Xylotrupes clinias Schaufuss, 1885

Prokofiev, Artem M., 2016, On the Phytophagous Scarabs of the Subfamilies Dynastinae, Rutelinae, and Melolonthinae from the Schouten Islands (Kepulauan Biak), Indonesian Papua (Coleoptera: Scarabaeidae), Species Diversity 21, pp. 71-77 : 72

Xylotrupes clinias Schaufuss, 1885

Xylotrupes clinias Schaufuss, 1885: 192 .

Material. 3 males, 4 females, Indonesia, Papua, Biak I ., Biak Kota, Samau village, Nirmala Hotel , 08– 20.11.2012, A . M . Prokofiev leg .; 2 males, 3 females, Biak Utar , near Napdori village, 2–3 km from right bank of Air Napdori river, black light, 10–11 and 18– 19.11.2012, A . M . Prokofiev leg.

Remarks. This species has been known hitherto from Sulawesi and the Moluccas eastward to the Kei Islands ( Rowland 2011). The populations from the main island of New Guinea and the Aru Islands were separated as X. carinulus Rowland, 2011 (loc.cit.). Surprisingly, the specimens from Biak possess well-developed pronotal carinae, which is not characteristic for a New Guinean species. A direct comparison of the Schouten specimens with specimens from Ceram and Ambon Is. ( X. clinias ) and Fak-Fak Mts., New Guinea ( X. carinulus ) shows their full identity with the former species. The presence of beetles morphologically identical to the Moluccan form on the Geelvink Bay islands indicates that the distribution of this form extends rather far eastward along the northwestern coast of New Guinea. On the other hand, the differences between X. clinias and X. carinulus may represent population variability rather than specific differences, inasmuch as both nominal species have the same structure of the raspulae ( Rowland 2003, 2011), and populations with developed pronotal carinae may be sparsely distributed among populations that lack such carinae. Arguing against this, however, Rowland (2011) considered the pronotal structure to be a very stable character for X. carinulus based on his examination of more than 200 males from the whole assumed range of distribution.