Desmoxytes rhinoceros sp. n.

Figs 1 A, B & 2–4.

Holotype male (CUMZ), Laos, Champasak Province, Paksong District, Tad Fane Waterfall, ca 970 m a.s.l., 15°11'03"N, 106°07'37"E, 20.07.2013, leg. C. Sutcharit.

Paratypes. 1 female (CUMZ), same District, Tad Gneueng Waterfall, ca 980 m a.s.l., 15°10'52"N, 106°08'23"E, 20.07.2013, leg. W. Siriwut. 1 female (CUMZ), same Province, Pakxe District, Pha Suam Waterfall, ca 190 m a.s.l., 15°16'36"N, 105°55'21"E, 20.07.2013, leg. C. Sutcharit. 1 female (CUMZ), Sekong Province, Lamam District, Tad Faek Waterfall, ca 140 m a.s.l., 15°14'44.60"N, 106°45'0.20"E, 20.07.2013, leg. S. Panha. 2 male, 4 females (CUMZ), 1 male, 1 female (ZMUM p2475), same Province, Kafey District, Ban Teu, forest near road, ca 470 m a.s.l., 15°25'03"N, 106°36'06"E, 17.10.2013, leg. C. Sutcharit and W. Siriwut.

Name. To emphasize the large anterobasal spine on the paraterga having the shape of a rhinoceros horn; a noun in apposition.

Diagnosis. Paraterga antler-shaped, with a prominent anterior spine at base; midbody metaterga with 2+2 and 4(5)+4(5) very evident spines in two transverse rows, one anterior, the other posterior; coloration of live specimens dark red; gonopod structure as in D. cattienensis, from southern Vietnam (Nguyen et al., 2006), but the new species differs in the solenophore being trifid terminally.

Description. Length 17–24 (male) or 20–25 mm (female), width of midbody pro- and metazonae 1.0–1.7 and 3.4–4.1 mm (male) or 1.9–2.5 and 3.8–5.0 mm (female), respectively.

Live coloration dark red (Fig. 1 A & B); paraterga and epiproct carmine red, head and antennae dark brownish, legs brown; coloration of alcohol material after four months of preservation faded to whitish or coral pink; head and antennae brown to pale brown; venter and a few basal podomeres pale brown to whitish, legs growing infuscate (brown) distad (Fig. 2 A–J).

Clypeolabral region and vertex sparsely setose, epicranial suture distinct. Antennae rather long (Figs 1 A, B & 2B), extending behind body segment 5 (male) or 3 (female) when stretched dorsally. In width, head <collum <segment 2 <3 <4 <5 <6–16 (both sexes); thereafter body gently and gradually tapering. Collum with three transverse rows of setigerous spines: 3+3 anterior, 3+3 intermediate and 1+1 posterior, anterior row being much larger than both others; paraterga stout and spiniform, directed dorsolaterad, with two strong anterior spines near base and ca 3/4 as high as paraterga (Fig. 2 A & B). Postcollum paraterga antler-shaped, especially well so in male, upturned, directed dorsolaterad, tip bent posteriad, with a prominent anterior spine at base and an evident spine at 3/4 extent of paraterga (Fig. 2 A–D, F–H); paraterga 9, 10, 12 and 13 each with one small, additional, subapical spine increasingly strong in segments 15–19. Ozopores (Op) lateral, located near notch at base of basal spine (Fig. 2 D). Tegument dull, prozonae finely shagreened, metazonae coarsely shagreened to microgranulate, surface below paraterga coarsely microgranulate, sterna delicately microgranulate (Fig. 2 A–J). Metaterga with two transverse rows of setigerous spines, lateral spines of posterior rows being much longer than others (Fig. 2 A, C & F): metaterga 2–6 with 2+2 anterior and 3+3 posterior spines; metaterga 7 and 8 with 2(1)+2(1) anterior and 3(4)+3(4) posterior spines; following metaterga with 2+2 anterior and 4(5)+4(5) posterior spines. Tergal setae short, mostly abraded. Axial line visible (female) or barely traceable (male). Transverse sulcus usually visible on segments 2–19 (Fig. 2 A, C & F), wide, line-shaped, shallow, reaching bases of paraterga, a little better developed in female. Stricture between pro- and metazonae narrow, shallow, beaded at bottom down to base of paraterga (Fig. 2 A, C & F). Pleurosternal carinae complete crests with a sharp caudal tooth only in segments 2 and 3 (Fig. 2 B, D & G). Epiproct unusual (Fig. 2 F, G & H), flattened dorsoventrally, with 4+4 setigerous spines near a subtruncate tip. Hypoproct nearly semi-circular, setigerous knobs at caudal edge evident and well-separated.

Sterna sparsely setose, without modifications; cross-impressions shallow; a paramedian pair of small, but evident, fully separated, setose cones between male coxae 4 (Fig. 2 I & J). Legs extremely long and slender, slightly incrassate in male, midbody ones ca 2.1–2.3 (male) or 1.3–1.5 times (female) as long as body height; male coxae 2 clearly elongated distoventrally (Fig. 2 E). Prefemora without modifications (Fig. 4 K), male tarsal brushes absent.

Gonopods (Figs 3 & 4) subfalcate. Coxite moderately long, slightly curved caudad, rather densely setose distodorsally. Prefemur densely setose, as long as femorite. Femorite stout, strongly enlarged distad, seminal groove running entirely on mesal face. Solenophore (= lamina medialis) well-developed, with three apical lobes, supporting a rather short flagelliform solenomere well separated at base from solenophore.

Remark. The coloration of this species is clearly aposematic.