Thinodromus facilis Gildenkov, 2000

Makranczy, György, 2013, Review of the southern African species of Thinodromus (Coleoptera: Staphylinidae: Oxytelinae), Acta Entomologica Musei Nationalis Pragae 53 (1), pp. 177-208 : 206-208

Thinodromus facilis Gildenkov, 2000

( Figs 3 , 19 , 36–39 , 62–63 , 67–69 , 85 )

Thinodromus (Thinodromus) facilis Gildenkov, 2000: 54 .

Material examined. DEMOCRATIC REPUBLIC OF CONGO: Congo Belge, P.N.G. [Parc National de la Garamba] Miss. H. De Saeger, II/fc/17 [cellule biologique II, 03°58′N, 29°22′E, 730m], 15.ii.1952, [dry gallery forest along the river banks of the river Garamba, dominated by Irvingia and Nauclea ], leg. H. De Saeger (3173), Berlèse: dry leaves littering the ground in shade (1 ♂, MRAC). ANGOLA: (distr. Benguela), Marco de Canavezes iii.1956; leg. E. Luna de Carvalho (10656.2) (1 ♂ 2 ♀♀, MRAC; 1 ♀, MGSC), Angola [Cuanza Sul or Kwanza-Sul,] Quirimbo [10°41′S, 14°16′E], v.1934; leg. K. Jordan (1 ♂, BMNH). ZAMBIA: South Luangwa NP, Mfuwe Crocodile Farm, 450m, 13°06′03″S, 31°47′32″E, 24.iii.1993, leg. M. Uhlig, lux (1 ♂, ZMHB). REPUBLIC OF SOUTH AFRICA: E. Transvaal, Kruger Pk., Skukuza [24°59′S, 31°36′E], (12–14)- xii-1985, FMHD #85-848, thorn scrub & riverine light traps, S. Peck P# 85-281 (1 ♀, FMNH).

Redescription. Measurements (in mm, n = 10): HW = 0.49 (0.47–0.51); TW = 0.45 (0.43– 0.47); PW = 0.58 (0.56–0.60); SW = 0.70 (0.67–0.73); AW = 0.79 (0.76–0.82); HL = 0.31 (0.28–0.33); EL = 0.18 (0.175–0.20); TL = 0.03 (0.02–0.035); PL = 0.41 (0.39–0.43); SL = 0.67 (0.64–0.70); SC = 0.62 (0.58–0.66); FB = 1.42 (1.36–1.50); BL = 2.72 (2.23–3.06). Lustre and colour: Body ( Fig. 3 ) rather shining due to varied but generally small punctures on head and pronotum and microsculpture-free (albeit smaller) interspaces on elytra. On abdomen punctation varies from tiny to medium-sized, but very sparse, interspaces large and smooth giving this body part a shiny appearance. Head and abdomen blackish dark brown, abdominal terga slightly reddish at the more transparent apices. Pronotum and elytra reddish dark brown, elytral apex may appear darker than rest. Mouthparts and legs reddish medium to dark brown, antennae dark brown except first (and partly second) antennomere brighter, reddish medium brown. Shape and sculpture: Head ( Fig. 36 ) quite transverse, eyes large and almost occupy sides, temples tiny. Pronotum transverse, first half of sides and anterior corners broadly rounded, hind corners also strongly obtuse-angled and rounded, therefore almost indiscernible. Pronotal side in hind half almost straight, with almost imperceptible concavity. Deflexed margin generally thin but visible all along sides and posterior edge, widest and most conspicuous in posterior half of sides. Horseshoe-shaped impression deep but not too wide, sides curve towards (but not reaching) middle of sides; with a feebly depressed area right in front of these arms and two indefinite impressions in middle of disc. Elytra ( Fig. 39 ) combined significantly broader than long, dilated towards apex, with small round impression posteriad scutellum and a feeble oblique depression across anterior half of elytral disc. Posterior elytral margin in outer 2/5 with membranous lobe pulled out in it. Apex of abdominal tergite VII with palisade fringe (widest medially). Punctation and microsculpture: Punctation of main body parts characterized by greatly varying sized punctures. Head rather shiny, with generally small, scattered punctures, hardly any trace of microsculpture. Puncture diameters much less than interspaces. On pronotum even more scattered and more varying sized punctures, with signs of slightly scabrous microsculpture in the hind corners. Elytral punctation consists of rather dense, large and deep (but still varying sized) punctures, with interspaces only a fraction of puncture diameters. Signs of microsculpture only in the scutellar area and outer posterior corners, otherwise look uneven surfaced but almost as shiny as head and pronotum. Abdominal punctation rather strong, at tergite bases with smaller but denser punctures, posteriorly punctures larger and deeper, towards apex more scattered. Pubescence: Semi-erect setation comes closest to what the author described as “two-sized” setation (cf. Thinodromus makokouensis Makranczy, 2009 and T. odzalensis Makranczy, 2009 ); on all body parts very fine but medium long semi-erect setae mix with few but long and stronger, erect setae. Primary and secondary sexual features: Female antennae ( Fig. 37 ) moderately elongate, middle antennomeres (articles 4–5) about half longer than wide, penultimate antennomeres (articles 9–10) slightly transverse (almost as long as wide). Male antennae ( Fig. 38 ) only imperceptably more slender. Male: MA of aedeagal internal sac long and thin, thread-like, ML much less transverse than usual, BM very tiny, BA somewhat curved in S-shape, AC smaller, reverse V-shaped with arms open in slightly less than right angle ( Figs 67–69 ), sternite VIII ( Fig. 62 ), tergite X ( Fig. 63 ); female: ringstructure and spermatheca ( Fig. 85 ).

Differential diagnosis. Thinodromus facilis appears to be allied to T. mateui Makranczy, 2009 , based on similarities in the general shape of the parameres, AC size and shape, ML being less transverse than usual, the whole structure of the apical part of the median lobe and also the female ringstructure. However, T. facilis differs from T. mateui in the much larger and longer BM, more curved (S-shaped) BA, parameres more slender and elongate (especially at apex). The female ringstructure of T. facilis is apparently completely devoid of any pores on the much less curved apical arch, while that of T. mateui has a more rounded apex with at least some scattered pores on it. Some other minor differences are suspected to be due to imperfect condition of the existing specimens and therefore not used here. It must also be noted that T. mateui is the smallest member of the so far discovered species in this group of Afrotropical species.

Distribution. This species appears to be wide-ranging and common in southern Africa, so far documented from the Democratic Republic of Congo, Angola, Zambia and the Republic of South Africa.

Figures

Figs 1–3. Habitus of Thinodromus species. 1 – T. gildenkovi sp. nov., male; 2 – T. meridionalis sp. nov., female; 3 – T. facilis Gildenkov, 2000, female.

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 34–39. 34–35 – Thinodromus meridionalis sp. nov. (34 – head and pronotum; 35 – elytron and abdominal base); 36–39 – T. facilis Gildenkov, 2000 (36 – head and pronotum; 37 – female antenna; 38 – male antenna; 39 – elytron and abdominal base). Scale bar: 0.47 mm for 34–35, 0.50 mm for 37–38, 0.53 mm for 36, 39.

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 64–69. 64–66 – Thinodromus meridionalis sp. nov., male (64–65 – aedeagus; 66 – paramere); 67–69 – T. facilis Gildenkov, 2000, male (67–68 – aedeagus; 69 – paramere). Abbreviations: AC – apical copulatory sclerite; BA – basal sclerites, BM – basomedial sclerites, MA – medioapical sclerites ML – medial lamellae. Scale bar: 0.10 mm for 64–66, 0.12 mm for 67–69.

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.