Platycerus yingqii Huang & Chen

Huang, Hao & Chen, Chang-Chin, 2009, Notes on the morphology, taxonomy, and natural history of the genus Platycerus Geoffroy from China, with the description of a new species (Coleoptera: Scarabaeoidea: Lucanidae), Zootaxa 2087, pp. 1-36 : 27-29

Platycerus yingqii Huang & Chen , sp. nov.

Type material. Holotype ( Fig. 1 ): CHINA: Shaanxi Prov.: 3, Bao-ji City, Mei-xian County, Mt. Taibaishan, Kai-tian-guan 1800m, 26.V.2008, H.Huang & X.-D. Yang leg. ( SHNU). Paratypes ( Figs. 2, 6, 7, 12, 13 , 16): CHINA: Shaanxi Prov.: 33, 3ƤƤ, same data as for the holotype (13, 1Ƥ in BMNH; 13, 1Ƥ in CHH; 13, 1Ƥ in CCCC).

Description. The description for those “discrete” characters can be found in the character matrix ( Table 1 ) or in the numbered part of the above stated list of characters. The description for those “continuous” characters can be found in the unnumbered part of the list of characters in which the new species are compared with Platycerus rugosus , Platycerus kitawakii , and Platycerus hongwonpyoi mongolicus .

Measurement. Body-length measured from apex of mandible to terminal tip of elytra: 11 mm for male holotype, 10.5–11.5 mm for male paratypes, and 9.7– 11 mm for female paratypes.

Length of elytra: 6.5 mm for male holotype, 6.2–6.9 mm for male paratypes, 6.0–7.0 mm for female paratypes.

Length of protibia: 2.5 mm for male holotype, 2.5–2.8 mm for male paratypes, 1.8–2.2 mm for female paratypes.

Length of mesotibia: 2.6 mm for male holotype, 2.5–2.6 mm for male paratypes, 1.9–2.2 mm for female paratypes.

Length of mesotarsi: 2.7 mm for male holotype, 2.7–3.0 mm for male paratypes, 1.7–1.8 mm for female paratypes.

Length of metatibia: 2.8 mm for male holotype, 2.8–3.0 mm for male paratypes, 2.3–2.6 mm for female paratypes.

Length of metatarsi: 2.8 mm for male holotype, 2.8–3.0 mm for male paratypes, 1.3–1.5 mm for female paratypes.

Ratio of mesotarsi length to mesotibia length: 1.04 for male holotype, 1.04–1.15 for male paratypes, 0.84–0.89 for female paratypes.

Ratio of metatarsi length to metatarsi length: 1.00 for male holotype, 1.00–1.07 for male paratypes, 0.54–0.60 for female paratypes.

Diagnosis. This new species is similar to Platycerus rugosus in most external features (such as male mandible, pronotum, and sclerotized male gentialia), but can be distinguished from the latter by the following combination of characters: dorsal color of males more brown; a ratio of metatarsi length to metatibia length in males being 1.00–1.07 versus 1.18–1.19 in Platycerus rugosus ; a ratio of metatarsi length to metatibia length in females being 0.54–0.61 versus 0.67 in Platycerus rugosus ; ventrites of males red, not black; incisor teeth closer to molae in male mandible; keels of penis not markedly broader near the proximal end than at other parts; flagellum on endophallus not bifurcate at base; endophallus with one-paired basal pouch and laterodorsal pouches protruded basad as free branches; hemisternite of female genitalia stouter with inner apex not very protruded.

In distribution and characters of the pronotum this new species is similar to Platycerus tabanai tabanai and Platycerus tabanai taibaishanensis , but can be easily distinguished from both of them by the following combination of characters: male mandible without a gap between apex and incisor teeth; posterior angle of pronotum sharper in both sexes; basal half of parameres more inflated; keels of penis not much broader near proximal end than at other parts; hemisternite of female genitalia with inner apex not strongly protruding (the characters in endophallus have not been studied for Platycerus tabanai tabanai and Platycerus tabanai taibaishanensis ).

In distribution and dorsal color of this new species is similar to Platycerus nagahatai , but can be easily distinguished from the latter by the following combination of characters: male mandible without a gap between apex and incisor teeth, with incisor teeth much closer to molae; posterior angle of pronotum angled in both sexes; ventrites of males bright red, not dark black; endophallus with anterior pouch absent, with onepaired basal pouches, one-paired laterodorsal pouches protruding basad as free branches and inflation immediately above ejaculatory area not large; hemisternite of female genitalia with inner apex not strongly protruding.

Discussion. An uncertainty is that the male specimens identified as Platycerus rugosus in this work were not collected from the type locality, the Dabashan Mountains. Instead, they were collected from the Micangshan Mountains, which are the western extension of the Dabashan Mountains and possess very similar fauna; however they match the original description of Platycerus rugosus in all the diagnostic characters, including the sclerotized male genitalia. The only problem is that the endophallus of Platycerus rugosus has not been studied for specimens from the type locality. Nevertheless, Platycerus yingqii can be easily distinguished from Platycerus rugosus at least by those characters in external features, the sclerotized male genitalia, and female genitalia.

Both Platycerus tabanai and Platycerus tabanai taibaishanensis were described from the same area in Qinling Mountains and based on male specimens as holotypes; they are somewhat similar to the new species in some characters, but can be distinguished by several important characters as stated in "diagnosis". There is detailed information on the characters of the male mandible and the sclerotized male genitalia in the literature for both Platycerus tabanai and Platycerus tabanai taibaishanensis . The relationship between Platycerus tabanai tabanai and Platycerus tabanai taibaishanensis needs an examination of more specimens and characters in endophallus; however this has nothing to do with the validity of Platycerus yingqii .

Type locality. China, Shaanxi Province, Bao-ji City, Mei-xian County, Mount Taibaishan.

Etymology. This new species is named after the son of the senior author, Ying-Qi Huang, who was born in summer of 2006.

Figures

FIGURES 1 – 15. Habitus of Platycerus in the same scale. 1 — Platycerus yingqii, dorsal view, male holotype; 2 — Platycerus yingqii, dorsal view, male paratype; 3 — Platycerus rugosus, dorsal view, male (Micangshan); 4 — Platycerus kitawakii, dorsal view, male (Dabashan); 5 — Platycerus hongwonpyoi mongolicus, dorsal view, male (Inner Mongolia); 6 — Platycerus yingqii, drosal view, male paratype; 7 — Platycerus yingqii, ventral view, male paratype as in 2; 8 — Platycerus rugosus, ventral view, male as in 3; 9 — Platycerus kitawakii, ventral view, male as in 4; 10 — Platycerus hongwonpyoi mongolicus, ventral view, male as in 5; 11 — Platycerus rugosus, dorsal view, male (Micangshan); 12 — Platycerus yingqii, dorsal view, female paratype; 13 — Platycerus yingqii, ventral view, female as in 12; 14 — Platycerus rugosus, dorsal view, female (Dabashan); 15 — Platycerus rugosus, ventral view, female as in 14.