Eosentomon inconditum Nakamura, 2010

Nakamura, Osami, 2010, Taxonomic revision of the family Eosentomidae (Hexapoda: Protura) from Japan 2701, Zootaxa 2701, pp. 1-109 : 55-58

Eosentomon inconditum Nakamura sp. nov.

Figs. 30–31; Table 13

Type specimens. Holotype female ( NSMT –Ap 493), Mt. Akanagi –san, Tokorono, Nikko –shi, Tochigi Prefecture, 36º48'33"N, 139º34'07"E, 1670 m elevation, Sasa field, 21-IX-1996, K. Furuno et al. leg . Paratypes: 2 males ( NSMT –Ap 494–495) , 1 female ( NSMT –Ap 496), same data as for the holotype .

Other specimens examined. One female, Ohashi, Minami –ku, Fukuoka –shi, Fukuoka Prefecture, 33º33'27"N, 130º25'56"E, 20 m elevation, grass land, 4-X-2003, T. Kubota leg.; 3 females , Mt. Omoto –dake, Ishigaki Island , Okinawa Prefecture, 24º25'05"N, 124º11'13"E, 170 m elevation, litter of a evergreen broad-leaved forest, 7-III-2002, S. Nagashima leg.; 1 female , Mt. Kubura –dake, Yonaguni Island , Okinawa Prefecture, 24º27'13"N, 122º57'30"E, 150 m elevation, litter of a forest dominated by L. chinensis var. subglobosa , 19-V-2000, H. Mizushima leg.

Description. Body length 611 (624–670) µm. Head 100 (104–110) µm long, 71 (74) µm wide. Setae and sensilla on head similar to the preceding species ( Figs. 30A–C); seta sp 1.4 times longer than p. On galea ( Fig. 30D) digits small, O longer than M and I, M and I close to each other. Mandible with 3 teeth ( Fig. 30E). Clypeal apodemes distinct ( Figs. 30A, B). Pseudoculus circular with a central depression ( Fig. 30F), 11 (12–13) µm long, PR = 10 (9).

Foretarsus length ( Figs. 30G, H) 68 (70) µm; claw 15 µm, TR = 4.8 (4.9–5.0); empodium equal to claw in length, 14 (14) µm, EU = 1.0; sensillum s slightly longer than claw, 16 (16) µm. Sensillum t1 closer to α 3 than to α 3', BS = 0.9 (0.9); t2 thinly spatulate; t3 slightly thick, reaching base of γ 5; a slightly nearer to γ 1 than to γ 2; b reaching base of β 6; c slightly broadened; d broadened, reaching base of α 6; e and g roundedly spatulate and long; f1 thinly spatulate; f2 short; a' at same level with α 3; b'1 nearer to δ 3' than to δ 4'; b'2 slightly broadened; c' absent. Length of middle tarsus 26 (34–37) µm, length of claw 9 (10–11) µm, empodium shorter than 1/5 of claw length ( Fig. 30I), 1 (1–2) µm long; hind tarsus 41 (42–45) µm, claw 11 (10–12) µm, empodium long and about 2/3 of claw length ( Fig. 30J), 7 (7–8) µm; on hind tarsus ( Fig. 30J) D2 and D4 similar, spine-like, but slender than D5.

Tracheal camerae contracted distally ( Fig. 30K). Central lobe trapezoidal ( Fig. 30L). Laterostigmata II–III distinct, without inner structure. On female squama genitalis ( Fig. 30M) S-shaped sclerotization on processus sternalis, caput processus of duck’s head-type; filum processus long; median and proximo-lateral sclerotization distinct. Male genitalis with short basiperiphallar setae.

Chaetotaxy as in Table 13. Chaetotaxy of thorax and abdomen similar to E. dubium , but abdominal tergites V– VI with four pairs of anterior setae, A1, A2, A4 and A5 ( Fig. 31A), and on abdominal tergite VIII P1a’ and P2 posterior to M4 ( Fig. 31E).

Diagnosis. This new species resembles E. dubium in many respects, but is differs from it by having four pairs of anterior setae on abdominal tergites V–VI (five pairs in E. dubium ), the linear shape of foretarsal sensilla a and b (in E. dubium , a broadened, b spatulate). Moreover, the present species (head length 100–110 µm and foretarsus length 68–70 µm) is larger than E. dubium (head length 85–89 µm and foretarsus length 57–58 µm).

Etymology. The specific name is derived from the long confusion of this species with E. udagawai .

Distribution. Japan (Honshu, Kyushu and Okinawa).