Thinodromus velutinus ( Sharp, 1887 ) Makranczy, 2014

Makranczy, György, 2014, Review of the Thinodromus circulus species group (Coleoptera: Staphylinidae: Oxytelinae), Acta Entomologica Musei Nationalis Pragae 54 (2), pp. 539-554 : 544-547

Thinodromus velutinus ( Sharp, 1887) comb. nov.

( Figs 11–12 , 15–20 , 31 )

Trogophloeus velutinus Sharp, 1887: 700 (original description), BERNHAUER & SCHUBERT (1911): 105 (catalogue). Carpelimus velutinus: HERMAN (1970) : 394 (catalogue), HERMAN (2001): 1709 (catalogue).

Type locality. Panama, Chiriquí, Volcán de Chiriquí [nowadays Barú]. The type locality probably refers to SE slope of the vocano above Boquete, approx. 8°47ƍ40ƎN 82°26ƍ50ƎW – 8°49ƍ50ƎN 82°29ƍ23ƎW.

Type material examined. HOLOTYPE: J, glued on mounting card ‘ Trogophloeus ; velutinus.Type; D.S.; V.de Chiriqui.; 4-6000ft. Champion \ Type; Holo- [orange framed disc] \ V. de Chiriqui,; 4,000 -6,000 ft.; Champion. \ B.C.A. Col. I. 2.; Trogophloeus ; velutinus,; Sharp. \ Sharp Coll.; 1905.-313. \ Holotypus; Trogophloeus ; velutinus Sharp ; ver. Makranczy, 2012 \ Thinodromus ; velutinus (Sharp) ; det. Makranczy, 2012’ ( BMNH).

Redescription. Measurements (in mm, n = 1): HW = 0.37; TW = 0.38; PW = 0.43; SW = 0.46; AW = 0.53; HL = 0.25; EL = 0.115; TL = 0.06; PL = 0.32; SL = 0.47; SC = 0.45; FB = 1.07; BL = 2.12. Lustre and colour: Body rather dull, especially head and pronotum, due to strong surface sculpture; rest of body with greasy lustre. Head and pronotum blackish dark brown, almost black. Elytra very dark brown, with very slight reddish tint in places. Abdomen blackish dark brown with slight reddish tint at apices of segments. Antennae reddish medium to dark brown, basal part noticeably lighter than apex. Legs and mouthparts reddish medium to dark brown, tibiae and tarsi somewhat lighter then femora. Shape and sculpture: Forebody as in Fig. 15 . Head ( Fig. 17 ) quite transverse, with large eyes and well developed, bulging temples approximately half the size of eyes. Neck well delineated (by different, alveolate microsculpture) but without distinct transversal groove. Antennae ( Fig. 16 ) rather short, antennomere 4 as long as broad, antennomere 5 1.10× longer than broad, antennomeres 9–10 1.18–1.21× broader than long. Pronotum strongly transverse, anterior corners broadly but not evenly rounded; corner still feebly marked. Posterior half of sides quite straight, posterior corners rounded and strongly obtuse-angled. Horseshoe-shaped impression slightly marked except posterior/median part where rather impressed; slight lateral depressions connected by it. Middle of disc bearing pair of shallow depressions. Marginal bead on pronotum from dorsal view seems absent, only traces on hind margin. Elytra ( Fig. 19 ) combined slightly broader than long, only gently dilated towards apex, with a pair of small, round impressions posteriad of scutellum; depressed area on elytron somewhat extending towards centre of disc. Posterior elytral margin (slightly oblique) with very thin bead and in outer 1/3 with small membranous lobe protruding. Apex of abdominal tergite VII with palisade fringe. Punctation and microsculpture: Head and pronotum with dense, deep, more or less umbilicate punctation with acinose microsculpture in between; only scattered tiny spots remaining with lustre. Interspaces only a fraction of puncture diameters, punctation only becoming sparser on middle of discs. Epistomal suture as shiny transversal line with slightly strigulate microsculpture. Elytral punctures smaller and more shallow, quite sparse in comparison, interspaces on average larger than puncture diameters. Surface rather more lustrous, microsculpture between punctures not so strong but noticeable. Abdomen with very small punctures and interspaces with imbricate microsculpture (more or less isodiametric cells) but not strong, so abdomen almost as lustrous as elytra. Pubescence: Body setation rather short, dense and equal sized on head and pronotum, a little longer on elytra, slightly less dense, with a few larger hairs at certain spots. Hairs very ¿ne but longer on abdomen, about as dense as on elytra; hairs on apices of segments rather long. Primary and secondary sexual features: Female tergite X as in Fig. 11 , spermatheca as in Fig. 12 , ringstructure as in Fig. 31 .

Differential diagnosis. Thinodromus velutinus is clearly allied to T. circulus , but is distinguishable by its strong punctation of the head and pronotum, and consequent great difference in lustre of head and pronotum compared to elytra and abdomen.

Distribution. Known only from the type locality in Panamá.

Remarks. The holotype is the only known specimen of this species, there are no additional data about its biology.

Figures

Figs 5–14. 5–10 – Thinodromus circulus (Bernhauer, 1922) (5 – mesotarsus; 6 – male sternite VIII; 7 – male tergite IX; 8 – male sternite IX; 9 – male tergite X; 10 – spermatheca); 11–12 – T. velutinus (Sharp, 1887) (11 – tergite X; 12 – spermatheca); 13–14 – T. chagosanus (Bernhauer, 1922) (13 – mesotarsus; 14 – platelike armature in hypopharynx). Scale bar: 0.06 mm for 14; 0.07 mm for 5, 13; 0.1 mm for 10–12; 0.12 mm for 8–9; 0.14 mm for 6–7.

Figs 15–19. Thinodromus velutinus (Sharp, 1887),female, SEM.15 – forebody; 16 – antennomeres 3–10; 17 – head and pronotum; 18 – mesotarsus; 19 – elytron. Scale bar:0.2 mm for 18; 0.25 mm for 16; 0.4 mm for 17, 19; 1.0 mm for 15.

Figs 20–24. 20 – Thinodromus velutinus (Sharp, 1887), tergite VIII; 21–22 – T. circulus (Bernhauer, 1922): 21 – tergite VIII, 22 – aedeagus; 23–24 – T. chagosanus (Bernhauer, 1922): 23 – male sternite IX, 24 – aedeagus. Scale bar: 0.1 mm for 20–21; 0.15 mm for 22–24.

Figs 31–35. 31 – Thinodromus velutinus (Sharp, 1887), female ringstructure. 32 – T. circulus (Bernhauer, 1922), female ringstructure. 33–34 – T. palustris (Bernhauer, 1922): 33 – male sternite IX, 34 – aedeagus. 35 – T.arcitenens (Fauvel, 1905), aedeagus. Scale bar: 0.1 mm for 31; 0.12 mm for 32, 35; 0.15 mm for 33; 0.2 mm for 34.