Eudigraphis kinutensis (Haga in Takashima and Haga, 1950 ),, 2020

Karasawa, Shigenori, Kawano, Keisuke, Fukaya, Shin-ichi & Tsurusaki, Nobuo, 2020, Upgrading of Three Subspecies of Eudigraphis takakuwai to the Species Rank (Diplopoda: Penicillata: Polyxenida: Polyxenidae), Species Diversity 25, pp. 89-102 : 99-100

Eudigraphis kinutensis (Haga in Takashima and Haga, 1950), stat. rev.

[Japanese name: Haiiro-fusayasude]

( Figs 1 , 4F , 5E, F , 6G, H )

Monographis takakuwai kinutensis Haga in Takashima and Haga, 1950: 24 , fig. 3 [male holotype (NSMT-My 140) from Kinuta (=Okura-cho), Setagaya Ward, Tokyo Prefecture, Japan, 17 October 1949, S. Haga leg.; 6 males and 7 females (MSMT-My 141) from the same locality, 17 October 1949]; Miyosi 1959: 58; Miyosi 1965: 741; Miyosi 1979: 478.

Eudigraphis kinutensis: Haga 1952: 15 ; Ishii and Tamura 1995: 233; Ishii 1999: 212; Ishii 2002: 289.

Eudigraphis takakuwai kinutensis: Ishii 1988: 958 , figs 12, 13; Murakami 1993: 97; Nguyen Duy-Jacquemin and Geoffroy 2003: 99; Ishii 2005: 820, 1 photo; Mimizu Club and Minagoshi 2013: 45, 2 photos; Minagoshi 2017: 50, 2 photos; Ishii 2018: 864, 1 photo.

Diagnosis. Body 2.5–3 mm long excluding caudal bundle with no difference between sexes. Body gray when alive. Mandible with 8 molar processes and 6 molar combs (for the details of diagnosis in mandible structure; see Ishii 1988). This species, when it is alive, can be easily distinguished from E. takakuwai and E. nigricans by its small and gray body ( Figs 4 , 5 ).

Brief description (based on specimens from Tottori University Campus, Tottori City, Tottori Prefecture). Body length (males) 2.6–3.0 mm (n =4, mean 2.7 mm). Caudal bundle 0.48–0.50 (n =2, mean 0.49).

Coloration. Head and tergites grey when photographed in the wild ( Fig. 4F ). Caudal bundle white ( Figs 4F , 5E ).

Head with an anterior row of ca. 20 trichomes per side and a posterior row of ca. 8 trichomes per side.

The antennae with 8 articles and 4 sensitive cones at the tip. Article VI with 3 thick basiconic sensilla (T) of equal length; article VII with 2 thick basiconic sensilla ( Fig. 6H ).

Clypeo-labrum with 7 scattered setae along posterior margin; anterior margin of labrum smooth, concaved at the middle part ( Fig. 6G ). Gnathochilarium with slender lateral palp with 7 cylindrical sensilla.

Specimens examined. TOKYO METROPOLIS. Shibuya Ward, Yoyogi Park (near Yoyogi Park Service Center ), Yoyogi-Jinnan-cho (35.672032, 139.692492), 34 m, under bark of a tree trunk of Zelkova serrata , (1 spm, 99% EtOH, 6 November 2017, SF) . Suginami Ward, Omiya 2 chome, Wadabori Park (south of the First Athletic Field ; 35.683649, 139.641538), 37 m, under bark of trunks of Zelkova serrata , (9 spms., 99% EtOH, 6 November 2017, SF) . Nerima Ward: Hikarigaoka 4 chome, Hikarigaoka Park (west of Konchu Harappa ; 35.763741, 139.62673638), under bark of trunks of Zelkova serrata (3 spms., 99% EtOH, 6 November 2017, SF) ; Shakujii-dai 1–26, Shakujii Park (35.737581, 139.598046), 40 m, under bark of trunks of Zelkova serrata , (8 spms., 99% EtOH, 17 October 2017, SF). —— HYOGO PREFECTURE. Sanda City, Yayoigaoka , Fukada Park (34.88625, 135.1999444), 190 m, on trunks of Zelkova serrata (ca. 30 spms., 25 September 2013, Takeshi Suzuki ; 20 spms., 27 September 2013, Takeshi Suzuki ). —— TOTTORI PREFECTURE. Tottori City: Ochidani Park, Bairi-an (35.499236, 134.243166), 10 m, under bark of trunks of Zelkova serrata , (30 spms., 99% EtOH, 10 November 2017, NT; 10 males, 22 females and 148 juv., 10 November 2017, NT) ; Koyama-cho Minami, Campus of Tottori University (in front of Fac. Engineering ; 35.515699, 134.172517), 16 m, under bark of trunks of Zelkova serrata , (2 males, 4 females and 19 juv., 99% EtOH, 13 November 2017, NT; 8 males, 10 females and 71 juv., 5 January 2019, NT) ; Koyama-cho Minami, Campus of Tottori University (backyard of the University Library ; 35.515328, 134.172726), 16 m, under bark of trunks of Zelkova serrata (8 juv., 99% EtOH, 13 November 2017, NT) ; Koyama-cho-Minami, Tenjinyama Hill (35.509638,134.176514), 20 m, under bark of trunks of Zelkova serrata (20 spms., 7 January 2018, NT). —— EHIME PREFECTURE. Matsuyama City, Ishite-gawa Park, Nagaki-machi (33.835279, 132.775741), 32 m, under bark of a tree trunk of Platanus × acerifolia (25 adults and 15 juv., 99% EtOH, 1 January 2018, NT). —— YAMAGUCHI PREFECTURE. Shimonoseki City, Ozuki Elementary School , Ozuki-cho, (3 adults and 4 juv., 99% EtOH, 7 January 2018, KK) .

Distribution. Honshu (southwestern part, Tochigi Prefecture and southward), and Shikoku ( Fig. 1 ).

Habitat. Under exfoliating bark of the trunks of deciduous broad-leaved trees, such as Zelkova serrata , Ulmus parvifolia (Ulumaceae) , and Platanus spp. ( Platanaceae ).

Ecology. This species is univoltine and overwinters as adults and juveniles of various stages. Egg batches can be seen from June to October according to an observation of a population in Ichihara City, Chiba Prefecture ( Ishii 1997). Number of eggs per egg batch was 31.7 on average ( Ishii 1997). Ishii (1997) reported that this species feeds upon the inner surface of exfoliated barks and lichens from the trunks of trees.

Remarks. Three different names have been used as Japanese name of this species: “Haiiro-chibi-ke-fusayasude”, “Haiiro-chibi-fusayasude”, “Haiiro-fusayasude”. Takashima and Haga (1950) used “Haiiro-chibi-ke-fusayasude” as Japanese name of the species (“subspecies” at that time) in their original description of the form. Miyosi (1959) dropped “ke”, that means “hair” in Japanese, from the name and used “Haiiro-chibi-fusayasude”, without stating any reason for the change (thus it is possible that this was just a typographical error). Murakami (1993) further dropped “chibi” from the name and used “Haiiro-fusayasude”. We suspect that this change was made for his solicitude on the fact that “chibi”, which means “small” or “little” in Japanese, had been often considered a kind of discriminatory word in the Japanese society. We adopt “Haiiro-fusayasude”, which represents “gray” + “tufted millipede” in Japanese, here, because (1) this name represents the diagnostic features of the species sufficiently, and (2) use of “chibi” in the names of animals remains controversial in Japan and we consider that we should avoid use of such words when possible to avoid insult or offense.

This species looks gray when perched on trunks of trees. However, specimens of the species dipped in ethanol do not look gray but have a light yellow-brown body laterally tinted with brown; hence preserved specimens are not easily discernible from E. takakuwai . This species also looks brown in photos when specimens were photographed with a flashlight against white background, or even in the stroboscopically illuminated photos taken in the field (e.g., Minagoshi 2017: 50). Thus, coloration of the body seems to change depending on incidence of lighting.

Figures

Fig. 1. Distribution of three species of Eudigraphis with source of samples used for molecular phylogenetic analysis. Localities of samples are shown in brackets. Sample numbers correspond to those in Table 1 and Figs 2, 3. Literature and new records were also incorporated.

Fig. 4. Typical habitats (A, C, E, arrowed) of Japanese Eudigraphis (B, D, F). A, B: E. takakuwai: A, Toyama Park, Shinjuku Ward, trunk of Zelkova serrata (17 October 2017); B, various stages were found under bark of trunks of Z. serrata at the same site. C, D: E. nigricans; C, Mizushiri Beach, Tottori City (18 October 2017); D, an adult found in the cavity under a rock. E, F: E. kinutensis; E, campus of Tottori University, Tottori City, Z. serrata (13 November 2017); F, E. kinutensis under the bark of trunks of Z. serrata (Ochidani Park, Tottori City, 10 November 2017).

Fig. 5. Dorsal (A, C, E) and ventral (B, D, F) views of Eudigraphis. A, B: E. takakuwai, female (Waita, Toyoura-cho, Shimonoseki City, 31 August 2017). C, D: E. nigricans, male (Uka, Toyoura-cho, Shimonoseki City, 1 September 2017). E, F: E. kinutensis (campus of Tottori University, Tottori City, 5 January 2018). All the scales = 1mm.

Fig. 6. Scanning electron microscope images of Eugdigraphis spp. A–C: E. takakuwai, male (Suzaki, Seiyo City); A, labrum and left antenna; B, ventral view of distal segments of left antenna; C, dorsal view of right part of head with 3 trichobothria a, b, c. D–F: E. nigricans, male (Mizushiri Beach, Tottori City); D, head; E, ventral view of labrum with lateral palps (LP) of gnathochilaria; F, Distal segments of left antenna (ventral view). G, H: E. kinutensis, male (Tottori University Campus); G, labrum; H, dorsal view of right antenna and trichomes on head.