Mecistocephalus rubriceps Wood, 1862

Published, First, 2007, The Mecistocephalidae of the Japanese and Taiwanese islands (Chilopoda: Geophilomorpha), Zootaxa 1396, pp. 1-84 : 35-37

Mecistocephalus rubriceps Wood, 1862

Figs. 46–48

[1] Mecistocephalus rubriceps Wood 1862 — J. Acad. Nat. Sc. Philadelphia (2)5: 42 (original description) Mecistocephalus rubriceps: Haase 1887 — Abh. Ber. zool. anthr. Mus. Dresden 1: 105 Mecistocephalus rubriceps: Pocock 1891 — Ann. Mus. civ. St. Nat. Genova 10: 423 Mecistocephalus rubriceps: Brölemann 1896 — Mém. Soc. Zool. France 8: 528

[2] Lamnonyx rubriceps: Silvestri 1919 — Rec. Ind. Mus. 16: 66 (redescription, key); fig. 12 (also as Lamnonyx rubescens ) Mecistocephalus rubriceps: Chamberlin 1920a — Can. Ent. 52: 186 Mecistocephalus rubriceps: Attems 1928 — Zool. Anz. 75: 119 (key) Mecistocephalus (Mecistocephalus) rubriceps: Attems 1929 — Tierreich 52: 136 (key) Mecistocephalus rubriceps: Attems 1930a — Arch. Hydrobiol. Suppl. 8: 116

[3] Mecistocephalus rubriceps: Attems 1930b — Mitt. Zool. Mus. Berlin 16: 164 (redescription); fig. 75 Mecistocephalus rubriceps: Verhoeff 1934 — Zool. Jahrb. Syst. 66: 38 Mecistocephalus (Mecistocephalus) rubriceps: Takakuwa 1936b — Trans. Nat. Hist. Soc. Formosa 26: 434 (key) Mecistocephalus (Mecistocephalus) rubriceps: Takakuwa 1938a — Annot. Zool. Japon. 17: 354 Mecistocephalus rubriceps: Chamberlin 1939 — Bull. Univ. Utah Biol. Ser. 29 (12) Biol. Ser. 5: 10 Mecistocephalus rubriceps: Verhoeff 1939 — Zool. Jahrb. Syst. 72: 82 (key) Mecistocephalus (Mecistocephalus) rubriceps: Takakuwa 1940 — Fauna Nippon. 9: 67 (key) Mecistocephalus rubriceps: Takakuwa 1943 — Bull. Biogeogr. Soc. Japan 13: 170 Mecistocephalus rubriceps: Attems 1947 — Ann. Naturhistor. Mus. Wien 55: 97 (key) Mecistocephalus (Mecistocephalus) rubriceps: Takashima 1949 — Acta Arachn. 11: 13 Mecistocephalus rubriceps: Wang 1951 — Serica 1: 46 (key)

[4] Mecistocephalus rubriceps: Attems 1953 — Mém. Mus. natn. Hist. Nat. Paris Ser. A Zool. 5: 141

[5] Mecistocephalus rubriceps: Wang 1953 — Ent. News 64: 1

[6] Mecistocephalus rubriceps: Wang 1956 — Quart. J. Taiwan Mus. 9: 158 Mecistocephalus rubriceps: Wang 1958 — Proc. X Intern. Congr. Ent.: 881

[7] Mecistocephalus rubriceps: Wang 1959 — Quart. J. Taiwan Mus. 12: 195 Mecistocephalus rubriceps: Lawrence 1960 — Faune Madagascar 12: 38

[8] Mecistocephalus (Mecistocephalus) rubriceps: Wang 1960 — Proc. XI Int. Congr. Entom.: 290

[9] Mecistocephalus rubriceps: Wang 1962 — Quart. J. Taiwan Mus. 15: 88 (key)

[10] Mecistocephalus rubriceps: Würmli 1972 — Verh. Naturf. Ges. Basel 82: 205 Mecistocephalus rubriceps: Demange 1981 — Rev. Zool. Afr. 95: 638 Mecistocephalus rubriceps: Lewis 1991 — Mem. Mus. Victoria 52: 350 Mecistocephalus rubriceps: Murakami 1993 — List Species Anim. Japan 5: 105 Mecistocephalus rubriceps: Wang & Mauriès 1996 — Mém. Mus. natn. Hist. Nat. Paris 169: 88 Mecistocephalus rubriceps: Shinohara 1999 — Pictorial Keys Soil Anim. Japan: 709 Mecistocephalus rubriceps: Bonato et al. 2001 — Ital. J. Zool. 68: 351

Diagnosis. A Mecistocephalus species with 49 leg­bearing segments. Body length reaching at least 5 cm in adults. Trunk without dark patches. Head 1.8–1.9 times as long as wide. Areolate part of the clypeus with smooth insulae, each side with 3–4 setae; clypeal ratio about 1. Anterior ala of the labrum subtrapezoidal, with the medial margin not reduced to a vertex. Intermediate lamella of the mandible with about 30 teeth; basal tooth large. Buccae with setae in the posterior half only. Forcipular article I with two teeth, one distal to the other, similar in size. Sternal sulcus apparently not furcate. Legs of the last pair with additional short ventral setae.

Type material. Syntypes: 2 specimens; sex, size and age not stated ( Wood, 1862).

Type locality. ‘Bonin Islands’[= Ogasawara Ids] ( Wood, 1862).

Depository of type material. National Museum of Natural History , Washington ( Wood, 1862, as ‘Smithsonian Institution’) .

Material examined. 5 specimens: 2 males, adult and subadult (55 and 41 mm respectively), and 3 females, adult (54, 54 and 55 mm), from Chichijima , Ogasawara Ids, Japan, 18.I.1996, K. Ishii leg., coll. AM .

Description. Body size of adults between about 4.0 and 5.5 cm, at least. Body colour orange, without dark patches; head and forcipular segment darker. Head 1.8–1.9 times as long as wide; frontal line present, rounded. Antennae 4.7–5.6 times as long as the head width. Apical sensilla about 10 µm long. Clypeus: clypeal ratio 1.0–1.2; areolate part with 3–4 smooth insulae (sometimes partially coalescent) on each side, in the medial part; 3–4 setae on each side of the clypeus, one seta inside each insula; plagulae usually bearing 1– 2 spine­like sensilla along the anterior margin. Labrum: anterior ala trapezoidal to subrectangular, medial margin at least one half as long as the medial margin of the posterior ala; internal margins of side­pieces convergent backwards; posterior margin of each side­piece sinuous, slightly convex close to both the internal and external ends. Spiculum present, buccae with some setae in the posterior half only. Mandible: about 8 well developed lamellae; first lamella with about 6 teeth; average intermediate lamella with about 28 teeth; basal tooth large, slightly longer than the teeth of the first lamella, with entire margin. First maxillae: anterior corners of coxosternum evidently projecting; each medial projection about 1.9–2.1 times as long as wide, internal margin with 6–8 long setae, distal lobe 2.2–2.8 times as long as wide, clavate; each telopodite about 3.8–4.0 times as long as wide, with 3–5 basal setae, distal lobe slightly clavate. Second maxillae: article I of telopodite about 3.3–4.0 times as long as wide; article III about 2.5–2.9 times as long as wide, with many setae; apical claw present. Forcipular segment: width to length ratio of exposed part of coxosternum 1.2–1.4; cerrus composed of two convergent rows of setae and a few setae on each side; dorsal ridge of pleura evident. Forcipules: article I about 1.6–2.2 times as long as wide, basal tooth similar to the distal tooth; articles II and III each with a tooth; tarsungulum with two small basal teeth, one dorsal to the other; poison calyx extending backwards to the distal part of the forcipular article I. A total of 49 leg­bearing segments. Sternal sulcus not furcate. Last leg­bearing segment: sternum as long as wide, about 40 pores on each coxopleuron; telopodites with dense short setae on ventral side of both sexes and one short apical spine.

Distribution in the considered area.

Ogasawara Islands : ‘ Bonin Islands’ (type locality) [1] [= Ogasawara Ids]; Chichijima (new) .

To be confirmed:

Taiwan: ‘Kosempo’ [2]; ‘ Shih­Tou Mountain, Hsin­Cho’ [6]; ‘ Taichung, Urai, Taipei, Sun­Moon Lake and KaoYung’ [7]; ‘Yan Ming Mountains’, ‘Kwan­Yin Mountains’ [8] .

General distribution. This species is surely present only in the Ogasawara Islands. Records from Taiwan, Philippines [5, 9], Indochinese Peninsula [4], Malay Archipelago [10] and Lesser Sunda [3] need confirmation (see Remarks).

Remarks. As the original description provided by Wood (1862) is very limited and almost useless, we identified our specimens of M. rubriceps mainly based on their provenance. Wood (1862) described a ‘central dark stripe’ both on the dorsal and on the ventral side of the two syntypes, but such a pattern is unknown in any other mecistocephalid (dark patches, when present, are usually arranged in two stripes separated by a blank central line) and we suspect that Wood described as pigment pattern the midgut full of ingested food. The only other species of Mecistocephalus recorded from Ogasawara Islands is M. ongi , which is clearly different from M. rubriceps in the absence of insulae and the high clypeal ratio.

M. rubriceps was recorded from a wide geographical range, but, as the original description was poor, we suspect that part of the published records are based on misidentifications. In particular, records from the Lesser Sunda by Attems (1930b) are obviously wrong, as they were based on specimens lacking smooth insulae on the clypeus, whereas the topotypic specimens examined by us bear very large smooth insulae. Another record from the Indochinese Peninsula by Attems (1953) is highly dubious. Based on the erroneous account by Attems, Takakuwa (1936b) described M. rubriceps as lacking clypeal smooth insulae, thus probably misleading other subsequent identifications.