Didrepanephorus subvittatus Benderitter, 1922

Qiu, Jian-Yue, Zhao, Ming-Zhi & Xu, Hao, 2021, Description of a new species of the genus Didrepanephorus Wood-Mason, 1878 (Coleoptera: Scarabaeidae: Rutelinae) from China with notes on allied species, Zootaxa 4933 (4), pp. 493-513 : 505-511

Didrepanephorus subvittatus Benderitter, 1922 .·镰'•龟

( Figs. 25–28 , 31–32 , 39–40 , 53–56 , 69–70 )

Didrepanephorus subvittatus Benderitter, 1922: 38 (type locality: “ Tonkin: Chapa”); Paulian 1958: 77; Muramoto 2006: 57, figs. 3–4 (habitus and genitalia of male).

Fruhstorferia subvittata (Benderitter) : Ohaus 1934a: 14; Ohaus 1934b: 121; Machatschke 1972: 54; Nagai 1984: 30 (subgenus Kibakoganea ); Muramoto 1993: 7 ( Vietnam: Vinh Phuc: Tam Dao), figs. 5 & 8 (habitus and genitalia of male); Krajčík 2007: 71 (subgeneric placement uncertain); Krajčík 2012: 110 (subgeneric placement unnoted).

Type material. The main parts of Benderitter’s collection are deposited in IRSNB and MNHN, but no conspecific specimen was previously labeled as type of Didrepanephorus subvittatus Benderitter, 1922 (Pol Limbourg, personal communication, August 2020; Antoine Mantilleri, personal communication, October 2020). While a female of this remarkable species bearing a handwritten label was found from IRSNB (Matthias Seidel, personal communication, October 2020), and its appearance and label data both match the original publication. Hence, this female is herein regarded as the holotype (by monotypy) of Didrepanephorus subvittatus Benderitter, 1922 : (♀, IRSNB, Figs. 53–56 ): Chapa, Tonkin, L. D. h. 1913 // WORLD SCARAB DATABASE, WSD00347524 // possible Holotype of Didrepanephorus subvittatus Benderitter, 1922 , det. M. Seidel 2020.

Additional material examined (4♂♂, 2♀♀). CHINA: Guangxi : 1♀ ( SHNU) , Shiwandashan Forest Park, Shangsi County, Fangchenggang , alt. 1,000 m, Zhong PENG leg. // mature larva in 2011.V.9, adult emerged in 2011. V.21; 1♂ ( SNNU), 2019.V.8, Shiwandashan Forest Park, Shangsi County , Fangchenggang , Tao ZHANG & Li-Bin MA leg.; 1♂ ( CZMZ), 2020.V.12, Niulan , Dongxing , Fangchenggang , You-Ping DENG leg .; VIETNAM: Vinh Phuc: 1♂, 1♀ ( MYNU) , 1992.VII, Tam Dao; 1♂ ( CZJZ), 1995.VII, Tam Dao .

Redescription (male). General: Body oval and convex, hairs and setae yellow ( Fig. 25 ). Head: Orange-brown. Clypeus flat, trapezoidal, anterior margin slightly emarginate; anterior angle almost right angle, sides strongly convergent anteriad and slightly swollen in basal half, roundly curved in middle, then almost subparallel in apical third; with dense, round large punctures, somewhat less punctured near anterior margin; margins with some long and short setae. Frontal-clypeal suture broadly interrupted medially, represented by a short carina at each side. Frons and vertex densely punctate with dense, semierect long setae. Eye-canthus wide and truncate at outer margin, not extends beyond outermost point of eye, anterior angle blunt. Antenna orange-brown, antennal club shorter than longer than antennomeres 2–7 combined. Labrum exposed, anterior margin slightly protruding at middle, dorsal surface rather sparsely microsculptured, with sparse, erect, short and long setae. Mandibles reddish-brown, broadest at base, lower margin shallowly constricted before base tooth, apex sharply bended upward. Maxillary palpi and labial palpi reddish-brown, simple. Mentum with sparse punctures and erect long setae, anterior margin distinctly concave in middle. Gula reddish-brown, smooth. Pronotum: Orange-brown, anterior margin and two large patch at each side of posterior half black. Strongly convex ( Fig. 31 ), about 1.44 times as wide as long, widest near middle. Anterior margin distinctly bisinuate; anterior marginal membrane distinct, obsolete before reaching anterior angle. Sides feebly concave and slightly convergent posteriad in basal half, roundly and broadly curved at middle, strongly convergent anteriad in apical half. Posterior margin broadly protruding in middle. Basal marginal line interrupted before scutellum, all other marginal lines completed. Anterior angle acute at apex and moderately protruding, posterior angle blunt at apex and slightly protruding. Surface with rather dense small punctures, rugopunctate along lateral margin. Most areas of surface with semierect short setae. Scutellum: Orange-brown, margin black. Nearly short triangular, lateral margin slightly curved, apex rounded. Surface with sparse large punctures and short setae except central part and margin. Elytra: Convex. Orange-brown; a longitudinal dark brown band along posterior part of lateral edge of disc, ended at apical umbone; dark brown along suture. Almost as wide as long, widest at middle. Intervals unrecognizable. Humeral umbone and apical umbone convex. Surface coarse, with sparse, shallow, round punctures and rather dense, semierect short setae. Epipleura glabrous. Ventral thoracic surface: Reddish-brown, posterior part of ventral mesothoracic surface orange-brown. Anterior margin of ventral prothoracic surface with dense long setae; base of ventral prothoracic surface with sparse long setae; ventral mesothoracic surface with sparse short hairs; ventral metathoracic surfaces with sparse long hairs except the area around midline. Prosternal process small, horizontally broad, shield-liked. Punctures on ventral mesothoracic surface C-shaped and gradually changed into sinuous striolae laterad. Metasternum with a distinct dark brown midline. Propygidium: Reddishbrown. Surface coarse, with dense, semierect short setae. Pygidium: Convex. Reddish-brown. Disc coarse, lateral and posterior portions indistinctly and transversely puncatate. Surface with sparse short setae. Abdomen: Reddishbrown, abdominal ventrites distinctly curved in lateral view, abdominal ventrites 1–4 slightly abbreviated ( Fig. 26 ). With sparse round punctures and semierect short setae. Posterior margin of abdominal ventrite 6 broadly and distinctly concave medially. Legs: Orange-brown to reddish-brown, with moderately dense, erect, long setae. Femora with dense punctures; tibiae with dense, coarse and irregular punctures. Inner protarsal claw simple and thickened, outer protarsal claw smaller and sharp at apex. Outer meso- and metatarsal claws widely and deeply spilt into two equal length branches respectively, the upper branches thinner and sharper. Inner meso- and metatarsal claws more curved than the outer ones. Protibia with three distinct and acute teeth. Protibial spur situates at the level of distal protibial tooth, vertically orient forwards. Meso- and metatibiae bidentate at apical edges, the upper tooth of meso- and metatibia distinctly protruding. Protarsus strongly thickened; protarsomeres 2–4 abbreviated; protarsomere 4 ventrally with a protrusion, protrusion blunt apically; meso- and metatarsomeres 4 each with an acute ventroapical protrusion, each protrusion with a pair of spines at base. Tarsomeres 5 of all legs with a small and blunt ventral protrusion in basal third. Aedeagus: As Figs. 39–40 .

Female: Body color darker ( Figs. 27–28 ). Mandible small, short, nearly triangular, apex curved upwards. Clypeus longer than in male, anterior margin distinctly emarginated and distinctly convex. Mandible reddish-brown, margin black; nearly triangular; outer edge bidentate, apical tooth acute and bends upwards, second tooth indistinct. Gula matt. Dorsal surface of head densely rugopunctate with short setae. Surface of pronotum shiny, with sparse, large, round punctures; posterior angle of pronotum more protruding. Lateral margin of scutellum almost straight. Intervals defined by rows of close and large punctures; primary stria 1 feebly convex, all primary striae with scattered small punctures; interstices with dense, irregular large punctures. Setae and hairs on the whole dorsal surface sparser, but a bit longer. Abdominal ventrites convex; abdominal ventrite 1 abbreviated medially, abdominal ventrites 2–4 almost equal in length ( Fig. 28 ); posterior margin of abdominal ventrite 6 straight medially. Protarsus thinner; metatibia stronger. Tarsomeres 4 of all legs each with an acute ventroapical protrusion, each protrusion of meso- and metatarsomeres 4 with a pair of spines at base.

Measurements. Body length: male 16.7–19.0 mm, female about 20.8 mm; body width: male 9.6–10.1 mm, female about 10.9 mm.

Differential diagnosis. Didrepanephorus subvittatus is characterized by the unique coloration pattern of the dorsal surface. Other differences between this species and its siblings are given in the differential diagnosis sections of D. heterocolor new species and D. nishiyamai .

Distribution. China: Guangxi (new record); Vietnam.

Natural history. In early May 2011, a larva was found in a rotten wood of broad-leaved tree from Mount Shiwandashan in southwestern Guangxi, and later it became a female after artificially breeding (personal observation, Zhong Peng, 2011). In early May 2019, single male has been collected by light trap from the same mountain (personal observation, Tao Zhang, 2019; Fig. 69 ).

Remarks. Didrepanephorus subvittatus was originally described based on a female from Chapa, northern Vietnam ( Benderitter 1922) where locates in Hoang Lien Son Mountain Range; thereafter, no records were known from this area. The rediscovery of this rare species from northern Vietnam was reported by Muramoto (1993) based on males from Mount Tam Dao, and the parameres was displayed for the first time. The occurrence of this beetle in China is here represented by three specimens from Guangxi.

Figures

FIGURES 25–28. Habitus of Didrepanephorus subvittatus Benderitter, 1922 (dorsal and ventral view). 25–26, male; 27–28, female. (both from Tam Dao).

FIGURES 29–32. Habitus of Didrepanephorus Wood-Mason, 1878 species (oblique view). 29–30, D. nishiyamai Muramoto, 2006: 29, male; 30, female. 31–32, D. subvittatus Benderitter, 1922: 31, male; 32, female.

FIGURES 33–40. Male genitalia of Didrepanephorus Wood-Mason, 1878 species (showing parameres in dorsal and ventral views). 33–34, D. mucronatus Arrow, 1921; 35–36, D. heterocolor new species (holotype); 37–38, D. nishiyamai Muramoto, 2006; 39–40, D. subvittatus Benderitter, 1922.

FIGURES 41–56. Type specimens of Didrepanephorus Wood-Mason, 1878 species. 41–46, syntype, labels, and male genitalia of D. bifalcifer Wood-Mason, 1878 (male, BMNH, photograph by Chuan-Bu Gao); 47–52, holotype, labels, and male genitalia of D. mucronatus Arrow, 1921 (male, BMNH, photograph by Chuan-Bu Gao); 53–56, holotype and labels of D. subvittatus Benderitter, 1922 (female, IRSNB, photograph by Matthias Seidel).

FIGURES 65–69. Habitat of Didrepanephorus Wood-Mason, 1878 species. 65–67, habitat D. mucronatus Arrow, 1921: 65, forest in Mount Jinuoshan, Jinghong (Yunnan, China); 66–67, male attracted by light trap and stayed on a nearby bush in Dadu- gang (Yunnan, China); 68, male of D. nishiyamai Muramoto, 2006 on the ground (Guangxi, China; photograph by Chao Li); 69, male of D. subvittatus Benderitter, 1922 attracted by light trap and stayed on a nearby leaf in Mount Shiwandashan (Guangxi, China; photograph by Tao Zhang).

FIGURE 70. Known distribution of four Didrepanephorus Wood-Mason, 1878 species. Type locality of D. mucronatus Arrow, 1921 is missing because the precise location is unknown.