fauna of Thailand - New records of millipedes and centipedes from Thailand (Myriapoda: Diplopoda, Chilopoda).Schubartiana 4: 23-34.LikhitrakarnNGolovatchSIPanhaS (2010a) The millipede genus Orthomorpha Bollman, 1893 in Thailand. 1. Revision of the sericata-group, with description of four new species (Diplopoda, Polydesmida, Paradoxosomatidae).Zootaxa 2361: 23-45.