Peltocercyon subopacipennis (Nakane, 1965)

Mai, Zuqi, Jia, Fenglong, Ryndevich, Sergey K., Angus, Robert, Minoshima, Yûsuke N., Fikáček, Martin & Růžička, Jan, 2025, Taxonomic Revision and Phylogeny of the Genus Peltocercyon d'Orchymont, 1925 (Coleoptera: Hydrophilidae: Megasternini), Zootaxa 5671 (1), pp. 1-74 : 60

Peltocercyon subopacipennis (Nakane, 1965)

Fig. 32C–I .

Cercyon subopacipennis Nakane, 1965: 53 . Type locality: Japan (Nagano Pref., Honshu ).

Peltocercyon subopacipennis (Nakane, 1965) . Hoshina, 2016: 131.

Type material. Holotype ( Fig. 32C–E ): male ( HUMS), “ Mt. Jyonen / Ⅹ/ 6. 1960 / 1500 m, K.K // Cercyon sp. B / Det. T. Nakane // Cercyon subopacipennis Nakane / Det. T. Nakane 1965 // HOLOTYPE ” . Paratypes ( Fig. 32F–I ): 1 female ( HUMS), “ Mt. Jyonen / VI/ 2. 1960 / 1300 m, K.K // Cercyon sp. B / Det. T. Nakane // Cercyon subopacipennis Nak. / Det. T. Nakane 1965 // PARATYPE ” ; 1 female ( HUMS), “ Mt. Jyonen / IX/ 15. 1960 / 1500 m, K.K // Cercyon sp. B / Det. T. Nakane // Cercyon subopacipennis // PARATYPE ” .

Remarks. This species has very dense microreticulation between the elytral ground punctures, in which aspect it is very similar to P. sanaii ( Hoshina, 2008) , comb. nov. Both species seem to differ in coloration of the type specimens: the holotype of P. subopacipennis has a black head with a yellowish brown pronotum and elytra ( Fig. 32C, D ), while the types of P. sanaii have dark reddish-brown head and pronotum, yellowish brown inverted triangular area on the basal part of the elytra ( Fig. 32A ). Larger material is needed to figure out whether this difference is due to intraspecific variation or whether it represents the species-diagnostic character.

Distribution ( Fig. 41 ). Japan (Hokkaido).

Figures

FIGURE 32. Type specimens of Cercyon sanaii (Hoshina, 2008) and Peltocercyon subopacipennis (Nakane, 1965). A, B: holotype of Cercyon sanaii. C–E: holotype of Peltocercyon subopacipennis and its labels. F–I: paratype of P. subopacipennis and its labels. A: dorsal view. B: ventral view. C: dorsal view. D: lateral view. E: labels. F: ventral view. G: labels. H: ventral view. I: labels.

FIGURE 41. Distribution map of species in Peltocercyon vagus group.