Decapauropus tribulosus Qian

Qian, Changyuan, Dong, Yan, Bernard, Ernest C. & Sun, Hongying, 2015, Records of Pauropoda (Pauropodidae, Brachypauropodidae, Eurypauropodidae, Sphaeropauropodidae) from China, with a key to the species and descriptions of three new species of Decapauropus, Zootaxa 4006 (3), pp. 521-539 : 528-531

Decapauropus tribulosus Qian sp. n.

Fig. 3

Type material. Holotype: ad.9 (female), Mao’er Mountains, Guangxi, 5 December 2012, leg. Qian. loc. MES 20121205. Paratype: ad.9 (female), Sanqingshan Mountains, Jiangxi, 8 July 2013, leg. Qian. loc. SQS20130708.

Etymology. From Latin tribulosus = tricuspid (referring to the paired clavate appendages and the acuminate process of the posterior part of the anal plate).

Description. Holotype length 0.68 (0.5) mm. Dorsal head (Fig. 3A) setae of short to medium length, subcylindrical, striate, blunt. Relative lengths of setae, 1st row: a 1 = 10, a 2 = 8.6 (7.9); 2nd row: a 1 = 8.6 (7.9), a 2 = 16 (18.7), a 3 = 16 (14); 3rd row: a 1 = 12.3 (13), a 2 = 10.6 (9.1) 4th row: a 1 missing on the holotype (14.1), a 2 missing on the holotype (15.3), a 3 = 15.7 (16), a 4 = 13.1 (?); the ratio a 1/ a 1– a 1 in 1st row 0.88 (0.90), 2nd row 0.48 (0.36), 3rd row 0.98 (1.0) and 4th row? (0.78). Temporal organs oval in tergal view, their length 1.6 times longer than the shortest distance between them. Head cuticle glabrous.

Antennal (Fig. 3C) segment 4 with four cylindrical setae; relative lengths of setae: p = 100, p ’ = 55.7 (61), p ” = 34.3 (36.9), r = 42.9(38); length of tergal seta p 0.81 (1.0) times that of tergal branch t, which is cylindrical, 1.9 (2.1) times longer than its greatest diameter and 1.7 times length of sternal branch s. Branch s 1.4 (1.7) times longer than its greatest diameter. Seta q cylindrical, blunt, 0.58 of length of s. Basal segment of F 2 much thinner than those of F 1 and F 3. Relative lengths of flagella (basal segments included) and base segments: F 1 = 100, bs 1 = 4 (5); F 2 = 46 (49), bs 2 = 4 (3); F 3 = 84 (92), bs 3 = 5 (6). F 1 5.0 (5.8) times as long as t, F 2 and F 3 2.5 and 4.5(5.2) times as long as s respectively. Distal calyces hemispherical, those of F 1 largest, flagella axes somewhat widened just below calyx. Globulus g 1.2 (1.4) times as long as wide; about nine bracts, capsule subspherical; width of g 0.7 times that of the greatest diameter of t. Antennae glabrous.

Setae of collum segment clavate, striate, appearing simple. Sublateral setae 2.3 times length of submedian setae; sternite process triangular, pointed; appendages narrowing distally and with flat caps; process with coarse surface.

FIGURE 3. Decapauropus tribulosus sp. n., holotype. A) Head, submedian and right part, tergal view. B) Pygidium, sternal view. C) Right antenna, tergal view. D) Tarsus of leg 9. E) Bothriotrix T 3.

Setae on tergites thin, cylindrical; 4 + 4 setae on tergite I, 6 + 6 on II–IV, 6 + 4 on V, 4 + 2 on VI. Tergites glabrous.

Relative lengths of bothriotricha: T 1 = 100, T 2 =101(103), T 3 (Fig. 3E) = 80 (74), T 4 = 97 (84), T 5 missing on the holotype (126). Axes simple, straight, thin, with almost erect, short, simple pubescence hairs. Axes of T3 thicker, blunt, with dense pubescence of oblique short hairs.

Setae on coxa and trochanter of leg 9 furcate with subcylindrical blunt branches. Tarsus of leg 9 (Fig. 3D) short, tapering, 3.5 times as long as its greatest diameter. Proximal seta long, tapering, with pubescence; distal seta clavate, blunt, with pubescence; their length 0.31 and 0.13 times length of tarsus, respectively. Cuticle of tarsus glabrous.

Posterior margin of pygidial tergum (Fig.3B) between st straight. Relative lengths of setae: a 1 = 100, a 2 = 80, a 3 = 171.4 (180), st = 28.6 (31). a 1, a 2 blunt, subcylindrical, glabrous; a 3 tapering, glabrous; st short, blunt, subcylindrical, inward; Distance a 1– a 1 3.2 times length of a 1; distance a 1– a 2 1.0 times as long as a 2– a 3; distance st– st 9.6(8) times as long as st and 0.85 length of distance a 1– a 1. Posterior margin of pygidial sternum with shallow indentation between b 1. Relative lengths of setae (a 1 = 100): b 1 = 422.9 (430), b 2 = 240 (231). All setae subcylindrical, blunt, glabrous. Distance b 1– b 1 equal to length of b 1; distance b 1– b 2 0.87 (1.1) times length of b 2.

Anal plate widening from its base, length 1.2 times longer than broad, with parallel lateral margins, posterior part with acuminate process; two appendages protruding backwards from sternal side near its base; appendages flagellate, curved inwards, blunt; length of appendages 0.4 times length of the plate; posterior margins and appendages glabrous.

Diagnosis. Decapauropus tribulosus sp. n. is resembling D. stenygros Scheller, 2005 from Gabon, Allopauropus inusitatus Scheller, 2009 from Tasmania and A. tristylus Guo, 2010 from China. All four species are very similar in the general shape of the antennae. The sternum of the species possesses seta b 3 as in A. inusitatus and A. tristylus (absent in D. stenygros and D. tribulosus ). Differences occur in the shape of the anal plate in these species. In D. tribulosus sp. n. the anal plate widens from its base, with parallel lateral margins; posterior part with acuminate process; two appendages protruding backwards from sternal side near its base; appendages flagellate, curved inwards, blunt; posterior margins and appendages glabrous. In D. stenygros the anal plate is directed obliquely upwards, broadest in the middle, lateral sides distinctly concave in proximal part, convex in the middle, posteriorly lengthened and tapering to a point; two diverging clavate glabrous appendages protruding backwards from sternal side of distal part of plate. In A. inusitatus the anal plate is spatulate, with a median lobe, lobe with small posteromedian incision, two appendages protruding from sternal side at the base of the posterior lobe, cylindrical but with small distal swelling, curved inwards and with short pubescence. In A. tristylus the anal plate has a median trapeziform process and two long, somewhat clavate appendages protruding backwards from the sternal side, which is pubescent and curved inwards.