Eosentomon simulans Nakamura, 2010

Nakamura, Osami, 2010, Taxonomic revision of the family Eosentomidae (Hexapoda: Protura) from Japan 2701, Zootaxa 2701, pp. 1-109 : 86-90

Eosentomon simulans Nakamura sp. nov.

Fig. 49; Table 20

Type specimens. Holotype female ( NSMT –Ap 518), Horaisan –jinja, Tanuma –machi, Tochigi Prefecture, 36º32'43"N, 139º28'44"E, 350 m elevation, litter of a forest dominated by Acer spp. , 13-VII-1997, K. Furuno et al. leg . Paratypes: 1 female ( NSMT –Ap 519), Mt. Komaga –take, Kanegasaki –machi, Iwate Prefecture, 39º11'21"N, 140º55'41"E, 1020 m elevation, litter of a forest dominated by F. crenata , 18-VIII-2001 , H. Tamura et al. leg.; 1 female ( NSMT –Ap 520), Mt. Tsukuba, Tsukuba –shi, Ibaraki Prefecture, 36º13'35"N, 140º05'54"E, 840 m elevation, litter of a forest dominated by F. crenata , 10-IX-1995, H. Sakayori leg.

TABLE 21. Differential characters of eight related Eosentomon spp. with two anterior and nine posterior setae on sternite VIII.

Shape of foretarsal sensillum b linear linear linear linear spatulate linear linear linear

Shape of foretarsal sensillum c linear linear broadened linear linear linear broadened linear surpassing not reaching surpassing not reaching surpassing not reaching Length of c not reaching Ύ3 surpassing Ύ3

Ύ3 Ύ3 Ύ3 Ύ3 Ύ3 Ύ3

Length of foretarsal sensillum d not reaching α6 reaching α6 reaching z reaching α6 reaching α7 reaching α6 reaching α7 reaching z

Shape of d linear broadened? broadened linear broadened linear broadened broadened thinly thinly thinly thinly

Shape of foretarsal sensillum f1 linear spatulate spatulate spatulate spatulate spatulate spatulate spatulate

Shape of foretarsal sensillum f2 short linear short linear linear thin linear linear linear broadened linear longer longer than longer than longer than longer than longer than Length of foretarsal sensillum b’1 same as b’2 same as b’2

than b’2 b’2 b’2 b’2 b’2 b’2

Shape of foretarsal sensillum b’2 linear spatulate linear linear linear linear spatulate linear

Empodium on middle tarsus short? long short short long short long short

Empodium on hind tarsus long long long short long short long long

Number of setae, sternites IX-X 6 6 6 6 6 4 6 6

Other specimens examined. Two females, Mt. Tsukuba, Tsukuba–shi, Ibaraki Prefecture, 36º13'35"N, 140º05'54"E, 840 m elevation, litter of a forest dominated by F. crenata , 4-XI-1995, H. Sakayori leg.; 1 male, Konsei–toge, Nikko–shi, Tochigi Prefecture, 36º49'07"N, 139º23'45"E, 2000 m elevation, litter of a forest dominated by T. diversifolia and Abies mariesii , 13-IX-1997, K. Furuno et al. leg.; 1 female, Madachi, Nikko–shi, Tochigi Prefecture, 36º47'14"N, 139º31'20"E, 1720 m elevation, litter of a forest dominated by T. diversifolia and B. ermanii , 4-VI-1997, K. Furuno et al. leg.; 1 male, Shizu, Mt. Nanatai–san, Nikko–shi, Tochigi Prefecture, 36º46'29"N, 139º29'32"E, 1720 m elevation, litter of a forest dominated by B. ermanii , Abies veitchii and T. diversifolia , 9-IX-1996, K. Furuno et al. leg.; 1 male, Tochimoto, Otaki, Chichibu–shi, Saitama Prefecture, 35º56'58"N, 138º53'57"E, 900 m elevation, 1-V-1991, Y. Kuwabara leg.

Description. Body length 683 (566–709) µm. Head 86 (87–96) µm long, 68 (62–65) µm wide. Setae aa, pa and m4 present, sensilla as and ps present ( Fig. 49A); seta sp 1.2 (1.2–1.3) times longer than p; sensilla pp rudimentary. Labral setae present ( Fig. 49B). Seta rs inflated, equal to sr in length ( Fig. 49B). On maxillary palpus ( Fig. 49C) sensilla md and ml similar to each other in shape and length. On galea ( Fig. 49D) digit O longer than M and I. Mandible with two teeth ( Fig. 49E). Clypeal apodemes weakly visible ( Figs. 49A, B). Pseudoculus almost circular, 10 µm long, with one central spot ( Fig. 49A), PR = 8.7.

Foretarsus length ( Figs. 49F, G) 61 (60) µm; claw 13 µm, TR = 4.8 (4.8); empodium 13 (13) µm, EU = 1.0 (1.0); sensillum s slightly longer than claw, 14 (14) µm long. Sensillum t1 close to α 3, BS = 0.8 (0.9); t2 thinly spatulate; t3 thin; a nearer to γ 1 than to γ 2; b and c thin; d broadened, reaching base of z; e and g roundedly spatulate and long; f1 small and spatulate; f2 thin; a' slightly broadened; b'1 closer to δ 3' than to δ 4’; b'2 thin; c' absent. Length of middle tarsus 28 (27–28) µm, length of claw 10 (10) µm, empodium short ( Fig. 49H), 1 (1–2) µm long; hind tarsus 33 (34) µm, claw 11 (11) µm, empodium long ( Fig. 49I), 8 (7) µm; on hind tarsus ( Fig. 49I) D2 and D4 thinly spine-like, D4 more slender than D2.

Tracheal camerae short and contracted distally. Central lobe sinuate. Laterostigmata II–IV distinct, without inner structure. On female squama genitalis ( Fig. 49J) S-shaped sclerotization on processus sternalis, caput processus duck’s head-like, filum processus long. Male with short basiperiphallar setae.

Chaetotaxy as in Table 20. Thoracic and abdominal chaetotaxy nearly identical to that of E. imperiale .

Diagnosis. Among the species possessing two anterior and nine posterior setae on the abdominal sternite VIII, this new species is similar to E. novemchaetum and E. ateruii in possessing a short empodium on the middle tarsus and a long empodium on the hind tarsus. This species differs from the latter two in the pseudoculus having one central spot (without inner structure in the latter two). The present new species is different from E. novemchaetum in having broadened d and spatulate f1 foretarsal sensilla (linear d and f in E. novemchaetum ), and from E. ateruii in the presence of labral setae (absent in E. ateruii ) and possession of linear sensilla t3 and c on the foretarsus (broadened in E. ateruii ). Differential characters of eight related species possessing two anterior and nine posterior setae on sternite VIII are summarized in Table 21.

Etymology. The specific name is derived from the similarity of this species to those with nine posterior setae on abdominal sternite VIII.

Distribution. Japan (Honshu).