Sunius acutissimus, Assing & A, 2008

Assing, V. & A, North, 2008, A revision of the Sunius species of the Western Palaearctic region and Middle Asia (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 40 (1), pp. 5-135 : 109-111

4.67. Sunius acutissimus nov.sp. ( Figs. 186-192 , Map 22 )

T y p e m a t e r i a l: Holotype 3: " Tadshikistan , Seravshan Rg. , Marguzor lakes, 5. lk [= lake] Hurdak [ca. 39°08'N, 67°57'E], 1950-2400 m, 20.-30.04.97, S. Pajdak leg. / Holotypus 3 Sunius acutissimus sp. n. det. V. Assing 2007" (cAss) . Paratypes: 4♀♀: same data as holotype (cSch, cAss) ; 1♀: "USSR Uzbekistan, Chamzabad, J. Viša lgt. / Fergana, 7.5.78 [overleaf]" (cBoh) ; 1♀: "USSR Uzbekistan, Chamza-Abad , 8.5.1977, J. Strejček lgt." (cBoh) ; 1♀: " Turkmenia mer., Bacharden [= Baherden; 38°26'N, 57°26'E], 26.4.1992, Lgt. Snížek" (cBoh) ; 13: " Asia c. USSR, 7.4.1986, Dzaus [?], Tian-Schan [= Tien-Shan], 1000 m. n, Z. Kačenka [?] lgt." (cAss) .

D e s c r i p t i o n: 4.3-5.0 mm. Habitus as in Fig. 186 . Coloration: head and abdomen blackish; pronotum dark brown to blackish brown; elytra, legs, and antennae reddish. Head 1.02-1.05 times as long as wide; puncturation similar to that of S. wrasei , coarse, extremely dense in lateral areas and moderately dense in median dorsal area ( Fig. 187 ); microsculpture absent. Eyes 0.40-0.45 times as long as postocular region in dorsal view. Antenna as in S. claviceps .

Pronotum approximately 1.05 times as long as wide and 0.90-0.95 times as wide as head ( Fig. 187 ); puncturation almost as coarse as that of head and extremely dense, impunctate midline very narrow (similar to S. claviceps ), sometimes not reaching anterior and posterior margins; interstices much narrower than diameter of punctures.

Elytra approximately of similar length and 1.10-1.15 times as broad as pronotum ( Fig. 187 ); puncturation similar to that of S. claviceps . Legs as in S. claviceps .

Abdomen slightly wider than elytra; puncturation and microsculpture as in S. claviceps ; posterior margin of tergite VII with palisade fringe.

E t y m o l o g y: The name (Latin, adjective) refers to the extremely acute ventral process of the aedeagus.

3: sternite VII with posterior margin moderately concave in the middle, pubescence in posterior median area directed diagonally postero-mediad ( Fig. 188 ); sternite VIII with posterior excision somewhat deeper than in S. claviceps ( Fig. 189 ); aedeagus of similar general morphology as in S. claviceps , as large as that of S. wrasei (0.84 mm), but with conspicuously acute ventral process.

C o m p a r a t i v e n o t e s: From all other species of the S. viator group, the new species is distinguished especially by the remarkably acute ventral process of the aedeagus. From S. claviceps , it is additionally separated by the darker coloration of the head and the pronotum, by the denser puncturation of the head, by the broader elytra, by the shape and chaetotaxy of the male sternite VII, and by the deeper posterior excision of the male sternite VIII. From S. wrasei , it is also distinguished by slightly smaller size, the darker coloration of the pronotum, the shorter antennae and legs, the shorter elytra, as well as by the shallower posterior concavity of the male sternite VII.

D i s t r i b u t i o n a n d b i o n o m i c s: The species has been recorded from few localities in Tajikistan, Uzbekistan, and Turkmenistan ( Map 22 ). Despite thorough search and the assistance of several colleagues, it has not been possible to identify the locality in the Tien-Shan (Dzaus?). The type specimens were collected at altitudes between 1000 and 2400 m in April and May.

Figures

Map 22: Distributions of species of the S. viator group in the Caucasus region and Middle Asia, based on examined records: Sunius claviceps (REITTER) (filled circles), S. acutissimus nov.sp. (open circles), S. basalis (REITTER) (open square), and S. splendidulus (BOHÁČ) (filled square).

Figs 186-192: Sunius acutissimus nov.sp., holotype: (186) habitus; (187) forebody; (188) male sternite VII; (189) male sternite VIII; (190-191) aedeagus in lateral and in ventral view; (192) apex of aedeagus in lateral view. Scale bars: 186-187: 1.0 mm; 188-191: 0.2 mm; 192: 0.1 mm.