Plebejus idas arshantyn, Churkin & Yakovlev, 2024

Churkin, Sergei V. & Yakovlev, Roman V., 2024, New data about Plebejus idas (Linnaeus, 1761) (Lepidoptera, Lycaenidae) from Mongolia with the descriptions of new subspecies, Ecologica Montenegrina 73, pp. 116-124 : 117-121

1. Plebejus idas arshantyn ssp. nova

https://zoobank.org/ urn:lsid:zoobank.org:act:D73F5DA0-4CAD-43DD-9EF0-81740DDED5B5

Plates 1 (upperside) −2 (underside): 5, 6, 7, 8, 17, 18.

Holotype: male, Mongolia, SW Mongolian Altai, Arshantyn Mts. (north-eastern slopes), Bayangol r., 22.06.2018, 1700−2000 m, S. Churkin.

Paratypes: 17 males, 9 females, same data, S. Churkin & V. Pletnev leg. ; 12 males, 1 female, same data, K. Kolesnichenko leg. ; 2 males, (south-western slopes), Khudagt loc., 20.06.2018, 2300−2400 m, S. Churkin & V. Pletnev leg. ; 3 males, same data, K. Kolesnichenko leg. ; 18 males, 9 females, W. Mongolia, Hovd aimak, Bulgan-gol basin, Arshantyn-Nuruu Mts., Bayan-gol basin, middle stream of Ulyastain-Sala river , 1700–2300 m, 12.07.2007, E. V. Guskova & R. V. Yakovlev leg.

Additional material: 2 males, 1 female, SW Mongolia, Dzhungarian Gobi , 45 km SW Bulgan-somon, Uvkhod-Ula Mt., 1200 m, 18- 19.06.2004, R. Yakovlev & D. Ryzhkov leg.

Description

Holotype FW length 13.5 mm, paratypes (males and females) 13−14 mm.

Antennae, palpi, body coloration and hairs seem to have no taxonomically valuable characters.

Male

Wings on upperside violet-blue with developed narrow marginal black stripe (1–1.5 mm).

Tips of veins darkened up to 2–3 mm from wing edge. FW sometimes with noticeable discal spot. HW often with developed black bordering spots. Wings relatively narrow, as in European specimens.

Wing underside light-grey, contrasting with large (but not magnified) dark spots with barely noticeable white rings around.

Underside of FW: postdiscal series of spots straight or slightly curved, submarginal series complete, orange segments thick, flattened, black segments well developed to outside as well as inside from orange spots.

Underside of HW: bluish suffusion not dense, developed up to basal spots; discal stroke developed; postdiscal spots large, space outside this row white, contrasting, usually bright, shaped as postdiscal band. Submarginal pattern: orange segments of spots well developed, bright, saturated (but not fused into one band), metallic scales forming large bluish bright spots to outside from orange segments.

Male genitalia: not identical to those of closest subspecies, but serious conclusions require a separate large-scale study.

Female

Wings completely dark-brown, FW without pattern, sometimes with only 1–2 poorly noticeable reddish spots, HW with ordinary submarginal pattern of yellow-orange arched spots with black spots outside. Almost no bluish suffusion on underside of HW.

Wing underside characters like those of male, but orange spots better developed (often forming one band on FW!), as well as metallic «plates».

Variability. Little. In three males – wide marginal band (2.5 mm), in one – thin, smoky; it is correlates with general developing of the black pigment on the underside (Figs 1−2: 17, 18). Note that females with blue color have not yet been found – even bases of wings are brown, without blue coating.

Butterflies from Uvkhod-Ula are somewhat smaller and darker (Figs 1–2: 18), we did not include them in the type series only because in such a complex group it is better to limit the type territory as much as possible.

Diagnosis

The new subspecies differs from the subspecies ssp. munkhbayar and ssp. boreas by the completely violet upperside, from ssp. belchir – by the developed pattern of the underside.

From the closest ssp. shadzgat it sharply differs by the series of characters: the light underside with a contrasting white postdiscal band; the developed submarginal pattern on the underside with bright metallic spots; the completely brown females with reduced orange pattern on FW upperside (and more developed on underside!). Additionally, the marginal band in males is narrowing, the postdiscal series on FW is poorly curved.

In shadzgat, the underside is darkened, almost always with brown tint, the postdiscal zone is either completely dark, or with non-contrasting whitish triangular spots (in one paratype all this zone is lightened, but without brightness or contrast, other characters of this male similar to sailjugemicus), all the pattern on the underside is less developed (including the metallic spots and pale yellowish segments of the submarginal row); the females have big blue spots on the wings, cut by darkened veins, where the orange pattern of FW is more developed from upperside. Additionally, the postdiscal series on the underside of FW is usually either heavily curved, or bent towards the wing base.

Thus, the smallest and palest specimens of the new subspecies are slightly similar to the brightest shadzgat, but only in the general coloring of the underside, the metallic «plates» remain poorly developed (besides, the big bright shadzgat have the developed black coloring of the wings upperside).

Distribution. Almost certainly endemic to the Arshantyn-Nuruu Mountains, which are a separate (though very small in area) zookhoron ( Yakovlev 2012). The distance between the type localities arshantyn and shadzgat is only 50 km, they are located in the basin of one river (Bulgan-Gola), but the difference in color is sharply expressed. Moreover, the type series of shadzgat has a certain variability, part of the specimens externally resemble munkhbayar in the underside, the others − sailjugemicus, which is indicated in the original description – but the series of the new taxon is rather monotonous, though collected from different sides of the range.

Bionomics. Mountain meadows. Infrequently. Unfortunately, the food plant could not be identified.

Etymology. Toponymic name.

Figures

Plate 1. Adult specimens of Plebejus (upper side): 1 – Plebejus idas baitag ssp. nova, male, holotype, SW Mongolia, Khovd aimak, Baitag Mts., Buduun Khargaityn r., 2000–2500m, 1–2.07.2018, S. Churkin leg. 2 – P. i. baitag ssp. nova, male, paratype, same data as 1. 3 – P. i. baitag ssp. nova, female, paratype, same loc. as 1, 2600−2700m, 2–3.07.2018, S. Churkin leg. 4 – P. i. baitag ssp. nova, female, paratype, same data as 3. 5 – P. i. arshantyn ssp. nova, male, holotype, SW Mongolian Altai, Arshantyn Mts. (north-eastern slopes), Bayangol r., 22.06.2018, 1700−2000 m, S. Churkin. 6 – P. i. arshantyn ssp. nova, male, paratype, SW Mongolian Altai, Arshantyn Mts. (south-western slopes), Khudagt loc., 20.06.2018, 2300−2400 m, S. Churkin. 7 – P. i. arshantyn ssp. nova, female, paratype, same data as 5. 8 – P. i. arshantyn ssp. nova, female, paratype, same data as 5. 9 – P. i. shadzgat, male, paratype, W. Mongolia, Hovd aimak, Bulgan-Gol basin, Uljastyin-Gol Valley, Shadzgat-Nuruu Mountains, 2500–3000 m, 25–26.06.2004, R. Yakovlev & D. Ryzhkov leg. 10 – P. i. shadzgat, male, paratype, same data as 9. 11 – P. i. shadzgat, female, paratype, same data as 9. 12 – P. i. shadzgat, female, paratype, same data as 9. 13 – P. i. sailjigemica, male, paratype, SE Altai, Sailjugem Mts., Dzhumaly R. (upper stream), 2500 m, 10−11. 07. 1991, G. Samodurov leg. 14 – P. i. sailjigemica, female, paratype, female, same data as 13. 15 – P. i. sailjigemica, female, female, Russia, SE Altai, Ukok Pl., 2100 m, 1−10.07.2009, S. Kakunin leg. 16 – P. i. sailjigemica (?), male, Kazakhstan, South Altai, Sarym-Sakty Mts., Tautekeli r., 2200 m, 28.06.2011, S. Toropov leg. 17 – P. i. arshantyn ssp. nova, male (form), paratype, same data as 5. 18 – P. i. arshantyn ssp. nova, male, SW Mongolia, Dzhungarian Gobi, 45 km SW Bulgan-somon, Uvkhod-Ula Mt., 1200 m, 18−19.06.2004, R. Yakovlev & D. Ryzhkov leg. 19 – P. i. boreas, male (munkhbayar-like form), Mongolia, Gobi-Altai Mts., Ikh-Borgyn Nuruu Mts., 20 km NW Orgen, 24.06.2002, 2250 m, S. Churkin leg. 20 – P. i. boreas, male (normal form), same data as 19.