Atheta (Microdota) altincisa, Assing, 2009

Assing, V., 2009, New species and additional records of Homalotini, Athetini, Pygostenini, and Lomechusini from Yunnan, China (Coleoptera: Staphylinidae: Aleocharinae), Linzer biologische Beiträge 41 (1), pp. 485-507 : 494-497

Atheta (Microdota) altincisa nov.sp. ( Figs 24-36 )

Holotype Ƌ: China: Yunnan [CH07-28], Nujiang Lisu Aut. Pref., Gaoligong Shan , side valley 19 km NW Liuku, 25°59'02"N, 98°42'23"E, 2730 m, devast. prim. for., litter sifted, 10.VI.2007, M. Schülke / Holotypus Ƌ Atheta altincisa sp.n. det. V. Assing 2007 (cAss). Paratypes: 5 exs.: same data as holotype, but "[ CH 07-28A]... 10.VI.2007 " (cSch, cAss); 2 exs.: same data as holotype, but "9./ 10.VI.2007 ... D.W. Wrase " (cSch, cAss) ; 2 exs.: same data as holotype, but leg. A. Pütz (cPüt, cAss) .

D e s c r i p t i o n: 2.2-2.5 mm. Habitus as in Fig. 24 . Coloration: body yellowishbrown to reddish-brown, occasionally with abdominal segment VI and adjacent parts of segments V and VII slightly darker; legs yellowish; antennae brown, with the basal 2-3 antennomeres yellowish to yellowish-brown.

Head slightly wedge-shaped, approximately as wide as long or weakly transverse ( Fig. 25 ); punctation rather sparse and extremely fine, barely noticeable; surface with distinct microreticulation and with weak shine. Eyes small ( Fig. 33 ), not projecting from lateral contours of head, approximately 1/5-1/4 the length of postocular region in dorsal view. Antennae gradually and distinctly incrassate apically, antennomere X approximately twice as wide as long ( Fig. 26 ).

Pronotum approximately 1.20-1.25 times as wide as long and 1.15-1.20 times as wide as head ( Fig. 25 ); maximal width in anterior half; posterior angles weakly marked, rounded; punctation and microreticulation similar to those of head; pubescence of midline directed cephalad.

Elytra 1.05-1.10 times as wide and at suture approximately 0.55 times as long as pronotum ( Fig. 25 ); punctation dense and fine, but more distinct than that of head and pronotum; microsculpture shallow, interstices somewhat shiny. Hind wings completely reduced. Metatarsomere I short, approximately as long as II.

Abdomen approximately 1.15 times as wide as elytra, widest at segment V; tergites III-V anteriorly with shallow impression; punctation very fine, moderately dense on tergite III, decreasing in density from tergites IV-VI, and very sparse on tergite VII; microsculpture very shallow on anterior tergites, distinct on posterior tergites; posterior margin of tergite VII with very narrow, barely noticeable rudiment of a palisade fringe; tergite VIII without apparent sexual dimorphism ( Figs 27, 31 ).

Ƌ: head in dorsal median area depressed or very weakly impressed ( Fig. 25 ); sternite VIII distinctly longer than tergite VIII, posteriorly distinctly projecting ( Fig. 28 ); median lobe of aedeagus shaped as in Figs 29-30 , internal sac with rather large and distinctly sclerotised internal structures; paramere as in Figs 34-35 .

♀: median dorsal area of head not depressed or impressed; sternite VIII somewhat longer than tergite VIII, middle of posterior margin deeply incised and densely furnished with yellowish stout modified setae ( Fig. 32 ); spermatheca as in Fig. 36.

E t y m o l o g y: The name (Latin, adjective) is composed of the adjectives alta (deep) and incisa, and refers to the conspicuous posterior incision of the female sternite VIII.

C o m p a r a t i v e n o t e s: Among its consubgeners known from China, A. altincisa is similar in external characters (pale coloration, small eyes, reduced elytra and hind wings) only to A. geostiboides and A. bicoloricornis . From the former it is distinguished by the apically more distinctly incrassate antennae with more transverse preapical antennomeres, the completely different shape of the male sternite VIII, by the different shape of the aedeagus, the much more strongly sclerotised and differently shaped internal structures of the aedeagus, the different shape of the paramere, especially of the apical lobe, as well as the different shape and chaetotaxy of the female sternite VIII (posterior margin in A. geostiboides only shallowly concave in the middle and with less dense and less stout modified setae), and the different shape of the spermatheca. From A. bicoloricornis , it is separated by a broader body, the distinctly paler coloration of the antennomeres IV-XI, by the depressed or impressed median dorsal area of the male head, by the unmodified male tergite VIII, and by the completely different male primary sexual characters. For illustrations of A. geostiboides and A. bicoloricornis see ASSING (2004a) and Figs 15-23 , respectively.

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 type locality is situated in the Gaoligong Shan, to the northwest of Liuku in western Yunnan province. As can be inferred from the adaptive reductions of pigmentation, eye size, and wings, as well as from the altitude (2730 m) of the type locality, the distribution of the species is probably restricted. The type specimens were sifted from litter in a degraded primary forest.

Figures

Figs 24-32: Atheta altincisa nov.sp.: (24) habitus; (25) forebody; (26) antenna; (27) male tergite VIII; (28) male sternite VIII; (29-30) median lobe of aedeagus in lateral and in ventral view; (31) female tergite VIII; (32) female sternite VIII. Scale bars: 24: 1.0 mm; 25: 0.5 mm; 26-28, 31-32: 0.2 mm; 29-30: 0.1 mm.

Figs 33-36: Atheta altincisa nov.sp.: (33) head in lateral view; (34-35) paramere; (36) spermatheca. Scale bars: 33-35: 0.2 mm; 36: 0.1 mm.

Figs 15-23: Atheta bicoloricornis nov.sp.: (15) habitus; (16) forebody; (17) head in lateral view; (18) antenna; (19) male tergite VIII; (20) male sternite VIII; (21-22) median lobe of aedeagus in lateral and in ventral view; (23) apical portion of paramere. Scale bars: 15: 1.0 mm; 16: 0.5 mm; 17-20: 0.2 mm; 21-22: 0.1 mm; 23: 0.05 mm.