Geostiba (Tropogastrosipalia) xirosica, Assing, 2017

Assing, Volker, 2017, A revision of Geostiba of the West Palaearctic region. XXV. New species from Georgia and Greece, and additional records (Coleoptera: Staphylinidae: Aleocharinae), Linzer biologische Beiträge 49 (2), pp. 1093-1106 : 1094-1096

Geostiba (Tropogastrosipalia) xirosica nov.sp. ( Figs 1-6 )

T y p e m a t e r i a l: Holotype 3: "Limni/Euböa (GR), Drimona, Mt. Xiros, oberh. Wasserfall, leg. Esser & Niefeldt 22-26.3.16 / Holotypus 3 Geostiba xirosica sp. n. det. V. Assing 2016" (MNB). Paratypes: 433, 6 ♀♀: same data as holotype (MNB, cAss).

E t y m o l o g y: The specific epithet is an adjective derived from Xiros Oros, the mountain where the type locality is situated.

D e s c r i p t i o n: Body length 2.0-3.0 mm; length of forebody 0.9-1.1 mm. Coloration variable: head brown to black; pronotum pale-red to blackish-brown; elytra reddish-yellow to pale-reddish; abdomen bicoloured, with the anterior segments and segment VIII pale-brown, and with the preapical segments more or less extensively blackish, or completely blackish; legs yellow; antennae reddish-brown, with the basal 2- 3 antennomeres pale-reddish.

Large 3: pronotum ( Fig. 1 ) distinctly oblong, approximately 1.15 times as long as broad, posterior margin broadly and shallowly concave; elytra with moderately elevated, narrow, oblong tubercle extending along anterior 3/5 of suture; anterior tergites of abdomen unmodified; tergite VII ( Figs 2-3 ) posteriorly with a flat and obliquely erect (lateral view), basally broad (antero-dorsal view) median spine; median lobe of aedeagus ( Figs 4-5 ) approximately 0.25 mm long and with straight, apically narrowed cristal process.

♀: pronotum approximately as broad as long, posterior margin broadly convex, in the middle truncate; spermatheca ( Fig. 6 ) not distinctive.

I n t r a s p e c i f i c v a r i a t i o n: As has been observed also in other species of the subgenus, the male secondary sexual characters are subject to pronounced intraspecific variation. In small males, the pronotum is only indistinctly oblong and has a truncate posterior margin, and the modifications of the elytra and the abdominal tergite VII are practically obsolete.

C o m p a r a t i v e n o t e s: Geostiba xirosica is readily distinguished from the two other Tropogastrosipalia species known from Evvoia, G. aculeata (COIFFAIT, 1968) (Likhás Peninsula, extreme northwest of Evvoia) and G. matsakisi (COIFFAIT, 1968) (Dirfys Oros in Central Evvoia), by the completely different shape of the male pronotum alone. In both G. aculeata and G. matsakisi , the male pronotum is not distinctly oblong and its posterior margin is convex or pointed in the middle. For illustrations of these species see ASSING (1999). In order to account for G. xirosica , the key in ASSING (2009) is modified as follows: 61 Species from Evvoia........................................................................................................61a - Species from mainland Greece..........................................................................................63 61a Male pronotum distinctly oblong, posterior margin broadly concave ( Fig. 1 ). Median lobe of aedeagus as in Figs 4-5 . NW-Evvoia: Xiros Oros ....................... G. xirosica nov.sp. - Male pronotum approximately as long as broad, posterior margin convex or pointed in the middle..........................................................................................................................62

D i s t r i b u t i o n: Xiros Oros (990 m) is situated in the northwest of Evvoia at 38°52'N, 23°19'E. According to the labels, the specimens were collected above Drimona waterfalls, which are situated at 38°52'N, 23°18'E, at an altitude of approximately 600 m.

Figures

Figs 1-6: Geostiba xirosica nov.sp.: (1) male head and pronotum; (2-3) male tergite VII in anterodorsal and in lateral view; (4-5) median lobe of aedeagus in lateral view; (6) spermatheca. Scale bars: 1-3: 0.2 mm; 4-6: 0.1 mm.