Aricia anteros kalmius Botman & Lukhtanov, 2024

Lukhtanov, Vladimir A., Botman, Roman V. & Gagarina, Anastasia V., 2024, DNA barcode based phylogeographic analysis of the Aricia anteros (Freyer, 1838) species complex (Lepidoptera: Lycaenidae) with description of a new subspecies from SE Europe, Zootaxa 5468 (3), pp. 505-522 : 512-519

Aricia anteros kalmius Botman & Lukhtanov , subsp. nov.

( Figs. 4 , 6–10 )

Type material. Holotype ♂ VL626, GenBank accession # PP404056, the Northern Black Sea region , Donetsk Region , Kalmius River basin, Orlivs’ke (Orlovskoe), 47.260°N, 37.743°E, 01 August 2023, R. V. Botman leg. (in coll. Zoological Institute of the Russian Academy of Sciences) . Paratypes: 8 males, 5 females with the same labels as the holotype; 4 males, 5 females with the same locality as the holotype, but collected 28 July 2023 ; 7 males, 7 females, Donetsk Oblast , Mariupol district , 117 km SSE from the center of Donetsk , left bank of the Kalmius river , Pyshchevyk vill., 47.242°N, 37.794°E, 16 June 2010, R. V. Botman leg. (all paratypes are deposited in the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia) .

Imago ( Fig. 4 ). The length of the front wings is 14–17mm. The fringe of the wings is white with contrasting black dots at the end of the veins. Sexual dimorphism is well expressed. In males, the upper side of the wings is greenish-blue with a rather wide marginal darkening and a black median spot on the fore wings, the hind wings with black marginal points and an indistinct rufous border. In females, the upper side of the wings is brown with a rufous border and black spots along the edge of the hind wings. The underside of the wings in males is gray, in females it is beige, most often with 1–2 ocelli in the central cell of the fore wings. The hind wings below have a white triangular spot crossing the postdiscal band, in which the first two ocelli are very close together and spaced from the third. The marginal pattern consists of white holes, in which there are red isolated holes, outlined from the inside by angular black brackets, and black dots in contact with the red holes. The difference in wing color between generations is insignificant, but in general it can be noted that males of the second generation (June) have a slightly lighter blue color than males of the third generation (late July and August).

Male genitalia ( Fig. 6 ). The male genitalia are similar to those of the nominotypical subspecies as figured by Nekrutenko (1980) and Jašić (1998). The uncus is divided by a deep notch into right and left sclerotized halves. Each half has two processes: the superior process that is straight and pointed at apex, and the inferior process that terminates with rounded lobe The gnatos is situated at the basis of the uncus and is in the form of short sclerotized hooks (=brachia). The juxta has two very long narrow branches. The aedeagus is relatively short, its apical part is slightly curved downwards. The valves have a typical shape for the genus Aricia , they are narrow, approximately three times as long as wide, with a protrusion on the dorsal side and a characteristic long longitudinal fold on the inner surface.

Egg. The laid eggs are hemispherical, pale green in color, about 0.55–0.65 mm in diameter and 0.25–0.35 mm in height; as the embryo develops, they darken and by the time the caterpillar emerges they are gray in color.

Caterpillar. The emerging caterpillar has a rather large brown-black head and a gray-green worm-like body with numerous small dark dots. The body is covered with sparse hairs, which originate from a gray-black wart, and are equal in length to the thickness of the body. The body length of the 1st instar caterpillar is approximately two millimeters. On the fifth day of life, the caterpillar acquires a woodlouse shape typical of lycaenids, with a length of 4–5 mm and a thickness of 1.7–2 mm. The head is small, dark brown. The body is light brown, with three longitudinal red-brown (dorsal and two lateral) stripes, between which, in the direction from the dorsal to the lateral stripes, there are elongated spots of the same color, forming oblique torn bands. In the rear part, the body is expanded in the form of a flattened scutellum and here the spots do not form a clear pattern, but are more or less evenly distributed throughout the scutellum. The hairs are small, sparse, and look invisible. By the eighth day of life, the caterpillar’s body length increases to 7–8 mm, and by the time of pupation (on days 12–15) it reaches 10–12 mm.

Pupa. The pupa is 9–10 mm long, immediately after pupation it is pale beige, and by the time the imago emerges it darkens to black, starting from the eyes.

Diagnosis. The new subspecies differs from A. anteros anteros and A. anteros dombaiensis by wider darkening in the marginal region of the fore and hind wings and a more diffuse border of this darkening with the main blue background of the wings. It also differs from A. anteros dombaiensis in the darker blue color of the upper side of the wings in males.

The new subspecies differs from the closest A. anteros dombaiensis by five fixed nucleotide substitutions in the studied 658 bp fragment of the COI gene: A↔G (in position 69), A↔G (in position 506), T ↔C (in position 525), T ↔C (in position 600), and T ↔C (in position 615). The new subspecies differs from A. anteros anteros by eight fixed nucleotide substitutions in the studied 657 bp fragment of the COI gene: A↔G (in position 48), A↔G (in position 69), T ↔C (in position 117), T ↔C (in position 249), A↔G (in position 516), T ↔C (in position 525), T ↔ C (in position 600), and T ↔C (in position 615).

Distribution and Biology.

There are old records for the species A. anteros from Crimea, as well as from the environs of the village of Pribuzhye in Nikolaev region and from Kharkov region in Ukraine ( Lvovsky & Morgun 2007), which could belong to the new subspecies A. anteros kalmius ssp. nov. However, all these records need to be verified. Currently, the only known location where the subspecies is recorded from 2004 to 2024 is the middle and the lower parts of the Kalmius River basin ( Figs 3 and 7 ). The subspecies is associated here with the remnants of virgin steppes in granite outcrops and dry rocky slopes with sparse vegetation ( Fig. 7 ). The southernmost habitat is located near the Chernenko farm in the Novoazovsky district (47.227°N, 37.745°E), the northernmost habitat is located near the village of Razdolnoe (47.619°N, 38.041°E) (personal message from Vladislava O. Ostashevskaya) in the Donetsk region.

The subspecies is associated with an endangered herbaceous plant, Beketov’s storksbill ( Erodium beketowii Schmalh. ), which is a local endemic to the south of the Donetsk region ( Kondratyuk & Ostapko 1990; Pljutsch & Botman 2006) ( Fig. 8 ).

It is worth noting that in addition to the banks of the Kalmius River, Beketov’s storksbill also grows in the middle part of the Kalchik River ( Plyushch & Botman 2006). Repeated excursions were undertaken in different months of 2019–2023 to the Kalchik River in search of A. anteros blues. However, neither imago nor preimaginal stages have yet been discovered. The exclusive localization of A. anteros kalmius ssp. nov. in the Kalmius River basin, the monophagy on Erodium beketowii , as well as the strong geographic isolation from the nearest populations of A. anteros in the Balkan Peninsula and the Caucasus gave grounds for the formation of A. anteros kalmius ssp. nov. as a distinct sublineage of A. anteros .

During the year A. anteros kalmius ssp. nov. has several (at least three or even four) generations, with imago flying from late April to October. The first two generations are clearly separated in time. Subsequent generations overlap with each other and can only be distinguished with great difficulty, taking into account the degree of preservation of the wings and wing pattern.

Adults (males) appear in late April or early May (the first males in 2004 were observed on May 2, in 2007— on April 29, in 2024—in mid-April), females appear somewhat later. The mass of first-generation butterflies is observed from around May 10th to the first week of June ( Fig. 9 ). The first-generation butterflies are more often found in granite outcrops—rocky areas and rocky ravines, where they fly low above the ground and often land on stones. They feed on various flowering plants such as Erodium beketowii , Salvia nutans L., Sedum acre L., Achillea L., Geranium L., Thymus L. and others.

Females lay eggs one at a time on unripe fruits, sepals, the underside of leaves (including withered ones), rosette scales and petioles of Erodium beketowii . Oviposition has also been observed on other, smaller plants located in close proximity to the host plant. All ovipositions are united by the female’s desire to lay an egg as close as possible to the base of the storksbill.

According to laboratory observations, the egg stage lasts from 4 days at a temperature of +25 degrees to 8 days at lower temperatures. The first instar caterpillar feeds by gnawing the petiole of the youngest leaf. While feeding, the caterpillar plunges halfway into the hole eaten out in the petiole, and then gnaws it completely, after which it begins molting, which occurs near the soil.

The caterpillars live under a cushion of last year’s leaves, where they damage the root part of the food plant. The caterpillars are also visited by ants of the genus Myrmica , but the biotic relationship between the species remains poorly understood. According to the field observations, the caterpillars of A. anteros kalmius ssp. nov. can only be found in those storksbill plants where ants are present. According to laboratory observations, the caterpillar of the last instar, when visited by an ant, puts forward two symmetrically located glands in the back of the body, after which the ants stop being interested in it for a while.

Pupation occurs in the litter near the root part of Erodium beketowii (according to field observations) or directly on the soil surface (according to laboratory data). The pupal stage lasts from 4–6 to 8 days.

Due to the nature of oviposition by females (one at a time for some time) at the end of the first generation (the end of May—the first days of June), one can observe flying adults (mostly males) together with caterpillars of different ages, and even occasionally pupae. Thus, in 2006, the first males of the second generation appeared on June 18, and adults were encountered until mid-August (the peak of flight occurred in mid-July). In 2007, the first males appeared in the first ten days of June, the peak of flight occurred on July 5–10, and by the third ten days adults were no longer encountered ( Fig. 10 ). The second-generation butterflies can be observed both in the above-mentioned habitats and on meadow vegetation bordering granite outcrops. Here, feeding occurs on flowers of Trifolium L., Arctium L., Cirsium Mill. , Achillea L., Salvia L. and other flowering plants. The next generation of caterpillars can be observed during July; their feeding pattern does not differ from the second generation, but, having reached the penultimate age, the caterpillars stop feeding and some of them prepare for wintering. The conditions under which wintering occurs currently remain unclear.

The timing of the flight of adults, their body size and the possibility of the emergence of the third and subsequent generations are most influenced by the amount of precipitation. In the dry year of 2007, adults stopped occurring three weeks earlier than in 2006, and in the relatively rainy years of 2005 and 2023, adults were found in large numbers in the last days of August. There may have been a third and additional subsequent generations of A. anteros kalmius ssp. nov. during these years. 2009 was curious in this regard, when early October frosts, followed by a sharp warming in late October, led to the release of an additional, but incomplete generation. Fresh males were encountered on November 2, 2009; however, no females were encountered. Emergence from wintering (diapause) is observed in early April. The caterpillars feed for 7–10 days, after which they pupate. In this generation, the pupal stage lasts 13–14 days.

Figures

FIGURE 3. A map that schematically shows the distribution of taxa included in the A. anteros species complex. The map is based on the work of Hesselbarth et al. (1995), ten Hagen & Schurian (2009) and original data.

FIGURE 4. Aricia anteros kalmius ssp. nov. A–B, Holotype, VL626, ♂, Donetsk Region, Orlovskoe, 47.260°N, 37.743°E, 01 Aug 2023 R.V.Botman. C–D, VL628, Paratype, ♂, Donetsk Region, Orlovskoe, 47.260°N, 37.743°E, 01 Aug 2023 R.V.Botman. E–F, Paratype, ♀, Donetsk Region, Orlovskoe, 47.260°N, 37.743°E, 01 Aug 2023 R.V.Botman. G–H, ♂, Donetsk Region, Mariupol district, 117 km SSE from the centre of Donetsk, left bank of the Kalmius river, Pyshchevyk vill. 47.242°N, 37.794°E, 16 June 2010, R. Botman leg. I–J, ♀, Donetsk Region, Mariupol district, 117 km SSE from the centre of Donetsk, left bank of the Kalmius river, Pyshchevyk vill. 47.242°N, 37.794°E, 16 June 2010, R. Botman leg. Scale = 2 cm.

FIGURE 6. Male genitalia of A. anteros kalmius ssp. nov. (specimen VL629 is shown).A Lateral view. B. Right valve, internal view and left valve, dorsal view. C. Uncus and branches of the gnathos, dorsal view.

FIGURE 7. The Kalmius River near Pyshchevyk village. 1 June 2006. Photo: R. Botman.

FIGURE 8. The host plant of A. anteros kalmius ssp. nov. Beketov’s storksbill (Erodium beketowii Schmalh). 5 May 2020. Photo: R. Botman.

FIGURE 9. Aricia anteros kalmius ssp. nov., butterflies of the first generation in nature. A, male, near Pyshchevyk village,11 May 2008. B, male, near Orlovskoe village, 15 May 2021. C, female on Sedum sp., near Pyshchevyk village, 01 June 2006. Photo: R. Botman.

FIGURE 10. Aricia anteros kalmius ssp. nov., butterflies of the second generation in nature. A, male, near Orlovskoe village, 1 August 2023. B, male, near Orlovskoe village, 1 August 2023. C, female, near Orlovskoe village, 1 August 2023. Photo: R. Botman.