Thoracochirus yunxianius, Li & Wang & Li & Zhou, 2013

Li, Guo-Feng, Wang, Chun-Mei, Li, Zhong-Wei & Zhou, De-Quan, 2013, A new species of the genus Thoracochirus Bernhauer (Coleoptera: Staphylinidae: Osoriinae) from Yunnan, China, Zootaxa 3750 (1), pp. 89-94 : 90-93

Thoracochirus yunxianius sp. nov.

( Figs. 1A–B , Figs. 2A–B , Figs. 3A–C , Figs. 4A–E )

Type material. Holotype: CHINA: Yunnan Prov.: ♂, Yun County, Man wan village, alt. 2000m, 24°44′N, 100°12′E, 23–27-VII-2013, Li Guo-feng leg. ( YFTC) . Paratypes: CHINA: Yunnan Prov.: 10♂♂, 7♀♀, same data as the Holotype ( YFTC) .

Description. BL: 6.81–8.30mm. HL: 0.59mm, PL: 1.35mm, EL: 1.57mm, HW: 1.47mm, PW: 2.00mm, EW: 1.80mm. Body subconvex, moderately stout, almost cylindrical, surface almost shining and setose. Body bicolored. Head, pronotum, elytra, abdomen (except for the yellowish -brown terminal segmnet) black; mouthpart, clypeus, antenna, femora, tibiae, tarsi, yellowish-brown. ( Figs. 1A–B ).

Male: Head transverse, frontal impression broadly depressed, lateral lobe convex and furnished frontally with a distinctly triangular tooth; clypeus elongate with frontal margin subarcuate, surface slightly crinkled, lateral margin covered with sparse and yellowish setae, frontal part with two convex tubercles; the median sulcus broad and deep, longer than the longitudinal diameter of eyes, vertex covered with densely punctures and long yellowish pubescence, except for the smooth lateral lobe.

Labrum ( Fig. 3B ) emarginated frontally, rounded laterally, covered with sparse long setae, on the side of anterior margin with two membraneous lobes projecting and ciliate. Mandible ( Fig. 2B ) robust, protruding and with setiferous puncture among three dorsal sharp tooth. Inner lobe of maxilla ( Fig. 2A ) elongate, with one robust and pointed teeth at the apex, the inner margin ciliate and dentate with 6 inconspicuous denticles, outer lobe smaller, top part and disc densely ciliate. Mentum ( Fig. 3C ) trapeziform and sparsely setaceous, with a curved groove, frontal margin medially tridentate, the median tooth more protruding than lateral teeth and basally depressed. Glossa frontally truncated. Paraglossa ciliate and separated from glossa ( Fig. 4E ).

Antennae long, distinctly geniculate, posteriorly reaching the middle of elytra, 1 st segment extra elongate, baculiform, apically emarginated, about as long as 2 nd –3th segments together, 2 nd longer than wide, 3 rd baculiform, long and narrowed at base, 4 th –5 th longer than wide, 6 th –10 th transverse,11 th coniform, bluntly pointed, about 2 times as long as 10 th, the relative length of segments from base to apex as 0.53: 0.20: 0.30: 0.20: 0.20: 0.20: 0.20: 0.20: 0.19: 0.19: 0.37. All segments covered with dense long setae.

Pronotum strongly transverse, frontal margin distinctly bisinuate, lateral sides slightly convex outward, posterior margin edged and protruding in the middle, posterior angle weakly angulate, median longitudinal sulcus narrow and evenly depressed but the posterior end expanded as inverse “Y”, disc densely covered with yellowish pubescence and umbilicate punctures, close to lateral region scattered with distinct long verrucous denticles. In marginal area, lateral line continuous, strongly bent upward at hind angle, and connecting with basal line of posterior constriction.

Protibiae slightly broadened apicad, crenulate externally, with 12 to 13 prominent denticles.

Elytra wider than long (ratio 1.15), almost quadrate, posterior margin subarcuate, dorsal disc with dense setae and rugous punctures, along lateral and frontal region sparsely scattered with indistinct verrucous denticles. Each elytron with a shallow sulcus paralled to suture. Wing developed.

Abdomen cylindrical, weakly broadened posteriorly, segments except 7 th and 8 th densely covered with setae, each segment with an anterior and a posterior rows of setae, with the anterior row sparser and the posterior one denser on lateral side.

Aedeagus ( Figs. 4A–B )with median lobe slightly bulbous at base, slightly curved behind basal orifice, posterior part slightly flat from lateral view, very weakly sclerotized on the dorsal side and slightly contracted at apex; parameres short and rounded at apex, with basal part protruding dorsally and connecting with each other to form a triangular construction. Ninth tergite ( Fig. 3A ) sclerotized and left and right plates separated, each with 6 setae of various length. Tenth tergite almost membraneous except for sclerotized apical part, posterior margin truncate, each side with 2 pairs setae. Ninth sternite ( Fig. 4D )composed of two plates, apical plate sclerotized except for membraneous apex, with 2 long setae and 2 pairs of short setae, basal plate less sclerotized and left and right part separated.

Female: Similar to male, but 9 th sternite ( Fig. 4C ) with hemisternite less sclerotized, anterior margin weakly protruding, second gonocoxite strongly sclerotized except for slightly membraneous apex, with 1 stout seta and 1 short seta.

Remarks. Thoracochirus yunxianius sp. nov. is similar to T. yingjiangensis Wu & Zhou from Yunnan, in the shape of the head, pronotum and elytra, but can be distinguished from the latter by the following characters (see key below): head near posterior-lateral margin scattered with no some small verrucous denticles; pronotum with median longitudinal sulcus narrow and evenly depressed but the posterior end expanded as inverse “Y”; elytra long lateral and frontal region sparsely scattered with indistinct verrucous denticles. Abdomen segments with anterior and posterior rows of setae and not vanished in the middle.

Etymology. The specific epithet is derived from the type locality “Yunxian”.

Habitat and distribution. The new species was found in dead wood. It is at present only known from the type locality in southwest Yunnan, China .

Figures

FIGURE 1. Thoracochirus yunxianius sp. nov. A. male habitus, dorsal view. B. female habitus, dorsal view. Scale bars: 1.00 mm.

FIGURE 2. Thoracochirus yunxianius sp. nov. A. Dorsal view of left maxilla. B. Dorsal view of left mandible. Scale bars: 0.20 mm.

FIGURE 3. Thoracochirus yunxianius sp. nov. A. Ventral view of male tergites 9 and 10. B. Labrum. C. Mentum. Scale bars: 0.20 mm.

FIGURE 4. Thoracochirus yunxianius sp. nov. A. ventral view of aedeagus. B. lateral view of aedeagus. C. female sternite 9. D. male sternite 9. E. Ligula and labial palpi. Scale bars: 0.20 mm.