Allopauropus circulus, Scheller, Ulf, 2014

Scheller, Ulf, 2014, New records of Pauropoda (Myriapoda) with descriptions of new taxa, Zootaxa 3866 (3), pp. 301-332 : 313-315

Allopauropus circulus n. sp.

Figs 1–10

Type specimen s. Holotype: ad. 9 (♀), France, Var, Mt Vinaigre, loc. #83-145, October 6, 1995, 81653, Y 43.5033, Berlese extraction of soil, depth 20–40 cm, February 24, 1995, A. Bedos & L. Deharveng leg. Paratype: 1 subad. 8 (♀), same data as holotype. Described below. Type specimens deposited in the Zoological Museum, University of Lund, Sweden.

Diagnosis. The new species belongs to a group of species characterized by a short anal plate with two posterior appendages, short pygidial setae a 1 and st and very long setae a 2 and a 3. It may be closest to A. maoriorum Remy (Remy, 1956) , a wide ranging species in the southern hemisphere (known from Australia, New Zealand, New Caledonia and Chile) but known also from Sabah in the Malaysian part of Borneo. The two species are very alike but can be distinguished by many obvious dissimilarities: the shape of the antennal globulus g, stalk short and wide in A. maoriorum , distinctly thin in A. circulus ; the shape of the bothriotricha T 3, axes increasing in width from the base and outwards, then being cylindrical, pubescence short, straight, oblique, not decreasing in width outwards and with long branched pubescence hairs arranged in whorls; the shape of the anal plate, with lateral corners, not circular; the posterior appendages of the anal plate appendages almost parallel, not diverging; and the size of the median lobe of the posterior margin of the pygidial sternum, small, not large.

Derivation of name. From the Latin circulus = circle, referring to the shape of the anal plate.

Description. Length. 0.47 (-0.65) mm.

Head (Fig. 1). Tergal setae of medium lengths, subcylindrical, annulated, blunt. Relative lengths of setae, 1st row: a 1 = a 2 = 10; 2nd row: a 1 = 13, a 2 = 19, a 3 = 17; 3rd row: a 1 = 11, a 2 = 14; 4th row: a 1 = 19, a 2 = 20, a 3 = 17, a 4 = 16; lateral group setae not studied. Ratio a 1 /a 1– a 1 in 1st and 3rd rows 1.1, 2nd 0.8, 4th 1.3. Temporal organs in tergal view short, length 0.9 of shortest interdistance; short but wide pistil near middle, length well 0.1 of the length of the temporal organ. Head cuticle glabrous.

Antennae (Fig. 2). No g´ on segment 3; segment 4 with 5 subcylindrical annulated setae, u thinnest, their relative lengths: p = 100, p' = 70 (-76), p'' = 61 (-67), p´´ ´= 33 (-38), r = 47 (-60), u = 3. Tergal seta p 1.1 (-1.2) times as long as the length of tergal branch t. The latter (2.4-) 2.5 times as long as its greatest diameter and 0.9 (-1.0) of the length of sternal branch s, that branch 2.1 times as long as its greatest diameter; anterodistal corner of s distinctly truncated. Seta q as p and p´ of 4th segment, (1.1-) 1.2 times as long as the length of s, insertion point of q just below the level of the insertion point of flagella F2. Relative lengths of flagella (basal segments included) and basal segments: F 1 = 100, bs 1 = (9-) 10 (-11); F 2 = 42 (-45), bs 2 = 7 (-8); F 3 = 89 (-91), bs 3 = 9 (-11). The F 1 3.2 (-3.3) times as long as t, F 2 and F 3 1.3 (-1.5) and 2.8 (-3.1) times as long as s respectively. Distal calyces of F 1 and F 3 large flattened, those of F 2 small, obliquely helmet-shaped, distal part of flagella axes almost not at all widened below calyces. Globulus g with short but distinct stalk, as wide as long, ≈9 bracts, capsule with flattened bottom, width of g almost as long as greatest with of t. Antennae glabrous.

Trunk (Figs 3–4). Setae of collum segment (Fig. 3) similar, furcate, main branch cylindrical, pointed, annulated, secondary branch rudimentary, pointed; sternite process triangular, narrow and blunt anteriorly, appendages cylindrical with subspherical caps with distinct collar, process and appendages glabrous. Setae on anterior tergites similar to submedian setae of head but lengthening and also growing thinner posteriorly, on posterior tergites with short oblique pubescence; 4+4 setae on tergite I, 6+4 on II, 6+6 on III-IV, 6+4 on V, 4+2 on VI. Submedian posterior setae on tergite VI (Fig. 4) thin, pointed, somewhat curved inwards, length 1.3 times as long as interdistance and (4.1-) 5.4 times as long as the length of pygidial setae a 1. Tergites glabrous.

Genital papillae (Fig. 5) with subcylindrical proximal half, distal part rounded on outer sides, papillae 1.7 times as long as their greatest diameter; distal seta not fully 0.5 of the length of the papilla. Setae on coxa and trochanter of 2nd pair of legs as on 9th pair of legs.

Bothriotricha (Fig. 6): Relative lengths: T 1 = T 2 = 100, T 3 = 82, T 4 = 65, T 5 = 129; axes simple, T 1 (Fig. 6) and T 2 very thin, proximal halves glabrous, distal halves with long sparse and partly branched hairs; posterior setae thicker, T 3 (Fig. 6) and T 5 with oblique simple pubescence hairs in proximal third, more outwards with longer and branched hairs in distinct whirls; T 5 with very delicate pubescence.

FIGURES 1–10. Allopauropus circulus n. sp. 1–4, 6–10, holotype ad. 9 (♀), 5, paratype ad. 9 (♂). 1, Head, right half, tergal view. 2. Left antenna, tergal view. 3. Collum segment, median and left part, sternal view. 4. Posterior part of tergite VI. 5. Genital papillae, anterior view. 6. T 3. 7. Seta on trochanter of leg 9. 8. Tarsus of leg 9. 9. Pygidium, posteriomedian and left part, sternal view. 10. Anal plate, lateral view. Scale: a: 3–7; b: 1–2, 8–10.

Legs (Figs 7, 8): Setae on coxa and trochanter (Fig.7) of leg 9 simple striate blunt. Tarsus of leg 9 (Fig. 8) distinctly tapering, 4.7 times as long as its greatest diameter; proximal seta long, tapering, glabrous, distal seta short, cylindrical, blunt, with short pubescence, proximal seta 0.6 of the length of tarsus and 5.8 times as long as distal seta. Cuticle of tarsus with short pubescence.

Pygidium (Figs 9, 10): Tergum: Posterior margin almost straight, only inconsiderable bulge between setae st. Relative lengths of setae: a 1 = 10, a 2 = (33-) 35 (-36), a 3 = (65-) 83, st = (2-) 3; all setae directed posteriorly, a -setae thin, tapering, a 1 almost straight, annulated, a 2 and a 3 very thin distally, the latter curved inwards, st very short, clavate, glabrous. Distance a 1– a 1 2.3 times as long as interdistance; distance a 1– a 2 as long as distance a 2– a 3; distance st–st 9 times longer than st and (1.1-) 1.2 times as long as distance a 1– a 1. Cuticle glabrous.

Sternum: Setae b 1 on small semi-circular lobes, margin in between straight with small median lobe having a broadly V-shaped median incision. Relative lengths of setae (pygidial a 1 = 10): b 1 = (43-) 48, b 2 = (25-) 29, b 3 = (12-) 15. b 1 cylindrical, annulated, blunt, b 2 and b3 tapering, pointed, particularly the former, b 1 0.9 of interdistance, b 2 1.5 times as long as distance b 1– b 2, b 3 0.4 of interdistance. Cuticle glabrous.

Anal plate (Figs 9, 10) pointing obliquely upwards, circular, glabrous and with two short clavate diverging appendages protruding backwards from distal part of sternal side, length of appendages (0.8-) 0.9 of the length of the plate.