Eosentomon kantoense Nakamura, 2010

Nakamura, Osami, 2010, Taxonomic revision of the family Eosentomidae (Hexapoda: Protura) from Japan 2701, Zootaxa 2701, pp. 1-109 : 60-63

Eosentomon kantoense Nakamura sp. nov.

Figs. 33–34; Table 14

Type specimens. Holotype female ( NSMT –Ap 497), Ozasa–bokujo, Kuriyama–mura, Tochigi Prefecture, 36º51'06"N, 139º36'47"E, 1000 m elevation, litter of a forest dominated by Castanea crenata and Q. crispula , 25- IX-1995, K. Furuno et al. leg. Paratypes: 1 female ( NSMT –Ap 498), same data as for the holotype; 2 males ( NSMT –Ap 499–500), Yakeyama, Fujiwara–machi, Tochigi Prefecture, 37º03'10"N, 139º40'35"E, 1020 m elevation, litter of a plantation of Thujopsis dolabrata , 7-X-1995, K. Furuno et al. leg.; 1 female ( NSMT –Ap 501), Satogawa, Satomi–mura, Ibaraki Prefecture, 36º49'13"N, 140º31'43"E, 600 m elevation, litter of a forest dominated by C. crenata and Acer spp. , 20-X-2001, H. Sakayori et al. leg.

Other specimens examined. One female, Yanagisawa, Takahagi–shi, Ibaraki Prefecture, 36º51'49"N, 140º34'38"E, 740 m elevation, litter of a forest dominated by Q. serrata and Q. crispula , 19-VI-1988, H. Tamura et al. leg.; 1 male, Takado, Takahagi–shi, Ibaraki Prefecture, 36º43'05"N, 140º43'29"E, 30 m elevation, litter of a forest dominated by C. cuspidata subsp. cuspidate , 2-XII-1988, H. Tamura et al. leg.; 1 female, Shiku, Takahagi–shi, Ibaraki Prefecture, 36º47'33"N, 140º35'52"E, 400 m elevation, litter of a forest dominated by Q. serrata and Q. acutissima , 2-XII-1998, H. Tamura et al. leg.; 1 female, Chikusan Danchi, Shimokimita, Takahagi–shi, Ibaraki Prefecture, 36º47'07"N, 140º35'50"E, 520 m elevation, 4-VI-1989, H. Tamura et al. leg.

Description. Body length 1339 (1098–1254) µm. Head 158 (146–168) µm long, 130 (105–128) µm wide. Setae aa, pa and m4 present, sensilla as and ps present ( Fig. 33A); seta sp 1.6 (1.4–1.6) times longer than p; sensilla pp rudimentary ( Fig. 33F). Labral setae present ( Fig. 33B). Seta rs inflated, shorter than sr ( Fig. 33B). On maxillary palpus ( Fig. 33C) sensillum md, 10 (10) µm, longer than ml of 8 (7) µm. On galea ( Fig. 33D) digits blunt and developed, O longer than M and I. Mandible with four teeth ( Fig. 33E). Clypeal apodemes distinct, side part short ( Figs. 33A, B). Pseudoculus 17 µm long, with no inner structure ( Fig. 33F), PR = 10 (9–10)

Foretarsus length ( Figs. 33G, H) 108 (110–123) µm; claw 26 (24–26) µm, TR = 4.2 (4.4–4.8); empodium 24 (23–24) µm, EU = 0.9 (0.9–1.0); sensillum s longer than claw, 27 (27–30) µm. Sensillum t1 nearer to α 3 than to α 3', BS = 0.7 (0.7–0.8); t2 thinly spatulate; t3 small, not surpassing base of α 7; a not reaching base of γ 2; b surpassing base of β 6; c not reaching base of γ 3; d surpassing base of α 5; e and g spatulate and long; f1 thinly spatulate; f2 short and slightly broadened; a' reaching base of α 3', at almost same level with or slightly proximal to t1; b'1 absent; b'2 thinly spatulate; c' not surpassing tarsus. Length of middle tarsus 57 (59–64) µm, length of claw 16 (17– 19) µm; hind tarsus 73 (74–81) µm, claw 18 (18–20) µm; empodia of both tarsi short and less than 1/8 of claw length ( Fig. 33I), 2µm long; on hind tarsus ( Fig. 33I) D2 and D4 thin spine-like, D4 thicker than D2; D5 a thick spine.

Tracheal camerae weak, distally contracted ( Fig. 34A). Central lobe trapezoidal, weak, often invisible ( Fig. 34E). Laterostigmata II–IV large, without inner structure. On female squama genitalis ( Figs. 34B, C) corpus processus thin, curved towards median edge, median sclerotization developed, filum processus long. Male with long basiperiphallar setae ( Fig. 34D).

Chaetotaxy as in Table 14. On thoracic tergites II and III, P1a and P2a seta-like and longer than P1, posterior to P1–P2. P1a on abdominal tergite I, P1a and P2a on II–VI and P2a on VII filiform and longer than P1 ( Fig. 34E); P1a on VII sensillum-like, 6 (5–6) µm long, and less than one-fifth length of P1, posterior to P1–P2 ( Fig. 34E); on tergite VIII ( Fig. 34F) P1a' with basal dilatation and anterior to P2; P2a capitulate.

Diagnosis. This species is similar to E. brevicorpusculum from China, E. savannahense and E. pseudoyosemitense White from USA ( Bernard, 1990; Copeland & White, 1978), E. caatingae Tuxen from Brazil ( Tuxen, 1976), and E. betschi Nosek from Madagascar ( Nosek, 1978) in having a semicircular caput processus on the female squama genitalis and the presence of anterior setae on abdominal sternite VIII. The present species, E. savannahense and E. caatingae differ from other three in the absence of foretarsal sensillum b'1. However, this new species is distinguished from E. savannahense and E. caatingae by six setae on abdominal sternite IX–X (four setae in latter two), and moreover from E. savannahense by pseudoculus without inner structure (with some longitudinal striae and a small central depression in E. savannahense ), the presence of foretarsal sensillum c' (absence in E. savannahense ) and two pairs of anterior setae on abdominal tergite VII (three pairs in E. savannahense ); and from E. caatingae in four pairs of anterior setae on abdominal tergite V (five pairs in E. caatingae ).

Chaetotaxic variation observed consisted of the asymmetric absence of A1 on the abdominal tergite VI in one male from Yakeyama ,

Etymology. The specific name is derived from the Kanto district, where all the specimens seen were exclusively collected.

Distribution. Japan (Honshu).