Ischnosoma molle, Assing & Schülke, 2017

Assing, Volker & Schülke, Michael, 2017, On the Ischnosoma fauna of Georgia (Coleoptera: Staphylinidae: Tachyporinae), Beiträge Zur Entomologie = Contributions to Entomology (Beitr. Entomol.) 67 (2), pp. 195-206 : 201-202

Ischnosoma molle spec. nov.

urn:lsid:zoobank.org:act:75E5A095-ACCC-4862-877D-76464BA33ABE

( Figs 24–32 , Map 2 )

Type material: Holotype : “N 41°39'12 E 41°45'36 (9), Georgien Adjara, Batumi 7 km NE 500–600 m, Brachat & Meybohm 24.6.2017 / Holotypus  Ischnosoma molle sp. n. det. V. Assing 2017” (cAss) . Paratypes: 1 , 1 : same data as holotype (cAss, cSch); 1 : “N 41°34'23 E 42°25'06 (6), Georgien Adjara, Skhalta - Tal 970 m, Brachat & Meybohm 22.6.2017 ” (cAss) .

Etymology: The specific epithet (Latin, adjective: soft) alludes to the weakly sclerotized aedeagus, including its internal structures.

Description: Body length 4.7–6.1 mm; length of forebody 2.1–2.5 mm; length of antenna 1.5–1.7 mm. Based on external characters ( Fig. 24 ) indistinguishable from I. solodovnikovi SCHÜLKE, 2001 (Northeast Anatolia: Trabzon, Rize).

: sternite VII ( Figs 25–26 ) with an oblong and extensive cluster of dense pale short setae in postero-median portion, near middle of posterior margin with modified short and stout setae; sternite VIII ( Figs 17–28 ) with broadly and deeply concave posterior margin, in posteromedian portion with cluster of dense and moderately long setae; aedeagus ( Figs 29–32 ) 0.75 mm long, apex of ventral process subapically abruptly narrowed and apically acute in ventral view; internal structures weakly sclerotized; parameres regularly tapering apicad and with approximately 13 setae each.

Comparative notes: Based on the highly similar external and male sexual characters (including the shape of the apex of the ventral process of the aedeagus), I. molle is undoubtedly most closely allied to I. solodovnikovi , from which it differs only by a denser postero-median cluster of setae on the male sternite VIII, a less oblong male sternite VIII with a more broadly and more deeply concave posterior margin and with a more defined cluster of denser and longer setae, and an aedeagus with a more acute apex of the ventral process (ventral view) and with less distinctly sclerotized internal structures of different shapes.

Distribution and natural history: This species is currently known from two localities in the southwestern Caucasus Minor, Adjara region, Southwest Georgia ( Map 2 ). Its known distribution is separated from the allopatric range of I. solodovnikovi by two major river valleys.

The specimens were collected by sifting leaf litter in a mixed deciduous forest with walnut, chestnut, beech, laurel, and rhododendron (type locality) and in a mixed deciduous forest with beech and rhododendron at altitudes between approximately 550 and 970 m (MEYBOHM pers. comm.).

Figures

Map 2: Distributions of species of the Ischnosoma spelaeum group in the Caucasus region, based on revised and reliable records: I. campbelli (black diamonds); I. major (white diamonds); I. molle (black circles); I. solodovnikovi (white circles). White square: doubtful locality “Helenendorf” (today Göygöl).

Figs 24–35: Ischnosoma molle spec. nov. (24–32), I. barbigerum spec. nov. (33), and I. caucasicum, paratype (34–35): forebody (24); male sternite VII (25, 34); postero-median portion of male sternite VIII (27, 33, 35); male sternite VIII (27); postero-median portion of male sternite VIII (28); median lobe of aedeagus in lateral view (29–30); apex of ventral process of aedeagus in lateral and in ventral view (31–32). Scale bars: 24: 0.5 mm; 25–30, 33–35: 0.2 mm; 31–32: 0.1 mm.

Figs 11–23: Ischnosoma barbigerum spec. nov. (11–18) and I. caucasicum from Krasnaya Polyana (19–23): forebody (11); male sternite VII (12); male sternite VIII (13, 19); postero-median portion of male sternite VIII (14, 20); (15–16, 21–22) median lobe of aedeagus in lateral and in ventral view; apex of ventral process of aedeagus in lateral and in ventral view (17–18, 23). Scale bars: 11: 0.5 mm; 12–16, 19–22: 0.2 mm; 17–18, 23: 0.1 mm.