Nipponentomon heterothrixi Yin & Xie, 1993

Bu, Yun, Wu, Dong Hui, Shrubovych, Julia & Yin, Wen Ying, 2013, New Nipponentomon species from northern Asia (Protura: Acerentomata, Nipponentomidae), Zootaxa 3636 (4), pp. 525-546 : 535-539

Nipponentomon heterothrixi Yin & Xie, 1993

Figs. 53–75 , Tables 2, 4

Material examined: Syntypes, 6 females (no. 3–6, 8, 9), 3 males (no. 1, 2, 7), collected in Hancongling, Dunhua County, Jilin Province, China, 43°07' N 128°01' E, elev. 800 m, 30 July 1990, coll. Zhong Wei Yan. We assign syntype specimen no. 2 (male) as the lectotype for N. heterothrixi , with the other eight specimens as paralectotypes. All type specimens are deposited in the Shanghai Entomological Museum (SEM).

Redescription. Adult body length 1300 µm (n = 9). Head length 160–170 µm. Dorsal side of head with modified setae sd4 and sd5, thickened and stumpy apically, seta d6 present. Posterior margin of head with seta d7 and sd7 subequal in length, d 7 25–28 μm, sd 7 27–30 μm, l5 7–8 μm. Clypeal pore cp and frontal pore fp present ( Fig. 53 ). Labrum very short, rounded. Pseudoculus broader than long, with short posterior extension, 7–10 µm, PR = 16–23 ( Fig. 54 ). Maxillary gland with large, densely granulated calyx; posterior filament short, 23 µm, with bilobed posterior dilation, CF = 6.9–7.3 ( Fig. 55 ). Maxillary palpus short, dorsal and lateral sensilla equal in length, slender ( Fig. 56 ). Labial palpus well developed, with broad basal sensillum ( Fig. 57 ). Labium with small teeth on inner margin.

Foretarsus length 100–105 µm, lacking sensillum b'; sensillum t1 filiform; t3 leaf–like; d and f thin with narrowly rounded apex; other sensilla parallel-sided ( Figs. 60, 61 ). Sensillum b thickened. Sensillum d located very close to short sensillum e. Sensillum a' located anterior to level of t2 insertion and surpassing base of seta α6. Seta β 1 and δ 4 sensilliform, short, thick and truncated on the apex. Claw long and slender, 40–43 µm, with one inner tooth. Empodial appendage short, 7–8 µm. Relative length of foretarsal sensilla: t3 <e <g <(a = b) <c <t1 <a' <d <t2 <(f = c'). BS = 0.67–0.73, TR = 2.3–2.5, EU = 0.16–0.2. Pores present near base of sensilla c and t3. Length of middle tarsus 49–51 µm, claw length 22–24 µm. Length of hind tarsus 55–57 µm, claw length 24–26 µm.

Adult chaetotaxy given in Table 4 . Setae on nota differing distinctly in length ( Fig. 58 ). Length ratio of pronotal setae 1: 2 as 2.8–3:1, 55–60 and 23–25 μm, respectively. Seta M on mesonotum short and slender, shorter than A2; on metanotum twice longer than on mesonotum, 26–28 μm and 50–56 μm respectively. Accessory setae P1a, P2a and P2a' modified, short, stumpy, rounded and thicken at tip; P3a and P4 subequal in length and shape, short, unmodified; P5 as small sensillum. Length ratio of P1: P1a: P2 on mesonotum as 6.3–7.9:1:8.1–9.6, 50–57 μm, 7–8 μm, and 63–67 μm respectively. Prosternum with seta M2, metasternum with A1 setae ( Fig. 59 ). Setae A2 and M2 on prosternum, and A2 on mesosternum and metasternum short, setiform.

Accessory setae on mesonotum, metanotum and tergites I–V sensilliform, blunt, 6–7 μm long ( Figs. 58 , 62 ), on tergites VI–VII longer and setiform, 12–15 μm long ( Fig. 63 ). Accessory setae on sternites I-VI setiform, on sternite VII slightly longer, 12–15 μm and 17–18 μm, respectively ( Figs. 64–68, 70, 72 ). Tergite I with four pairs of A- setae ( Fig. 62 ). Tergites V–VII anteriorly with two parallel cuticular lines connected dorsally by short convergent lines. Sternite III with 5 A -setae and 6 P -setae ( Fig. 66 ). Sternites IV–VII anteriorly with two parallel cuticular lines as on the tergites. Posterior margin of sternite and laterotergites VIII smooth. Seta 1a on tergite IX slightly shorter than seta 1. Hind margin of tergites X–XI with distinct ciliation ( Fig. 74 ). Posterior margin of tergite XII smooth, sternite with delicate serration in central part.

Body porotaxy given in Table 2. Mesonotum and metanotum with pores al and sl. Prosternum without pores; mesosternum and metasternum each with single median pores located posterior of Ac ( Fig. 59 ). Pores psm present on tergites I–VII, psl present on tergites V–VII, al on tergites II–VII ( Figs. 62, 63, 69, 71 ). Sternites I–VII each with single median pore, situated in central part and posterior to Ac setae in II–IV, location of median pore on sternite V variable, posterior, anterior or parallel to Ac; anterior to Ac on sternites VI and VII ( Figs. 64–68, 70, 72 ). Pore psm on tergite VIII with several surrounding teeth. Tergite XII with single median pore, sternite with 1+1 anterolateral pores.

Abdominal appendages with 4, 2, 2 setae. Subapical seta of abdominal appendages II and III nearly same length as apical seta, 15 μm and 14 μm, respectively.

Abdominal segment VIII with distinct striate band and with two irregular, parallel rows of small scattered denticles anteriorly. Comb VIII composed of 8–12 irregular teeth ( Fig. 73 ).

Male squama genitalis with 7+7 setae ( Fig. 75 ). Female squama genitalis with short and blunt acrostyli.

Chaetal variability. The body chaetotaxy of ventral side is quite variable, while the dorsal side is relatively stable: tergite IV asymmetrically with P1a' (1 specimen), sternite I with 3 P -setae (1), sternite II with 4 A -setae (1), sternite III with 3 (1) or 4 (1) A -setae, sternite IV with 4 A -setae (1), sternite VII with 8 P -setae (2), sternite IX with 5 setae (1).

Dorsal Ven t ral Distribution. China (Jilin), Korea.

Diagnosis. Nipponentomon heterothrixi is characterized by a short labrum, presence of seta d6 on head, extremely long sensilla f and c' on foretarsus, sensilliform β 1 and δ 4, presence of seta P2a' on mesonotum and metanotum, 8/14 setae on tergite I, 5/8 setae on sternites IV–VI.

Remarks. The head chaetotaxy, body porotaxy, as well as measurements of some important setae of N. heterothrixi Yin & Xie, 1993 were not provided in original description. Holotype and paratypes were also not designed. In the present paper, we give a redescription of the speices and all missing data are supplemented. A lectotype is also assigned for the species.

Figures

FIGURES 53 – 61. Nipponentomon heterothrixi Yin & Xie (lectotype). 53) Head, dorsal view; 54) Pseudoculus; 55) Canal of maxillary gland; 56) Maxillary palpus; 57) Labial palpus; 58) Nota, right side; 59) Metanotum; 60) Foretarsus, exterior view; 61) Foretarsus, interior view. Arrows indicate pores. Scale bars: 20 µm.

FIGURES 62 – 75. Nipponentomon heterothrixi Yin & Xie (lectotype). 62) Tergite I, left side; 63) Tergite VII, left side; 64) Sternite I; 65) Sternite II; 66) Sternite III; 67) Sternite IV; 68) Sternite V; 69) Lateral part of tergite VI; 70) Sternite VI; 71) Lateral part of tergite VII; 72) Sternite VII; 73) Comb; 74) Hind margin of tergites X – XI; 75) Male squama genitalis. Arrows indicate pores. Scale bars: 20 µm.

Tables

TABLE 4. Adult chaetotaxy of Nipponentomon heterothrixi Yin & Xie, 1993.

	Formula	Setae	Formula	Setae
Th. I	4	1,2	4+4 6	A1, 2 M1, 2 P1, 2, 3
Th. II	8 18	A2, 3, 4, M P1, 1a, 2, 2a, 2a ', 3, 3a, 4, 5	5+2 4	Ac, 2, 3, M P1, 3
Th. III	10 18	A1, 2, 3, 4, M P1, 1a, 2, 2a, 2a ', 3, 3a, 4, 5	9+2 4	Ac, 1, 2, 3, 4, M P1, 3
Abd. I	8 14	A1, 2, 3, 5 1, 1a, 2, 2a, 3, 3a, 4	3 4	Ac, 2 P1, 1a
Abd. II	10 16	A1, 2, 3, 4, 5 P1, 1a, 2, 2a, 3, 4, 4a, 5	3 5	Ac, 2 Pc, 1a, 2
Abd. III	10 16	A1, 2, 3, 4, 5 P1, 1a, 2, 2a, 3, 4, 4a, 5	5 6	Ac, 1, 2 P1, 1a, 2
And. IV–VI	10 16	A1, 2, 3, 4, 5 P1, 1a, 2, 2a, 3, 4, 4a, 5	5 8	Ac, 1, 2 P1, 1a, 2, 3
Abd. VII	8 16	A2, 3, 4, 5 P1, 1a, 2, 2a, 3, 4, 4a, 5	3 9	Ac, 2 Pc, 1, 1a, 2, 3
Abd. VIII	6 15	A1, 4, 5 Pc, 1, 1a, 2, 2a, 3, 3a, 5	4 2	1, 2 1a
Abd. IX	12	1, 1a, 2, 2a, 3, 4	4	1, 2
Abd. X	10	1, 2, 2a, 3, 4	4	1, 2
Abd. XI	6	1, 3, 4	6
Abd. XII	9		6