Eosentomon imperiale Nakamura, 2010

Nakamura, Osami, 2010, Taxonomic revision of the family Eosentomidae (Hexapoda: Protura) from Japan 2701, Zootaxa 2701, pp. 1-109 : 52-55

Eosentomon imperiale Nakamura sp. nov.

Figs. 28–29; Table 12

Type specimens. Holotype female ( NSMT –Ap 491), Imperial Palace, Chiyoda –ku, Tokyo, 35º41'05"N, 139º45'05"E, 20 m elevation, litter of a plantation of Prunus spp. , 2-III-2000, O. Nakamura et al. leg . Paratype: 1 female ( NSMT –Ap 492), same data as for the holotype .

Other specimens examined. One female, Takado, Takahagi–shi, Ibaraki Prefecture, 36º43'05"N, 140º43'29"E, 30 m elevation, 2-XII-1988, litter of a forest dominated by Castanopsis cuspidata subsp. cuspidata, H. Tamura et al. leg.; 1 female, Akanagi –san, Tokorono, Nikko –shi, Tochigi Prefecture, 36º48'33"N, 139º34'07"E, 1760 m elevation, Sasa field, 21-IX-1996, K. Furuno et al. leg .

Description. Body length 800 (630–852) µm. Head 95 (91–94) µm long, 61 (64–66) µm wide. Setae aa, pa and m4 present, sensilla as and ps present ( Fig. 28A); seta sp 1.3 (1.2) times longer than p; sensilla pp rudimentary. Labral setae present ( Fig. 28B). Seta rs simple, longer than sr ( Fig. 28B). On maxillary palpus ( Fig. 28C) sensilla md and ml similar to each other in shape and length. On galea ( Fig. 28D) digits small and similar to each other. Mandible with 2 teeth ( Fig. 28E). Clypeal apodemes distinct ( Fig. 28B). Pseudoculus 14 µm long, PR = 6.

Foretarsus length ( Figs. 28F, G) 63 (61–67) µm; claw 13 (12–13) µm, TR = 5.2 (5.2–5.5); empodium13 (11– 13) µm, EU = 1.1 (0.9–1.0); sensillum s longer than claw, 16 (16–18) µm. Sensillum t1 closer to α 3 than to α 3’, BS = 0.8; t2 thinly spatulate; t3 surpassing tarsus; a nearer to γ 1 than to γ 2, not reaching base of γ 2; b large and clubshaped; c linear, reaching base of γ 3; d broadened and long, reaching nearly to base of α 7; e and g roundedly spatulate and long; f1 thinly spatulate; f2 reaching base of γ 5; a' thin; b'1 broadened, nearer to δ 3’ than to δ 4 '; b'2 thin; c' absent. Length of middle tarsus 32 (30–33) µm, length of claw 9 (8–10) µm, empodium 6 (5–7) µm long; hind tarsus 39 (38–41) µm, claw 10 (9–11) µm, empodium 7 (6–7) µm; empodia of both tarsi longer than 1/2 of claw length ( Figs. 28H, I); on hind tarsus ( Fig. 28I) D2 and D4 spine-like; D4 slightly thicker than D2, but more slender than D5.

Tracheal camerae thick and short ( Fig. 28J). Central lobe invisible. Laterostigmata II–IV large, with no structure ( Fig. 28K). On female squama genitalis ( Fig. 29A) S-shaped sclerotization on processus sternalis, caput processus of duck’s head type, alae processus rod-like, filum processus short. Male unknown.

Chaetotaxy as in Table 12. 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. 29B); P1a on VII sensillum-like and about one-third length of P1, 5 µm long, at hind margin ( Fig. 29C); on tergite VIII P1a' oblong and anterior to P2; P1a' and P2 at almost same level with M4; P2a falcate; 1 and 2 on tergite XI microchaetae ( Fig. 29F). A pair of ventral anterior setae on telson small and sensillum-like ( Fig. 29G).

Diagnosis. Among the species possessing two anterior and nine posterior setae on the abdominal sternite VIII, this new species is similar to E. dimecempodi in possessing long empodia on the middle and hind tarsi. However, it differs from E. dimecempodi in having the pseudoculus without inner structure (three longitudinal lines in E. dimecempodi ) and the shapes of several foretarsal sensilla: broadened t3 and linear b’ 2 in the new species, linear t3 and spatulate b’ 2 in E. dimecempodi .

Etymology. The specific name is derived from the type locality, the "imperial" palace.

Distribution. Japan (Honshu).