Contribution to the knowledge of the genus Zygaena Fabricius, 1775, in Iran (Lepidoptera, Zygaenidae). Part X: On two newly discovered Mesembrynus taxa from the western Alborz

Two well-defined Zygaena taxa are described from the central Alborz range in Iran and are placed as subspecies of two known Mesembrynus species. Both taxa inhabit biotopes on the northern side of the main Alborz range, areas that are climatically influenced by the Caspian Sea. Zygaena speciosa oseyii ssp. n. is represented by the most north-westerly populations of Z. speciosa Reiss, 1937, from Kuh-e Samamus, Gardaneh-ye Tondrokosh and from Kuh-e Khash-Chal, all of which are characterized by the absence of melanistic forms, while the nominotypical populations exhibit only melanistic forms. Zygaena tamara dailamica ssp. n. differs from all known populations of Z. tamara by having a different red colora tion while the red abdominal cingulum is restricted to one segment. Moreover, consistent differences are found in the larval phenotype although several cross-breedings (Z. tamara tamara Christoph, 1889 × Z. tamara dailamica ssp. n.) were successful. Zusammenfassung. Aus dem zentralen Elbursgebirge/Iran werden zwei außergewöhnliche Zygaena-Taxa beschrieben und bereits bekannten Mesembrynus-Arten subspezifisch zugeordnet. Die Fundorte beider Taxa befinden sich nördlich des Elburs-Hauptkammes; sie sind klimatisch bereits vom Kaspischen Meer beeinflußt. Zu Zygaena speciosa oseyii ssp. n. ziehen wir die nordwestlichsten Populationen vom Kuh-e Samamus, vom Gardaneh-ye Tondrokosh und vom Kuh-e Khash-Chal. Diese Populationen unterscheiden sich von der Nominatform durch das Fehlen melanistischer Formen. Zygaena tamara dailamica ssp. n. weicht von allen bekannten Z. tamara-Population durch eine andere Rotfärbung so wie durch einen stets einfachen, roten Abdominalring ab. Auch im Raupenphänon bestehen konstante Unterschiede; Kreuzungsversuche (Z. tamara tamara Christoph, 1889 × Z. tamara dailamica ssp. n.) verliefen jedoch erfolgreich.


Introduction The high-mountain Mesembrynus-species of the Alborz Range (Iran)
Traditionally the genus Zygaena comprises three subgenera, Agrumenia Hübner, [1819], Zygaena, and Mesembrynus Hübner, [1819], but only the last subgenus appears to be a well-defined monophylum based on molecular data (Niehuis et al. 2007). In contrast to the other two paraphyletic subgenera, the larvae of Mesembrynus live on acyanogenic plants, mainly Apiaceae (only a few species secondarily switched to Lamiaceae and Asteraceae). Naumann (2000) and Hofmann (2000) have provided detailed information on the rediscovery (the latter author also on the biology) of Zygaena cacuminum Christoph, 1877, in the Shah-Kuh region, while Hofmann and Kia-Hofmann (2008) have described the bionomics and distribution of Z. speciosa Reiss, 1937, both of these taxa being closely related, endemic Iranian species that are restricted to the oreal biome of the Alborz Range where Z. cacuminum inhabits cushion zone biotopes in the eastern Alborz, while Z. speciosa has been recorded only from the central part. As each species was known only from a single locality before 2001 (Hofmann and Kia-Hofmann 2008: 35), both were regarded at that time as unilocal and monotypic. However, Hofmann and Kia-Hofmann (2008) recorded new locality data and were able to show that neither of these species is restricted to a single site.
Zygaena speciosa and Z. cacuminum are geographically well separated, a wide gap of ca. 250 km existing between Shah-Kuh and the Kuh-e Damavand. Phenotypically, Z. cacuminum is distinguished by having on the forewings a quadrangular spot 4, a well-developed spot 6 and especially by the lack of melanistic tendencies on the hindwings. Hitherto, both high-mountain species were considered to be monotypic and represented only by populations consisting of very similar phenotypes.
On several expeditions to the central and western Alborz in 2006 and 2010 the authors had the opportunity to accrue new data on the tamara-like populations and also on Z. speciosa; those on the latter were partly incorporated in an earlier publication (Hofmann and Kia-Hofmann 2008). Of great taxonomic and zoogeographical interest are these most westerly populations, as they show that Z. speciosa actually is a polytypic species with a second subrange which is inhabited by purely non-melanistic populations. Etymology. Dedicated to Abbas Oseyi (Karaj), who accompanied the second author when discovering the first population at Kuh-e Samamus.
Description. A group of strictly non-melanistic populations. Black ground colour of forewings with greenish sheen, more greyish and more translucent in females. Hindwings with black border of medium width, stronger at apex and with a double-tooth in the beginning of anal field at the tornus, but never invading the discal area. Forewing spots 1+2, 3+4 and 5 well developed and always present, spots 1+2+2a forming the basal blotch, with spot 2 elongate, longer than spot 1, while spot 2a is vestigial. Spot 3 small, ovoid, spot 4 larger, quadrangular; both spots always separated by the cubitus stem vein. Spot 5 of similar size and form as spot 4, but standing more vertically, isolated from spot 6. The latter (spot 6) more variable: it can be absent in both sexes (20%), but more frequently in the males, it can be vestigial and reduced to a few scales (25%), or well developed as a normal spot in the costal part (25%), or reniform, the upper part then smaller (30%). Red patagia and red abdominal cingulum present on one segment, well developed in females, reduced or vestigial in males. The abdominal cingulum can even be absent or reduced to only a few red lateral scales (20%).
Remarks. Specimens from two other populations that are not from the type-locality are well separated geographically and differ slightly from the type-series; while they can be assigned to oseyii subsp. n., they are not included in the type-series.
Diagnosis. In specimens from Gardaneh-ye Tondrokosh (Figs 13-18), spot 6 is always present and larger, the black ground colour of the males is more bluish and the hindwing border is narrower with a very weak expansion at the apex. In specimens from Kuh-e Khash-Chal (Figs 19-21), spots 5 and 6 are mostly closer together and occasionally they are even connected to each other. Otherwise both populations look similar to Z. speciosa oseyii ssp. n. from the type-locality (Figs 10-12). The difference between oseyii ssp. n. (Figs 10-21) and the nominotypical subspecies from the type-locality in the Alam-Kuh region (Figs 4-6) is extraordinarily strong. In contrast to the nominotypical population from Hezarchal (and from those from Dizin-Shemshak and from Kuh-e Tochal), the more north-westerly located populations (Figs 10-21) from between Kuh-e Khash-Chal and Kuh-e Samamus do not exhibit a tendency for melanism. The hindwings are red with a variable broad border and are never darkened, while the border never forms a "tooth" along the anal vein. Spot 6 is either strongly reduced or predominantly completely missing in Z. speciosa speciosa, while it is predominantly present or at least vestigial in Z. speciosa oseyii ssp. n. Not a single specimen from all of these three new localities can be confused with specimens from Alam Kuh, Dizin-Shemshak or from Kuh-e Tochal, nor can any single specimen from these localities be incorporated into the series of oseyii ssp. n. The localities of the most easterly population of oseyii ssp. n. (Kuh-e Khash-Chal) and Z. speciosa speciosa are less than 40 km from each other as the crow flies and, surprisingly, the population nearest to the Alam-Kuh population even exhibits the most reddish forms of all three known populations. Genitalia. Differences in genitalia structures within species-groups of Zygaena (Hofmann and Tremewan 2010) are often poor, especially in the manlia-group, and significant characters for separating closely related taxa are obviously lacking (Hofmann and Keil 2011: 244-245), which is why fertile hybrid-crossings in captivity were relatively easily to obtain (Hofmann 2000b, Hofmann andKia-Hofmann 2010).
We found slight differences in the uncus and lamina dorsalis of the male genitalia between Z. speciosa speciosa (Figs 30-32, 36, 37) and Z. speciosa oseyii ssp. n. (Figs 33-35, 38, 39), but we do not interpret them as prezygotic mechanisms of isolation. The uncus of the nominotypical subspecies is more cone-shaped, attenuated at the end (compare Figs 30 and 33), while the lamina dorsalis is broadest at the middle part and becomes narrower toward the base (compare Figs 31 and 34), in contrast to Z. speciosa oseyii ssp. n. in which this structure is more pyramidal-like, broadest at its base. However, there may be variation in these structures and even if dissections of a series would confirm these as constant characters, they would nevertheless not prevent successful pairings, but may reflect strict isolation with diverse developments in the post-glacial period. Furthermore, if one takes the 100% separation in phenotype into account, a clear tendency for species-specific differentiation on the way to distinct biospecies becomes obvious.
Bionomics. Detailed data on the bionomics with figures of larvae, host-plants and biotopes, together with a distribution map that includes the populations of Z. speciosa oseyii ssp. n., have been provided by Hofmann and Kia-Hofmann (2008: 25-49). At all three localities, Z. speciosa oseyii ssp. n. is syntopic with Z. carniolica.
Distribution. In addition to the type-locality, Z. speciosa oseyii ssp. n. is known from two further sites, both of which are located further east of the Kuh-e Samamus (Fig. 22). All three sites are situated at altitudes between 3270 and 3700 m. A gap of ca. 40 km between ssp. oseyii and ssp. speciosa remains unexplored. Further prospecting, especially in the Kuh-e Sialan region, will show that either there is a transitional zone with mixed populations or a sharp divide between the melanistic and 'normal' forms.

Figs 40-72
Remarks. The pure red populations of the Kendevan region have been described as ssp. kendevanica Tremewan, 1977, and populations with the same phenotype are found further south-west to Zanjan (Figs 49-54). Similar pure red populations occur in the Van Gölü region in eastern Turkey (ssp. placida Bang-Haas, 1913), while the Zagros range, the Iranian Talysh and Azerbaijan-e Sharqi are predominantly inhabited by populations with mixed characters of yellow forewings and red hindwings (Figs 43-45) or yellow fore-and hindwings (46)(47)(48). A unique character that distinguishes all of these populations of Z. tamara from all other Mesembrynus species is the red abdominal cingulum that is present on two to three segments in the females and on three segments in the males (Figs 40-54, 63), a character that is in strong contrast to the newly discovered populations from the northern side of the Alborz range, which we here describe as Zygaena tamara dailamica ssp. n. [64][65][66][67][68][69][70]72 Material. Holotype ♂, 31 mm wingspan, "Iran, Prov. Qazvin, Hir NE, Gardaneh-ye Anbarkesh, N-Seite, 2780-2900m, 13.7.2006, coll. A. Hofmann (to be deposited later in SMNK).

Etymology. Dailam (persian ‫‬
‫‪‬ملید‬ ) is the historical name of the mountain region on the southwest side of the Caspian Sea. Because of its mountain location Dailam was for a long time protected from the attacks of invading Arabs, its inhabitants much later being converted to Islam. The centre was the Assassin fortress of Alamut, a castle at 2100 m altitude that was regarded as impregnable, but was destroyed in 1275 by the Mongols.  Description. Black ground colour with greenish or greyish sheen. Coloration of forewing spots warm red but without a tendency to orange. Hindwings less densely scaled, slightly translucent. Spots 1+2+2a forming a large basal blotch that is always well separated from the spot pair 3+4. Spot 3 smaller than spot 5, connected to the largest spot (spot 4). Spot 5 quadrangular, attached to spot 6, in the majority with a groove in the upper part, occasionally isolated, especially in the males. Spot 6 large, pear-shaped when separated from spot 5. Spot 6 completely absent in one female. Hindwings with a narrow greyish black border that can be broadened slightly at the apex. Red patagia and red abdominal belt always present on one segment, the latter closed ventrally. Tegulae consistently black in males, in females sometimes mixed with a few red scales. Legs greyish white in both sexes.
Diagnosis. Imago: From all other populations of Z. tamara the new subspecies is well separated by the one-segmented red cingulum on the abdomen (Fig. 62). Moreover, the red coloration is colder, less orange than in the red populations of Z. tamara (Z. tamara placida, Z. tamara kendevanica). The distance between the spot pairs 1+2+2a and 3+4 of these subspecies is broader than that in Z. tamara dailamica ssp. n., thus forming a broad black band of ground colour.
Preimaginal stages: Already the L1 larva is darker than larvae of Z. tamara from other localities. This is even more obvious in the diapausing stage. Post-diapause larvae and fully-grown larvae exhibit a more dirty-yellow ground colour with more brownish grey-yellow on the verrucae. While the fully-grown larvae of Z. tamara are nearly unicolorous without contrasting elements, those of dailamica ssp. n. are much more strongly marked with the anterior dorsal spots (ADS) well developed and the yellow dorso-subdorsal spots well visible and present on 10 segments (Figs 64-69). Moreover, constant differences exist in the sclerotization of the pupae and even in the coloration of the cocoon (Figs 70-72). The exuviae of dailamica ssp. n. are dark brown, in contrast to the light-to mid-brown coloration in all other known populations of Z. tamara. The coloration of the cocoon is consistently slightly darker, less yellowish but light white-brownish with a tinge of green. Cocoons of Z. tamara from Zanjan, Baneh (Kurdestan), Golujeh (Azerbaijan-e Sharqi) or from Dorud (Lorestan) are light yellow to white (Fig. 71).
Bionomics. All habitats of Z. tamara dailamica ssp. n. are treeless slopes with a combination of arboreal, oreal and eremic vegetation, e.g. Securigera varia (L.) Lassen (Fabaceae) is found in the immediate vicinity of Onobrychis cornuta (L.) Desv. (Fabaceae), Eryngium billardieri Delar. (Apiaceae), Astragalus (Tragacanthus) (Fabaceae) cushions and yellow-flowering Phlomis (Lamiaceae), typical for the narrow transitional zone between the humid Hyrcanian and the more arid eremic regions. At the first locality (Gardaneh Anbarkesh), Z. tamara dailamica ssp. n. is syntopic with Z. cambysea Lederer, 1870, while at the more northerly sites it is syntopic with Z. haberhaueri Lederer, 1870. In the more humid valley that lies between the two mountain ranges, where there is intensive agriculture, plenty of orchards and many villages, only Z. loti (Denis & Schiffermüller, 1775) and Z. dorycnii Ochsenheimer, 1808, were found; just 100-200 m higher up, the vegetation changes rapidly and becomes much drier and is partly grazed intensively by goats and sheep. These are the biotopes where, in the vicinity of Tamol, Z. tamara dailamica ssp. n. and Z. haberhaueri were accompanied by these two species, a faunistic combination that is atypical for Z. tamara. In its biotopes, Z. tamara is usually accompanied by species typical of the Zagros arid climate, e.g. Z. turkmenica Reiss, 1933, Z. escalerai Poujade, 1900, Z. rosinae Korb, 1903 cambysea. The sympatry in the vicinity of Tamol represents a faunistic mixture comprising two species that are typical for the northern side of the Alborz Range (Z. dorycnii, Z. loti), while the latter species does not even cross the Alborz main chain to the south.
After 10.00 h, moths were observed nectaring at the pinkish flowers of Salvia, but preferred to sit on the flower heads of some Dipsacaceae, viz. a white and bluish Scabiosa sp. and a tall white-flowered Cephalaria sp. Several copulae were found sitting on dry stems or on the flowers of scabious during the afternoon after 15.00 h, rarely on cushions of an Acanthophylum sp.
Distribution. Zygaena tamara dailamica ssp. n. was found only at altitudes between 2250-3000 m. Its distribution is restricted to the central Alborz range between north of Qazvin and south of Tonekabon and extends over two north-westerly/south-easterly ranging mountain chains with a valley of 1700-1900 m in between. In its most northerly sites Zygaena tamara dailamica ssp. n. inhabits slopes that are open to the Caspian Sea.