Review of the millipede genus Kronopolites Attems, 1914 (Diplopoda, Polydesmida, Paradoxosomatidae), with the description of a new species from Laos.

The millipede genus Kronopolites currently comprises 11 species, including a new species from northern Laos: Kronopoliteslunatus sp. n. The generic diagnosis is updated, a key given to all known species, and their distributions are mapped.

Introduction

The flat-back millipede genus Attems, 1914 is widespread in tropical Asia ranging from the Himalayas of Kashmir, India in the west to Taiwan in the east (Fig. 4). This genus belongs to the mainly Southeast Asian tribe in the family which is one of the largest families in the entire class , dominating the millipede fauna of Indo-Australia (Jeekel 1968, Nguyen and Sierwald 2013). The genus currently contains 10 described species (Golovatch 2013a, 2013b, 2014): (Pocock, 1895), the type-species which is widespread in central and southeastern China, Attems, 1937, from northern Vietnam, (Verhoeff, 1939), from northern Taiwan, Hoffman, 1963, from Jiangxi Province, China, Jeekel, 1982, from northern Thailand, Golovatch, 1983, from the Kashmir Himalaya, India, Golovatch, 2009, from northern Vietnam, Golovatch, 2013 and Golovatch, 2014, both from Yunnan Province, China, as well as Golovatch, 2013 from Sichuan Province, China.

Figure 4.

Distribution of (11 species). Inverted filled triangle, more or less from west to east: Golovatch, 1983; Filled circle: Jeekel, 1982; Open circle: Golovatch, 2013; Asterisk: Golovatch, 2014; Filled square: Golovatch, 2013; Open triangle: sp. n.; Crossed square: Golovatch, 2009; Cross circle: Attems, 1937; Open diamond: (Pocock, 1895); Filled triangle: Hoffman, 1963; Open square: (Verhoeff, 1939).

The present study treats some new material collected in Laos during several field trips. Prompted by the discovery of a new species, the authors have revised the entire genus adding a new diagnosis and updating both the catalogue and key to species. In addition, its distribution is mapped.

Material and methods

Material was collected in northern Laos in 2014 by SP and members of the Animal Systematics Research Unit, Chulalongkorn University. Specimens were preserved in 75% ethanol, and morphological investigations were carried out in the laboratory using an Olympus stereomicroscope. of gonopods coated with gold were taken using a SEM JEOL JSM–5410 LV microscope. The gonopods were then removed from stubs and returned to alcohol after examination. Digital images of freshly fixed specimens were taken in the laboratory and assembled using the “CellD” automontage software of the Olympus Soft Imaging Solution package. In addition, line drawings of gonopod characters were also prepared. The types are housed in the , Bangkok, Thailand.

Scanning electron micrographs

Museum of Zoology, Chulalongkorn University

Collecting sites were located by GPS using the WGS84 datum.

In the catalogue sections, D stands for the original description, subsequent descriptive notes or appearance in a key, R for a subsequent record or records, and M for a mere mention.

Taxonomic part

Family Daday, 1889 Subfamily Daday, 1889 Tribe Attems, 1898

Attems, 1914

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Diagnosis.

Body medium-sized to large (ca 23–42 mm long, ca 1.6–6.5 mm wide), with 20 segments. Paraterga from poorly to strongly developed, mostly without lateral incisions. Transverse metatergal sulcus distinct. Sterna usually modified, an acute cone often present near each coxa. Sternal lobe or cone(s) between ♂ coxae 4 present or absent. Pleurosternal carinae usually well-developed.

Gonopods rather simple to relatively complex; coxites elongate, subcylindrical, distoventrally sparsely setose, without tubercles; prefemoral (= setose) part of telopodite moderate to relatively large, 1/3–1/2 as long as acropodite; femorite rather slender to stout, slightly curved, enlarged distad, with an evident groove on mesal face and a distinct distolateral sulcus demarcating a postfemoral part; the latter typically carrying a fork consisting of two lateral/ventral processes: usually a smaller basal process b with its tip pointed basad to prefemoral part, and a larger, normally suberect or ventrally curved process a; solenophore strongly developed, slender, slightly longer than or nearly as long as femorite, strongly curved mesad, sometimes with a membranous, distally strongly expanded end, almost completely sheathing a flagelliform and longer solenomere; seminal groove running entirely or mostly mesally along an excavate femorite, then directed slightly dorsad in distal part of femorite to follow onto solenomere thereafter.

Type species.

Pocock, 1895, by original designation.

Other species included.

Attems, 1937, (Verhoeff, 1939), Hoffman, 1963, Jeekel, 1982, Golovatch, 1983, Golovatch, 2009, Golovatch, 2013, Golovatch, 2013, Golovatch, 2014, sp. n.

Remarks.

Pocock (1895) described the type species in PageBreak Brandt, 1833, from a single female from Chee Foo, China. Soon after that Brölemann (1896), having received a male of this species from Chou-San Island, China, gave a more detailed description, including that of gonopod structure. Attems (1914) proposed a new genus, , and designated as type species.

Attems, 1937

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This species was described from Hagiang, Hagiang Province, Vietnam (Attems 1937), later redescribed from the type locality (referred to as Ha Giang, 22°50'N, 105°E, 20 miles south of the Vietnam-China frontier) (cf. Hoffman 1963).

Hoffman, 1963

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This species was described from Kuling, 29°30'N, 116°E, 10 miles south of Kiukiang, Kiangsi (= Guangxi) Province, China (Hoffman 1963).

Golovatch, 2014

This species has been described from near Wenchian, 3365 m a.s.l., 27°20'35"N, 99°52'34"E, 214 National Road, Yunnan (not Sichuan!) Province, China (cf. Golovatch 2014).

(Verhoeff, 1939)

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This species had been erroneously listed as a synonym of by Wang and Mauriès (1996: 86) and by Korsós (2004: 23) until these mistakes were corrected by Chen et al. (2006). In fact, is endemic to northern Taiwan (Verhoeff 1939, Chamberlin and Wang 1953, Wang 1957), occurring below 1000 m a.s.l.: FuShan Botanical Garden, 726 m a.s.l., Ulai, Taipei County; Yang Ming Shan National Park, ca. 750 m a.s.l., near YuYouRen Tomb, Taipei City, Taiwan (Chen et al. 2006).

Jeekel, 1982

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Jeekel (1982) described this species from several places in northern Thailand: Hakka village, 50 km N of Chiang Rai City, 800–900 m a.s.l.; Mac Chan (= Mae Chan), Mae Chan District, Chiang Rai Province; Doi Suthep National Park, Chiang Mai Province. Later, Enghoff (2005) reported new specimens of this species in his checklist: Doi Pha Hom Pok National Park, Northwest of Fang, 1550–1660 m a.s.l.; limestone area, 1300 m a.s.l., Doi Chiang Dao National Park; Kontathan (= Montha Than) Waterfall area, Doi Suthep National Park, Chiang Mai Province.

Golovatch, 2009

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This species was described from Hoang Lien National Park, ca 2000 m a.s.l., west of Sapa, Lao Cai Province, Vietnam (Golovatch 2009).

Golovatch, 1983

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This species was described from Pir Panjal Mountains, 2600 m a.s.l., Tangmarg, Jammu and Kashmir State, India (Golovatch 1983). New specimens were collected near the ruins of Pari Mahal Monastery, 1500 m a.s.l., Srinagar, Jammu and Kashmir State, India (Golovatch 1984).

Golovatch, 2013

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This species has been described from north of Lijiang, 27°01'N, 100°12'E, 2400 m a.s.l., Yunnan Province, China (Golovatch 2013a).

Golovatch, 2013

This species was described from NW of Mianning, 2955 m a.s.l., 28°39'13"N, 101°58'34"E, Sichuan Province, China (Golovatch 2013b).

(Pocock, 1895)

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This species is especially widely distributed in mainland China: Chee Foo (Pocock 1895); Chou San Island (Brölemann 1896); Lan Tschou, Gansu (Attems ); Pei-shui-ho, 700 m a.s.l., northeastern Sichuan and southern Gansu (Attems 1937); Wenchow (= Yung-chia), Chekiang Province; Chekiang Province (Chamberlin and Wang 1953), Hangchow, Chekiang Province (Hoffman 1963); Taibai Shan Mountains, 1300–1700 m a.s.l.; southern slopes, above Houshenzi, 33°51'N, 107°50'E, Shaanxi Province; Bei Shan National Park, 36°56'N, 102°39'E, ca 90 km NE of Xining, Gansu (not Qinghai) Province (corrected here versus Golovatch 2013a); Grotte du Cirque (Circus Cave), Zheng Xiong County, Yunnan Province; Cave Yan Bao Dong, Zheng Xiong County, Yunnan Province; Cave Ha Chong Dong, near Xingren Huawu, Guizhou Qianxi Province, China (Geoffroy and Golovatch 2004).

sp. n.

http://zoobank.org/BCEF7CDD-7BE6-4B47-B02D-5FA3F658A242

Figs 1 , 2 , 3

Figure 1.

sp. n., ♂ paratype. A, B anterior part of body, dorsal and lateral views, respectively C segments 10 and 11, dorsal view D segments 9–11, lateral view E–G posterior part of body, lateral, dorsal and ventral views, respectively H, I sternal cones between coxae 4, subcaudal and sublateral views, respectively.

Figure 2.

sp. n., ♂ holotype, right gonopod. A–D mesal, lateral, subcaudal and suboral views, respectively. Scale bars: 0.1 mm.

Figure 3.

sp. n., ♂ holotype, right gonopod. A–D right gonopod, mesal, lateral, oral and caudal views, respectively. Scale bar: 0.2 mm.

Holotype

♂, Laos, Xieng Khouang Province, Phookood District, Cave Pra, ca 1180 m a.s.l., 19°30'02"N, 102°52'20"E, 02.07.2014, leg. R. Srisonchai.

Paratype.

1 ♂, Laos, Luang Prabang Province, Chomphet District, Kacham Waterfall, ca 440 m a.s.l., 19°38'57"N, 102°04'52"E, 01.07.2014, leg. C. Sutcharit.

Name.

To emphasize the lateral crescent-shaped processes on the gonopod.

Superficially very similar to , but differs in the smaller size, the width of midbody pro- and metazonae being 2.4–2.5 and 3.1–3.2 mm, respectively (versus 4.5 mm and 6.5 mm, respectively); tarsal brushes are present until ♂ leg 9 (versus absent), and gonopod process b is > 2 times as long as process a (versus shorter), process a being clearly curved (versus nearly straight) while process b is enlarged and lies adjacent to the femorite (versus clearly separated from the femorite). Eventually, it keys out closest to (see Key below).

Description.

Length 28.4–29.5 (♂), width of midbody pro- and metazonae 2.4–2.5 and 3.1–3.2 mm (♂), respectively.

Live coloration mostly dark, blackish brown; antennae and head dark brown to light brown, venter and a few basal podomeres light brown to yellow-brown; coloration of alcohol material after four months of preservation faded to dark brown; antennae and epiproct light brown to light yellow, venter and a few basal podomeres light brown to pallid (Fig. 1A–I).

Clypeolabral region and vertex densely setose, epicranial suture distinct. Antennae moderately long (Fig. 1A), extending behind body segment 3 (♂) when stretched dorsally. In width, segment 4 < 3 < head < 5 < collum < segment 2 < 6–17 (♂); thereafter body gently and gradually tapering. Collum with three transverse rows of setae: 4+4 anterior, 3+3 intermediate and 4+4 posterior; lateral incisions absent; caudal corner of paraterga very broadly rounded, declined ventrad, produced behind rear tergal margin (Fig. 1A, B).

Tegument smooth and shining, prozonae finely shagreened, metaterga finely rugulose (Fig. 1A, C, F); surface below paraterga finely microgranulate (Fig. 1B, D, E). Postcollum metaterga with two transverse rows of setae: 3+3 in anterior (pre-PageBreaksulcus) and 3+3 in posterior (post-sulcus) row, traceable as insertion points. Tergal setae long and slender, mostly abraded, about 1/3 as long as metaterga. Axial line barely traceable both on pro- and metazonae. Paraterga strongly developed (Fig. 1A–F), lying rather high (at upper 1/3 of body), slightly upturned, but lying below dorsum; anterior edge broadly rounded and narrowly bordered, fused to callus; caudal corner very narrowly rounded, starting from segment 15 extending increasingly well beyond rear tergal margin (Fig. 1E, F); lateral edge without incisions (Fig. 1A, C, F); posterior edge nearly straight. Calluses on paraterga narrow, delimited by a sulcus both dorsally and ventrally. Ozopores evident, lateral, lying in an ovoid groove at about 1/4 in front of posterior edge of metaterga. Transverse sulcus usually distinct (Fig. 1A, C, F), slightly incomplete on segment 19, complete on metaterga 3–18 (♂), narrow, line-shaped, shallow, reaching bases of paraterga, faintly ribbed at bottom. Stricture between pro- and metazonae evident, broad and deep, ribbed at bottom down to base of paraterga (Fig. 1A–F). Pleurosternal carinae complete crests with a sharp caudal tooth on segments 2–7, thereafter increasingly strongly reduced until segment 17 (♂). Epiproct (Fig. 1E–G) conical, flattened dorsoventrally, with two small apical papillae; PageBreaktip subtruncate; pre-apical papillae small, lying close to tip. Hypoproct roundly subtriangular, setiferous knobs at caudal edge small and well-separated (Fig. 1G).

Sterna densely setose, without modifications, but with two small, rounded, fully separated, setose cones between ♂ coxae 4 (Fig. 1H, I). Legs rather long and slender, midbody ones ca 1.2–1.3 (♂) as long as body height (Fig. 1A, B, F, G); prefemora without modifications, tarsal brushes present until ♂ leg 9.

Gonopods (Figs 2, 3) rather complex; coxa a little curved caudad, sparsely setose distoventrally. Prefemur densely setose, about 1/3 as long as femorite + postfemoral part. Femorite rather stout, with an evident mesal groove and a strong distolateral sulcus demarcating a postfemoral part; the latter well-developed, with very prominent, bipartite, crescent-shape, lateral processes: process a rather short, coiled and pointed; process b long and coiled, also pointed; solenophore clearly curved, long, expanded distomesally, trifid, lamina medialis supporting a long flagelliform solenomere.

This is the first to be found in Laos.

Conclusions

To date, 11 species have formally been described in PageBreak, mostly found in China (5 species) and northern Vietnam (2 species). Only a single species each has been reported from northwestern India, northern Thailand, northern Taiwan and northern Laos (Fig. 4). There is little doubt that many more species are to be found in the future.

1	Coloration with a contrasting pattern, some parts of body segments being much paler, some other ones much darker	2
–	Coloration rather uniformly brown to brown-blackish, only venter and legs largely yellowish (Fig. 1A–I)	8
2	Paraterga relatively poorly developed, set low (mostly at about upper 1/3 of segments), caudal corners of midbody paraterga usually not projecting behind rear tergal margin, at most narrowly rounded (Fig. 1C, D)	3
–	Paraterga usually relatively well developed, mostly set higher, caudal corners of midbody paraterga produced behind rear tergal margin, acuminate	6
3	Sternal cones on ♂ coxae 4 missing; processes a and b of gonopod nearly independent, slender and long. Northern Thailand	Kronopolites fuscocingulatus
–	Sternal cones on ♂ coxae 4 present, processes a and b of gonopod on a broad common stem, shorter. China	4
4	Surface of metaterga rather smooth; gonopod femorite slender, process a longer, process b shorter, beak-shaped	Kronopolites swinhoei
–	Surface of metaterga rugose; gonopod femorite stout, processes a and b of gonopod different	5
5	Process a of gonopod short and spiniform, process b large and axe-shaped	Kronopolites rugosus
–	Processes a and b of gonopod subequal in length, ribbon-shaped	Kronopolites semirugosus
6	Coloration dark brown with yellow paraterga; sternal cones between ♂ coxae 4 missing; processes a and b of gonopod short and small, sharing a very distinct common stem; Kashmir Himalayas	Kronopolites occidentalis
–	Colour pattern different, rear halves of prozonae and fore halves of metazonae usually being black-brown, remaining parts yellowish; sternal cones between ♂ coxae 4 present; processes a and b of gonopod longer and slenderer, their shared base far less conspicuous	7
7	Process a of gonopod somewhat shorter than process b. Northern Vietnam	Kronopolites acuminatus
–	Process a of gonopod somewhat longer than process b. Jiangxi Province, China	Kronopolites biagrilectus
8	Paraterga relatively well developed (Fig. 1A, C, F); pleurosternal carinae evident in ♂ segments 2–16; process a of gonopod clearly shorter than b	9
–	Paraterga rather poorly developed; pleurosternal carinae evident until ♂ segment 10 at most; processes a and b of gonopod subequal in length	10
9	Sternal cones between ♂ coxae 4 present; ♂ tarsal brushes missing; solenophore with conspicuous bipartite, complex, apical processes	Kronopolites montanus
–	Sternal cones on ♂ coxae 4 missing; ♂ tarsal brushes present until legs of segment 17; solenophore simple and slender, with a little branch set off before apex	Kronopolites davidiani
10	Sternal cone between ♂ coxae 4 single, large. Northern Taiwan	Kronopolites formosanus
–	Two small sternal cones between ♂ coxae 4 (Fig. 1H, I). Northern Laos	Kronopolites lunatus sp. n.