Arrup holstii ( Pocock, 1895 )

Published, First, 2007, The Mecistocephalidae of the Japanese and Taiwanese islands (Chilopoda: Geophilomorpha), Zootaxa 1396, pp. 1-84 : 8-11

Arrup holstii ( Pocock, 1895)

Figs. 2–5

[1] Geophilus (?) Holstii Pocock 1895 — Ann. Mag. nat. Hist. (6) 15: 352 (original description); pl. XI: fig. 1, 1a

? ‘ Geophilus ’? Holstii: Attems 1914 — Arch. Naturgesch. 80 A: 132

[2] Prolamnonyx holstii: Silvestri 1919 — Rec. Ind. Mus. 16: 85 (redescription, key); fig. 25

Prolamnonyx holstii: Chamberlin 1920a — Can. Ent. 52: 187

Prolamnonyx holstii: Attems 1929 — Tierreich 52: 155 (key); fig. 165

Prolamnonyx holstii: Takakuwa 1934a — Annot. Zool. Japon. 14: 363

Prolamnonyx holstii: Takakuwa 1934b — Bot. & Zool. Tokyo 2: 707 (key)

[3] Prolamnonyx holstii: Takakuwa 1934c — Bot. & Zool. Tokyo 2: 881 (redescription); fig. 20–22

Prolamnonyx holstii: Takakuwa 1936a — Trans. Nat. Hist. Soc. Formosa 26: 162

[4] Prolamnonyx holstii: Takakuwa 1938a — Annot. Zool. Japon. 17: 355

Prolamnonyx holstii: Takakuwa 1938b — Bot. & Zool. Tokyo 6: 2030 (key)

[5] Prolamnonyx holstii: Takakuwa 1940 — Fauna Nippon. 9: 92 (key); fig. 95–96

[6] Prolamnonyx holstii: Takakuwa 1941 — Acta Arachn. 6: 13

[7] Prolamnonyx holstii: Takakuwa 1942a — Acta Arachn. 7: 39, 42

Prolamnonyx holstii: Takakuwa 1943 — Bull. Biogeogr. Soc. Japan 13: 165

Prolamnonyx holstii: Attems 1947 — Ann. Naturhistor. Mus. Wien 55: 105 (key)

[8] Prolamnonyx holstii: Takakuwa & Takashima 1949 — Acta Arachn. 11: 57

Prolamnonyx holstii: Takashima 1949 — Acta Arachn. 11: 13

Prolamnonyx holstii: Chamberlin & Wang 1952 — Proc. Biol. Soc. Washington 65: 178

[9] Prolamnonyx holstii: Takashima & Shinohara 1952 — Acta Arachn. 13: 9 (key); fig. 1: D

[10] Prolamnonyx holstii: Miyosi 1955a — Misc. Rep. Res. Inst. Nat. Resources Tokyo 38: 151, 152

[11] Prolamnonyx holstii: Paik 1958 — Kyungpook Univ. Theses Coll. 2: 356

[12] Prolamnonyx holstii: Paik 1961 — Kyungpook Univ. Theses Coll. 5: 76

[13] Prolamnonyx holstii: Shinohara 1961a — Sc. Rep. Yokosuka City Mus. 6: 76

Arrup holstii: Crabill 1964 — Proc. Biol. Soc. Washington 77: 165

[14] Prolamnonyx holstii: Shinohara 1964a — Sci. Invest. Tanzawa Mts: 380

[15] Prolamnonyx holsti [sic]: Shinohara 1964b — Fukushima Seibutsu 7: 6

[16] Prolamnonyx holstii: Shinohara 1966 — Ecol. St. Biotic Comm. Nat. Park Nat. St. Tokyo 1: 124

[17] Prolamnonyx holstii: Shinohara 1971 — Fuji­san Tokyo: 1011

[18] Prolamnonyx holstii: Murakami 1975a — Bull. natn. Sci. Mus. Tokyo, ser. A Zool. 1: 89

[19] Prolamnonyx holstii: Murakami 1975b — Bull. natn. Sci. Mus. Tokyo, ser. A Zool. 1: 157

Prolamnonyx holstii: Titova 1975 — Zool. Zh. 54: 44

[20] Prolamnonyx holstii: Shinohara 1979 — Edaphologia 19: 32

[21] Prolamnonyx holstii: Shinohara 1981a — Edaphologia 24: 52

[22] Prolamnonyx holstii: Shinohara 1981b — Misc. Rep. Nat. Park Nat. St. Tokyo 12: 89

Prolamnonyx holstii: Murakami 1993 — List Species Anim. Japan 5: 105

Prolamnonyx holstii: Wang & Mauriès 1996 — Mém. Mus. natn. Hist. Nat. Paris 169: 89

Prolamnonyx holstii: Shinohara 1999 — Pictorial Keys Soil Anim. Japan: 709; fig. 4 (703)

[23] Prolamnonyx holstii: Ishii 2000 — Mem. natn. Sci. Mus. Tokyo 35: 106

Arrup holstii: Bonato et al. 2003 — Syst. Entom. 28: 550, 551

Arrup holstii: Foddai et al. 2003 — J. Nat. Hist. 37: 1261

Diagnosis. An Arrup species with body length reaching at least 2 cm. Frontal line curved. Distal article of the telopodite of the second maxillae without claw. Poison calyx of males almost reaching the posterior end of the forcipular coxosternum. Tooth of the forcipular article I sharp but quite small and projecting forward; tooth of the tarsungulum sharp. Sternum of the last leg­bearing segment as long as wide.

Type material. Holotype: male, about 20 mm long, adult ( Pocock, 1895).

Type locality. ‘Ashinoju’, Honshu ( Pocock, 1895).

Depository of type material. The Natural History Museum, London (holotype); National Science Museum, Tokyo, Japan (proposed neotype) .

Material examined. 3 specimens: 1 male, adult (about 20 mm), from Ashinoju, Honshu (date and collector not stated) (holotype, preserved in alcohol 70%), coll. NHML ; 2 males, subadult (20 and 21 mm), from Hon­ noo, Mobara City, Chiba Pref., Honshu , 3.XII.1997, K. Ishii leg., coll. NSMT and AM (the 20 mm specimen in coll. NSMT is proposed as neotype) .

Description. Body length of adults reaching at least about 2 cm. Body colour yellow, without dark patches. Head 1.5 times as long as wide; frontal line curved. Antennae about 3.5 times as long as the head width. Apical sensilla about 8 µm long. Clypeal setae: a median pair anterior to the plagulae and a group on each side of the clypeus, reaching the antero­lateral corners. Clypeal ratio about 4–5. Labrum: anterior ala triangular, medial margin reduced to a vertex; internal margins of side­pieces quite parallel, not touching each other; posterior margin of each side­piece sinuous, slightly convex close to the internal and external ends. Mandible: about 5–7 lamellae; first lamella with 5–6 teeth; average intermediate lamella with about 10–14 teeth, the teeth similar to each other. First maxillae: anterior corners of coxosternum not projecting; each medial projection about 1.8 times as long as wide, the internal margin with few spines, the distal lobe 1.6 times as long as wide, aligned to the external margin of the projection, clavate at the tip; each telopodite 2.6– 2.8 times as long as wide, distal lobe attenuated and curved; hyaline scales present on the dorsal side of medial projections. Second maxillae: article I of telopodite about 2.4–3.0 times as long as wide; article III about 2.2– 3.0 times as long as wide, with few setae; apical claw absent, replaced by 3–4 small tubercles. Forcipular segment: width to length ratio of exposed part of coxosternum 1.1; cerrus absent; each pleuron without a distinct dorsal ridge, scapular points not reaching the anterior margin of coxosternum. Forcipules: article I about 1.9–2.5 times as long as wide, distal tooth sharp and short, with subparallel margins, not projecting evidently but quite close to the forcipular article; article II without a distinct tooth; article III with a small tubercle; tarsungulum with a sharp basal tooth; poison calyx of male elongate, extending backwards to the posterior end of the forcipular coxosternum. Last leg­bearing segment: sternum sub­triangular, as long as wide; about 12 coxal pores on each coxopleuron; telopodites usually with dense short setae on the ventral side, with one short apical spine.

Distribution in the considered area.

Honshu: ‘Ashinoju’ [1] (type locality); ‘Kamatura’ [2]; ‘Hakone­machi’ [3]; ‘Tokyo’ [3, 9, 16, 22]; ‘Ito’, Yatsu’, Zushi’ [5]; ‘Manazuru’ [13]; Mt. Tanzawa (Dodaira, Hinokiboramaru, Hiruga­take) [14] (transcribed from Japanese); ‘M. Fuji’ [17]; ‘Imperial Palace (Fukiage­garden)’ [20, 23]; Hon­noo, Mobara City (new).

To be confirmed:

Hokkaido: Sapporo [3] (transcribed from Japanese); Teshikaga­cho [5] (transcribed from Japanese).

Honshu: Akita, Asamushi, Nagoya, Osaka, Suwa, Yamashina­ku [3] (transcribed from Japanese); Kanazawa, Kouzo, Odawara, O­shima, Tsuruga [5] (transcribed from Japanese); Mt. Daimanji, Okinoshimacho [6] (transcribed from Japanese); Hachijo­jima and Aoga­shima Ids [10] (transcribed from Japanese); Fukushima pref., Iwaki [15] (transcribed from Japanese); ‘Nasu Imperial Villa’ [21].

Shikoku: ‘Sikoku’ [4].

Kyushu: Kokura, Mt. Hiko , Oita [3] (transcribed from Japanese); Fukuoka [5] (transcribed from Japanese) .

Ryukyu Islands: ‘Mayaa­abu cave, Mashiki, Ginowan­shi’, ‘Uganju­gama cave, Toobaru, Chatan­son, Nakagami­gun’, ‘Tarumai­abu cave, Kubara, Yonaguni­chô’ [18]; ‘Nishibûmabaru­dô Cave’ [19].

Taiwan: ‘Formosa’ [4]; Tainan [5] (transcribed from Japanese); Taira [15] (transcribed from Japanese);

General distribution. Based on the observed specimens, this species occurs surely only from the surroundings of Tokyo, Honshu. All other records from Hokkaido to Taiwan, as well as from Eastern China [5, 8], the Korean Peninsula [4, 5, 11], Cheju Id. [7], and Quelpart Id. [7, 12], need confirmation, due to possible misidentification (see also Remaks).

Remarks. As the original description of A. holstii is inadequate to fix the true identity of this species in respect to other species in the genus, we examined the holotype of A. holstii , of which however only the posterior part of the trunk survives, whereas the anterior part, including the head and the forcipular segment, is most probably lost (J. Beccaloni, pers. comm.); a handwritten label associated with the holotype documented that the specimen was already incomplete in 1962. Crabill, after examining the holotype when still complete, described ( Crabill, 1964) the poison calyx as ‘extremely long, extending to the base of trochanteropraefemur, and doubling back on itself’, most probably meaning that the calyx extended to the posterior part of the forcipular coxosternum. Therefore we confidently identified specimens of A. holstii mainly on the basis of the combination of the estimated body length, the extension of the calyx (at least in males, Fig. 5), the shape of the forcipular teeth and the number of coxal pores in respect to the body size. Worth notice is that some of these specimens were collected quite close to the type locality of A. holstii . The only species of Arrup found close to this locality are Arrup ishiianus n. sp., and A. obtusus Takakuwa, 1934 . The first differs from A. holstii in the larger body size, the different shape of the tarsungular tooth and the elongation of the calyx in males; the latter in the much higher number of coxal pores.

As the holotype of A. holstii is in bad condition and lacks anatomical parts bearing fundamental diagnostic characters, and as the taxonomy of the whole genus Arrup is still in flux, we regard it necessary to designate a neotype for A. holstii , according to Art. 75 of the International Code of Zoological Nomenclature (ICZN, 1999), in order to fix the identity of this species unambiguously. An application to this end will be submitted to the International Commission on Zoological Nomenclature. We propose to designate as neotype a male specimen, 20 mm long, from Hon­noo, Mobara city, as described under Material examined ( Figs. 2–5), which agrees with the available description for A. holstii in all the main diagnostic traits (size, number of coxal pores, elongation of calyx, forcipular and maxillar structure).

Mecistocephalus indecorus Attems, 1901 was described on a single male from Peking ( China) and was later considered a synonym of A. holstii by Silvestri (1919). Following the improved knowledge of the genus Arrup and the great number of species described since 1919, we consider this synonymy unwarranted. No other specimens have been referred to as M. indecorus and Attems himself completely ignored this nominal species in his monograph of world Geophilomorpha ( Attems, 1929) .

Arrup holstii was the earliest species of Arrup to be described and it remained the only known Japanese species for about four decades, until the description of other closely related species by Y. Takakuwa in the Thirties. As a consequence, most of the Arrup specimens collected to date have been identified as belonging to A. holstii , often without adequate examination. Therefore, putative records of this species have been published from a very large geographic range, encompassing the entire area considered here. Our examination of new material, however, suggests that the actual distribution of A. holstii is probably more restricted than previously thought and that many of the published records are probably based on misidentified specimens. In the distribution given above we considered reliable the localities from Honshu placed very close to the type locality, while listing others among doubtful records.

Specimens from Tottori prefecture, western Honshu (1 male, adult, 21 mm, and 1 female, subadult, 16 mm, both from Mt. Kenashi , Kofu­cho , Hino­gun , 810–860 m, 23.IX.1999, N. Tsurusaki leg., coll. AM; 1 female, adult, 18 mm, from Tenjin­san, Koyama, Tottori city, 21.IV.1993, N. Tsurusaki leg., coll. AM) and from Shikoku (1 male, adult, 18 mm, from Ochiai­toge Pass, 1320 m, western slope, Higashiiyaya­son, Miyoshi­gun, Tokushima Pref., 13.X.1985, T. Tanabe leg., coll. TT) possibly refer to A. holstii , but a better knowledge of the intraspecific variation of this species is needed to confirm this identification. These specimens differ from the typical A. holstii for the longer tooth of the forcipular tarsungulum and the shorter clypeal setae (these traits are particularly conspicuous in the male from Mt. Kenashi ; figs. 6–7) .