Eosentomon hitakami Nakamura, 2010

Nakamura, Osami, 2010, Taxonomic revision of the family Eosentomidae (Hexapoda: Protura) from Japan 2701, Zootaxa 2701, pp. 1-109 : 46-49

Eosentomon hitakami Nakamura sp. nov.

Figs. 25–26; Table 10

Type specimen. Holotype female ( NSMT –Ap 480), Mt. Komaga–take, Kanegasaki–machi, Iwate Prefecture, 39º11'21"N, 140º55'41"E, 920 m elevation, litter of a forest dominated by F. crenata and Q. crispula , 18-VIII-2001, H. Tamura et al. leg.

Description. Body length 787 µm. Head 103 µm long, 68 µm wide. Setae aa, pa and m4 present, sensilla as and ps present ( Fig. 25A); seta sp 1.2 times longer than p; sensilla pp rudimentary. Labral setae present ( Fig. 25B). Seta rs inflated, 14 µm long, longer than sr, 11 µm ( Fig 25B). On maxillary palpus ( Fig. 25C) sensillum md as long as ml, but the former slightly thicker than the latter. On galea ( Fig. 25D) digit O longer than M and I. Mandible with four teeth ( Fig. 25E). Clypeal apodemes distinct, side arm slightly club-shaped ( Figs. 25A, B). Pseudoculus circular, 8 µm long, with a central spot and weakly V-shaped structure ( Fig. 25F), PR = 12.5.

Foretarsus length ( Figs. 25G–I) 66 µm; claw 13 µm, TR = 5.2; empodium 13 µm, EU = 1.0; sensillum s longer than claw, 19 µm. Sensillum t1 closer to α 3 than to α 3', BS = 0.9; t2 not reaching base of y; t3 short and thick; a closer to γ 1 than to γ 2; b and c linear; d long, surpassing base of α 6; e and g roundedly spatulate and long; f1 spatulate; f2 thin; a' at same level with α 3; b'1 closer to δ 3' than to δ 4'; b'2 short, not reaching base of α 6; c' absent. Length of middle tarsus 32 µm, length of claw 9 µm; hind tarsus 39 µm, claw 11 µm; empodia of both tarsi short ( Figs. 25J, K), 1 µm long; on hind tarsus ( Fig. 25K) D2 and D4 similar, thin spine-like.

Tracheal camerae thick and distally contracted ( Fig. 26A). Central lobe incised. Laterostigma II distinct, but small, without inner structure. On female squama genitalis ( Fig. 26B) S-shaped sclerotization on processus sternalis, caput processus of duck’s head-type, filum processus short, median sclerotization present. Male unknown.

Chaetotaxy as in Table 10. Thoracic and abdominal chaetotaxy similar to E. ateruii .

Diagnosis. This new species is similar to E. ateruii , E. novemchaetum and E. dimecempodi in possessing two anterior and nine posterior setae on abdominal sternite VIII, but differs from them in the short empodium on hind tarsus (long in the other species). Moreover, the present new species differs from E. ateruii in the presence of labral setae (absent in E. ateruii ), from E. novemchaetum in pseudoculus with a central spot and weakly V-shaped structure (no inner structure in E. novemchaetum ), and from E. dimecempodi in the short empodium on middle tarsus (long in E. dimecempodi ).

Chaetotaxic asymmetry consisted of the absence of seta 1a on one side of abdominal sternite X.

Etymology. The specific name, a noun in apposition, is derived from the old appellation for the Isawa district, Iwate Prefecture, where the type locality is included.

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