Thinodromus tibialis ( Fauvel, 1907 )

Makranczy, György, 2013, Review of the southern African species of Thinodromus (Coleoptera: Staphylinidae: Oxytelinae), Acta Entomologica Musei Nationalis Pragae 53 (1), pp. 177-208 : 186-187

Thinodromus tibialis ( Fauvel, 1907)

( Figs 28–31 , 55–59 , 81 )

Trogophloeus tibialis Fauvel, 1907: 13 .

Thinodromus tibialis: HERMAN (1970: 387) .

Type material examined. LECTOTYPE (here designated): ♂, “ Naivasha [approx. 00°43′13″S, 36°25′43″E, 1900m]; 12 \ tibialis; Fvl. \ Coll. et det A. Fauvel; Trogophloeus ; tibialis Fauv. ; R.I.Sc.N.B. 17.479 \ Ex-Typis \ Lectotypus; Trogophloeus ; tibialis Fauvel ; des. Makranczy,2001 \ Thinodromus ; tibialis (Fauvel) ; det. Makranczy, 2001” ( ISNB). PARALECTOTYPES (3 specimens):“Naivasha; 12 \ Coll.et det A.Fauvel; Trogophloeus ; tibialis Fauv. ; R.I.Sc. N.B. 17.479 \ Ex-Typis \ Paralectotypus; Trogophloeus ; tibialis Fauvel ; des. Makranczy, 2001 \ Thinodromus ; tibialis (Fauvel) ; det. Makranczy, 2001” (1 ♀, ISNB), “Afrique Orle Anglaise; Naivasha; (Rift-Valley); Ch.Alluaud XII. 1903 \ Coll. et det A. Fauvel; Trogophloeus ; tibialis Fauv. ; R.I.Sc. N.B. 17.479 \ Ex-Typis \ Paralectotypus; Trogophloeus ; tibialis Fauvel ; des. Makranczy, 2001 \ Thinodromus ; tibialis (Fauvel) ; det. Makranczy, 2001” (1 ♀, ISNB), “Afrique or. Anglaise; Naivasha; Rift-Valley [04°10′N, 10°10′E]; Ch. Alluaud XII.1903 \ Paralectotypus; Thinodromus ; tibialis Fauvel ; des. Makranczy, 2001” (1 ♂, coll. Jarrige, MNHN) .

Redescription. Measurements (in mm, n = 3): HW = 0.49 (0.48–0.50); TW = 0.47 (0.46– 0.47); PW = 0.59 (0.57–0.60); SW = 0.75 (0.74–0.76); AW = 0.82 (0.81–0.83); HL = 0.34 (0.33–0.35); EL = 0.19 (0.18–0.20); TL = 0.03 (0.025–0.04); PL = 0.42 (0.41–0.425); SL = 0.73 (0.72–0.75); SC = 0.70 (0.69–0.71); FB = 1.55 (1.52–1.58); BL = 3.04 (2.95–3.10). Lustre and colour: Moderately shining, due to setation of body and traces of microsculpture on elytra. Head and abdomen blackish dark brown but apices of tergites (because of more transparency) reddish. Pronotum and elytra reddish dark brown, elytral apex appears somewhat darker. Mouthparts and antennae uniformly medium to dark brown, first antennomere conspicuously brighter, orange/light brown. Legs medium brown, middle of tibiae darkest. Shape and sculpture: Head ( Fig. 28 ) quite small and short, eyes occupy most of side, leaving a small but significant, remarkably rounded temple. Pronotum transverse, first half of sides and anterior corners broadly rounded, posterior constriction of sides towards base a bit stronger than in most congeners, posterior corner more gently rounded, conspicuous. Horseshoe-shaped impression rather deep and sides (while also deep, gradually constricting) obliquely run towards margins at 1/4 of pronotal length (but not reach it). Anterior half of disc centre with three smaller impressions, not well marked. Deflexed margin very thin but apparent along whole length of sides and in the same extent along basal edge. Elytra ( Fig. 31 ) combined a little broader than long, dilated posteriorly; with a shallow indefinitely bordered impression posteriad scutellum plus very slight, indefinite, oblique depression from shoulder area to middle of suture. Posterior elytral margin with membranous lobe only apparent in outer half, conspicuously pulled out near outer corners. Apex of abdominal tergite VII with palisade fringe (widest medially). Punctation and microsculpture: Head with medium large but rather dense punctation, interspaces a fraction of puncture diameters, but shiny. Pronotum with on average slightly larger punctures but also larger interspaces; only appearance of microsculpture the slightly scabrous posterior pronotal corners. Elytra with even larger (and more uniform) punctures, even less dense (except scutellar area and shoulders) than on pronotum. Abdominal terga medially as deeply punctured as elytra but punctures become smaller towards apices; almost without trace of microsculpture in grooves behind basal ridges. Pubescence: Whole body with fairly long, semi-erect setation, but only apices of tergites with really long setae. Sizes of setae do not differ greatly on the forebody, but abdominal terga have much finer and smaller setae also near the bases. Primary and secondary sexual features: Female antennae ( Fig. 29 ) moderately elongate, middle antennomeres (articles 4–5) roughly as long as wide, penultimate antennomeres (articles 9–10) slightly transverse. Male antennae ( Fig. 30 ) just a little bit more slender. Male: MA of aedeagal internal sac elongate, curved, spoon-like, ML less transverse than in other species, BM very elongate, gently broadening medially, BA rather short, more or less straight, AC reverse V-shaped but at tip obtuse-angled, arms curved inwads ( Figs 55–57 ), sternite VIII ( Fig. 58 ), tergite X ( Fig. 59 ); female: ringstructure ( Fig. 81 ).

Differential diagnosis. Thinodromus tibialis is most similar to T. meridionalis , both with the frontal edge of the parameres gently pulled ahead while being evenly rounded, the parameres of these species are unusually and evenly broad. Other shared features include a spoon-like broadened apical formation of MA, conspicuous laterally enlarged flap-like appendages of a sclerite adjacent to the otherwise rather small ML. The most important genitalic differences for both male and female are listed under T. meridionalis sp. nov. Other slight differences are deemed to be due to the specimens being too few, rather old and in less than perfect condition. This is especially true for T. tibialis , where all known specimens are more than a 100 years old and plates of the terminalia seem to be with membranous apical edges slightly deformed/shrunk, and do not allow solid conclusions for a diagnosis.

Distribution. The species is still only known from its original type material from Kenya.

Remarks. When describing the species, A. Fauvel likely received the series of specimens from Ch. Alluaud with fewer sets of locality labels, and hence hand-copied the collecting data to the specimens he retained in his collection, now deposited in ISNB. The single specimen examined by me in MNHN (being likely part of the original Alluaud collection) does not have any identification label by Fauvel, but clearly bears the original locality label according to which Fauvel prepared the hand-written copies for the specimens now deposited in ISNB. As all specimens are conspecific and there is no contradictory evidence, I consider all mentioned specimens as syntypes. Because additional syntypes may still exist, I am designating here the single male from Fauvel’s collection as the lectotype.

Figures

Figs 28–33. 28–31 – Thinodromus tibialis (Fauvel, 1907) (28 – head and pronotum; 29 – female antenna; 30 – male antenna; 31 – elytron and abdominal base); 32–33 – T. gildenkovi sp. nov. (32 – head and pronotum; 33 – elytron and abdominal base). Scale bar: 0.45 mm for 28–31, 0.55 mm for 32–33.

Figs 52–57. 52–54 – Thinodromus rhodesianus (Scheerpeltz, 1974), male (52–53 – aedeagus; 54 – paramere); 55–57 – T. tibialis (Fauvel, 1907), male (55–56 – aedeagus; 57 – paramere).Abbreviations:AC – apical copulatory sclerite; BA – basal sclerites, BM – basomedial sclerites, MA – medioapical sclerites ML – medial lamellae. Scale bar: 0.10 mm for 55–57, 0.12 mm for 52–54.

Figs 58–63. 58–59 – Thinodromus tibialis (Fauvel, 1907), male (58 – sternite VIII; 59 – tergite X); 60–61 – T. meridionalis sp. nov., male (60 – sternite VIII; 61 – tergite X); 62–63 – T. facilis Gildenkov, 2000, male (62 – sternite VIII; 63 – tergite X). Scale bar: 0.10 mm for 59–61 and 63, 0.15 mm for 58 and 62.

Figs 81–85. 81–83 – female ringstructures.81 – Thinodromus tibialis (Fauvel, 1907); 82 – T. dasys Gildenkov, 2000; 83 – T. nigerius Gildenkov, 2000. 84–85 – female ringstructures with spermathecae. 84 – T. facilis Gildenkov, 2000; 85 – T. gildenkovi sp. nov. Scale bar: 0.10 mm for 85, 0.12 mm for 81 and 83–84, 0.14 mm for 82.