Motuotrichius yangi Huang & Chen, new species

(Figs. 1–22)

Type material. Holotype (Figs. 1–3): CHINA: ♂, SE Tibet, Motuo County, Hanmi, ca. 2100m, 29.VII.2011, X.- D. Yang leg. (Entomological Laboratory of Shanghai Normal University, Shanghai, China). Paratypes (2 ♂♂, 5 ♀♀ in total): CHINA: 1 ♀, SE Tibet, Motuo County, Hanmi, 2000m, 9.VIII.2005, Hao Huang leg. (Canadian Museum of Nature, Ottawa, Canada); 1 ♂, 2 ♀♀, same label data as holotype except, 4.VIII.2011 (C.-C. Chen Collection, H. Huang Collection); 1 ♂, 2 ♀♀, SE Tibet, Motuo County, 80k, 12.VIII.2012, X.- D. Yang leg. (H. Huang Collection).

Etymology. This new species is named in honor of Mr. Xiao-Dong Yang, our good friend who collected the male specimens of this new species.

Holotype description. The generic characters mentioned above will not be repeated herein.

Length of pronotum-elytra measured from apex of pronotum to the caudal end of elytra: 10.2 mm.

Entire body slender like in Indotrichius Krikken, 2009 species. Head including clypeus, eyes and antennae similarly shaped as in Indotrichius ornatus (Jordan, 1895), but with the following differences: clypeus with lateral margins more parallel, not contracted forwards; dorsal surface of head dark green and unmarked, with clypeus metallic; antenna testaceous, with first antennomere and club somewhat green. Pronotum similarly shaped as in Epitrichius fraterculus, with basolateral corner of pronotum distinctly deflexed; dark green in color and unmarked; heavily punctate everywhere, with white, subappressed setae along lateral margins. Scutellum semicircular and transverse, dark green. Elytra glabrous to the naked eyes and similarly shaped as in Indotrichius ornatus, but a little longer than in the latter; each elytron with 10 complete longitudinal series of irregular punctures, and with additional incomplete series of punctures between first and second striae (counting from suture); interspaces between striae rather flat, sparsely dusted with minute punctures; each elytron with a large anterior orange patch and a small posterior orange patch on the dark green base. Pygidium yellow with midline unmarked, evenly clad with erect, fine setae. Legs slender, with the dorsal surface of protibia dark metallic green, and with all other parts of legs black on dorsal surface, not in great contrast with the body as in Indotrichius ornatus. Ventral surface of the body and the legs black and concolorous. Pilosity of ventral surface of body well developed and pale yellow.

Male genitalia (Figs. 15–22): parameres simple, symmetric, depressed, and without branches. Internal sac pigmented and clad with microsetae at middle and apex, without lateral patches formed by larger and darker scales (internal sac of Indotrichius ornatus (Fig. 23) bears three well-separated, large patches formed by markedly larger scales than in Motuotrichius yangi).

Description of male paratypes. Individual variation is found in the size of the orange patches on the elytra, which can be smaller than in the holotype or entirely absent (Fig. 4).

Description of female paratypes (Figs. 5–6). Sexual dimorphism is only found in the size of the orange patches on the elytra: the anterior patches of female are nearly half as long as elytra, markedly longer than in male.

Remarks. The little-known species Trichius dombrowskii Nonfried, 1906 from Manipur, India was described by Arrow (1910) based on a translation of the original description by Nonfried (1906) to have the following characters distinguishable from Motuotrichius yangi: 1) “length 16 mm ”; 2) body “shining coppery red beneath”; 3) pronotum “lightly channelled along the middle”; 4) pronotum “bearing an impression, consisting of closely set punctures, and opaque” near “base of the scutellum”; 5) pronotum green in colour, “the sides having a white margin, with a spot of the same nature almost in the middle”; 6) “elytra dull green, white-spotted”; 7) “pygidium coppery red, closely shagreened, with a large round white spot on each side”; 8) “sides of the abdominal segments white-spotted”; 9) “legs slender, coppery red”; 10) “front tibiae bidentate”. Based on the original description translated by Arrow (1910), Trichius dombrowskii should be placed in the genus Tibiotrichius Miyake, 1994.

Field observations. The new species is sympatric with Indognorimus costipennis and Indotrichius gorodinskii in the Motuo area of southeastern Tibet. However, it occurs in higher elevations than Indognorimus costipennis and Indotrichius gorodinskii. The first specimen of Motuotrichius yangi was captured by the first author using a high net from the canopy of a forest at Hanmi, Motuo. The others were observed perching on the leaves of plants.