Eosentomon ateruii Nakamura, 2010

Nakamura, Osami, 2010, Taxonomic revision of the family Eosentomidae (Hexapoda: Protura) from Japan 2701, Zootaxa 2701, pp. 1-109 : 25-27

Eosentomon ateruii Nakamura sp. nov.

Fig. 13; Table 4

Type specimens. Holotype female ( NSMT –Ap 462), Mt. Komaga –take, Kanegasaki –machi, Iwate Prefecture, 39º11'21"N, 140º55'41"E, 820 m elevation, 18-VIII-2001, litter of a forest dominated by F. crenata, H. Tamura et al. leg . Paratype: 1 female ( NSMT –Ap 463), same data as for the holotype .

Description. Body length 800 (754) µm. Head 95 (94) µm long, 62 µm wide. Seta aa, pa and m4 present, sensilla as and ps present ( Fig. 13A); seta sp equal to p in length; sensilla pp rudimentary. Labral setae absent ( Fig. 13B). Seta rs inflated and equal to sr in length ( Fig. 13B). On maxillary palpus ( Fig. 13C) sensilla md and ml similar to each other in shape and length. On galea ( Fig. 13D) digit O longer than M and I, M and I close to each other. Mandible with three teeth ( Fig. 13E). Clypeal apodemes distinct ( Figs. 13A, B). Pseudoculus 10 (11) µm long, without inner structure ( Fig. 13A), PR = 10 (9).

Foretarsus length ( Figs. 13F, G) 60 (62) µm; claw 12 (13) µm, TR = 5.2 (5.1); empodium 13 (13) µm, EU = 1.1 (1.0); sensillum s longer than claw, 14 (16) µm. Sensillum t1 closer to α 3 than to α 3’, BS = 0.8 (0.9); t2 thin; t3 thick, surpassing base of α 7; a near γ 1; b almost reaching base of β 6; c broadened, reaching base of γ 3; d broadened, reaching base of z; e and g roundedly spatulate and long; f1 spatulate; f2 thin; a' posterior to δ 3', reaching nearly to level of α 3’; b'1 nearer to δ 3' than to δ 4’; b'2 linear; c' absent. Length of middle tarsus 26 (28) µm, length of claw 9 µm, empodium short, 1 µm long; hind tarsus 32 (34) µm, claw 10 µm, empodium long ( Fig. 13H), 8 (7) µm; on hind tarsus ( Fig. 13H) D2 and D4 spine-like, but more slender than D5.

Tracheal camerae contracted distally ( Fig. 13I). Central lobe incised ( Fig. 13J). Laterostigma II–III distinct, without inner structure. On female squama genitalis ( Figs. 13K, L) caput processus of duck’s head-type, median sclerotization developed, proximo-lateral sclerotization present. Male unknown.

Chaetotaxy as in Table 4. On thoracic tergites II–III, P1a and P2a seta-like; P1a posterior to P1–P2; P2a nearer to P2 than to P3. P1a on abdominal tergite I, P1a and P2a on II–VI, and P2a on VII filiform and longer than P1 ( Fig. 13M); P1a on VII sensillum-like and about one-third length of P1, 5 µm long, at hind margin ( Fig. 13N); on tergite VIII P1a' oblong and anterior to P2; P1a' and P2 at almost same level with M4; P2a falcate ( Fig. 13O); 1 and 2 on tergite XI microchaetae. A pair of ventral anterior setae on telson small and sensillum-like.

Diagnosis. This new species is similar to E. novemchaetum Yin and E. dimecempodi Yin from China ( Yin, 1965, 1990, 1999) in possessing two anterior and nine posterior setae on the abdominal sternite VIII, but differs from E. novemchaetum in the shapes of broadened sensilla t3, c and d on foretarsus (linear in E. novemchaetum ), and from E. dimecempodi in having the pseudoculus without inner structure (with three longitudinal lines in E. dimecempodi ), the short empodium on the middle tarsus (long in E. dimecempodi ) and the shapes of broadened sensilla t3 and c on foretarsus (linear in E. dimecempodi ).

Chaetotaxic variation observed consisted of the asymmetric absence of A2 on abdominal tergite IV of one female.

Etymology. The specific name is named after "Aterui", who was a distinguished chieftain of the Hitakami district, as the present Isawa district containing the type locality was called 1200 years ago.

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