Delias sanaca bidoupa Monastyrskii & Vu, 2021

Monastyrskii, Alexander L. & Lien, Vu Van, 2021, New taxa and new records of butterflies from Vietnam (Lepidoptera, Papilionoidea), Zootaxa 5048 (4), pp. 486-510 : 488-491

Delias sanaca bidoupa Monastyrskii & Vu subspec. nov.

( Fig. 1–3 )

Description: Female. Length of forewing: HT 44mm; PT 48 mm; antennae black with greyish club, 18.0–19.0 mm.

Forewing upperside ( Figure 1-A, C ). Ground colour black with pattern of whitish spots: 1. Series of subterminal spots extends from cell R 3 to Cu 1b; the spot in cell Cu 1b is double; 2. Series of postmedian elongated spots extends from R 3 to Cu 1b, though spots in R 4 and R 5 are absent; spot in cell Cu 1b is double and small whitish spot in cell M 1 is shifted towards the subterminal spot; 3. Large elongated whitish spot located at distal part of discal cell near discocellular veins. Forewing underside ( Figure 1-B, D ). Ground colour black; the wing pattern similar to that in upperside, but all spots brighter and more distinct; subterminal spots in cells R3, R5 and M1 are yellow. Discal cell includes long whitish streak which is ended by the large elongated whitish spot. Hindwing upperside ( Figure 1 A, C ). Ground colour black with pattern of whitish spots; Dorsal area within cells 3A, 1A+2A and Cu 1b is whitish yellow; small bright yellow spots are located at basal area in cell Sc+R 1 and around humeral vein; bright white streak in discal cell; series of subterminal whitish spots extend from cell Rs to Cu 1b; larger postmedian whitish spots extend from cell Rs to Cu 1b. Hindwing underside: ( Figure 1 B, D ) Ground colour black; the wing pattern similar to the upperside, but all spots smaller and more distinct; all subterminal spots are yellow; postmedian spots in cells M 3 and Cu 1a are also yellow; whitish streak within discal cell has yellowish distal part.

Male is unknown.

Female genitalia ( Figure 2 ): Corpus bursae oval with appendix bursae round; ductus bursae rather long and thin; signum broad, invaginated formed bi-oval flat structure both sides of which armed with short spines. Antrum is weakly developed but sterigma and lamella postvaginalis are prominent. Sterigma is the pair prominent invaginated structure having some well sclerotised vanes (blades). The lamella postvaginalis is triangular. Posterior apophyses thin and short; anterior apophyses not differentiated (vestigial).

Diagnosis: The new taxon closely resembles Delias sanaca perspicua Fruhstorfer, 1910 distributed in China, Laos, and northern Vietnam ( Nakamura & Wakahara, 2012). The male specimen figured in that work resembles both specimens collected near Mt. Bi Doup. Several wing pattern elements are similar (e.g., the pattern of yellow spots on the underside of both wings). However, the wing pattern of D. s. perspicua figured by Pinratana, 1983; Ek-Amnuay, 2012; Wu & Hsu, 2017 differs by having larger whitish and yellow spots on both sides of the wings. The female genitalia of D. sanaca and other species of the belladonna group have never been published. When compared with D. belladonna , D. berinda , and D. sanaca perspicua , the female genitalia of D. sanaca bidoupa are most similar to D. sanaca perspicua from China, with a similar corpus bursa, signum, sterigma and lamella postvaginalis ( Figure 3A–B ); however, the lamella postvaginalis of D. berinda from China is more rounded ( Figure 3C–D ).

The male of the new taxon is unknown, and our study was based only on the morphology of a single female. We therefore regard this taxon of Delias sanaca from Lam Dong province as a separate, distinctive subspecies rather than a full species. Nevertheless, the new taxon requires additional study.

Type material: Holotype: CENTRAL VIETNAM: ♀ Lam Dong province, Bi Doup N.P., 06.IV.2002, ALM leg.; evergreen forest at 1,500 m . Paratype ♀: from the same locality and date as HT .

Distribution: Females of this rare taxon are thus far known only from the vicinity of Mt. Bi Doup where they were discovered along an evergreen forest stream at 1,600 m.

Etymology: The new taxon is named after Mt. Bi Doup where the type specimen was discovered and collected.

Figures

FIGURE 1. Delias sanaca bidoupa Monastyrskii & Vu subspec. nov. A–B—HT♀, central Vietnam, Lam Dong province, Bi Doup N.P.; C–D—PT♀; upperside on the left; underside on the right

FIGURE 2. Female genitalia of Delias sanaca bidoupa Monastyrskii & Vu subspec. nov.—PT♀: Ab—appendix bursae; Bc—bursa copulatrix; Db—ductus bursae; Ds—ductus seminalis; Si—signum; St—sterigma; Lp—lamella postvaginalis; Ap— apophysis posterior; Pa—papilla analis.

FIGURE 3. A–B: Female genitalia of Delias sanaca perspicua Fruhstorfer (southern China); C–D: Female genitalia of Delias berinda adelma Mitis (central China). A, C—a part of bursae copulatrix with signum; B, D—genitalia in ventral view: Db— ductus bursae; Ds—ductus seminalis; Si—signum; St—sterigma; Lp—lamella postvaginalis; Ap—apophysis posterior; Pa— papilla analis (with permission of Dr. Shao-ji Hu)