Desmoxytes flabella Srisonchai, Enghoff & Panha

Srisonchai, Ruttapon, Enghoff, Henrik, Likhitrakarn, Natdanai & Panha, Somsak, 2018, A revision of dragon millipedes I: genus Desmoxytes Chamberlin, 1923, with the description of eight new species (Diplopoda, Polydesmida, Paradoxosomatidae), ZooKeys 761, pp. 1-177 : 1

Desmoxytes flabella Srisonchai, Enghoff & Panha sp. n. Figs 43, 44, 45, 46, 47, 48

Holotype.

Male (CUMZ), THAILAND, Trang Province, Palian District, Tham Khao Ting, 7°09'31"N, 99°48'10"E, ca. 42 m a.s.l., 8 July 2017, leg. C. Sutcharit, R. Srisonchai and ASRU members.

Paratypes.

13 males, 4 females (CUMZ), 1 male, 1 female (ZMUC), 1 male (ZMUM), 1 male (NHMW), 1 male (NHMUK), same data as holotype. 3 males, 3 females, 2 juveniles (CUMZ), THAILAND, Trang Province, Palian District, Tham Khao Ting, 7°09'31"N, 99°48'10"E, ca. 42 m a.s.l., 31 August 2015, leg. C. Sutcharit, R. Srisonchai and ASRU members.

Further specimens, not paratypes.

7 males, 3 females (CUMZ), THAILAND, Satun Province, Thung Wa District, Tham Khan Ti Phol, 7°05'08"N, 99°47'54"E, ca. 80 m a.s.l., 8 July 2017, leg. C. Sutcharit, R. Srisonchai and ASRU members.

Diagnosis.

Collum with one row of 3+3 setae (anterior row); paraterga wing-like (not knife-shaped); metaterga 2-19 with 2+2 tubercles in anterior row and 2+2 tubercles in posterior row; male femora 5 and 6 modified; lamina lateralis (ll) distally rough, anterolaterally with 2-3 distinct furrows; process (plm) of lamina medialis very short. Similar in these respects to D. perakensis sp. n. Differs from that species by having body black or brownish black contrasting with yellowish brown paraterga; paraterga narrower; process (plm) of lamina medialis indistinctly demarcated from distal lobe (dlm); distal lobe (dlm) of lamina medialis with one lamella.

Etymology.

The name is a Latin noun, referring to the shape of process (plm) and the distal lobe (dlm) on lamina medialis which somewhat resemble a handheld fan or flyswatter.

Description.

SIZE: Length 32-35 mm (male), 34-36 mm (female); width of midbody metazona ca. 2.2 mm (male), 2.5 mm (female). Width of head <collum = body ring 2 = 3 = 4 <5-16, thereafter body gradually tapering toward telson.

COLOUR (Fig. 43 A–C): In life with body brownish black or black; metaterga and antenna black (except distal part of antennomere 7 and antennomere 8 whitish); surface below paraterga, head and epiproct brownish black; paraterga yellowish brown; sterna and legs brown; a few basal podomeres brownish white.

ANTENNAE (Fig. 44D): Moderately long and slender, reaching to body ring 6 (male) and 4-5 (female).

COLLUM (Fig. 44A): With 1 transverse anterior row of 3+3 setae; paraterga of collum low, elevated at ca. 10°-15°, directed caudolaterad, with 2 distinct notches on lateral margin.

TEGUMENT: Moderately shining; collum and metaterga coarsely microgranulate; prozona finely shagreened; surface below paraterga coarsely microgranulate; sterna and epiproct smooth.

METATERGA (Fig. 44 A–C): With 2 transverse rows of conspicuous tubercles; metaterga 2-19 with 2+2 anterior and 2+2 posterior tubercles.

PARATERGA (Fig. 44E, F): Directed caudolaterad on body rings 2-17, elevated at ca. 45° (male) 45° (female); directed increasingly caudad on body rings 18 and 19; anterior margin with 2 distinct notches, on lateral margin of body rings 9, 10, 12, 13, 15-18 with tiny denticle near the tip.

TELSON (Fig. 45 C–G): Epiproct: tip emarginate; lateral setiferous tubercles inconspicuous; apical tubercles conspicuous, small, knob-like. Hypoproct subtrapeziform, broad; caudal margin round, with two conspicuous setiferous tubercles.

STERNA (Fig. 46): Cross-impressions shallow. Sternal lobe between male coxae 4 swollen, suberect, subtrapeziform when seen in posterior view, tip usually truncate (in some specimens slightly round).

LEGS (Fig. 45 H–J): Long and slender. Male femora 5 and 6 strongly humped ventrally in middle portion.

GONOPODS (Figs 47, 48): Coxa (cx) subequal in length to prefemur. Cannula (ca) quite long and slender. Telopodite quite stout. Prefemur (pfe) ca. 2/3 as long as femur. Femur (fe) somewhat stout, slightly enlarged distally. Mesal sulcus (ms) and lateral sulcus (ls) conspicuous, very deep. Postfemur (pof) conspicuous, ventrally narrow and short. Solenophore (sph) well-developed: lamina lateralis (ll) rough, anterolaterally with 2-3 distinct furrows, deep; ventral ridges (vrl) conspicuous: lamina medialis (lm) well-developed; process (plm) very short, indistinctly demarcated from distal lobe; distal lobe (dlm) distally with one lamella; broad lobe (blm) thick, clearly demarcated from distal lobe (dlm) by a narrow and deep indentation. Solenomere (sl) long, apically twisted.

Distribution and habitat.

Known only from the type locality and a few nearby localities. The new species is restricted to limestone habitats (Fig. 43D), and it is sympatric with D. delfae at Tham Khao Ting and Tham Khan Ti Phol. Unlike the bright orange D. delfae , which was easily spotted crawling on branches of shrubs and on rocks, the new species, blackish brown, was found on rocks where it was quite hard to see. This suggests that these two species, although sharing the same habitat, may show microhabitat differences, but this has not yet been studied in detail. We assume that the new species is distributed along limestone mountain ranges in a narrow area at the border between Trang and Satun Provinces. This species should be regarded as endemic to the Thai fauna.

Coexisting species.

Desmoxytes delfae co-occurs at the same localities.