Thinodromus sudanensis (Scheerpeltz, 1974)

Makranczy, György, 2013, Review of the southern African species of Thinodromus (Coleoptera: Staphylinidae: Oxytelinae), Acta Entomologica Musei Nationalis Pragae 53 (1), pp. 177-208 : 185-186

Thinodromus sudanensis (Scheerpeltz, 1974)

( Figs 17–18 , 22 , 77–78 )

Trogophloeus (Carpalimus) sudanensis Scheerpeltz, 1974b: 5 .

Thinodromus sudanensis: GILDENKOV (2000: 51) .

Type material examined. HOLOTYPE: ♀, “ Sudan; Dahr [Bahr] el Ghazal.; Wau [04°10′N, 10°10′E] \ 19.2.1963; [R.] Linnavuori \ Trogophloeus ; (Carpalimus); sudanensis; nov.spec. \ ex coll.; Scheerpeltz \ Typus; Trogophloeus ; sudanensis; O. Scheerpeltz \ Holotypus; Trogophloeus ; sudanensis Scheerpeltz ; ver. Makranczy, 2011 \ Thinodromus ; sudanensis (Scheerpeltz) ; det. Makranczy, 2011” ( MZHF) . PARATYPE: ♀, “ Sudan; Dahr [Bahr] el Ghazal.; Wau \ 19.2.1963; [R.] Linnavuori \ Trogophloeus ; (Carpalimus); sudanensis; n.sp. \ ex coll.; Scheerpeltz \ Typus; Trogophloeus ; sudanensis; O. Scheerpeltz \ sudanensis; Schp. \ Paratypus; Trogophloeus ; sudanensis Scheerpeltz ; ver. Makranczy, 2011 \ Thinodromus ; sudanensis (Scheerpeltz) ; det. Makranczy, 2011” ( NHMW) .

Redescription. Measurements (in mm, n = 2): HW = 0.63 (0.625–0.63); TW = 0.53 (0.515–0.54); PW = 0.70 (0.68–0.72); SW = 0.81 (0.79–0.83); AW = 0.91 (0.88–0.94); HL = 0.39 (0.37–0.40); EL = 0.25 (0.25–0.255); TL = 0.02 (0.015–0.02); PL = 0.50 (0.48–0.51); SL = 0.79 (0.77–0.80); SC = 0.75 (0.73–0.77); BL = 3.35 (3.19–3.51); FB = 1.74 (1.67–1.80). Lustre and colour: Body rather shining due to shiny interspaces of not so dense punctation. Forebody and abdomen pitch black with almost absence of brownish or reddish tint. Mouthparts and antennae dark brown, legs reddish medium brown with apices of tibiae and tarsi much lighter, reddish medium brown. Shape and sculpture: Head ( Fig. 17 ) rather transverse, eyes occupy sides, temples barely discernible. Pronotum transverse, sides straight in posterior half, posterior corners rounded, inconspicuous, first half of sides and anterior corners strongly rounded. Sides of a rather deep horseshoe-shaped impression anteriorly with an adjoining shallow depression on lateral parts of disc; center of disc marked by a pair of smaller, similarly shallow impressions. Deflexed margin wider than usual and fully apparent laterally, although more prominent in posterior half. Elytra ( Fig. 18 ) combined significantly broader than long, gently dilated towards apex; a shallow oval impression posterior of scutellum and a feeble oblique impression across anterior half of disc. Posterior elytral margin with wider membranous lobe not apparent on whole length but conspicuously pulled out near outer corner in a small concavity of posterior margin. Apex of abdominal tergite VII with palisade fringe (widest medially). Punctation and microsculpture: Head punctation medium large and medium deep, but with rather sparse interspaces roughly equal to puncture diameters. Pronotal punctation with similarly sparse and medium deep, somewhat varying sized punctures, only posterior corners with some discernible scabrous microsculpture. Elytra with very large and deep punctures, more close to each other (interspaces less than 1/3 of puncture diameters), but surface without microsculpture, so shiny. Abdominal tergites with medium deep and medium sparse punctation, interspaces often larger than puncture diameters; traces of microsculpture only in transversal grooves posteriad basal ridges. Pubescence: Forebody, even the eyes, covered by conspicuously long, erect, often strong and dark setae, mostly of uniform size and sparse spacing. Setae on head and posterior part of pronotum appear shorter and more dense. On abdominal terga with setae sparse, long and erect, on posterior edge a row of very long setae. Primary and secondary sexual features: Female antennae ( Fig. 22 ) moderately elongate, middle antennomeres (articles 4–5) about as long as wide, penultimate antennomeres (articles 9–10) slightly transverse. Male: unknown; female: tergite X ( Fig. 77 ), spermatheca and ringstructure ( Fig. 78 ).

Differential diagnosis. As the male of T. sudanensis is unknown, it is rather difficult to compare it to the other species. Judging by the female genitalia, the most similar species must be T. gabonicus as both share a more “heart-shaped” ringstructure, with that of T. sudanensis being much wider at the base. The apex of the ringstructure is more square and less broad in T. gabonicus , while rather equally rounded and with the highest density of pores on both sides of the apex in T. sudanensis ; the inner arms of the basal loop are also wider in the latter species. These are the only two species known with such heart-shaped ringstructures, with the apex not pointed and not widened, so it is expected that their male genitalia might also bear similarities.

Distribution. Only known from South Sudan.

Remarks. SCHEERPELTZ (1974) mentioned two specimens in the original description, a holotype and a paratype with the same collecting data, without noting their sex. Two specimens were found in the Scheerpeltz collection in NHMW, both bearing labels reading “Typus”, and I therefore consider them type specimens. The one intended to be the paratype can be recognized by the “bottom label” (i.e. the label which is usually attached to the first specimen of the series retained by Scheerpeltz). The holotype does not bear this label, as Scheerpeltz probably intended to return it to MZHF from where the material was on loan. Both type specimens are females and now labelled accordingly. In the catalogue of the MZHF collection by SILFVERBERG (1988), the holotype is listed as being already present in the MZHF (erroneously listed as “ sudanicus ”, the last entry on p. 25.), but this is not true according to the information I got from J. Muona in February 2013. The holotype is now forwarded to MZHF.

Figures

Figs 13–18. 13–16 – Thinodromus nigerius Gildenkov, 2000 (13 – head and pronotum;14 – female antenna; 15 – male antenna; 16 – elytron and abdominal base); 17–18 – T. sudanensis (Scheerpeltz, 1974) (17 – head and pronotum; 18 – elytron and abdominal base). Scale bar: 0.5 mm for 13–16, 0.7 mm for 17–18.

Figs 19–27. 19 – Thinodromus facilis Gildenkov, 2000, female protarsus; 20 – T. gildenkovi sp. nov., male protarsus; 21 – T. gildenkovi sp. nov., male, fringe of tergite VII. Antennae. 22 – T. sudanensis (Scheerpeltz, 1974), female; 23 – T. meridionalis sp. nov., female; 24–25 – T. gildenkovi sp. nov. (24 – female; 25 – male); 26–27 – T. dasys Gildenkov, 2000 (26 – female; 27 – male) Scale bar: 0.065 mm for 19, 0.08 mm for 20, 0.12 mm for 21, 0.24 mm for 24–25, 0.3 mm for 22 and 26–27, 0.33 mm for 23.

Figs 77–80. 77–78 – Thinodromus sudanensis (Scheerpeltz, 1974), female (77 – tergite X; 78 – ringstructure and spermatheca); 79 – T. capensis (Bernhauer, 1934), female ringstructure; 80 – T. meridionalis sp. nov., female ringstructure with spermatheca. Scale bar: 0.09 mm for 79–80, 0.11 mm for 78, 0.14 mm for 77.