Tychus depexus Peyerimhoff, 1905

Sabella, Giorgio, Besuchet, Claude & Kurbatov, Sergey A., 2011, A review of the Tychus algericus species group (Coleoptera: Staphylinidae: Pselaphinae), North Africa, Zootaxa 3065, pp. 38-48 : 42-43

Tychus depexus Peyerimhoff, 1905

( Figs. 2 , 9–10 , 16 )

Tychus depexus Peyerimhoff, 1905: 229 ; Jeannel, 1956: 137, Fig. 139

Type material. Lectotype, 3, present designation. NORTHERN ALGERIA: Blida province: Mouzaia Mount, Bereani river, 19.III.1905 (P. M. de Peyerimhoff) ( MNHN, general collection). Paralectotypes: 3, same data of lectotype ( MNHN, general collection); 2 3, same data of lectotype ( MHNG).

Additional material examined. NORTHERN ALGERIA: Blida province: 3, Mouzaia Peak, (P. M. de Peyerimhoff) ( MNHN, Raffray collection); 2 3, idem, VII.1905 (P. M. de Peyerimhoff) ( MNHN, general collection); Ƥ, idem (H. Normand) ( INAT); 3, Le Lac, 13.VI.1905 ( MNHN, general collection); 2 ƤƤ, Mouzaia Mount ( MNHN, general collection); Ƥ, Mouzaia, IV.1909 ( MNHN, general collection); 2 3 and Ƥ, idem, IV. 1909 ( MHNG); 6 3 and 4 Ƥ Ƥ, Chiffa Gorges, Singes stream, 280–380 m, 4.V.1988 (C. Besuchet, I. Löbl & D. Burckhardt) ( MHNG); 3 Chiffa Gorges, III.1909, (P. M. de Peyerimhoff) ( MNHN, general collection); 3, idem, III.1909 (P. M. de Peyerimhoff) ( MHNG); 6 ƤƤ, Atlas de Blida, Chréa, Les Glacières, 1.100 m, 3.V.1988 (C. Besuchet, I. Löbl & D. Burckhardt) ( MHNG).

Redescription. Body length 1.35–1.40 mm, uniformly brown with yellowish legs and yellow palpi.

Head slightly longer (0.250–0.260 mm) than wide (0.235–0.245 mm), frontal rostrum 0.135–0.140 mm wide and 0.050 mm long. Eyes with 10–16 ommatidia. Last article of maxillary palpi 0.190–0.200 mm long and 0.080 mm wide. Antennae ( Fig. 2 ) 0.690–0.700 mm long, club 0.275–0.280 mm long; scape and anteonnomere II distinctly longer than wide; III slightly longer than wide, antennomeres IV–VIII distinctly wider than long.

Pronotum wider (0.300– 0.310 mm) than long (0.280–0.290 mm).

Elytra wider (0.560–0.575 mm) than long (0.400– 0.425 mm).

Abdomen with 1st tergite 0.185–0.190 mm long.

Male. Posterior margin of mesotrochanters extended into long median spine, mesotibiae with small subapical spur, metatibiae with apical spur, all abdominal sternites slightly flattened at middle. Aedeagus ( Figs. 9–10 ) 0.310– 0.325 mm long, with sinuate and canaliculate dorsal apophysis of median lobe enlarged at apex and bearing two spine-like apophyses. First apophysis on mesal margin beneath apex, very short and directed medially, second apophysis on distal third of ventral surface is bigger and directed laterally. Ventral portion of median lobe very large at base directed laterally and constricted at the apex. Ventral portion of median lobe bearing long spine-like apophysis on lateral margin.

Female. Eyes smaller (10–12 ommatidia) than male (14–16 ommatidia), telisternite as in Fig. 16 .

Comparative notes. T. depexus can be distinguished from the other species of the group by the uniformly brown colour of both males and females, the reduced eyes (10–16 ommatidia), the shape of the ventral portion and the dorsal apophysis of median lobe of the aedeagus, and the feature of the female telisternite. Also, only the male of T. depexus has all abdominal sternites slightly flattened at the middle (slightly convex in other species of the group).

Distribution. The species is known only from few localities in the northern Algeria in the Blida province (Mouzaia Mount, Chiffa Gorges, Chréa).

Figures

FIGURES 1 – 4. Antennae of Tychus algericus group species. Scale: 0, 1 mm. 1 — Tychus algericus, male from Fernana. 2 — Tychus depexus, male from Mouzaia Mount. 3 — Tychus vaucheri, male from Dardara. 4 — Tychus similis sp. n., holotype, male from Dély Ibrahim.

FIGURES 9 – 10. Aedeagus of Tychus depexus, male from Mouzaia Mount. Scale: 0, 1 mm. 9 — Ventral view. 10 — Lateral view.

FIGURES 15 – 16. Telisternites of female of Tychus algericus group species, dorsal view. Scale: 0, 1 mm. 15 — T. algericus, female from Akfadou Forest. 16 — T. depexus, female from Mouzaia Mount.