Myllaena ambulans, Assing, 2018

Assing, Volker, 2018, On some Myllaena species in the East Mediterranean and Caucasus regions (Coleoptera: Staphylinidae: Aleocharinae), Linzer biologische Beiträge 50 (2), pp. 1015-1032 : 1030

Myllaena ambulans nov.sp. ( Figs 33-43 , Map 3 )

T y p e m a t e r i a l: Holotype ♂: " ARMENIA [19] - 35 km NW Sisian , 39°40'59''N, 45°46'50''E, 2070 m, stream valley, sifted, 3.VII.2016, V. Assing / Holotypus ♂ Myllaena ambulans sp. n. det. V. Assing 2018" (cAss) . Paratypes: 2♂♂, 3♀♀: same data as holotype (cAss) ; 1♀: same data, but leg. Schülke ( MNB) ; 3♂♂, 7♀♀: " ARMENIA [20]- 35 km NW Sisian , 39°41'01''N, 45°46'46''E, 2080 m, swampy meadow, 3.VII.2016, V. Assing" (cAss) ; 7 exs., same data, but leg. Schülke ( MNB) ; 1♂: " ARMENIA [33] – S Spitak , 2000 m, 40°45'45''N, 44°16'23''E, bank of small stream, 7.VII.2017, V. Assing " (cAss) ; 1♀: same data, but leg. Schülke ( MNB) ; 1♂: " ARMENIA [36] – S Martuni , Sulema Pass, 39°57'58''N, 45°14'13''E, 2340 m, near stream, 8.VII.2017, V. Assing " (cAss) .

E t y m o l o g y: The specific epithet is the present participle of the Latin verb ambulare (to walk) and alludes to the reduced hind wings.

D e s c r i p t i o n: Body length 1.8-2.2 mm; length of forebody 0.95-1.05 mm. Coloration: body blackish-brown to black; legs dark-brown to blackish-brown with paler tarsi; antennae blackish-brown.

Head ( Fig. 33 ) wedge-shaped. Eyes relatively small, not protruding from lateral contours of head, shorter than the distance from posterior margin of eye to posterior constriction of head in lateral view. Antenna approximately 0.6 mm long; antennomeres IV-VIII approximately as long as broad (sometimes weakly oblong), IX-X transverse.

Pronotum ( Fig. 33 ) 1.3-1.4 times as broad as long and 1.3-1.4 times as broad as head; posterior margin not sinuate near posterior angles.

Elytra ( Fig. 33 ) short, approximately 0.65 times as long as pronotum. Hind wings reduced, rudiments only slightly protruding from under the elytra when fully unfolded. Posterior margin of abdominal tergite VIII with palisade fringe.

♂: posterior margin of tergite VIII obtusely pointed in the middle ( Fig. 39 ); sternite VIII ( Fig. 40 ) of similar length as sternite VIII, posterior margin convex and with long thin setae; median lobe of aedeagus 0.32-0.35 mm long and shaped as in Figs 34-37 ; paramere ( Fig. 38 ) nearly 0.5 mm long, with very long and slender apical lobe.

♀: tergite VIII ( Fig. 41 ) of similar shape as in male; sternite VIII ( Fig. 42 ) approximately as long as tergite VIII, posterior margin very weakly convex, nearly truncate, with long and rather stout marginal setae; spermatheca as in Fig. 43.

C o m p a r a t i v e n o t e s: Myllaena ambulans belongs to a group of small-sized species including M. minuta (GRAVENHORST, 1806), M. gracilis (MATTHEWS, 1838), and M. infuscata KRAATZ, 1853. It is distinguished from M. infuscata , the only species of this group recorded from Armenia and with elytra of reduced length, by even shorter elytra ( M. infuscata : elytra usually 0.75-0.80 times as long as pronotum), very short hind wings, darker average coloration ( M. infuscata : body mostly dark-brown to blackishbrown), the shapes of the apex of the ventral process (lateral view) and internal structures of the aedeagus, a less oblong and posteriorly less acute female tergite VIII, and by a larger distal portion of the spermatheca capsule with a more pronounced cuticular invagination. For illustrations of the primary sexual characters of M. infuscata see Figs 44- 47.

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: This species is currently known from three localities in North, Central, and South Armenia ( Map 3 ). The specimens were collected from moist litter near streams, on stream and river banks, and in a swampy meadow at altitudes of 1680-2340 m.

Figures

Map 3: Distribution of Myllaena ambulans in Armenia.

Figs 33-38: Myllaena ambulans: (33) forebody; (34-37) median lobe of aedeagus in lateral and in ventral view; (8) paramere. Scale bars: 33: 0.5 mm; 34-38: 0.1 mm.

Figs 39-47: Myllaena ambulans (39-43) and M. infuscata from Armenia (44-47): (39) male tergite VIII; (40) male sternite VIII; (41) female tergite VIII; (42) female sternite VIII; (43, 46-47) spermatheca; (44-45) median lobe of aedeagus in lateral and in ventral view. Scale bars: 39-42: 0.2 mm; 43-47: 0.1 mm.