Tachyusa impressa Eppelsheim, 1877

Pa ṡnik, Grzegorz, 2006, A revision of the World species of the genus Tachyusa Erichson, 1837 (Coleoptera, Staphylinidae: Aleocharinae), Zootaxa 1146, pp. 1-152 : 76-78

Tachyusa impressa Eppelsheim, 1877 ( Figs. 70–72)

Tachyusa impressa Eppelsheim, 1877: 101 .

Type material. Lectotype (here designated): ♂: Kaukaz, Leder, Am Kura bei Borshom [Borjomi] ( NMW) . Paralectotypes: 2♀♀: same data as the lectotype ( NMW) .

Taxonomic notes. See taxonomic notes under T. flavolimbata .

Additional material. Azerbaijan: Lenkoran, Leder, 1 ex ( NMW). Georgia: Mzcheta

near Tbilisi , 12–13.VI.1986, Wrase & Schülke, 1 ex ( ISEA) ; 4 exx ( ZMHB); 12– 13.VI.1987, Wrase & Schülke, 1 ex ( ZMHB) ; 4–23.VII.1987, Wrase & Schülke, 3 exx ( ISEA) ; 7 exx ( ZMHB); Tbilisi , city border, 6.VII.1987, Wrase & Schülke, 1 ex ( ZMHB) ; Kura River near Borzhomi [Borjomi], Reitter, 1 ex ( HNHM) ; Eppelsheim , 1 ex ( NMW) ; Leder , 1 ex ( NMW) ; Michailowo , Kura River, Leder, 1 ex ( NMW) . Azerbaijan or Armenia: Caucasus , Arax River valley (“ Araxesthal ”), Leder­Reitter, 1 ex ( NMW) ; “ Caucasus ” (localities not specified), Kolenati, 1 ex ( NMW) ; Leder , 1 ex ( DEI) ; Leder , 2 ex ( NMW) ; Leder­Reitter , 1 ex ( IRSNB) .

Redescription. Body. Length 2.9–3.3 mm, convex, parallel­sided, glossy; body colour dark brown to pitchy brown; elytra reddish brown to dark brown, three basal tergites often paler, brown, legs reddish brown, antennae red.

Head circular in outline, convex, eyes relatively small, moderately protruding from lateral contours of head, length of each seen from above slightly shorter than postocular region; surface of head without microsculpture; puncturation fine and dense. Antennae short, clearly increasing in width apically, antennomeres 2 and 3 subequal in length, antennomeres 4–8 longer than wide, antennomeres 9–10 sexually dimorphic, quadrate in male and slightly transverse in female, antennomere 11 nearly conical.

Pronotum trapezoid in outline, lateral sides gradually narrowed in straight line to obtuse hind angles; before base with small and shallow transverse impression; surface without microsculpture; puncturation fine, moderately dense and asperate; pubescence at midline directed posteriorly.

Elytra subquadrate, at suture as long as pronotal length at midline; surface lacking microsculpture; puncturation fine, dense and asperate.

Abdomen parallel­sided, bases of tergites 3–5 each with deep transverse impression, impressions with 7–8 longitudinal ridges, tergal puncturation fine and relatively sparse, punctures small and weakly visible, surface without microsculpture.

Male. Aedeagus as in Figs. 70–71.

Female. Spermatheca as in Fig. 72.

Remarks. Tachyusa impressa is similar to T. nitella , from which it differs by the pronotal pubescence at midline directed entirely posteriorly, the more convex pronotum, the sparser elytral puncturation and mainly by the shape of the aedeagus.

Distribution. Tachyusa impressa is known so far only from Azerbaijan and Georgia.