A review of the genus Eremohadena Ronkay, Varga & Fábián, 1995 subgenus Megahadena Ronkay, Varga & Gyulai, 2002 with description of a new species (Lepidoptera, Noctuidae, Xyleninae)

Abstract: The subgenus Megahadena Ronkay, Varga & Gyulai, 2002 of Eremohadena Ronkay, Varga & Fábián, 1995 is revised and a new species, E. (M.) peterschucherti sp. nov. from Pakistan, Baltistan, is described. The adults and the genitalia of both sexes are illustrated for all three species: E. (M.) rjabovi (Boursin, 1970), E. (M.) megaptera (Boursin, 1970), and the new species.


Diagnosis:
The original description still includes the characters of the later separated subgenus Iberihadena, therefore a short characterisation of Megahadena is provided here.The most typical apomorphy of the group is the striking dissymmetry of the male clasping apparatus (Figs 1, 3, 5) which is expressed mostly in the two harpes (claspers), in the shape and sclerotisation of the two cuculli.The aedeagus (phallus) is long and straight, not arched and distally tapering as in Eremohadena, the vesica is shorter and less complex, lacking the strong medial curve and the terminal cornutus being typical of Eremohadena and only smaller or larger scobinate or finely spinulose fields are present, consisting of minute, rather hair-like spiculi.The diagnostic features of the female genitalia (Figs 2,4,6) are the sclerotised antrum and long, flattened ductus bursae and the small appendix bursae versus the only partly sclerotised antrum having smaller sclerotised plates, the rather membranous ductus bursae with characteristically sclerotised and folded ribbons in the internal walls of the ductus bursae and the fairly separated fundus and appendix bursae in Eremohadena.
The external appearance of the adults is most similar to that of the immunis lineage of Iberohadena and the pexa species group of Eremohadena s. str.but the moths are larger in size, having more robust body ("Megahadena"; wingspan 53-64 mm vs 44-52 mm) than the species having similar wing shape and forewing pattern.

Bionomics and distribution:
The species are xeromontane, appearing at medium-high and high montane steppes and semi-deserts.The moths are on the wing from May to October.The range of the subgenus extends from eastern Turkey via the Elburs region and new species distinct from E. (M.) megaptera, i.e.E. (M.) peterschucherti sp.nov.

MATERIAL AND METHODS
The method of surveys was traditional taxonomic, based on materials of state museums and private collections, electronic databases and digitalised microscopic slides.We revised the comprehensive type material and other important voucher specimens from several internationally important European collections (see: Abbreviations).
The genital dissections were made with the technique published by Fibiger & Goater (1997)

Diagnosis:
The diagnostic features of the genus, in comparison with Pseudohadena s. str.are given in detail in the original description and later, in the 9th volume of the Noctuidae Europaeae (Fibiger & Hacker, 2007).

Bionomics and distribution:
The members of the genus inhabit often both the xeromontane and the lowland desert and steppe biotopes (hence the derivation of the generic name).The species are univoltine, having a characteristic life cycle: the freshly emerged moths are active in the spring and the early  The external appearance of the three Megahadena species is very similar, there is no key feature for their separation though the hindwing of E. (M.) rjabovi is somewhat paler than in the other two species.
The distinctive characters of the male genitalia of E. (M.) rjabovi (Fig. 5) are the longer and slenderer valvae with much longer and almost symmetrical, acute subapical ventral processes, the much longer harpes of both sides, without apical dilatations, and the strongly reduced scobinate-spinulate areas of the vesica.The two other congeners (Figs 1 and 3) have shorter and broader valvae with well-expressed medial costal lobe and more asymmetrical cuculli, shorter and weaker subapical ventral processes, shorter and apically strongly dilated and flattened harpes and larger and denser spinulose areas in the vesica.The female genitalia of E. (M.) rjabovi (Fig. 6) have, in comparison with E. (M.) megaptera (Fig. 2) and E. (M.) peterschucherti (Fig. 4), more calyciform antrum, straighter ductus bursae without medio-lateral dilatation but with tapering anterior section and smaller, more elongated appendix bursae.

Bionomics and distribution:
The species occurs in arid and xeric, rocky steppes and montane semi-deserts, between 1000-3200 m in altitude.The moths appear in May and in the lower regions have a long summer diapause while in the high montane biotopes they are active also in the midsummer period.The species is known to occur in south-eastern Turkey and northwestern Iran; it is local and rare.

Diagnosis:
The moths are very similar externally to the other Megahadena species, having somewhat sharper defined forewing pattern than in its close relatives, especially of E. (M.) peterschucherti while the hindwings are paler than in this latter species but darker than those of E. (M.) rjabovi.
The male clasping apparatus of E. (M.) megaptera (Fig. 1) differs from that of E. (M.) peterschucherti (Fig. 3) by the somewhat differently shaped cuculli (the left one is smaller, the right one is broader and the ventroapical processes are shorter and less acute on both sides) and the smaller flattened apical parts of both harpes.The male genitalia of these two species differ conspicuously from those of E. (M.) rjabovi (Fig. 5) by the shorter and broader valvae with more asymmetrical cuculli and smaller, weaker ventro-apical processes and shorter, distally strongly dilated harpes, and the much stronger spinulose fields of the vesica.The female genitalia of E. (M.) megaptera (Fig. 2) and E. (M.) peterschucherti (Fig. 4) are also very similar but the former species has larger and broader sclerotised antrum, more posteriorly positioned lateral lobe and less curved but broader anterior end of ductus bursae, having smaller antero-lateral appendage at junction to appendix bursae.The ductus bursae of both species is remarkably broader than that of E. (M.) rjabovi possessing large mediolateral lobe and broader anterior section at junction to appendix bursae; the appendix is also much larger in E. (M.) megaptera and E. (M.) peterschucherti than in E. (M.) rjabovi.

Diagnosis:
The new species differs externally from the other two close relatives by its rather uniformly darker, usually dark greyish-brown hindwings and the weaker defined forewing crosslines and stigmata.Wingspan 54-62 mm.The diagnostic features of the male genitalia of E. (M.) peterschucherti (Fig. 3), compared with those of E. (M.) megaptera, are the larger, broader flattened apical parts of both harpes, the narrower right and more angular left cucullus and the longer and more acute subapical ventral processes in both valvae.The new species has shorter and broader valvae than in E. (M.) rjabovi, having large medial costal lobe, considerably shorter and thinner subapical processes and differently shaped, less angular cuculli, and the harpes are shorter on both sides, having large flattened apical parts while the longer harpes of E. (M.) rjabovi are evenly slender throughout.Finally, the new species has large spinulose fields in the vesica which are reduced in the westerly distributed relative.
In the female genitalia, the antrum of E. (M.) peterschucherti (Fig. 4) is smaller, more funnel-like than in E. (M.) megaptera (Fig. 2), the ductus bursae is the broadest in its medial third and the anterior section has larger rugose-ribbed appendage at junction to appendix bursae.The ductus bursae of the new species is much broader and more arched anteriorly than in E. (M.) rjabovi (Fig. 6), its anterior section is considerably broader and has a large lateral appendage which is missing in the latter species, and the appendix bursae is larger, more ample and more sclerotised.

Bionomics and distribution:
The species was collected only once at the type locality in Baltistan, in August.

SYSTEMATIC PART Genus Eremohadena Ronkay, Varga & Fábián, 1995
Ronkay et al. (2011)l capsule, everted vesica and female copulatory organ were stained with eosin red then mounted to Euparal.The images are preserved in the photo catalogue of Heterocera Ltd, Budapest and the image database of the MHNG.Terminology of genitalia followsRonkay et al. (2011).