Review of the pill millipede genus Hyperglomeris Silvestri, 1917 (Diplopoda, Glomerida, Glomeridae) with description of two new species from Laos Author Likhitrakarn, Natdanai https://orcid.org/0000-0002-1306-317X Program of Agriculture, Faculty of Agricultural Production, Maejo University, Chiang Mai 50290, Thailand Author Srisonchai, Ruttapon https://orcid.org/0000-0002-7142-0999 Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand Author Siriwut, Warut Animal Systematics and Molecular Ecology Laboratory, Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand Author Jirapatrasilp, Parin https://orcid.org/0000-0002-5591-6724 Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand Author Jeratthitikul, Ekgachai Animal Systematics and Molecular Ecology Laboratory, Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand Author Panha, Somsak Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand & Academy of Science, The Royal Society of Thailand, Bangkok 10300, Thailand Author Sutcharit, Chirasak Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand jirasak4@yahoo.com text ZooKeys 2023 2023-05-26 1163 177 198 http://dx.doi.org/10.3897/zookeys.1163.103950 journal article http://dx.doi.org/10.3897/zookeys.1163.103950 1313-2970-1163-177 F9AC8A4547D245D9BB121A3DB16ABCB0 274E0A227A255CBF88E3CD3703C1AE45 Hyperglomeris bicaudata Likhitrakarn sp. nov. Figs 1 , 2 , 3A, B Material examined. Holotype : Laos - Houaphanh • ♂ (CUMZ-GLO006); Viengxay District , Limestone mountain area near Kaysone Phomvihane Cave ; elev. 890 m a.s.l. ; 20°20'24"N , 104°13'44"E ; 6 Jul. 2014 ; R. Srisonchai , C. Sutcharit , K. Inkhavilay leg.; CUMZ ; Paratypes : Laos - Houaphanh • 1 ♀ ; same collection data as holotype ; • 3 ♀♀ (CUMZ-GLO004); Viengxay District , Ban Tham Na Tan , Limestone mountain area; elev. 860 m a.s.l. ; 20°27'28"N , 104°08'43"E ; 5 Jul. 2014 ; R. Srisonchai , C. Sutcharit , K. Inkhavilay leg.; CUMZ; OQ661871 • 1 ♂ , 2 ♀♀ (CUMZ-GLO007); Viengxay District , Limestone mountain area near vocational-technical school around kilometre 31; elev. 840 m a.s.l. ; 20°24'15"N , 104°15'4"E ; 6 Jul. 2014 ; R. Srisonchai , C. Sutcharit , K. Inkhavilay leg.; CUMZ; OQ661872 . Name. To emphasize the caudal margin of the anal shield being more (♂) or less (♀) strongly bisinuate medially; adjective in feminine gender. Diagnosis. Its unique color pattern is similar to that of H. nigra Golovatch, 2017, from Vietnam (Golovatch, 2017), but the two species differ by the thickness of the contrasting paler bands at the lateral and caudal edges of all tergites (ca. 1/3 vs. 1/5 x as high as tergite height), the number of striae at the lateral edge of midbody tergites (2 vs. 3), the number of ommatidia (10+1(2) vs. 8+1), coupled with two tibial processes (one large process and one small cone vs. two small tibial cones), and the caudal edge of the anal shield (two strongly bisinuate medially vs. slightly emarginate medially). Description. Body length of stretched holotype 13.2 mm, width 8.3 mm. Body length of stretched paratypes 13.5 mm (♂), 13.5-15.5 mm (♀), width 9.5 (♂), 8.5-9.5 mm (♀). Coloration of live animals (Fig. 1A-D ): body blackish, with contrasting pale yellow to orange yellow, rather broad bands at the lateral and caudal edges of all tergites, ca. 1/3 x as high as each tergite height, including collum, thoracic and anal shields. Head and antennae black, only labrum and Toemoesvary's organ yellowish. Venter and legs dark brown to brown with a pale yellowish claw and the posterior part of each tarsus; coloration in alcohol faded after eight years of preservation (Fig. 1E-G ), body pale black to charcoal, with contrasting pale yellow to whitish bands. Head and antennae grey to blackish. Venter and legs pale brown to brownish. Figure 1. Hyperglomeris bicaudata sp. nov. A-D ♂ paratype (CUMZ-GLO006), habitus, live coloration E-G ♂ holotype (CUMZ-GLO006) habitus in dorsal, ventral, and lateral views A, C unrolled, sublateral views B, D rolled, sublateral and subdorsal views, respectively. A-D not to scale. Labrum sparsely setose (Fig. 1F ). Gnathochilarium with 2+2 palps of subequal length. Ocular fields whitish, 10+1(2) ommatidia, cornea convex, oval in shape, translucent. Antennae with four evident apical cones, segment 6 ca. 2.1-2.4 x as long as high. Organ of Toemoesvary typical, horseshoe-shaped, oblong-oval, elongate, ca. 1.5-1.8 x as long as broad (Fig. 1F ). Collum as usual, with two transverse striae (Fig. 1F ). Thoracic shield with a small hyposchism field not projecting caudad past tergal margin. Striae 4-6, mostly superficial, only lower 3 or 4 lying above schism, one level with schism, remaining 1 or 2 below schism, with 4 and 5 complete, crossing the dorsum (Fig. 1G ). Terga 3 and 4 rather broadly rounded laterally (Fig. 1G ). Following terga in front of pygidium faintly concave medially at caudal edge and with two striae starting above lateral edge, sometimes first stria fading away towards midway. Caudal edge of anal shield more (♂, Figs 1C, E, F, G , 2A ) or less (♀, Fig. 2B )) strongly bisinuate medially. Figure 2. Hyperglomeris bicaudata sp. nov. A, C, E, F ♂ holotype (CUMZ-GLO006) B ♀ paratype (CUMZ-GLO006) D ♂ paratype (CUMZ-GLO007) A, B anal shield edge in venter view, male and female, respectively C leg 17, anterior view D leg 18, anterior view E, F telopod, posterior and anterior views, respectively G tip of syncoxital lobes (not to scale). Scale bars: 1 mm ( A-F) . Abbreviations: cx coxa, cxl coxal lobe, fe femur, fp femoral process, pf prefemur, pfc prefemoral cone of telopod, sh syncoxital horn of telopod, sl syncoxital lobe of telopod, sn syncoxite notch, sx syncoxite, ta tarsus, tc tibial cone, ti tibia, tp tibial process. Male legs 17 (Fig. 2C ) strongly reduced, with a rather high, often irregularly rounded coxal lobe (cxl) and a 4-segmented telopodite. Figure 3. Leg 18 A, B Hyperglomeris bicaudata sp. nov., ♂ paratype (CUMZ-GLO007), left, anterior and posterior views, respectively C, D Hyperglomeris inkhavilayi sp. nov., ♂ paratype, right, anterior, and posterior views, respectively. Scale bars: 1 mm. Male legs 18 (Figs 2D , 3A, B ) simple, rather strongly reduced, without any evident outgrowths; syncoxite membranous, on either side with a simple, small, and narrowly ogival syncoxite notch (sn) and a 4-segmented telopodite. Telopods (= male legs 19) (Fig. 2E-G ) with a very large, broad and roundly subtrapeziform syncoxital lobe (sl) flanked by two short, spiniform, obliquely truncate, setose syncoxital horns (sh), level with syncoxital lobe (Fig. 2F ). Telopodite 4-segmented, with a spine apically. Prefemur subellipsoid, with an evident, rather small, distad tapering, tuberculiform, distomesal prefemoral cone (pc) (a reduced trichostele), ca. 1/4-1/5 x as long as femur. The latter in caudal view with a prominent, stout, finger-shaped, distomesal femoral process (fp) devoid of a trichostele, produced apically to ca. 3/4 tibia. Tibia elongate, gently tapering distad and curved apically basad towards process on femur, with an evident, caudad curved, distolateral tibial process (tp) and a small, short and pointed distomesal tibial cone (tc). Tarsus smallest, subcylindrical, moderately sigmoid, strongly curved, narrowly rounded apically. Remarks. Unique to this species is that the caudal margin of the anal shield shows two more (♂, Figs 1C, E, F, G , 2A ) or less (♀, Fig. 2A ) pronounced paramedian knobs. That the male is equipped with such modifications is quite usual in various lineages of Glomerida (e.g., Liu and Golovatch 2020 ), but their presence in the female, albeit not as strongly as in the male, is really striking. This distinguishing character can be hypothesized as possibly playing an important role in a courtship process or being associated with courtship behavior. Certain male structures dedicated to interactions with females during courtship have often diverged relatively quickly during evolution, causing these features to change into species-specific differences ( Eberhard 2004 ). Noteworthy examples of such characters are antennae, legs and heads in springtails ( Collembola : Bourletiellidae ) ( Kozlowski and Aoxiang 2006 ) and stridulation organs in giant pill millipedes (Sphaerotheria) ( Wesener et al. 2011 ) that may not be involved directly in sperm transfer but are associated with mating behavior. In order to understand the relationship between these types of traits and their function in the glomerids, it is essential to examine the mating behavior of this species.