Eosentomon furunoi Nakamura, 2010

Nakamura, Osami, 2010, Taxonomic revision of the family Eosentomidae (Hexapoda: Protura) from Japan 2701, Zootaxa 2701, pp. 1-109 : 38-42

Eosentomon furunoi Nakamura sp. nov.

Figs. 21–22; Table 8

Type specimens. Holotype female ( NSMT –Ap 471), Mt. Nokogiri–yama, Ashio–machi, Tochigi Prefecture, 36º40'41"N, 139º20'21"E, 1998 m elevation, litter of a forest dominated by Tsuga diversifolia and R. bracycarpum , 5-X-1997, K. Furuno et al. leg. Paratype: 1 male ( NSMT –Ap 472), same data as for the holotype.

Other specimen examined. One maturus junior, same data as for the holotype.

Description. Body length 1378 (1248) µm. Head 109 (113) µm long, 84 (89) µm wide. Setae aa, pa and m4 present, sensilla as and ps present ( Fig. 21A); seta sp 1.4 times longer than p; sensilla pp rudimentary. Labral setae present ( Fig. 21B). Seta rs inflated, shorter than sr ( Fig. 21B). On maxillary palpus ( Fig. 21C) sensillum md longer than ml. Digits on galea small, O longer than M and I ( Fig. 21D). Mandible with three teeth ( Fig. 21E). Clypeal apodemes distinct ( Figs. 21A, B). Pseudoculus about 16 µm long, with no inner structure, PR = 7.

Foretarsus length ( Figs. 21F, G) 125 (120) µm; claw 27 (28) µm, TR =4.8 (4.6); empodium 22 (26) µm, EU = 0.8 (1.0); sensillum s longer than claw. Sensillum t1 nearer to α 3 than to α 3', BS = 0.8 (0.7); t2 thinly spatulate; t3 small and thinly club-shaped; a not reaching base of γ 2; b surpassing base of β 6; c not reaching base of γ 3; d slightly broadened distally and almost reaching base of α 5; e and g spatulate and long; f1 slightly spatulate; f2 small and thinly club-shaped; a' reaching base of α 3', at almost same level with t1; b'1 thin, at halfway between δ 3' and δ 4'; b'2 thinly spatulate; c' small, not surpassing base of δ 6. Length of middle tarsus 67 (65) µm, length of claw 19 (18) µm; hind tarsus 80 (88) µm, claw 21 (22) µm; empodia of both tarsi shorter than 1/10 of claw length ( Fig. 21H); on hind tarsus ( Fig. 21H) D2 and D4 similar, spine-like.

Tracheal camerae weak, often invisible ( Fig. 22A). Central lobe weak, slightly sinuate ( Fig. 22B). Laterostigmata II–IV large, without inner structure; those on V–VII small. On female squama genitalis ( Fig. 22C) caput processus thin and curved toward median edge, corpus processus weak, alae processus long, filum processus short, proximo-lateral and median sclerotization present. Male genitalis with long basiperiphallar setae ( Fig. 22D).

Chaetotaxy as in Table 8. On thoracic tergites II–III, P1a and P2a seta-like; P1a posterior to P1–P2 and halfway between P1 and P2. P1a on abdominal tergite I, P1a and P2a on II–VI and P2a on VII filiform and longer than P1; P1a on VII sensillum-like and shorter than one-seventh length of P1, 4 µm long, posterior to P1–P2; on tergite VIII ( Fig. 22E) P1a' without basal dilatation and anterior to P2; P2a short linear.

Maturus junior. Body length 923 µm. Head 107 µm long, 89 µm wide; pseudoculus indistinct. Foretarsus length 118 µm; claw 24 µm, TR = 5.0; empodium 23 µm, EU = 0.95; sensillum s 28 µm; BS = 0.8. Length of middle tarsus 62 µm, length of claw 17 µm; hind tarsus 78 µm, claw 20 µm.

Diagnosis. This species is similar to E. asahi from Japan ( Imadaté, 1961a, 1974b, 1995), China ( Yin, 1999; Yin & Xie,1993) and Khabarovsk, Russian Far East ( Nakamura, 2004a) and E. juni Imadaté from Japan ( Imadaté, 1994c, 1995). These species commonly have foretarsal sensillum b'1, four pairs of anterior setae on the abdominal tergite V–VI, two pairs of anterior setae on the abdominal tergite VII, two anterior and seven posterior setae on the abdominal sternite VIII, six setae on the abdominal sternites IX–X and pseudoculus without inner structure. However, the present species differs from the latter two in the form of female squama genitalis. Eosentomon asahi belongs to the swani -group and E. juni to the wheeleri -group ( Tuxen 1964), but the present new species does not belong to either group. The present species is distinguished from E. asahi by the positions of foretarsal sensilla t1 closer to α 3 than to α 3' (closer to α 3' in E. asahi ) and a' at almost same level with t1 (same level with α 3 in E. asahi ), and from E. juni by the shapes of inflated seta rs (simple in E. juni ) and rudimentary sensilla pp (distinct in E. juni ) and the value of PR (7 in E. furunoi sp. nov., 11–12 in E. juni ).

Chaetotaxic variation observed consisted of the asymmetric presence of A5 on the abdominal tergites III, IV and VI in maturus junior.

Etymology. The specific name is dedicated to Mr. Katsuhisa Furuno, who kindly supplied me with ample materials from Tochigi Prefecture.

Distribution. Japan (Honshu, known only from the type locality).