Eosentomon yambaru Nakamura, 2010

Nakamura, Osami, 2010, Taxonomic revision of the family Eosentomidae (Hexapoda: Protura) from Japan 2701, Zootaxa 2701, pp. 1-109 : 99

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Eosentomon yambaru Nakamura

sp. nov.

Eosentomon yambaru Nakamura   sp. nov.

Figs. 55–56; Table 23

Type specimens. Holotype female ( NSMT –Ap 526), Mt. Nishime –dake, Kunigami –son, Okinawa Island , Okinawa Prefecture, 26°47'48''N, 128°16'29''E, 327 m elevation, 6-VII-2001, S. Karasawa et al. leg GoogleMaps   . Paratypes: 2 males ( NSMT –Ap 527–528), same data as for the holotype GoogleMaps   .

Other specimens examined. One male, one maturus junior, same locality as for the holotype, 27-II-2003, S. Karasawa et al. leg GoogleMaps   .

Description. Body length 741 (748–830) µm. Head 128 (122–128) µm long, 97 (96) µm wide. Setae aa, pa and m4 present, sensilla as and ps present ( Fig. 55A); seta sp 1.7 times longer than p; sensilla pp rudimentary. Labral setae present ( Fig. 55B). Seta rs inflated, shorter than sr ( Fig. 55B). On maxillary palpus ( Fig. 55C) sensillum md distinctly longer than ml. On galea ( Fig. 55D) digit O slightly longer than M and I. Mandible with two or three teeth ( Fig. 55E). Clypeal apodemes distinct ( Figs. 55A, B). Pseudoculus without inner structure ( Figs. 55A, F), 10 (10–11) µm long, PR = 13 (11–12).

Foretarsus length ( Figs. 55G, H) 107 (108–109) µm; claw 22 (22) µm, TR = 5.1 (5.0–5.1); empodium 22 (22) µm, EU = 1.0; sensillum s as long as claw. Sensillum t1 slightly nearer to α 3' than α 3, BS = 1.2 (1.0–1.2); t2 thin; t3 thin, surpassing tarsus; a broadened; b surpassing base of β 6; c linear; d reaching base of f2; e and g roundedspatulate and long; f1 thin, reaching base of γ 5; f2 shorter than f1; a' slightly broadened, reaching base of b’1; b'1 between bases of δ 3' and δ 4', reaching base of b’2; b'2 reaching base of α 6; c' anterior to α 6, reaching base of δ 6. Length of middle tarsus 53 (47–52) µm, length of claw 16 (15–16) µm; hind tarsus 67 (63–66) µm, claw 18 (16– 17) µm; both empodia short and less than 1/7 of claw length ( Fig. 55I), 2 µm long; on hind tarsus ( Fig. 55I) D2 and D4 spine-like, D4 more slender than D2.

Tracheal camerae short and distally contracted. Central lobe trapezoidal and inner line incised ( Fig. 56A). Laterostigmata II –IV large, with no inner structure; those of V and VI small. On female squama genitalis ( Fig. 56B) caput processus of duck’s head type, filum processus short, small accessory sclerotization present, proximo-lateral sclerotization present. Male squama genitalis with short basiperiphallar setae   .

Chaetotaxy as in Table 23. On thoracic tergites II–III, P1a and P2a seta-like; P1a posterior to P1–P2; P2a slightly nearer to P2 than to P3. P1a on abdominal tergite I, P1a and P2a on II–VI and P2a on VII filiform, but shorter than P1; P1a on VII short, slightly capitulate ( Fig. 56E), 4 µm long, at hind margin; on tergite VIII ( Fig. 56F) P1a' with basal dilatation and slightly anterior to P2; P2a' short linear.

Diagnosis. The present species is similar to E. riyuetanense Nakamura   from Taiwan ( Nakamura, 1997) and E. daii Yin   from China (Yin, 1982, 1999). These three species have in common a pseudoculus without inner structure, the position of P1a at the hind margin of abdominal tergite VII, foretarsal sensillum t1 near α 3', and the presence of b'1. However, this new species is different from E. riyuetanense   in having two pairs of anterior setae on abdominal tergite VI (three pairs in E. riyuetanense   ), seta rs shorter than sr (same length as sr in E. riyuetanense   ), capitulate P1a on abdominal tergite VII (linear in E. riyuetanense   ) and basal dilatation of P1a' on abdominal tergite VIII (not dilated in E. riyuetanense   ); and from E. daii   in having three, two and one pairs of anterior setae on abdominal tergites V–VII, respectively, (four pairs on V–VI and two pairs on VII in E. daii   ), and the presence of median sclerotization on the female squama genitalis (absent in E. daii   ).

Etymology. The specific name, a noun in apposition, is derived from the name of the northern part of Okinawa Island, Yambaru, where the type locality is involved.

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


National Science Museum (Natural History)


Royal British Columbia Museum - Herbarium


Mykotektet, National Veterinary Institute