Nipponentomon nippon (Yoshii, 1938)

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 : 542-544

Nipponentomon nippon (Yoshii, 1938) , new record to Chinese fauna

Figs. 85–98 , Tables 2, 6

Material examined. Two females (no. SJLW-6-2, SJLW-6-4), 1 larva II (no. SJLW-6-6), collected in broad-leaved forest near the Sanjiaolongwan Lake, Huinan County, Jilin Province, China, 42°20'59'' N 126°25'59'' E, 668 m elev., 15 July 2008, collected by D. H. Wu. Specimens are deposited at SEM and NEIGAE.

Description (Chinese specimens). Adult body length 1600–1650 µm (n=2). Head elliptic, length 175–180 µm, width 130–135 µm. Labrum slightly protruded. Setae sd4 and sd5 short and sensilliform, seta d6 absent. Clypeal pore cp and frontal pore fp present ( Fig. 85 ). Pseudoculus length 8–9 μm, PR=19–23 ( Fig. 86 ). Maxillary gland calyx large, with lateral racemose appendices and one helmet-like dorsal appendix, posterior dilation swollen. Posterior dilation of maxillary gland 30 μm long, CF = 5.8–6.0 ( Fig. 87 ). Maxillary palpus with two setiform sensilla. Labial palpus well developed, with one sausage-like sensillum.

Foretarsal length 95–100 µm, claw length 5 µm, TR =2.7–2.9; empodium length 8–11 µm, EU = 0.23–0.31. Dorsal sensillum t1 filiform, t2 slender and long, t3 leaf-like, BS = 0.82–0.89. Exterior sensillum a broad, b and c filiform, c slightly longer than b, d slender and short, e slender and surpassing base of g, f broad at base and long, slightly surpassing base of claw, g filiform and surpassing base of claw. Interior sensillum a' broad, b' absent, and c' filiform and surpassing base of claw ( Figs. 91, 92 ). Relative length of sensilla: t3 <(t1= b = g) <(d = a') <e = c <a <f <(t2 = c'). Setae β 1 and δ 4 setiform. Claw with one inner tooth. Two pores close to base of a and t3 present.

Adult chaetotaxy given in Table 6 . Length ratio of P1: P1a: P2 on metanotum as 1.1: 1: 1.4, P1a subequal to the length of P1, 18 μm, 16 μm, and 22 μm, respectively; seta P2a short, sensilliform. Setae A2 and M2 on prosternum, A2 on mesosternum and metasternum sensilliform ( Figs. 88–90 ).

Tergite I with three pairs of anterior setae and six pair of posterior setae ( Fig. 93 ). Tergite VII with eight pairs of porterior setae, P1a longer than P2a. Sternites IV–VI with 5/8 setae. Tergite and sternite of abdominal segment VIII with two irregular rows of small, scattered granules ( Fig. 96 ). Hind margin of tergite IX with small teeth in middle part and fine ciliation on lateral part. Hind margin of tergites X–XI with distinct, long ciliation, XII smooth ( Fig. 95 ). Hind margin of sternites IX and X with thick scattered teeth ( Fig. 96 ). Hind margin of sternite XI smooth, XII with delicate serration.

Body porotaxy given in Table 2. Pronotum without pores, mesonotum and metanotum with pores sl and al. Prosternum with one median pore, mesosternum and metasternum each with two median pores situated anterior to level of setae M ( Figs. 88–90 ). Tergite I with pores psm ( Fig. 93 ). Tergites II–VI with pores psm, psl and al. Tergite VII with pores psm and al. Pore psm on tergite VIII with several surrounding teeth. Tergites IX–XI without pores, XII with single median pore. Sternites I–VI each with single median pore, situated in posterior part, and anterior to setae P1. Sternite VII with one anteromedial pore on the anterior line and two posterolateral pores ( Fig. 94 ). Sternite VIII with one median pore, situated anterior to A1. Sternites IX and X each with one anteromedial pore situated on anterior line ( Fig. 96 ). Sternite XI without pores. Sternite XII with 1+1 anterolateral pores.

Subapical and apical setae of second and third appendages subequal in length. Striate band on abdominal segment VIII well developed. Comb on abdomen VIII rectangular, with 8–10 long teeth ( Fig. 97 ).

Dorsal Ven t ral

Segment Formula Setae Formula Setae Female squama genitalis with short blunt acrostylus, apically tripartite ( Fig. 98 ).

Distribution. China (Jilin); Japan; Korea.

Diagnosis. Nipponentomon nippon (Yoshii, 1938) is characterized by slightly protruded labrum, claw with one inner tooth, sensilla f and c' of moderate length, setiform seta β 1 and δ 4, absence of seta d6 on head, P1a on mesonotum and metanotum weakly differentiated and subequal in length to P1, five anterior setae on sternites I–VI, anteromedial pore and posterolateral pores on sternite VII, medial pore on sternite VIII and anteromedial pores on sternites IX and X.

Remarks. The head chaetotaxy, length of setae on the body, and porotaxy of Nipponentomon nippon (Yoshii, 1938) are supplemented in the present paper. In order to confirm the porotaxy of N. nippon , four specimens (two females and two males) of N. nippon from Japan (Honshu, Rokurigahara, Kanbara, 36°25'45'' N 138°33'26'' E) loaned by Dr. O. Nakamura were carefully studied. We found that the porotaxy of N. nippon from Japan is nearly identical to that of Chinese specimens, except for a difference on the mesosternum and metasternum (1+1 medial pores in Chinese specimens, 1 medial pore in Japanese specimens). Chinese specimens (maximum 1650 µm) are shorter than Japanese specimens (maximum 1800 µm).

Figures

FIGURES 85 – 98. Nipponentomon nippon (Yoshii, 1938) (specimen no. SJLW- 6 - 4). 85) Head, dorsal view; 86) Pseudoculus; 87) Canal of maxillary gland; 88) Prosternum; 89) Mesosternum; 90) Metasternum; 91) Foretarsus, exterior view; 92) Foretarsus, interior view; 93) Tergite I, right side; 94) Sternite VII; 95) Hind margins of tergites IX – XII; 96) Sternites VIII – X; 97) Comb on abdominal segment VIII; 98) Acrostylus. Arrows indicate pores. Scale bars: 20 μm.

Tables

TABLE 6. Adult chaetotaxy of Nipponentomon nippon (Yoshii, 1938).

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