Pieris euorientis euorientis Verity, 1908

Ge, Si Xun, Jiang, Zhuo Heng, Wang, Jia Qi, Song, Kui, Zhang, Chao & Hu, Shao Ji, 2023, A revision of the Pieris napi - complex (Lepidoptera: Pieridae) and similar species with distribution in China, Arthropod Systematics & amp; Phylogeny 81, pp. 257-287 : 257

Pieris euorientis euorientis Verity, 1908 stat. rev.

Pieris napi var. euorientis Verity, 1908; Rhopalocera Palaearctica (13-14): 147, (17-20): pl. 32, f. 44; TL: “Sajan” (original description)

Pieris euorientis Verity, 1908; Eitschberger (1983): Herbipoliana 1(1-2): 131 (upgraded as distinct species)

Pieris dulcinea euorientis ; Tuzov et al. (1997) (as subspecies of Pieris dulcinea )

Pieris napi euorientis ; Tadokoro et al. (2014): Butterflies 65: 26 (as subspecies of Pieris napi )

Description.

Both wings white on the upperside and a pale yellowish hue on the underside. Male (Fig. 11S, U ): apical spot grey, merging as a small dark subtriangular spot on the apex or nearly absent. The 1st discal spot and outer spot present but rather faint on both upperside and underside, while the 2nd spot vaguely developed on the underside. Female (Fig. 11T, V ): all spots distinctly developed on the upperside, while relatively faint on the underside. Brownish or blackish powder distinctly narrowed along all veins on both sides, relatively broader at the apex.

Distribution.

Russia, Mongolia (Altai and Sayan Mts, Siberia and Transbaikalia)

Phenology.

Univoltine from June to July ( Tuzov et al., 1997).

Male genitalia.

(Fig. 5J ) basal part of uncus moderately narrower than the distal margin of tegumen, as a concave between uncus and tegumen; uncus slightly convex at its median part, apical half of uncus digitation.

Female genitalia.

Not examined.

Note.

This species rather resembles the spring form of P. dulcinea which can only be distinguished by a comparison of the apical spot (more or less merging in this species while always separated into several triangles in P. dulcinea ) and the 1st discal spot (both species faint but in P. euorientis relatively more developed). Males can be easily distinguished from the summer form of P. dulcinea in having: apical spot merged (separate in P. dulcinea ), and 1st discal spot faint (strongly developed in P. dulcinea ) and 2nd discal spot absent (present in P. dulcinea ) on the upperside. This taxon shows monophyly in our phylogenetic analysis and its position is distant from P. napi ; therefore, we consider this taxon to be a distinct species. It is noteworthy that in the re-description of the species by Eitschberger (1983) a series of specimens from Tanu-Ola (Tanguura Mountains) were considered as belonging to this species, while in this study, we found morphological differences between topotypes of P. euorientis and specimens from regions south or west of the Tanguura Mountains (See notes in Pieris mihon Yakovlev, 2006 stat. nov.). Combined with our phylogenetic results, this indicates that populations from the Tanguura Mountains and the regions to the south or west represent a distinct species (Fig. 12 ): Pieris mihon Yakovlev, 2006 stat. nov. As the redefined Pieris euorientis euorientis , we did not find female specimens of the summer form in the type locality or adjacent regions, thus this knowledge gap needs to be filled in future research.

Figures

Figure 5. Tegumen and uncus of male genitalia in dorsal view. Scale bar represents 1 mm.

Figure 11. Habitus of species related to Chinese species of Pieris napi - complex. Composite pictures on the left show the upperside, on the right show the underside. A - B Pieris ochsenheimeri ochsenheimeri Staudinger, 1886. C - E Pieris napi sauron Yakovlev, 2004 comb. nov. F - H Pieris napi bryonides Sheljuzhko, 1910 comb. rev. I - L Pieris napi muchei Eitschberger, 1983. M - N Pieris napi napi (Linnaeus, 1758). O - R Pieris bryoniae wolfsbergeri Eitschberger, 1983. S - V Pieris euorientis euorientis Verity, 1908 stat. rev. Scale bar represents 10 mm. (B, F, I, K, L, O-R, V reference Eitschberger, 1983; T and U reference Tshikolovets et al., 2009; C reference Yakovlev, 2004 as black and white photos consistent with original description).

Figure 12. Distribution map of Pieris euorientis Verity, 1908 stat. rev. and Pieris mihon Yakovlev, 2006 stat. nov.