Hyleoglomeris suwannakhuhensis, Likhitrakarn & Jeratthitikul & Sapparojpattana & Siriwut & Srisonchai & Jirapatrasilp & Seesamut & Poolprasert & Panha & Sutcharit, 2024

Likhitrakarn, Natdanai, Jeratthitikul, Ekgachai, Sapparojpattana, Pichsinee, Siriwut, Warut, Srisonchai, Ruttapon, Jirapatrasilp, Parin, Seesamut, Teerapong, Poolprasert, Pisit, Panha, Somsak & Sutcharit, Chirasak, 2024, Six new species of the pill millipede genus Hyleoglomeris Verhoeff, 1910 (Diplopoda, Glomerida, Glomeridae) in Thailand revealed by DNA-barcoding, Contributions to Zoology 93 (4), pp. 289-323 : 305-307

Hyleoglomeris suwannakhuhensis

Likhitrakarn, Sutcharit & Panha, sp. n.

Figs 7, 8

Holotype ♂ ( CUMZ-GLO039 ), Thailand, Nong Bua Lamphu Province, Suwannakhuha District, Wat Tham Phupha Thamsathit , outside cave area, elev. ca. 110 m a.m.s.l., 17°37’39“N, 102°10’12”E, 10/09/2022, leg. N. Likhitrakarn and P. Jirapatrasilp.

Paratypes. 2 ♂♂, 3 ♀♀, 1 Juvenile ( CUMZ-GLO039 ) , 3 ♀♀, 2 Juveniles ( MUC-GLO039 ), same locality, together with holotype .

Name. To emphasize the type locality, adjective in feminine gender.

Diagnosis.This new species is distinguished from its congeners by its distinct colour pattern. Body predominantly blackish, highlighted by paler bands along both lateral and caudal edges of all terga (fig. 7). Furthermore, a small bulbous projection at the tip of the syncoxite horns (sh), these being higher that the small, rounded, subrectangular syncoxite lobe (sl) (fig. 8E, C, D), coupled with a stout, rounded, subtriangular, strongly curved femoral process (fp) of the telopod (fig. 8D).

Description. Body length of unrolled holotype, 6.6 mm, width 3.8 mm. Body length of unrolled paratypes, 5.5–5.7 mm (♂), 6.2– 6.8 mm (♀), width 3.4–3.8 (♂), 3.6–3.8 mm (♀).

Colour of live animals (fig. 7A, B): Body blackish, with contrasting pale yellow to carrot-orange, rather broad bands along both lateral and caudal edges of all terga, including collum, thoracic and anal shields, width of bands approximately 1/3 height of each tergum, without contrasting axial stripes in dark area (fig. 7A, B). Head and antennae black, only labrum and Tömösváry’s organs yellowish. Venter and legs dark brown to brown with claws and posterior parts of each tarsus pale yellowish. Colour faded after eight years of preservation in alcohol (fig. 7C–E), body of preserved specimens blackish or pale to dark brown, with contrasting pale yellow to whitish bands; in central area and along edges of collum and thoracic shield dark faded to a pale yellowish shade (fig. 7D, E). Anterior sides of terga 3–11 each with a pair of large, sublateral, yellowish to pale yellowish bands reaching neither caudal nor lateral edges (fig. 7A, C–E). Axial stripe yellow and complete, connecting terga 3–5 and gradually shortened in subsequent terga (fig. 7C); posterior yellowish band of anal shield extended to approximately half height of tergum (fig. 7E); head and antennae dark brown to yellowish brown; venter and legs pale yellow-brown to yellowish.

Labrum sparsely setose (fig. 7D). Gnathochilarium with 2 + 2 palps of equal length. Eyes blackish, with 7(8)+1 ommatidia, cornea highly convex and translucent. Antennae with four evident apical cones, antennomere 6 elongated, approximately 1.8–2.6 times as long as its height (fig. 7A, D). Tömösváry’s organ typical, horseshoe-shaped, oblong-oval, elongate, approximately 1.6–2.2 times longer than broad.

Collum normal, with two transverse striae. Thoracic shield with a small hyposchism field, not extending behind tergal margin (fig. 7E). Striae 7–8, mostly superficial, only lower 2 lying above schism, one level to schism, 4–5 lying below schism, with 4–5 complete and crossing the dorsum (fig. 7E). Terga 3 and 4 broadly rounded laterally (fig. 7E). Following terga in front of pygidium faintly concave medially at caudal edge and with two striae starting above lateral edge, first stria occasionally fading away mid-dorsally. Pygidium very faintly concave medially at caudal edge (fig. 7D).

♂ legs 17 (fig. 8A) simple, rather strongly reduced, with a moderately sized to high, often rounded coxal lobe (cxl) and a 4-segmented telopodite.

♂ legs 18 (fig. 8B) simple, slightly reduced, without any evident outgrowths. Syncoxite membranous, with a small, broadly archshaped syncoxite notch (sn) and a 4-segmented telopodite.

Telopods (= ♂ legs 19) (fig. 8C–E) with a rather small, subrectangular, rounded syncoxite lobe (sl), flanked by two elongated, spiniform, setose syncoxite horns (sh), with small bulbous structures apically, notably higher than syncoxite lobe (fig. 8D–F). Telopodite 4-segmented, with a spine apically. Prefemur (fig. 8D) subrectangular, with a distinctive, elongated, robust, tuberculiform, distomesal prefemoral trichostele (pft), in anterior view extending apically approximately half or nearly to distal boundary of femur. Femur (fig. 8C, D) subtrapeziform, with a stout and relatively short femoral trichostele (ft), in anterior view extending apically to approximately 1/3–1/4 length of prefemoral trichostele (pft), and in posterior view a rounded subtriangular femoral process (fp) curved strongly anterolaterally and gently tapering into an acuminate tip rounded distally (fig. 8D).

Tibia robust, tapering gently distad and curved basad towards femoral process, with a small, distolateral tibial process (tp) strongly curved mesad (fig. 8C, D). Tarsus the smallest, subcylindrical, moderately sigmoid, strongly curved, narrowly rounded apically, with a robust and small terminal seta (fig. 8C, D).

DNA barcode. The nearest neighbour to this new species seems to be H. fanxipan with an interspecific COI divergence of 12.65% (table 2).

Remarks. The live specimen revealed its body to be primarily black, but faded in ethanol, especially along the anterior edges (fig. 7C, E). However, a lighter band along the posterior edge of each tergum is still visible and could be used for species identification.