Dorcus yongreni Huang and Chen, 2016

Huang, Hao & Chen, Chang-Chin, 2016, Two new species of stag beetles (Coleoptera: Lucanidae) from western Yunnan, China, Insecta Mundi 2016 (516), pp. 1-8 : 3-4

Dorcus yongreni Huang and Chen , new species

( Fig. 45 –47, 49–50, 52, 54–55)

Type material. Holotype ( Fig. 45 , 54): YUNNAN: ♂, Ruili City , Longchuan County, 1800m, 15–17. IX.2015, Xiao-Dong Yang and Yong-Ren Chang leg. ( SHNU) . Paratypes: YUNNAN: 1 ♂, 1 ♀, same data as for the holotype ( CCCC) ; 3 ♂♂, Ruili City, Longchuan, 1800m, IX.2016, Xiao-Dong Yang leg. ( CCCC) .

Holotype description. Length of body: 24.3 mm. Ground color of the whole body dark brownish red on both surfaces, appearing darker on underside than on upper side. Head. Nearly as long as pronotum, sub-rectangular. Dorsal surface of head depressed between eyes. Anterior canthus half as long as eye, hardly reaching the outer limit of eye. Clypeolabrum ( Huang and Chen 2010) short and very transverse, slightly concave at anterior margin. Mandible 1.5 times as long as head, generally shaped as in other known species of the elegans group ( Huang and Chen 2013), but with an additional subbasal tooth like in Dorcus apatani (Okuda and Maeda) . Mentum rather straight at anterior margin. Pronotum. A little wider than head, rather broadly arched at anterior part, with the widest point well before the middle, and with the lateral angles sharply pointed. Protibia with clear double teeth at outer apex, and with 4–5 smaller teeth at outer lateral margin. Meso- and meta- tibiae smooth at outer margin. Elytra. With weakly developed longitudinal depressions. Male genitalia (Fig. 52, 54). Basal piece with cephalic portion abruptly contracted. Ventral plate of basal piece broad and markedly excavated at anterior margin. Median lobe well pigmented on ventral surface and not divided by a dark median line. Permanently everted internal sac (flagellum) nearly as long as the entire aedeagus, trifurcate near middle, and with the lateral branches rather short.

Description of male paratypes. Length of body varies from 17.5 mm to 28.0 mm. There is no variability in the male genitalia.

Description of female paratype (Fig. 47). Length of body: 20.5 mm. Habitus generally as in female of Dorcus chucheni Huang and Chen , with punctures on elytra merged longitudinally into at least 10 closely arranged striae. Pronotum similar to that of all other species of the elegans group, with lateral angles sharply pointed and with the lateral margins posterior to the angles deeply concave.

Diagnosis/Remarks. This new species is very similar to Dorcus apatani (Okuda and Maeda) from Lower Subansiri, Arunachal Pradesh, northeastern India, but can be distinguished by the following combination of male characters (female of Dorcus apatani is still unknown): 1) pronotum broader anteriorly, with lateral margins not concave at anterior third; 2) mentum flat at anterior margin, not concave in the middle; 3) aedeagus with basal piece a little more elongate; 4) median lobe of male genitalia not divided by a median dark line; 5) flagellum a little longer, with lateral branches markedly longer. This new species can be easily distinguished from all the remaining species of the elegans group, recently revised by Huang and Chen (2013), because of the additional subbasal tooth on each male mandible.

Distribution. CHINA: Yunnan: Ruili area.

Etymology. This new species is named in honor of Mr. Chang Yong-Ren, a good friend who helped us to discover this new species.

Figures

Figures 44–46. Habitus illustrations of males under same scale. 44) Dorcus apatani from NE India. 45) Dorcus yongreni n. sp., holotype. 46) Dorcus yongreni n. sp., paratype. Figure 47. Habitus illustration of Dorcus yongreni n. sp., paratype, female. Figures 48–50. Mentum of male. 48) Dorcus apatani from NE India. 49–50) Dorcus yongreni n. sp. Figures 51–52. Aedeagus in ventral view under same scale. 51) Dorcus apatani from NE India. 52) Dorcus yongreni n. sp., holotype. Figures 53–55. Flagellum flattened in full-face view under same scale. 53) Dorcus apatani from NE India. 54–55) Dorcus yongreni n. sp. Red arrows indicating the differences between the two species.