Tropimenelytron schuelkei, 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 : 490-491

Tropimenelytron schuelkei nov.sp. ( Figs 8-14 )

Holotype Ƌ: China: Yunnan [ CH 07-08], Dali Bai Auton. Pref., Diancang Shan 43 km NW Dali, 3078 m, 25°59'35"N, 99°52'06"E, W pass, Rhodod., oaks [sic], bamboo, sifted, 29. V.2007, M. Schülke / Holotypus Ƌ Tropimenelytron schuelkei sp.n. det. V. Assing 2007 (cAss).

D e s c r i p t i o n: 3.9 mm. Habitus as in Fig. 8 . Coloration: head dark-brown; pronotum reddish-brown; elytra yellowish-brown; abdomen reddish-brown, with the anterior 3/4 of segment VI slightly darker; legs yellowish; antennae dark-brown, with the basal 3 antennomeres yellowish brown.

Head oblong and of ovoid shape, 1.15 times as long as wide; punctation extremely fine, barely noticeable; surface with distinct microreticulation and subdued shine. Eyes small, not projecting from lateral contours of head, approximately 1/3 the length of postocular region in dorsal view ( Figs 9-10 ). Antennae gradually incrassate apically, antennomere X approximately 1.5 times as wide as long ( Fig. 11 ).

Pronotum approximately as wide as long and 1.3 times as wide as head; maximal width in anterior half; posterior angles weakly marked ( Fig. 9 ); punctation fine; microreticulation similar to that of head.

Elytra short and distinctly dilated posteriad, approximately 1.2 times as wide and at suture 0.60 times as long as pronotum; humeral angles weakly marked ( Fig. 9 ); punctation dense and very fine; microreticulation more pronounced than that of head and pronotum. Hind wings reduced. Metatarsomere I slightly longer than II.

Abdomen approximately as wide as elytra, widest at segments V / VI; tergites III-V anteriorly with shallow impression; punctation very fine, sparse on tergites III-V and VIII, extremely sparse on tergites VI-VII; posterior margin of tergite VII without palisade fringe.

Ƌ: elytra with pair of posteriorly diverging oblong elevations ( Fig. 9 ); abdominal tergites III-VI without tubercles; tergite VII at posterior margin with small median tubercle and with several small granula on either side of tubercle; posterior margin of tergite VIII truncate and weakly serrate ( Fig. 12 ); posterior margin of sternite VIII convex; median lobe of aedeagus as in Figs 13-14 .

♀: unknown.

E t y m o l o g y: The species is dedicated to my friend and colleague Michael Schülke, who collected the holotype.

C o m p a r a t i v e n o t e s a n d s y s t e m a t i c s: The genus Tropimenelytron was described by PACE (1983), who attributed it to Scheerpeltz, although the latter had not provided a valid description. Several years later, PACE (1991) regarded Tropimenelytron as a subgenus of Pelioptera KRAATZ 1857 , based on the similar morphology of the ligula and of the ventral aspect of the thorax. GUSAROV (2002) examined the type species and additional representatives of both Pelioptera and Tropimenelytron , and reinstated the latter as a distinct genus, a concept tentatively proposed already by ASSING (2000).

According to SMETANA (2004), five species of Tropimenelytron were previously known from China ( T. eremita (PACE 1998) , T. kowloonense (PACE 1998) , T. lii (PACE 1998) , T. viaticum (PACE 1998)) and Taiwan ( T. pacei ( SMETANA 2004)) . From the four species recorded from mainland China, T. schuelkei is readily separated by external characters alone (much shorter elytra, reduced hind wings, smaller eyes, a more slender head, and paler coloration). From the brachypterous, microphthalmous, and pale-coloured T. pacei from Taiwan, the new species is distinguished by larger size ( T. pacei : 2.7 mm), larger eyes (in T. pacei composed of approximately 15 ommatidia), the much larger and differently shaped elevations on the male elytra, the different modifications of the male tergite VII, and by the slightly different shape of the median lobe of the aedeagus. For illustrations of the four species from the Chinese mainland see PACE (1998c). Tropimenelytron pacei is figured (as Geostibida smetanai) by PACE (1998b).

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 west of Gongshan in western Yunnan province. The adaptive reductions of the eyes, wings, and pigmentation, as well as the altitude of the type locality suggest that the distribution of the species is probably restricted.The holotype was sifted in a mixed forest at an altitude of 3020 m.

Figures

Figs 8-14: Tropimenelytron schuelkei nov.sp.: (8) habitus; (9) forebody; (10) head in lateral view; (11) antenna; (12) male abdominal segments VI-VIII; (13-14) median lobe of aedeagus in lateral and in ventral view. Scale bars: 8: 1.0 mm; 9, 11-12: 0.5 mm; 10: 0.2 mm; 13-14: 0.1 mm.