Hemipauropus quadrangulus Qian & Bu

Qian, Chang-Yuan, Bu, Yun, Dong, Yan & Luan, Yun-Xia, 2018, Study on the Pauropoda from Tibet, China. Part I. The genera Decapauropus and Hemipauropus (Myriapoda), ZooKeys 754, pp. 33-46 : 39-41

Hemipauropus quadrangulus Qian & Bu sp. n. Figs 5, 6

Material examined.

Holotype, adult with nine pairs of legs, male (slide no. XZ-PA2015037) (SNHM), China, Tibet, Motuo county, Beibeng town, extracted from the soil samples in a broad-leaved forest, alt. 1500 m, 29°30'N, 95°38'E, 5-XI-2015, coll. Y. Bu & G. Yang.

Etymology.

From Latin quadrangulus meaning four angles and referring to the shape of the base of the anal plate.

Diagnosis.

Hemipauropus quadrangulus sp. n. is distinguished from the other species in the genus by the shape of the anal plate, which has a peculiar small Shuriken base and 6+6 setae on tergite IV.

Description.

Length. 0.85 mm (Fig. 6A).

Head (Fig. 5B). Tergal setae rather long, leaf-shaped, with short pubescence, lateral setae including a3 of 2nd row and a4 of 4th row, cylindrical, tapering in distal half, pointed. Relative lengths of setae, 1st row: a1 =?, a2 =10; 2nd row: a1 =?, a2 =?; a3 = 15; 3rd row: a1 =?, a2 = 10.7; 4th row: a1 = 11.4, a2 = 12.9, a3 =?, a4 = 10; lateral group setae: l1 = 24.3, l2 = 25.7, l3 = 20. Ratio a1/a1-a1 in 1st to 3rd row unknown, in 4th row 0.9. Temporal organs oval in tergal view, length 1.4 of shortest interdistance; pistil absent. Head cuticle with very fine granules, temporal organs glabrous.

Antennae (Figs 5A, 6H). Setae on segments 1-3 folioform. Segment 4 with four setae, p and p’ subcylidrical, p" leaf-shaped, r very thin, p’ and p" striate; relative lengths of setae: p = 10, p’ = 9.3, p" = 3.3, r = 4. Tergal branch t somewhat fusiform, 3.8 times as long as greatest diameter and 0.95 of the length of sternal branch s; that branch 2.9 times as long as greatest diameter; anterodistal corner truncated. Seta q 1.3 times as long as seta p’ of segment 4, 0.95 of the length of s. Relative lengths of flagella (base segments included) and base segments: F1 = 100, bs1 = 17.3; F2 = 46.7, bs2 = 14.7; F3 = 101.3, bs3 = 14.7. F1 3.3 times as long as t, F2 and F3 1.2 and 2.5 times as long as s respectively. Distal organ of F1 and F2 consisting of densely arranged pubescent bracts around sessile capsule, F3 with flat calyx; flagella axes below distal organs not widened in F1 and F2, slightly in F3. Globulus g pyriform, 0.2 of the length of s, diameter 0.8 of greatest diameter of t; 8-10 bracts; capsule subspherical. Antennae almost glabrous.

Trunk. Setae of collum segment broad, phylliform, pubescent, secondary branch rudimentary and inserted just below the middle; sublateral setae length 20 μm, 1.3 times as long as submedian setae; sternite process broad, pointed anteriorly; appendages two-parted with low caps. Process with pubescence and appendages glabrous (Figs 5C, 6B). Tergites indistinctly divided transversally, II–IV with reticular pattern on both sides of the dividing line, only posterior of that line on VI (Fig. 6 C–G). Setae cylindrical, 4+4 setae on tergite I (Fig. 6C), 6+6 on II–V (Figs 6 D–G), 4 only on VI (Fig. 6G). Submedian posterior setae on VI 0.2 of inter-distance and 0.4 (-0.5) of the length of pygidial setae a1. Tergites glabrous.

Bothriotricha . Relative lengths: T1 = 100, T2 = 104.8, T3 =?, T4=104.8, T5 =?. Axes thin, simple, straight, pubescence hairs exceedingly short.

Genital papillae (Figs 5F, 6I). Longish, conical with narrowing and extended distal half, 1.6 times as long as wide, seta short, 0.3 of the length of papilla. Coxal seta of leg II as on leg I, length 10 μm (Fig. 6I).

Legs. Fairly long. Setae on coxa and trochanter of leg IX furcate, main branch leaf-shaped, secondary branch subcylindrical, blunt, 0.5 of the length of seta (Figs 5E, 6J). Tarsus of leg IX long, broad, 60 μm in length, 4.3 times as long as greatest diameter; proximal seta short, blunt, length 10 μm, with pubescence, distal seta shorter and blunt, length 9 μm, with pubescence. Proximal seta 0.2 of the length of tarsus, 2.5 times as long as distal seta. Cuticle of tarsus almost glabrous (Fig. 5D).

Pygidium. Tergum (Fig. 5G). Cuticle glabrous. Posterior margin smooth and round between st. Setae of very different lengths, a1 leaf shaped, pubescent, a2 subcylindrical, almost straight, a3 thin, tapering, pointed, a2 and a3 glabrous. st very short, pointed, converging; relative lengths of setae: a1 = 10, a2 = 13.8, a3 = 31.3, st = 6.3. Distance a1-a1 1.6 times as long as a1; distance st–st 3.0 times as long as st and 1.2 times as long as distance a1-a1. Sternum (Fig. 5H). Posterior margin with a little indention; b1 blunt, striate distally. Relative lengths (pygidial a1 = 10), b1 = 27.8, 0.8 of their inter-distance.

Anal plate simple and glabrous, with a little base, the base like a Shuriken; posterior median forked part 5.8 times as long as broadest basal part.

Remarks.

This species resembles H. macropus Scheller, 2009 from the Philippines and H. clava Scheller, 2013 from Australia. They can be readily distinguished by the shape of the anal plate (with little Shuriken base in H. quadrangulus sp. n. vs. broad base and two lateral spines in both H. macropus and H. clava ) and by the numbers of the setae on tergite IV (6+6 setae in H. quadrangulus sp. n. and H. clava vs. 6+4 setae in H. macropus ).