Thinodromus rhodesianus (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 : 183-184

Thinodromus rhodesianus (Scheerpeltz, 1974)

( Figs 10–12 , 50–54 )

Trogophloeus (Carpalimus) rhodesianus Scheerpeltz, 1974a: 56 .

Type material examined. HOLOTYPE: ♂, “S. Afr. S. Rhodesia [ Zimbabwe]; Victoria Falls [approx. 17°55′34″S, 25°51′22″E, 900 m]; 16-17.V.[19]51. No. 308 \ Swedish South Africa; Expedition; 1950-1951; [P.] Brinck - [G.] Rudebeck \ Trogophloeus ; (Carpalimus); rhodesianus; n.sp. \ Holotypus \ Typus; Trogophloeus ; rhodesianus; O. Scheerpeltz \ Trogophloeus ; (Carpalimus); rhodesianus n.sp.; det. Scheerpeltz. 1968 \ Zool. Mus. Lund Sweden; Staphylinidae ; Type No.; 589:1 \ ZML 2002 ; 122” ( ZMLU).

Redescription. Measurements (in mm, n = 1): HW = 0.58; TW = 0.50; PW = 0.67; SW = 0.80; AW = 0.91; HL = 0.38; EL = 0.23; TL = 0.03; PL = 0.49; SL = 0.83; SC = 0.78; FB = 1.72; BL = 3.35. Lustre and colour: Body rather dull due not only to punctation but very fine and dense setation giving a somewhat dusted appearance. Head and abdomen blackish dark brown, pronotum and elytra dark brown with some reddish tint. Mouthparts and antennae dark brown, latter with basal antennomeres not lighter than rest. Legs dark brown but apices of tibiae plus tarsi lighter, medium to light brown. Shape and sculpture: Head ( Fig. 10 ) quite transverse, eyes large, occupy sides of head, leaving free just discernible temples. Pronotum transverse, first half of sides and anterior corners broadly rounded, hind half just a little concave; posterior corner obtuse-angled and rounded, feebly marked. Horseshoe-shaped impression deep but rather broad, therefore less prominent, pronotal disc laterally with larger, shallow depressions extending towards anterior corners, middle of disc with two smaller impressions. Deflexed margin thin but evenly apparent along whole side length, on posterior margin present, slightly obvious. Elytra ( Fig. 12 ) combined significantly broader than long, dilated towards apex, with a small, very shallow round impression posteriad scutellum and feeble impressions directed from shoulder to 2/3 of suture length. Posterior elytral margin in the outer 1/3 with thin membranous lobe (not apparent on whole width) pulled out. Apex of abdominal tergite VII with palisade fringe (widest medially). Punctation and microsculpture: Head punctation rather dense, interspaces only a fraction of puncture diameters. Punctures medium sized but deep, surface covered by coriaceous microsculpture. Pronotal punctures a little larger but almost as dense, microsculpture becomes stronger, more scabrous along sides and posterior edge. Elytral punctures larger and dense, despite small interspaces some microsculpture obvious. Abdominal tergites with smaller punctures and less dense than on elytra but in interspaces with coriaceous microsculpture turning stronger in grooves behind basal ridges. Pubescence: Body covered by remarkably short and rather dense setation, setae with more or less even sizes and density except some longer setae near posterior margins of abdominal terga; setae rather pressed down, their direction most obvious on head where uniformly forward. Primary and secondary sexual features: Male antennae ( Fig. 11 ) rather elongate, middle antennomeres (articles 4–5) nearly twice as long as broad, penultimate antennomeres (articles 9–10) a tiny bit longer than broad. Male: MA of aedeagal internal sac thin and very elongate with outward curving ends, ML moderately transverse, BM very elongate on apical part (conspicuously broadening near base), BA rather elongate and more or less straight, AC reverse V-shaped with arms in acute angle and with forward directing apical projection ( Figs 52–54 ), sternite VIII ( Fig. 50 ), tergite X ( Fig. 51 ); female: unknown.

Differential diagnosis. Thinodromus rhodesianus can be considered to be more distantly allied to T. dasys , T. gildenkovi sp. nov. and T. decorsei , but differences are numerous. The female of this species is unknown, so it cannot be compared to those of the aforementioned three taxa. In the male aedeagus, the apex of the subapical edge of the median lobe body is rather elongate (in this respect most similar to T. gildenkovi sp. nov., less to the others), incrassate and truncate at its apex. Possessing an apical projection of AC relates the species to T. decorsei , while a rather strong laterally directed “emargination” in the sclerotization in the basal 1/3 of the parameres unite all four species. The sibling of this species is T. makokouensis Makranczy, 2009 (with also only the male known), the most striking difference between them is the more emarginate apex of male sternite VIII in T. makokouensis, AC with a strong perpendicular apical projection in T. rhodesianus (but otherwise similar shape), basal part of the parameres with a very similar form and sclerotization, apical lobe of the subapical edge of median lobe body is similarly elongate, but less constricted at its base in T. makokouensis . The apex of the paramere of T. rhodesianus is much more narrowed, while broader and evenly rounded in T. makokouensis .

Distribution. Known only from Zimbabwe, but as the type locality lies on the border with Zambia, it surely occurs there, also.

Remarks. The closest known relative of this species appears to be T. makokouensis Makranczy, 2009 . Females are unknown from both species.

Figures

Figs 7–12. 7–9 – Thinodromus capensis (Bernhauer, 1934), male (7 – head and pronotum; 8 – antenna; 9 – elytron and abdominal base); 10–12 – T. rhodesianus (Scheerpeltz, 1974), male (10 – head and pronotum; 11 – antenna; 12 – elytron and abdominal base). Scale bar: 0.44 mm for 7, 9–12, and 0.50 mm for 8.

Figs 46–51. 46–47 – Thinodromus dasys Gildenkov, 2000, male (46 – sternite VIII; 47 – tergite X); 48–49 – T. gildenkovi sp. nov., male (48 – sternite VIII; 49 – tergite X); 50–51 – T. rhodesianus (Scheerpeltz, 1974), male (50 – sternite VIII; 51 – tergite X). Scale bar: 0.10 mm for 49 and 51, 0.13 mm for 47–48 and 50, 0.15 mm for 46.

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.