Geostiba (Tropogastrosipalia) impressiventris, Assing, 2009

Assing, V., 2009, A revision of Geostiba of the Western Palaearctic region. XIX. New species from Turkey and Iran and additional records, with an updated key and a catalogue of the species of the Eastern Mediterranean, the Caucasus, and adjacent regions (Coleoptera: Staphylinidae: Aleocharinae), Linzer biologische Beiträge 41 (2), pp. 1191-1246 : 1208-1209

Geostiba (Tropogastrosipalia) impressiventris nov.sp. ( Figs 48-52 )

Holotype Ƌ: " Iran, Prov. Gilan [IR08-25], Siahkal County, Elburz Mts., S-Slope, Deylaman- Barresar road, sifted, 1688 m, 36°51'07.9"N, 49°49'67.3"E [recte: 36°51.079'N, 49°49.673'E], 07.VI.2008, leg. A. Pütz / Holotypus Ƌ Geostiba impressiventris sp.n. det. V. Assing 2009" (cPüt) . Paratype Ƌ: same data as holotype (cAss).

D e s c r i p t i o n: Small and slender species; body length 2.1-2.7 mm. Habitus as in Fig. 48 . Coloration: head and abdomen, except for the paler apex, blackish; pronotum reddish-brown; elytra yellowish to yellowish-brown; legs yellowish; antennae reddish brown, with antennomeres I-III yellowish.

Head 1.0-1.1 times as long as wide ( Fig. 49 ); punctation extremely fine, barely noticeable; surface with shallow microreticulation. Eyes weakly convex and moderately small, approximately half the length of postocular region in dorsal view.

Pronotum with weakly pronounced sexual dimorphism ( Fig. 49 ), weakly transverse, approximately 1.05 times as wide as long, and approximately 1.2 times as wide as head; punctation as fine as that of head; microreticulation clearly more distinct than that of head.

Elytra with moderately pronounced sexual dimorphism, approximately 0.5 times as long and 1.10-1.15 times as wide as pronotum; punctation more, microsculpture less distinct than that of head and pronotum ( Fig. 49 ).

Abdomen slightly wider than elytra; tergite III apparently with, tergites IV-V without sexual dimorphism; punctation fine and sparse; posterior margin of tergite VII with narrow rudiment of a palisade fringe; posterior margin of tergite VIII weakly convex in both sexes ( Fig. 51 ).

Ƌ (with fully developed secondary sexual characters): pronotum in the middle of posterior margin weakly pointed ( Fig. 49 ); elytra with rather sparse granulose punctation, shallowly and extensively depressed or impressed across both elytra, without sutural carinae or elevations ( Fig. 49 ); abdominal tergite III with rather large median impression of somewhat semicircular shape ( Fig. 48 ); tergite VII with short, apically acute, suberect median process at posterior margin ( Figs 50-51 ); posterior margins of tergite and sternite VIII broadly convex; aedeagus with slender cristal process ( Fig. 52 ).

♀: unknown.

E t y m o l o g y: The specific epithet (Latin, adjective) alludes to the impressed male abdominal tergite III.

C o m p a r a t i v e n o t e s: Geostiba impressiventris is readily distinguished from the other three species of Tropogastrosipalia known from Iran, G. sengleti , G. huberi , and G. sarica , by the small and slender body, the modifications of the male elytra, the characteristic impression on the male abdominal tergite III (a unique autapomorphy distinguishing this species from all other Geostiba !), and by the shape of the cristal process of the aedeagus.

D i s t r i b u t i o n a n d b i o n o m i c s: This species is known only from one locality in Siahkal county, Gilan province, northern Iran, where the two type specimens were sifted at an altitude of almost 1700 m.

Figures

Figs 48-52: Geostiba impressiventris nov.sp. from the environs of Qolqol: (48) male habitus; (49) male forebody; (50) male abdominal segments VII-VIII in lateral view; (51) male abdominal segments VII-VIII in dorsal view; (52) median lobe of aedeagus in lateral view. Scale bars: 48: 1.0 mm; 49-51: 0.5 mm; 52: 0.1 mm.