Otostigmus astenus Kohlrausch 1878

Otostigmus astenus (Kohlrausch, 1878)

(Figs 14–19)

Branchiotrema astenon Kohlrausch, 1878: 22, Taf. 6 fig.6, 1879: 70, Taf. 6 fig.6, 1881: 72, Taf 4 fig 13. Tonga.

Branchiotrema Luzonicum Kohlrausch, 1878: 23, 1879: 71, 1881: 73. Philippines.

? Branchiotrema calcitrans Kohlrausch, 1878: 23, 1879: 71, 1881: 73. Australia.

? Otostigma luzonicum: Meinert, 1886:184. East India, Kooloo Valley, [Kullu, Himanchal Pradesh, India].

Otostigma orientale: Haase, 1887: 73. Taf. 4, fig. 72. nec O. orientalis Porat, 1876. SW Borneo [Kalimantan]; Jaluit, Marshall Islands; Yap, Caroline Islands [Federated States of Micronesia] (in part).

Otostigma orientale var acutidens Haase, 1887: 74. Hermit Island, Bismarck Archipelago [Papua New Guinea].

? Otostigma discretum Silvestri, 1894: 628. New Guinea, Moroka [Papua New Guinea].

? Otostigmus orientalis: Pocock, 1894: 312. Indonesia, Flores

? Otostigmus orientalis: Pocock, 1895: 350. Philippines.

Otostigmus punctiventer: Pocock 1898a: 61. nec Tömösváry 1885. New Britain.

Otostigmus astenon: Pocock, 1898b: 327. Funafuti, Tuvalu, Ellice Islands [Tuvalu].

Otostigmus astenus: Kraepelin, 1903: 114, fig. 51. Solomon Islands; Samoa; Mariana Islands; Seychelles (This last locality probably refers to Brölemann’s (1895) record of O. orientalis which clearly is not O. astenus).

Otostigmus astenus: Kraepelin, 1904: 246. Matupi [Irian Jaya, Indonesia]; Philippines; Marianas; New Caledonia.

Otostigmus barbouri Chamberlin, 1914: 386 figs 1–3. New Guinea [Indonesia, Irian Jaya].

Otostigmus glaber Chamberlin, 1920: 12. Fiji.

Otostigmus astenus: Kraepelin, 1916: 4. Australia.

Otostigmus astenus: Chamberlin, 1920: 13. Fulaga, Solomon Islands.

Otostigmus (O.) astenus: Attems, 1930a: 143, fig. 174. Amongst the localities listed are Ambon, Maluku Islands, Indonesia; Teoeen, and Banda Sea. I am unable to find the original references to these.

Otostigmus astenus: Attems, 1934: 49 (in key) & 50 (fig. 7).

Otostigmus astenus: Attems, 1938a: 337. Cambodia.

Otostigmus (O.) astenus: Takakuwa, 1938: 357. Yap, Caroline Islands [Federated States of Micronesia].

Otostigmus (O.) glaber: Takakuwa, 1938: 357. Yap.

Otostigmus astenus: Chamberlin, 1944: 2. North Dutch New Guinea [Irian Jaya].

Otostigmus astenus: Wang, 1951: 53. Philippines.

Otostigmus glaber: Wang, 1951: 53. Philippines.

Otostigmus astenus: Wang, 1955: Lan Yu Islet, China [Taiwan].

? Otostigmus. glaber: Lawrence, 1960: 72. Madagascar (introduced). The record should be checked.

Otostigmus glaber: Würmli, 1972: 95, Abb 11, 12. Sumba Is, Indonesia.

nec Otostigmus (O.) glaber: Lewis, 1992: 441.

Otostigmus (O.) astenus: Lewis, 2000: 438, figs. 20–30. Rennell Island, Somolons; New Britain, Papua New Guinea.

Otostigmus (O.) astenus: Lewis, 2001:21. West Timor, Indonesia.

Otostigmus astenus: Chao, 2002: 21. Lan Yu, Taiwan.

Otostigmus. astenus: Chao & Chang, 2003: 4 (in key), fig.15.

Otostigmus (O.) astenus: Song, Gai, Song, & Zhu, 2005: 296.

Otostigmus`astenus: Chao, 2008: 46, figs 48–51 & map 6.

NB Most records of O. punctiventer probably refer to O. astenus.

Diagnosis (based on the material described here and descriptions of O. astenus from Rennell Island and New Britain (Lewis 2000), O. glaber Chamberlin, 1920 from Fiji and O. barbouri Chamberlin, 1914, from Kalimantan (Lewis, 2002b)). Antennomeres (18), 19, 20 or 21, the basal 2.2 to 2.33 (atypically 2.66) glabrous. Forcipular coxosternum with three main teeth (rarely four) the inner two partially fused, the outer separated. Commonly with additional small outer tooth, less often an additional inner one giving five in all. Tergites without lateral keels, spines sometimes present on posterior tergites. Sternites with incomplete paramedian sutures occupying anterior 25 to 50% in mid and hind body (66% in juvenile specimens) often ending in a weak depression and sometimes with weak posterior median depression as well. NB Lewis (2000) stated incorrectly that they were complete. Sternite 21 with sides diverging, parallel or converging posteriorly. Coxopleuron with two or three apical spines, or two apical and one subapical spine, one or two lateral and one or two dorsal. Ultimate leg prefemora with four rows of small spines. First four to first 12 (17) pairs of legs with two tarsal spines, the subsequent to 20 with one tarsal spine. Ultimate leg with or without a tarsal spine.

Type material examined. ZMUH. Holotype with three labels: Branchiotrema astenon (n.sp.) (Kohlr.) Mus. Godeffroy 1009, Eua, Tonga. Otostigmus orientalis Por. Orig. zu O. asthenon (Kohlr.) MG 15305. Eua and Branchiotrema astenon Kohlrausch, 1 Ex Holotype.

Description. NB Kohlrausch’s (1878) original description was based on four specimens and is very brief. There now appears to be only one specimen of the original four. Kohlrausch’s 1881 description gave more data and details of this are here given in parentheses where appropriate. Length 40 mm. Antennomeres 19 and 20[r], (18/18, 19/19, 19/? and 19/20) the basal 2.2 glabrous (2½).Forcipular coxosternal tooth plates with three main teeth which are worn (fig. 14), (mostly three, one has four). Process of trochanteroprefemur with indication of one inner tooth.

Tergites with paramedian sutures complete from 5, marginate from 7 with very weak lateral corrugations and a weak low median keel from 8 to 20. Tergite 21 with shallow depression occupying posterior 48%.

Sternites with indistinct paramedian sutures, absent or very short on anterior segments, occupying anterior 25 to 33% on 14 to 17 without clear depressions. Sternite 21 with sides diverging posteriorly, the posterior border incurved and with a weak median longitudinal depression (fig.15).

Coxopleural process long with three apical spines on right, two and one subapical on left and with two lateral and one dorsal spine on each near the apex (fig. 15). Ultimate legs regenerated, with very small prefemoral spines. The right with VL 1, DM 1, CS1, the left with VL 4, VM 3, DL 5 in two irregular rows but no corner spine (fig. 16). (VL 3–4, VM 1–2, DM 4–5).

Tarsal spurs of leg 1 not seen. Two tibial spurs on legs 2, 3 and 4 on left, on leg 2 on right. Two tarsal spurs on legs 2 to 9 and on 12 and 17 on the left, on 2 to 9 and 13 and 14 on right. The remaining legs to 19 on left and 20 on right with one tarsal spur. Ultimate legs without tarsal spurs.

Other material. BMNH. Cormocephalus calcitrans L Koch Upolu, Australasia. (Samoa) Reg no. BMNH 13.6. 18.7.27. NB Kohlrausch (1881) gives this as a synonym (in litt.) of Brachiotrema calcitrans it is not clear whether his holotype and Koch’s specimen are the same. Weidner (1960) gives Cormocephalus calcitrans in Museum Godeffroy, Catalog IV, 53, Hamburg 1869 as a nomen nudum.

Description. Length 42 mm. Antennomeres 17 [r] + 17[r], the basal 2½ glabrous dorsally (fig. 17). Forcipular coxosternal tooth plate with three main teeth on right this arrangement apparent on left but there are three additional smaller teeth (fig. 18). Forcipular trochanteroprefemoral process with two low inner teeth. Tergite paramedian sutures complete 8, marginate from 8, median keel from 15 to 18, without lateral corrugations or spines. Tergite 21 with slight posterior depression. Sternite paramedian sutures occupying anterior 26% of sternite 6, 50% on sternite 13. Sternite 21 with sides converging posteriorly and posterior margin concave (fig. 19). Coxopleuron with two apical spines, one or two lateral and one or two dorsal spines. Left ultimate leg prefemoral spines VL 3, VM 2, M 2, DM 2 and CS 1. Right with VL 4, VM 0, M 2, DM 2 and CS 1. Legs 1 to 7 with two tarsal spurs, 8 to 20 or 21 with one.

BMNH. Otostigmus astenon Kohl. New Georgia (Solomon Islands). HMS Penguin 94.10. 26 1–5, 95.10. 10 17–18. Four specimens 69, 64, 62 and 56 mm.

Description. Antennomeres 16[d] 20[1] 21[3], the basal 2.25 to 2.33 glabrous. Forcipular coxosternum with 3+3 main teeth (6+6 teeth in spm 1). Tergite paramedian sutures complete 6, marginate from 8 or 9. Without keels but with fine tubercles on 18 to 20 in spm 2, otherwise without spines. Tergite 21 with weak posterior depression. Sternite with short anterior paramedian sutures occupying 25–33% of posterior sternites. Sternite 21 parallel sided or with sides slightly converging posteriorly. Coxopleura with three or (specimen 1) four apical spines, each with one or two lateral and dorsal spines. Ultimate leg prefemora: Specimens 1 and 3 with VL 5, VM 2,1 or 2, M 4 or 3, DM 2 or 3 and CS1, Specimen 2 with VL 2, VM 1, M 2 and DM 1, 2, CS 1. Specimen 4 lacks ultimate legs. Legs 1 to 5 with two tarsal spurs, 6 to 19 or 20 with one, ultimate without.

BMNH. Four specimens 49, 38, 37 and 41 mm labelled Ot. punctiventer Tomosv. New Britain A. S. Willey 1906.4.16.88, and one specimen 49 mm, New Britain 98.12.6.4. A. Willey.

Description. Antennomeres 17[r] 19[r] 20, 21, 22[r] or 23, the basal 2.25 to 2.33 glabrous. Forcipular trochanteroprefemoral teeth 3+3. Tergite paramedian sutures complete 5, marginate from 7, 8 or 11 without keels or spines. Sternite paramedian sutures occupying anterior ½ to ½ on posterior sternites. Sternite 21 with sides converging posteriorly or almost parallel. Coxopleuron with 2 or 3 end spines, 2 lateral spines and 1 (2) dorsal spines. Ultimate leg prefemoral spines (two specimens only): VL5 (3), VM 3–4, M3 (2), DM 2, CS 1. Two tarsal spurs on first three, four or six pairs of legs, the remainder to 20 with one, ultimate without.

Remarks. Haase (1887) noted under Otostigma orientale that in young animals the last sternite was usually posteriorly narrowed and deeply notched (Br. calcitrans Kohlr.), then wider and more shallowly emarginate (Br. luzonicum Kohlr.) until finally, in full grown animals they were mostly strikingly widened posteriorly and weakly emarginate or angularly incised.

Attems (1930a page 143) incorrectly gave O. completus Chamberlin 1920 as a synonym of O. astenus. It is a junior synonym of O. angusticeps Pocock, 1898 (Lewis, 2003). Otostigmus glaber recorded from Nepal (Lewis, 1992) is not O. astenus. It has subsequently been described as a new species: O. beroni Lewis, 2001. Lewis (2002b) suggested that specimens hitherto identified as O. glaber should be checked as they may not be O. astenus.

Distribution. Madagascar (introduced) otherwise eastwards from Cambodia to Oceania namely: Taiwan; Philippines; Sulawesi, Indonesia (Flores, Central Sumba, West Timor, Ambon, Teoeen, Laut Banda (Banda Sea), Irian Jaya); Solomon Islands, Papua New Guinea (New Britain and Hermit Island, Bismarck Archipelago); Australia; New Caledonia; Samoa Islands; Marianas; Caroline Islands (Yap); Tonga Islands; Fiji.