Leptusa (Neopisalia) triangulata, Assing, 2017

Assing, Volker, 2017, On the Leptusa fauna of the Caucasus region (Coleoptera: Staphylinidae: Aleocharinae), Linzer biologische Beiträge 49 (2), pp. 1049-1074 : 1068-1069

Leptusa (Neopisalia) triangulata nov.sp. ( Figs 14-16 , 21-23 , Map 7 )

T y p e m a t e r i a l: Holotype 3: "N 41°37'52 E 42°29'33 (3), Georgien Adjara, Danisparauli 1790 m, Brachat & Meybohm 21.6.2017 / Holotypus 3 Leptusa triangulata sp. n. det. V. Assing 2017" (cAss). Paratypes: 1♀: same data as holotype (cAss).

E t y m o l o g y: The specific epithet (adjective) alludes to the triangular projection at the base of the ventral process of the aedeagus (lateral view).

D e s c r i p t i o n: Body length 2.5-2.7 mm; length of forebody 1.10-1.15 mm. Coloration: body reddish-brown to brown; legs dark-yellowish; antennae reddish.

Head ( Fig. 14 ) of orbicular shape; punctation very fine and moderately dense, barely noticeable in the pronounced microreticulation. Eyes small, composed of approximately 10 ommatidia with pigmentation, and approximately one-fourth as long as postocular region in dorsal view. Antenna relatively long, distinctly incrassate apically; antennomere IV weakly transverse; antennomeres V-X of increasing width and increasingly transverse; antennomere X approximately twice as broad as long.

Pronotum ( Fig. 14 ) distinctly transverse, approximately 1.3 times as broad as long and 1.2 times as broad as head; maximal width in anterior half; posterior angles obtusely marked; punctation dense and fine, more distinct than that of head; interstices with pronounced microsculpture.

Elytra ( Fig. 14 ) moderately short, approximately 0.8 times as long as pronotum; punctation more distinct than that of head and pronotum; interstices with distinct microsculpture. Hind wings completely reduced.

Abdomen broader than elytra; punctation fine and moderately dense, sparser on posterior than on anterior tergites; interstices glossy, with very shallow microsculpture composed of short transverse (tergites III-V) and isodiametric (tergites VI-VIII) meshes; posterior margin of tergite VII with narrow rudiment of a palisade fringe; posterior margin of tergite VIII ( Fig. 21 ) very shallowly concave in the middle; tergite VII with sexual dimorphism.

3: tergite VII with narrow and minute median tubercle posteriorly; sternite VIII angularly produced posteriorly; median lobe of aedeagus ( Fig. 15 ) 0.41 mm long, at base of ventral process with pronounced triangular projection in lateral view; paramere ( Fig. 16 ) approximately as long as median lobe, apical lobe moderately long and slender.

♀: posterior margin of sternite VIII ( Fig. 22 ) obtusely produced in the middle, but less so than in male; spermatheca as in Fig. 23.

C o m p a r a t i v e n o t e s: Regarding the shape of the aedeagus, L. triangulata is similar to L. migrituber , L. spoliata ASSING, 2002 (Northeast Anatolia), and L. longilobata ASSING, 2007 (Northeast Anatolia). It is distinguished from all of them by a smaller pronotum (in relation to the head), smaller eyes, a more glossy abdomen with shallower microsculpture composed of isodiametric and short transverse meshes, and additionally as follows:

from L. migrituber by the shapes of tergite VIII and the male sternite VIII, by the position of the triangular position of the triangular projection at the base of the ventral process of the aedeagus, and by the differently shaped apex of the ventral process of the aedeagus;

from L. spoliata by darker coloration, a more slender habitus, a head of orbicular shape ( L. spoliata : head somewhat wedge-shaped), a shallower posterior concavity of tergite VIII, the presence of a minute tubercle on the male tergite VII, and by a ventral process of the aedeagus with a less pronounced triangular projection and an apex of different shape;

from L. longilobata by darker coloration, a more slender habitus, a head of orbicular shape ( L. longilobata : head somewhat wedge-shaped), the presence of a minute tubercle on the male tergite VII, a ventral process of the aedeagus with a less pronounced triangular projection and an apex of different shape, and by a shorter apical lobe of the paramere.

For illustrations of L. spoliata and L. longilobata see ASSING (2002, 2007).

According to the original description of L. khnzoriani (East Racha, Georgia), this species has an aedeagus of similar shape as that of L. triangulata , but is distinguished by reddish-yellow coloration, elytra with an elevated suture and a large impression on either side of the suture, oblong median tubercles on the male tergites VII and VIII, and a much smaller aedeagus (according to the illustrations approximately 0.32-0.33 mm) ( PACE 1982). Moreover, according to an illustration provided by PACE (1989), the distal cuticular invagination of the spermatheca is very small and shallow in L. khnzoriani .

D i s t r i b u t i o n a n d n a t u r a l h i s t o r y: The type locality is situated in the east of Adjara province, Southwest Georgia, not far from the border with the Turkish province Ardahan, in the transitional zone between the Lesser Caucasus and the Pontic Mountains ( Map 7 ). The specimens were sifted from litter in a mixed forest with dominant fir and with rhododendron undergrowth (MEYBOHM pers. comm.) at an altitude of 1790 m.

Figures

Map 7: Distributions of species of the subgenus Neopisalia in the Caucasus region: L. gibbera (black circles), L. subnivalis (white circles), L. migrituber (white diamonds), L. svanetica (black diamond), L. substricta (white star), L. triangulata (black star), and L. sica (black triangles).

Figs 9-16: Leptusa migrituber nov.sp. (9-13) and L. triangulata nov.sp. (14-16): (9, 14) forebody; (10) male tergites VI-VII; (11-12, 15) median lobe of aedeagus in lateral view; (13, 16) paramere. Scale bars: 9-10, 14: 0.5 mm; 11-13, 15-16: 0.2 mm.

Figs 17-27: Leptusa migrituber nov.sp. (17-20), L. triangulata nov.sp. (21-23), and L. longalata nov.sp. (24-27): (17) male tergite VIII; (18) male sternite VIII; (19, 21) female tergite VIII; (20, 22) female sternite VIII; (23) spermatheca; (24) forebody; (25-26) median lobe of aedeagus in lateral and in ventral view; (27) paramere. Scale bars: 17-22, 24: 0.2 mm; 23, 25-27: 0.1 mm.