Sphaerobelum schwendingeri, Wesener, 2019

Wesener, Thomas, 2019, First records of giant pill-millipedes from Laos (Diplopoda, Sphaerotheriida, Zephroniidae), Zootaxa 4563 (2), pp. 201-248 : 238-239

Sphaerobelum schwendingeri new species

Figure 25

Material examined: Type material. 1 M holotype (MHNG LT 10/03) from Laos;, Vientiane Province , trail to Tham Pou Kham, W. of Vang Vieng (N18°55'32", 102°23'58"E), 240 m, secondary forest on limestone hill, leg. 7.IX.2010, P. Schwendinger. 1 M paratype ( MHNG LT 10 /03), same data as previous. 1 F paratype ( SMF), from Laos , Vientiane Province , Vang Vieng, Tham Pou Kham, 260 m (N18°55.549', 102°23.734'E), outside cave, close to cave stream, at rocks, leg. by hand, 13.III.2007, P. Jäger & F. Steinmetz .

Other material examined: 1 M, 1 imm. F (SMF) from Laos, Vientiane Province, Van Vieng, across Nam Song, Tham Chang, in or in front of cave (N18°54.550', 102°26.527'E), 270 m, leg. by hand, P. Jäger & S. Packheiser, 22.Vii.2018. 1 M (ZFMK MYR8103), same data as previous.

Diagnosis: S. schwendingeri n. sp. belongs to a group of Sphaerobelum species in which the mesal margin of the femur is unmodified ( Fig. 25B ). S. schwendingeri n. sp. shares only with S. hirsutum , S. clavigerum , S. nigrum n. sp., S. splendidum n. sp. and S. laoticum n. sp. the presence of a "hook" at telopoditomere 4 of the posterior telopods( Figs 25F, G ). S. schwendingeri n. sp. differs from S. hirsutum in the presence of glabrous tergites, from S. clavigerum in the presence of a short locking carina on the anal shield. It differs from S. nigrum n. sp. in the presence of a cylindrical antennomere 6, the presence of 8–10 ventral spines on the tarsi ( Fig. 25B ), and the presence of a strongly curved telopoditomere 4 of the posterior telopod, all characters only shared with S. splendidum n. sp. and S. laoticum n. sp. For a differentiation of S. schwendingeri n. sp. with S. splendidum n. sp. see above. For a differentiation to S. laoticum n. sp. see above.

Description: based on male holotype and paratypes of both sexes.

Measurements: holotype male: body length 27.3 mm. Width, of thoracic shield = 13.3 mm (= widest). Height, of thoracic shield = 7.4 mm high (= highest). Female: Body length: broken and rolled up, ca. 37 mm. Width, of thoracic shield = 18 mm (unclear of broadest, broken). Coloration: in preserved specimens tergites black, posterior third olive. Head and collum black, anterior half of head green. Antennae and legs orange-red.

Head: Eyes with ca. 70 ocelli. Last antennomere thickened. Apical disc with 73/71 apical cones (male), or 36/ 37 (female). All antennomeres covered by long setae. Organ of Tömösváry located inside antennal groove.

Gnathochilarium: structure typical of the order. Palpi sensory cones located in several clusters. Mandibles: not dissected.

Stigmatic plates: first stigmatic plate widely rounded, apex well-rounded, slightly curved towards coxa 1 ( Fig. 25A ). Laterotergites: laterotergite 1 and 2 slightly elongated into a short, broad process. Collum: with glabrous surface, margins with few isolated setae. Thoracic shield: surface glabrous, but covered with small pits like tergites, setae only in grooves. Shallow grooves beset with numerous long setae, slope towards groove without keels. Tergites: glabrous, shiny. Anterior third with a few setae only visible when the specimen is rolled up, producing a golden sheen. Tips of paratergites of midbody tergites projecting posteriorly. Endotergum: inner section without any setae or spines. Middle area with a single row of sparse elliptical, cuticular impressions, distance between impressions larger than their diameter. Apically 3-4 dense rows of short marginal bristles, the longest just protruding up to half of length to tergal margin. Bristles not smooth, but with numerous small spicules. Anal shield: sexually dimorphic, in female slightly flattened, in male weakly bell-shaped. Glabrous. Underside without locking carinae. Legs: leg-pair 1 with 2 ventral spines, leg-pair 2 with 6, leg-pair 3 with 6. First two legpairs without an apical spine. Leg-pairs 4–21 with 6–8 ventral spines and one dorso-apical spine. In leg 9 femur 1.7 times, tarsus 3.8 times longer than wide ( Fig. 25B ). All podomeres densely setose. Coxa with a well rounded process. Coxa process absent at first leg ( Fig. 25A ) and sharp-edged at second ( Fig. 25C ).

Female sexual characters: Vulva large, covering mesal 2/3 of coxa, extending mesally to anterior third of prefemur ( Fig. 25C ). Operculum rounded, central part recessed, mesal margin broadly projecting into a sharpedged triangle slightly as higher than remaining operculum. Subanal plate: not examined.

Male sexual characters: gonopore large, covered by small, inconspicuous plate. Anterior telopods ( Figs 25D, E ): Consisting of three telopoditomere above syncoxite. Last telopoditomeres completely fused. Telopoditomere 1 rectangular, slightly longer than wide. Telopoditomere 2 large, as long as telopoditomere 3. Process of telopoditomere 2 located posteriorly, apex visible in anterior view. Process of telopoditomere 2 wide, projecting to length of telopoditomere 3, strongly curved, apically with a well-rounded tip. Telopoditomere 3 massive, cylindrical, straight, apically slightly tapering. Posterior side with three large spines. In anterior view all telopoditomeres covered by long setae, in posterior view telopoditomeres 2 and 3 only with marginal setae. Posterior telopods ( Figs 25F, G ): telopoditomere 1 rectangular, slightly longer than wide. Immovable finger (process of telopoditomere 2) shorter than movable finger, consisting of telopoditomeres 3 and 4. Immovable finger with a spine in anterior view, a characteristic, distally swollen apex, slightly swollen. Apically broader than base, at tip in anterior view with a few large, crenulated teeth. Telopoditomere 3 elongated, at midpoint with a triangular extension carrying a spine towards immovable finger. Telopoditomere 4 tapering, anterior half strongly curved 90° towards immovable finger, which it overlaps. At inner margin with two larger spines. Entire telopoditomere 1 at both sides covered with long setae. Telopoditomere 2 anterior side completely covered by setae except for tip of immovable finger, posterior side glabrous except for lateral margin. Telopoditomere 3 only basally in anterior view with setae, remaining part, as well as telopoditomere 4 glabrous.

Derivatio nominis: schwendingeri, noun in apposition, after the Arachnologist Peter Schwendinger, great collector of arthropods in Southeast Asia.

Figures

FIGURE 25. Sphaerobelum schwendingeri n. sp. A–C female paratype (ZMUC), D–G male holotype (MHNG). A: coxa of first right leg with first stigmatic plate; B: 9th left leg; C: coxa and prefemur of second leg with vulva; D: left anterior telopod, anterior view; E: left anterior telopod, posterior view; F: right posterior telopod, anterior view; G: right posterior telopod, posterior view. Abbreviations: Cx = coxa; O = operculum of vulva; Pre = prefemur; St-Pl = stigmatic plate; Syn-Cx = syncoxite. Scale bars = 1 mm.