Plebejus anikini azhbogdo Churkin, Kolesnichenko & Yakovlev, 2019

Churkin, Sergei V., Kolesnichenko, Kirill A. & Yakovlev, Roman V., 2019, Two new taxa of Plebejus Kluk, 1780 (Lepidoptera, Lycaenidae) from the Gobi desert, Mongolia, Zootaxa 4695 (1), pp. 45-58 : 52-55

Plebejus anikini azhbogdo Churkin, Kolesnichenko & Yakovlev , ssp. n.

Plate 1 and 2, figs. 13 (holotype), 14–18 (paratypes).

Holotype: ♂, S Mongolia, Mongolian Altai , Gobi-Altai aimak, 10 km ESE Altai somon, Hadat-Miangan-Bulag spring, 1500 m, 15.07.2013, 44°34’30”N, 095°02’17”E, K. Kolesnichenko leg. ( ZISP).

Paratypes: 20 ♂, 18 ♀, same data, K. Kolesnichenko leg. ; 17 ♂, 13 ♀, SW Mongolia, Gobi Altai aimak, 62 km SSE Bugat somon, N slopes of Adz-Bogdo Range, Zoolon-Suuzhijn-Bulag spring, 45°05’25”N, 094°48’05”E, 1350 m.a.s.l., 28.06.2017, R. Yakovlev leg.

Description.

Male. Holotype forewing length 14 mm, paratypes 14 –15 mm in both series.

Fringes white with narrow blackish inner part from upperside.

Upperside common violet-blue with few scattered white scales in costal part of forewing. Unfresh specimens look dull with obvious dark veins, however, this is merely a result of loss of several scales (see specimen on Pl. 1:13). Black margins thin, darkened end of veins usually not clearly expressed.

Forewing underside dark gray with brownish hue; submarginal series practically fully reduced (only blackish traces of spots sometimes obvious); postdiscal row almost straight, spots have normal size and each spot, including developed discal spot, surrounded by whitish ring.

Hindwing underside of same colour as forewing underside, postdiscal area sometimes lighter. Bluish-green basal suffusion narrow but obvious because of dark ground colour. Black spots small, reduced in size, basal series often not complete; postdiscal series complete (8 spots), each spot as well as the discal spot surrounded by whitish ring; cubital spot shifted toward the base. Submarginal spots consist of 3 segments—very thin v-shaped blackish inner segment, reduced and pale yellowish-orange segment, and very small metallic plate. Orange segments usually obvious only in anal and cubital spots; metallic plates distinctively bluish as a rule, their external parts darkened and not shining so that shape of the plates becomes rectangular. Thin white lines or whitish triangles usually developed in area between postdiscal and submarginal series.

Female. FW length 14 –15.5 mm in both series, one female 13.0 mm.

Fringes whitish, with very thin dark inner part joined with blackish thick spots at end of veins.

Upperside brown with deep violet bases of wings, this colour often widely spreads across disc. In latter case, wings violet (shining or usually dull) and darkened towards margins, often with pale whitish glimpses between veins near wide brownish marginal bands. Rare dark forms mainly brownish with bluish-violet bases of wings. Forewing discal spot developed and often outlined by white ring. Hindwing with full series of black oval submarginal spots between darkened veins, each spot surrounded by pale whitish ring; rarely pale yellowish colour also obvious.

Forewing underside brownish with slightly obvious yellowish segments in submarginal spots. Hindwing un- derside brownish-gray, all main features as in males, submarginal spots more developed with obvious but pale and small yellowish-orange segments, metallic plates usually bigger but blackened externally and fully reduced in upper part of series.

Individual variation. Not so obvious. Butterflies from Zoolon-Suuzhijn-Bulag are statistically darker and dimmer than specimens collected south of Adz-Bogdo. However, coloured form featured in Plate 1: 16 is numerous in both localities. Females are very variable but fully brownish form is not recorded. Forms with s-curved postdiscal underside row are also absent.

Male genitalia (Pl. 3: 4, Pl. 4: 3–4, Pl. 5: 7–10). Labis (parts of the uncus) with long and thin ends, which obviously gracile from lateral view. Valva without developed convexities (ventral convexity, however, slightly expressed), with moderately smoothed outlines. Distal projection (“upper lip”) wide, lower distal projection (“lower lip”) thin and very short, end of lip gradually narrowed. Branches of juxta straight in basal parts, then distinctively curved and strongly moved apart while distal ends again moderately straight.

Aedeagus thin, proximal part with developed ventral inflation but not too widened compared with distal part, latter not thin but with narrowing in the middle and widened near distal end. Aedeagus curved, curving moved distally from joining of proximal and distal parts—thus joining place straight, and distal part further curved downwards. Curving weakly expressed. Proximal part no shorter than distal part.

Characters of genitalia in two studied populations very similar, only butterflies from Zoolon-Suuzhijn-Bulag have heavier aedeagus with wider proximal part.

Diagnosis. The size of both subspecies of P. anikini is nearly the same as in P. germani , but really large specimens (over 15.5 mm) are not known.

P. anikini can be easily differentiated from both other Mongolian relatives by a reduced submarginal pattern on the hindwing underside, pale and often unobvious orange lunules and thin dull metallic plates. Compared with P. germani , P. anikini has a brownish (not grayish) underside ground colour, thus, all black spots are distinctively surrounded by the whitish rings, the size of the spots is obviously smaller. The differences with P. chrisreai are listed above.

The new subspecies differs from the nominotypical P. anikini by the following distinctions: females always have developed violet-blue colour on upperside, submarginal pattern on the hindwing underside is strongly reduced so that the metallic plates often lose the rounded shape and half (at least) of the submarginal spots have neither an orange colour nor metallic scales.

The new taxon belongs to P. anikini because it has the same combination of specific features of the male genita-lia—labis are thin and long, the valva has no visible sharp convexities at the dorsal and ventral surfaces (contrary to P. germani ), the lower lip is very narrow and shortened (contrary to both other species), the curving of the aedeagus is distally moved from the place of joining of the proximal and distal parts (contrary to P. germani ).

Some characters of the genitalia look even more similar to that of P. chrisreai , except for the shape of the lips (the ratio of the distal and proximal parts of the aedeagus is also different). The branches of juxta are not straight but not gradually convex—it looks absolutely specific but the juxta of P. anikini is not studied because the genitalia of the available male were not cut into sclerites.

Compared with the nominate taxon, the aedeagus of P. a. azhbogdo is more curved (however, this character seems variable), the lower lip has a different shape (in P. a. anikini the lower lip is very short and very narrow distally, while in the new taxon it is only gradually narrowed), the cutout between the lips is no more developed than in P. germani or P. crisreai , while in P. anikini this cutout is spectacularly expressed. The taxonomic value of the latter feature is unknown. Theoretically, if all these distinctions are confirmed, the status of the taxon can be changed.

Bionomics (Pl. 6: 2). The true foodplant is unknown. Both series were collected on flowers and grass near the spring, the species of bush surrounding the oasis is unknown. The situation seems very similar to that of nominate subspecies (see above).

Distribution (Pl. 7). The subspecies inhabits foothills of the Azh-Bogdo massive in Transaltaian Gobi. Etymology. Toponimic name.