Stylopauropus bifurcus (Zhang et Chen)

Qian, Changyuan, Dong, Yan, Guo, Hua, Chu, Kelin & Sun, Hongying, 2013, Pauropods (Myriapoda: Pauropoda) from eastern China, descriptions of three new species and revision of Pauropus bifurcus Zhang & Chen, 1988, Zootaxa 3608 (2), pp. 116-126 : 117-118

Stylopauropus bifurcus (Zhang et Chen)

( Figure 1 )

Pauropus bifurcus Zhang et Chen 1988

Type material. Holotype. ad.9 (male), Tianmu Mountain, Zhejiang, 13 September 2009, leg. Dong et al. Paratypes. ad.9 (female), Laoshan Mountain, Jiangsu, 24 May 2010, leg. Qian & Dong.

Description. Length. 0.50 (–0.95) mm

Head. Tergal setae short or of medium length, subcylindrical, densely annulate, blunt. Relative lengths of setae, 1st row: a 1=10, a 2=9(–10); 2nd row: a 1=7.1(–10), a 2=11(–15), a 3=13(–15); 3rd row: a 1=12.9(–14), a 2=(13–)16; 4th row: a 1=(10–)16, a 2=20(–27), a 3=(15–)19, a 4=16(–18); The ratio a 1/ a 1– a 1 in 1st row 0.88(–1.0), 2nd row 1.6, 3rd row (0.6–)0.75 and 4th row 0.67(–0.83). Head cuticle glabrous.

Antennae. Segment 4 with four cylindrical setae; Relative lengths of setae: p =100, p' =31.3(–34), p'' =56.3(–68), r =(22–)25; Tergal seta p 0.67(–0.8) times as long as tergal branch t. The latter fusiform, 3.4(–3.6) times as long as its greatest diameter and (1.1–)1.3 times as long as sternal branch s; that branch (2.3–)2.4 times as long as its greatest diameter. Seta q cylindrical, with pubescence, (0.95–)1.1 times as long as s. Relative lengths of flagella (basal segments included) and basal segments: F 1=100, bs 1=8(–9); F 2=73(–75), bs 2=8(–10); F 3=(81–)85, bs 3=(7–)9. The F 3 thinnest; F 1 (2.3–)2.5 times as long as t, F 2 and F 3 2.0(–2.1) and (2.2–)2.3 times as long as s, respectively. Distal calyces subspherical; distal part of flagella axes fusiform. Globulus g 2.2 times as long as wide; about nine bracts, capsule subspherical; width of g 0.7(–0.8) of the greatest diameter of t. Antennae almost glabrous.

Trunk. Setae on tergites thin, cylindrical; 4+4 setae on tergite I, 6+6 on II–IV, 6+4 on V, 4+2 on VI. Relative lengths of bothriotricha: T 1=100, T 2=95(–98), T 3=105(–108), T 4=(103–)107, T 5=136(–140), all with simple straight axes; all with pubescence thin erect.

Legs. Tarsus of leg 9 slender, (4.8–)5.1 times as long as greatest diameter; setae curved, point, pubescent, proximal seta short, pointed, 0.1(–0.3) of length of tarsus, 0.28(–0.32) of length of distal seta.

Pygidium. Tergum. Relative lengths of setae: a 1=100, a 2=(120–)122, a 3=122(–128), st =66.7(–70). All setae but st point, with short oblique pubescence; st blunt, subcylindrical, glabrous; distance a 1 -a 1 (1.2–)1.5 times as long as a 1; distance a 1- a 2 (0.9–)1.0 times as long as a 2– a 3; distance st - st 1.2(–1.5) times as long as st and 0.54 of length of distadnce a 1- a 1.

Sternum. Posterior margin with shallow indentation between b 1. Relative lengths of setae (a 1=100): b 1=322(–325). All setae subcylindrical, blunt. Distance b 1- b 1 0.87(–0.95) of length of b 1.

Anal plate. 2.8 times as long as broad, with a deep indentation posterior incision separating two long bifurcate; plate and appendages glabrous.

The genus Pauropus Lubbock, 1867 was first reported from China based on a single species, Pauropus bifurcus Zhang & Chen, 1988 . It may be characterized by the following: anterior margin of sterna antennal branch s longer than posterior margin; the character of stalk of antennal globulus g longer than globulus itself; pygidial sternum with setae b 1. However, these characters are the same as characters of the genus Stylopauropus . The genus Stylopauropus (= Pauropus Lubbock 1867 ; Haase 1885; Silvestri 1894; Brölemann1895) was separated from Pauropus by Cook in 1896, and it was described on the basis of Stylopauropus pedunculatus (Lubbock, 1867) (original binomen: Pauropus pedunculatus Lubbock, 1867 ). In contrast to the genus Stylopauropus , the primary features of Pauropus are anterior and posterior margins of sternal antennal branch s subsimilar in length; antennal globulus g short-stalked; and pygidial sternum with setae b 1 +b 2 +b 3. According to our reexamination, specimens of the species Pauropus bifurcus have closer affinities to Stylopauropus than to Pauropus . In addition, according to DNA barcoding we found this species to be close to other species of the genus Stylopauropus (unpublished data).

Figures

FIGURE 1. Stylopauropus bifurcus (Zhang et Chen) (male). A, right antenna, sterna view. B, tarsus of leg 9. C, pygidium, tergal view.