Hyleoglomeris lobus, Nguyen & Sierwald & Marek, 2019

Nguyen, Anh D., Sierwald, Petra & Marek, Paul E., 2019, The pill millipedes of Vietnam: a key to genera and descriptions of five new species (Diplopoda: Glomerida: Glomeridae), Raffles Bulletin of Zoology 67, pp. 260-297 : 279-289

Hyleoglomeris lobus , new species

( Figs. 24–35 )

Material examined. Holotype: 1 male ( FMNH INS 3716132 ) Vietnam, Ninh Binh Province, Nho Quan District, Cuc Phuong National Park, Bong , botanic garden, trail starting from restaurant, 20.3483°N, 105.5979°E, 22 September 2016, coll. P. Sierwald et al.

Paratypes: 2 males, 4 females ( FMNH INS 3716064 ) same as holotype ; 2 males, 14 females (IEBR–Myr 653) same as for holotype, but 28 July–2 August 2017, coll. Anh D. Nguyen.

Etymology. Named after a strongly bilobed syncoxial lobe of the telopod (feminine adjective).

Diagnosis. The new species is differentiated by the following character combination: Telopods with strongly bilobed syncoxial lobe; femoral process directed caudo-mesad, tip strongly hooked with a large tubercle at 2/3 length.

Description. Holotype male (FMNH INS 3716132). Width of 2nd tergum 5.3 mm. Body length 7.5 mm.

Exoskeleton: Terga black with two paramedian triangular yellow spots anteriorly ( Fig. 24 ). Collum uniformly darkish brown with a large, marbled yellowish-brown, transverse oval spot ( Figs. 25C, D ). Second tergum black with a broad M-shaped yellow pattern anteriorly ( Fig. 24 ). Terga 3–11 black with two paramedian yellow spots, two small lateral yellow oval spots ( Fig. 25A ). Lateral and caudal tergal margins whitish yellow. Antennae brown. Anal shield black with yellow paramedian semielliptical spots anteriorly ( Fig. 25B ). Terga smooth, glossy.

Head: Ocelli 8+1 ( Figs. 27E, F , 31B ), lenses convex, black contrasting against to brownish background of head. Tömösváry organs transverse oval, paler than brownish background of head, ca. 1.5× wider than long, margins regular, not concave ( Figs. 27D , 31A, B ). Antennomere 6 largest, clavate, longer than antennomeres 4+5 combined ( Figs. 27B, C , 31A, C, D ). Antennal tip with four large apical sensory cones. Gnathochilarium: well developed cardines (ca), gula (gu) and triangular stipites (sp), fused lamellae lingualis (ll) and a small mentum (me) ( Figs. 28A, B , 32A, B ). Mandible ( Figs. 32C, D ): with external, internal teeth (ex & in), 10 rows of pectinate lamellae (pl), folded intermediate area (ia) ( Fig. 32D ), single transverse groove on molar plate (mp) shallow and narrow. Tergites: Collum semicircular ( Figs. 28C, D ), dark brown, with a very large marbled yellowish-brown, transverse oval spot, and two transverse striae ( Figs. 25C, D , 26B , 28D ). Second tergum with a small, narrow hyposchism reaching beyond caudal tergal margin – appearing as a posteriorly directed nubbin like lobe – with 11 superficial striae and complete, regular transverse striae laterally and dorsally ( Figs. 28 C–E, 33A–C). Other terga without striae. Anal shield rounded at caudal margin ( Figs. 25D , 26B ). Legs: Leg-pair 1 in males ( Figs. 29A, B ) and females ( Figs. 29C, D , 33D ) with pronounced mesal setiferous coxal tubercle. Leg-pair 2 in females with vulva located within the coxae, on the posterior side, mesal plate visible ( Figs. 30C, D , 33E ).

Leg-pair 17 in males ( Fig. 34A ) strongly reduced, with 4 podomeres (podomere 3 very short), with a rounded, outer coxal lobe, coxae with an apical setiferous spine. Leg-pair 18 ( Fig. 34B ) less strongly reduced (podomere 3 very small) with a syncoxial notch, coxae with an apical setiferous spine. Telopods ( Figs. 34 C–E, 35): stout; syncoxial lobe strongly concave medially, forming two paramedial tubercles ( Figs. 35B, E , see arrow). Syncoxial horns highly elevated, directed ventrally, tips broadly truncated, and bearing a spine. Prefemur micropapillate laterally and posterolaterally ( Fig. 35F ). Prefemoral trichostele (pret) long, prominent, fingershaped whereas femoral trichostele (fet) slightly smaller and posterolaterally ( Figs. 34 C–E, 35A–D). Femoral process (dfp) directed mesally, tip strongly recurved, bearing a large tubercle at 2/3 length ( Figs. 34 C–E, 35A–D). Tibia with a small, transverse, triangular process (tp) mesally ( Fig. 35A, D ). Tarsus curved, bearing two apical setae.

Variation. Width of second tergum 4.8–5.3 mm (males), 4.8–7.0 mm (females), body length 6.5–8.5 mm (males), 11.5–13.0 mm (females).

Remarks. Of eight species recorded from Vietnam, the new species differs from troglobiotic species in darker body pigmentation. The species is also similar to its topotypical congener, H. fedorenkoi from Xuan Son National Park, but differs in the shape of the syncoxial lobe and horns, and the structure of femoral process. Hyleoglomeris fedorenkoi has a high, sub-quadrate, syncoxial lobe; syncoxial horns directed mesoventrad, lower than syncoxial lobe, without an apical spine. In contrast, H. lobus , new species, has a strongly bilobed syncoxial lobe; syncoxial horns highly elevated, directed ventrad, tip broadly truncated, with an apical spine.

RAFFLES BULLETIN OF ZOOLOGY 2019

Figures

Fig. 24.Hyleoglomeris lobus new species from Cuc Phuong National Park, habitus. Photo by: Anh D. Nguyen, image not to scale.

Fig. 25. Hyleoglomeris lobus new species, holotype (FMNH INS 3716132) from Cuc Phuong National Park, Ninh Binh Prov, northern Vietnam. A, whole body, dorsal view; B, lateral view; C, lateroventral view; D, ventral view. Scale bar = 1 mm.

Fig. 26. Hyleoglomeris lobus new species, holotype (FMNH INS 3716132) from Cuc Phuong National Park, Ninh Binh Prov, northern Vietnam. A, whole body, under UV light, dorsal view; B, ventral view; C, lateral view. Scale bar = 1 mm.

Fig. 27. Hyleoglomeris lobus new species, paratype (FMNH INS 3716064) from Cuc Phuong National Park, Ninh Binh Prov, northern Vietnam. A, C, head, anterior view, normal light; B, D, UV light; E, lateral view, normal light; F, UV light. Scale bar = 1 mm.

Fig. 28. Hyleoglomeris lobus new species, paratype (FMNH INS 3716064) from Cuc Phuong National Park, Ninh Binh Prov, northern Vietnam. A, gnathochilarum, ventral view, normal light; B, UV light; C, thoracic shield and collum, anterior view, normal light; D, UV light; E, lateral part of thoracic shield, normal light; F, UV light. Scale bar = 1 mm (A, B, E, F); 2 mm (C, D).

Fig. 29. Hyleoglomeris lobus new species, holotype (FMNH INS 3716132) from Cuc Phuong National Park, Ninh Binh Prov, northern Vietnam. A, male first legs, normal light; B, UV light; C, paratype female first legs, normal light; D, UV light. Scale bar = 1 mm.

Fig. 30. Hyleoglomeris lobus new species, female paratype (FMNH INS 3716064) from Cuc Phuong National Park, Ninh Binh Prov, northern Vietnam. A, anal part of body, ventral view, normal light; B, UV light; C, female second legs and vulva, posterior view, normal light; D, UV light. Scale bar = 1 mm.

Fig. 31. Hyleoglomeris lobus new species, female paratype (FMNH INS 3716064) from Cuc Phuong National Park, Ninh Binh Prov, northern Vietnam. A, head, anterior view; B, lateral view; C, D, antenna and antennal tip. Scale bar in µm.

Fig. 32. Hyleoglomeris lobus new species, female paratype (FMNH INS 3716064) from Cuc Phuong National Park, Ninh Binh Prov, northern Vietnam. A, B, gnathochilarum, external and internal view; C, D, mandible. Scale bar in µm.

Fig. 33. Hyleoglomeris lobus new species, female paratype (FMNH INS 3716064) from Cuc Phuong National Park, Ninh Binh Prov, northern Vietnam. A, thoracic shield and collum, anterior view; B, lateral part of thoracic shield, anterior view; C, dorsal view; D, female first legs; E, female vulva, posterior view. Scale bar in µm.

Fig. 34. Hyleoglomeris lobus new species, holotype (FMNH INS 3716132) from Cuc Phuong National Park, Ninh Binh Prov, northern Vietnam. A, leg 17, under UV light; B, leg 18, under UV light; C, telopods, under UV light, posterior view; D, anterior view; E, telopods, normal light, posterior view; F, anterior view. Scale bar = 0.5 mm (A–B); 1 mm (C–F).

Fig. 35. Hyleoglomeris lobus new species, holotype (FMNH INS 3716132) from Cuc Phuong National Park, Ninh Binh Prov, northern Vietnam. A, telopods, anterior view; B, posterior view; C, right telopod, posterior view; D, anterior view; E, syncoxial lobe and horns, anterior view; F, micropapillae pattern. Scale bar = 200 µm (A–E); 100 µm (F).