Taxonomic notes on Palearctic taxa of Galacticidae, a little-known family of Lepidoptera (Galacticoidea)

Galacticidae is a poorly known family in the Palearctic Region. The range of the family covers the Mediterranean Zone of North Africa, as well as Western Asia, Eastern Russia, Central Asia and the Eastern Palaearctic. The included taxa are summarised in a checklist. Available type material was examined and redescriptions of some species are provided. Two genera are recognised and diagnosed: Homadaula Lower, 1899 with four species and Zarcinia Chrétien, 1915 with five species. Bahrlutia Amsel 1935, syn. nov. is a junior synonym of Zarcinia and Galactica Walsingham, 1911 syn. nov., the name bearing type genus of the family, proves to be a junior synonym of Homadaula. The male and female genitalia are the principal characters for defining genera and diagnosing species in this family. The hitherto unknown genitalia of seven species are illustrated for the first time. Zarcinia stshetkini sp. nov. is described from Tajikistan and Afghanistan. Not all taxonomic problems could be solved. Three species remain as incertae sedis.


Introduction
The family Galacticidae was established by Minet (1986) on the basis of morphological descriptions by Clarke (1943) and Inoue et al. (1982), and by a proposal of Friese (1966). It was again recognised as a separate family by Kyrki (1990) by upgrading the Homadaula Group sensu Kyrki (1984), but without discussing taxonomic evidence. Four genera were included in the family: Homadaula Lower, 1899, Zarcinia Chrétien, 1915, Bahrluthia Amsel,1935, and Galactica Walsingham, 1911 with the latter as the type genus. Valid autapomorphies of the family were provided by Dugdale et al. (1998) who established the superfamily Galacticoidea. Autapomorphies were recognised as genital modifications in both sexes exemplified by Australian species of Homadaula: • male tergum VIII forming a hood over segments IX and X which are deeply incorporated within segment VIII, • female genitalia with genital opening on a penis-like tube projecting from membrane between segments VII and VIII.
The taxonomy of the family has not been revised until now. In the past, the genera were introduced without descriptions of the genitalia, which subsequently turned out to be the most significant features in the discrimination of taxa. Mey (2004) provided a synopsis of nominal genera and Dissection of the genitalia was performed according to the procedure described by Robinson (1976). The genitalia were embedded in Euparal. Chlorazol Black was used for staining female genitalia. The cleared abdomens of some non-type specimens are on the corresponding pins in polyethylene vials with glycerin. Prior to embedding the cleared genitalia on microscope slides or into glycerin vials, they were drawn using a camera lucida attached to a Leica MZ12 compound microscope.
The terminology used in the descriptions of species largely follows Mey (2004). The treatment and sequence of the genera and species are arranged alphabetically.
As explained in the introduction, this article is not designed as a revision in its proper sense. Therefore, the species are not described according to a fixed scheme but are treated in a way providing mainly new faunistic records, references and hitherto unknown details.  Meyrick, 1922 China, Japan H. caradjae (Walsingham, 1911) [Galactica], comb. nov. Algeria H. punctigera (Rebel, 1910) [Paraprays] Uzbekistan, Kyrgistan H. schaeuffelei (Amsel, 1959) [Bahrlutia], comb. nov.

Key to genera of Palaearctic species of Galacticidae
The genera and species of Galacticidae cannot be distinguished by external characters alone. Contrary to the opinions of Chrétien (1915) and Amsel (1935), who established their genera on seemingly deviating wing characters of wing venation, the genera and species of the family exhibit a corresponding fore-and hindwing venation with only minor variations that are insufficient for a generic separation. The presence or absence of the henia in the females and the corresponding short or elongated phallus in the males are the principal features for accepting two different genera. However, the occurrence of a henia is not a character restricted to Galacticidae, but occurs also in other families such as Tineidae (e.g., Infurcitinea Spuler, 1910), Scythrididae (e. g. Episcythris Amsel, 1939, Scythris Hübner, 1825, Gelechiidae (e.g., Teilopsis Sattler, 1960) and in Lycaenidae (e.g., Lysandra sp.). In these families, this character is not used for separating and accepting different genera. In Galacticidae, the presence or absence of the henia is considered important enough to justify the grouping of species in two different genera.  (7): 305-306. Remarks. In the phylogenetic tree of Heikkilä et al. (2015), which was based on a combination of molecular and morphological data, the family emerged in the Apoditrysia as sister group of Tortricoidea. A similar result was recovered by the molecular study of Regier et al. (2013). This placement is in contrast to the morphological results of Friese (1960Friese ( , 1962Friese ( , 1966, Moriuti (1963) and Kyrki (1984Kyrki ( , 1990) who considered the group as belonging to the Yponomeutoidea. Alternative systematic positions in Tineoidea or Urodidae were proposed by Common (1990) and Heppner (1998) respectively. In fact, there are a number of morphological traits which are shared by Galacticidae and various groups in Tineoidea and Yponomeutoidea. To these characters should be added the presence of an unscaled, transparent patch in the hindwings at the wing base lying between Cu1 and Cu2. This character went widely unnoticed and, occurring in most examined species of Galacticidae, must be included in the taxonomic diagnosis of the family. The similar transparent patch in Yponomeuta has an array of ridges, which may be used to produce sounds (Agassiz 2017). These ridges do not occur in the transparent patches of Galacticidae. The function of such patches and their occurrence in Microlepidoptera were recently investigated by O'Reilly (2021), who coined the term aeroelastic tymbals for those hyaline spots. They produce ultrasound by wingbeat movements and are thus acoustically active structures serving as an anti-bat defence.  Meyrick (1914), Meyrick (1917), Caradja and Meyrick (1935), Clarke (1943Clarke ( , 1967; Friese (1962), Inoue et al. (1982), Kyrki (1984), Minet (1986), Common (1990), Nielsen and Edwards (1996), Dugdale et al. (1998), Holloway et al. (2001), Mey (2004Mey ( , 2007Mey ( , 2011, Hirowatari et al. (2013). Paraprays Rebel, 1910: 13-14. Type species P. punctigera Rebel, 1910; by monotypy, type locality: Alai Mts.

Diagnosis.
Male genitalia with tergum IX reduced or with uncus and remnants of gnathos invaginated into segment VIII, phallus short, not projecting, sclerotized, dagger-like and pointed, ankylosed with larger anellus forming a structure with complicated morphology. Female genitalia with segment VII with sclerotised sternum and tergum, sometimes fused to a certain degree; dorsal side of tergum a broad, bilobed or compact plate without median, shallow groove; caudal margin of sternum VII symmetrical in ventral view, ostium bursae a small opening on tip of elongate and freely projecting, sterigmal tube (= henia), membranous or weakly sclerotised; ductus bursae barely longer than bursa copulatrix; bulla seminalis absent or present; bursa with or without signa. Meyrick, 1922 Homadaula anisocentra Meyrick, 1922: 47, type

Remarks.
In the genitalia slides of both the holo-and paratype, the henia of the female genitalia is clearly visible. This character is an apomorphic and diagnostic feature of Homadaula. Its presence in G. caradjae necessitates the transfer of this species to the genus Homadaula Lower, 1899, which has priority over Galactica Walsingham 1911. The name of the family is not affected by this taxonomic change.
The species was never reported again since it was collected in North Africa. The male sex is unknown, which renders the identification of the species difficult. The species resembles Z. schaeuffelei, and new material from Northern Africa would be necessary to clarify the identity of H. caradjae.
The species is similar to H. anisocentra by sharing the grey-brown colour of the adults and the similar pattern of forewings. In the male genitalia, the long tergal plate and the form of the phallic apparatus (= fused with the anellus) have a similar architecture in both species.
Redescription. Adult (Fig. 3) Length of forewing 7-9 mm, wingspan 15.5-18.2 mm (n = 6); head brown-grey, frons with appressed scales, vertex and scape with semi-erected, porrect scales; labial palpi as long as eye-diameter, straight, uniformly grey-brown; unscaled proboscis pale grey; antennae filiform, 0.5 of forewing length, finely ciliated on ventral side; fore-tibia with epiphysis, tarsomeres of fore and mid-legs brown, not flecked on dorsal sides, spurs 0.2.4.; forewing brown-grey, with very small, black dots (6-10) along R and Cu, one larger dot in end of cell, dots on termen absent, underside grey-brown; hindwing somewhat paler than forewing, fringes grey; wing venation with accessory cell in forewing and complete M present in cell; hindwing with M3 and Cu1a confluent over short distance; retinaculum with grey-brown scales on underside of Sc.
Male genitalia : tergal plate of segment VIII nearly rectangular, with emarginated apex in dorsal view; pleurae and sternum membranous, simple, not lobe-like; segment IX vestigial, uncus arched, scale-like, on lateral corners attached to tergal plate and on this point with long, upcurved process; gnathos asymmetrical, valva long, dorsal process broad, elongate, directed dorsad, of apical part shorter, rounded apically; phallus short, fused sub-basally with anellus.
Female: unknown. Distribution (Fig. 17). The species is known from the Alai Mts. situated between Kyrgyzstan and Uzbekistan. Margelan in the Ferghana Valley is the second known locality of the species collected probably in 1896 by the Austrian entomologist Josef Haberhauer .
H. schaeuffelei is an unusual species of the genus by showing a completely cream-white, external appearance of the adults, resembling externally H. caradjae.
Redescription. Adult (Figs 5-8). Length of forewing 5-7 mm, wingspan 11.5-14.8 mm (n = 3); head white, frons with appressed scales, vertex and scapes with semi-erected scales; labial palpi as long as eye-diameter, straight, white and with brown patch on second segment; unscaled proboscis yellow-brown; antennae filiform, 0.5 of forewing length, finely ciliated on ventral side; fore-tibia with epiphysis, tarsomeres of fore and mid-legs pale brown on dorsal side, hind legs white, spurs 0.2.4.; forewing white, with small, black scales on termen and in cell forming short, indistinct or distinct patches in basal half; hindwings white, fringes white; wing venation with accessory cell in forewing and M present in cell, R4 and R5 with a short stalk, originating from distal end of accessory cell; hindwing with M3 and Cu1a confluent over short distance; one frenular bristle in male, two in females; retinaculum with white scales on underside of Sc.
Male genitalia . Tergal plate of segment VIII tapering from broad base towards an acute apex in dorsal view; pleurae membranous, simple, not lobe-like; segment IX vestigial, uncus and gnathos absent, valvae long, dorsal process broad, elongate, directed dorsad and laterad, length of apical part longer, somewhat curved dorsad, rounded apically; phallus with large bulbus ejaculatorius and short, sickle-shaped phallus, connected sub-basally with anellus.
Female genitalia (Figs 24-26). Tergum VII with median, shallow groove extending to caudal margin; sternum VIII slightly overlapping with tergum laterally; distal margin of sternum VII in ventral view slightly asymmetrical, ostium bursae on tip of henia, originating in central position of inter-segmental membrane, ductus bursae shorter than bursa, small bulla seminalis present, signa in oval bursa copulatrix absent.
Biology. Host plant unknown. Adults have been collected at the lights in March and June at elevations of 800-900 m and at lower elevations.
Distribution. Iran and Pakistan.

Diagnosis.
Male genitalia with tergum IX reduced and invaginated into segment VIII, phallus elongated, sclerotized and asymmetrically screwed; female genitalia with segment VII with sclerotised sternum and tergum; dorsal side of tergum (= tergal plate) with median, shallow groove; caudal margin of sternum VII symmetrical or asymmetrical in ventral view, ostium bursae a large, rounded opening in central or lateral position of intersegmental membrane between segments VII and VIII, rim of ostium sclerotised, antrum present; ductus bursae longer than bursa copulatrix; bulla seminalis present or absent; bursa without signa. (Amsel, 1935)  Diagnosis. Zarcinia ghorella externally resembles Z. walsinghami. It can be distinguished by characters of female abdomen and genitalia, e.g., tergum and sternum VII overlapping in lateral view, median groove of tergum VII in central position and bulla seminalis absent.

Zarcinia ghorella
Redescription. Adult (Fig. 9). Length of forewing 5.6 mm, wing span 13 mm (n = 1). Head white, frons with appressed scales, vertex and scapes with semi-erected scales; labial palpi as long as eye-diameter, straight, white and with a small black patch on tip of second segment; unscaled proboscis pale brown; antennae filiform, 0.5 of forewing length, very shortly ciliated on ventral side; fore-tibia with epiphysis, tarsomeres of fore and mid-legs brown to black on dorsal side, white-ringed at tips, hind legs white, spurs 0.2.4.; forewing white, with small black spots on termen and costa, a second line of small spots parallel to spot line on termen, further spots scattered on wing and forming a round crowd in basal half; hindwing white, yellow-brown towards apices, fringes white; wing venation with accessory cell in forewing and M present in cell, hindwing with M3 and Cu1a shortly confluent or connected in a point; three frenular bristles in females; retinaculum with white scales on underside of Sc.
Female genitalia (Figs 36-38). Tergum and sternum of segment VII shortly overlapping in lateral view, tergum VII with median, shallow groove broad not reaching caudal margin; distal margin of sternum VII in ventral view strongly asymmetrical, ostium bursae with sclerotised rim and antrum on right hand side in intersegmental membrane, close to right, sternal margin, ductus bursae longer than bursa, signa in oval bursa copulatrix absent.

Remarks.
In the original description two available specimens were mentioned. One is obviously lost, and the remaining individual is the one which was designated by Amsel as the type, which is interpreted here as a valid holotype designation. Amsel (1935) established the genus Bahrlutia by certain differences in the wing venation, which he observed by comparing his species with the original illustration of Z. nigrosignatella. In fact, there are no such differences, and Amsel was probably misled by an incorrect figure of Chrétien (1915).
The descriptions of three, unrevised species summarised in the incertae sedis group are more or less in agreement with the description of Z. ghorella. In the case of conspecifity with one or all of these species, which could be detected in the future, Z. ghorella would become a synonym of one of those species. Remarks. The holotype of the species could not be traced in the MNHN and is probably lost. The two females from the Staudinger collection agree in external appearance with the illustrations and description of the type specimen and are interpreted here as representing Z. nigrosignatella. The female genitalia are illustrated in Figs 45-47. In contrast to other congeners, the ostium bursae is small and situated in the intersegmental membrane in a central position, and the distal margin of sternum VII is straight and symmetrical.  Mey 3/04;31.v.1949;14.vi.1949, genitalia slide Mey 22/21;16.vi.1949, all leg. Y. Stshetkin;1 ♀, Lower Vahsh River, Tigrovaja Balka, 9.x.1949, leg by the dorsal process of the valva, which is directed caudad and shorter than the apical part, whereas it is directed distad and longer in Z. walsinghami. The pallus is as long as the valva and double twisted in contrast to Z. walsinghami, whose phallus is simply curved and shorter than half length of the valva. The distal tip of the tergal plate is lobe-like and rounded with a short, median tip in the new species, but triangular and acute in Z. walsinghami. In the female genitalia, the bulla seminalis is absent and the ductus bursae much longer than the bursa in the new species Description. Adult (Figs 1, 15). Length of forewing 6-7.5 mm, wingspan 13-16.5 mm (n = 11); head white, frons with appressed scales, vertex and scapes with semi-erected scales; labial palpi as long as eye-diameter, straight, white and with a brown patch on second segment; unscaled proboscis pale brown; antennae filiform, 0.5 of forewing length, finely ciliated on ventral side; fore-tibia with epiphysis, tarsomeres of fore and mid-legs brown on dorsal side, hind legs white, spurs 0.2.4.; forewing white, with small black spots on termen and costa, forming short, oblique streak in basal half; hindwing white, fringes white; wing venation ( Fig. 32) with accessory cell in forewing and M present in cell, hindwing with M3 and Cu1a shortly stalked or from a point; one frenular bristle in male, four to five in females; white scales of retinaculum on underside of Sc.
Female genitalia (Figs 39-41). Tergum VII with median, shallow groove extending beyond caudal margin; distal margin of sternum VII in ventral view asymmetrical, ostium bursae with sclerotised rim, on right hand side in intersegmental membrane, close to sternal margin, ductus bursae longer than bursa, signa in oval bursa copulatrix absent.

Zarcinia walsinghami
Diagnosis. Zarcinia walsinghami resembles Z. stshetkini sp. nov. The males differ in the form of the valva and the size of the phallus. In the female genitalia, the bulla seminalis is present in Z. walsinghami and absent in Z. stshetkini sp. nov.
Description. Adult (Fig. 13). Length of forewing 8-9 mm, wingspan 17-20 mm (n = 3); head white, frons with appressed scales, vertex and scapes with semi-erected scales; labial palpi longer as eye-diameter, straight, white and with a brown patch on second segment; unscaled proboscis pale grey; antennae filiform, 0.5 of forewing length, finely ciliated on ventral side; tarsomeres of fore and mid-legs brown on dorsal side, tips white, hind legs white, spurs 0.2.4.; forewing white, with numerous small, black spots, forming no distinct streak in basal half; hindwing white, pale brown towards tips, fringes white; wing venation as in Fig. 32 with accessory cell in forewing and M present in cell, hindwing with M3 and Cu1a fused over a short distance; one frenular bristle in male, three in females; white scales of retinaculum on underside of Sc.
Male genitalia . Tergal plate of segment VIII nearly triangular with broad base and acute apex in dorsal view; pleurae membranous; segment IX vestigial, gnathos a pair of asymmetrical, triangular pieces, valvae long, dorsal process trapezoid, directed distad, apical part as long as dorsal process; phallus tubular, thin and curved, as long as half of valva length, connected sub-basally with bifid anellus.
Female genitalia . Tergum VII with median, shallow groove extending beyond caudal margin; distal margin of sternum VII in ventral view asymmetrical, ostium bursae with sclerotised rim, on right hand side in intersegmental membrane, close to sternal margin, ductus bursae longer than bursa, signa in oval bursa copulatrix absent, bulla seminalis present, inserted to ductus bursae close to ductus seminalis.
Biology. The species was reared by Knyazev et al. (2016), who also described the larvae. The food plant was identified by as Limonium caspicus Willdenow, a species with a wide distribution around the northern part of the Caspian Sea to southern Siberia and Kazakhstan. The larvae live in webs spun throughout the affected leaves and flowers (Fig. 49). When fully crown the larvae spin cocoons between leaves and inflorescences of the host plant and overwinters in this stage. Judging from collecting dates of adults, the species probably has two generations per year. Distribution (Fig. 17). Dagestan, eastern Russia, Kazakhstan. Remarks. Galactica walsinghami was described from specimens from Indersky Salt Lake near Uralsk in northern Kazakhstan. The species remained uncollected for more than 100 years. Anikin et al. (2006) synonymised Zarcinia melanozestas Meyrick, 1925 with G. walsinghami without providing evidence and data from freshly collected specimens, but mentioned Limonium gmelini (Plumbaginaceae) as the host plant of the species. The type locality of Z. melanozestas in Dagestan is Khasaviurt Town (= Chasav`urt, 43°15'N, 46°37'E, 121 m), which is situated on the western side of the Caspian Sea. The collecting site lies in the arid steppe zone, which reaches the foothills of the eastern Caucasus in this area. Knyazev et al. (2016) reported localities and specimens collected in Western Siberia and mentioned the general occurrence of the species in the steppe zone of Eastern Russia (Sinev 2008), western Siberia and northern Kazakhstan.
Photos of adults were published by Knyazev et al. 2016 andAnikin et al. 2017. The male genitalia were photographed by D.S. Shovkoon from genitalia slides made by G. Friese. The latter author designated a lectotype (Nr. 862) and paralectotype (Nr. 863) but did not publish the designations. The photo of the male paralectotype is provided in Fig. 35. Turati (1930) synomymised his species Calantica bootella Turati, 1926 with B. walsinghami. This action was initiated by a proposal of Caradja, who considered both species as conspecific. The Figure 17. Distribution of Homadaula punctigera (Rebel), Zarcinia stshetkini sp. nov. and Z. walsinghami (Caradja) in Central Asia. synonymy was assumed by comparing images of adults and was not based on examination of the genitalia, which is the only way to determine generic affiliations in this family. The synonymy is therefore doubtful. The species is either a synonym of H. caradjae, Z. ghorella, Z. nigrosignatella, Z variinotella or represents a distinct species.
Zarcinia spec. Remarks. According to the genitalia, the single female represents an undescribed species. It mainly differs from Z. ghorella, Z. stshetkini sp. nov. and Z. walsinghami in the median position of the ostium bursae in the intersegmental membrane ventrally between segment VII and VIII. The abdominal segments are more melanised than in other species and especially the surface of sterna VI and VII have a rough surface formed by minute denticules (Fig. 48).
With only one female individual at hand, the species is not named and described here. More material including males should be collected in the area of the known locality, which would provide a more adequate basis for a species description.

Species incertae sedis
Homadaula variinotella (Chrétien, 1915) Psecadia variinotella Chrétien, 1915: 339, type locality: Gafsa, Tunisia, lectotype in MNHN [not examined]. Galactica variinotella: Sattler (1967: 140). Remarks. The male lectotype was designated by Sattler (1967: 140) who transferred the species provisionally from the family Ethmiidae to Galactica. The genitalia were unfortunately not examined and not illustrated. From the original description alone, the generic affiliation cannot be determined. The type is missing in the MNHN.

Discussion
The taxonomy of Homadaula and Zarcinia is still far from being resolved. The types of a number of species are missing and the opposite sex of others are unknown. We can only hope for freshly collected material of both genera coming from Microlepidoptera samples of the known type localities in North Africa and adjacent regions. Unfortunately, faunistic studies in these areas are difficult to carry out at present, and we probably have to be satisfied with a poor knowledge on the family for a while. The host plant of Zarcinia walsinghami was identified by Knyazev et al. (2016) as Limonium caspicum Willdenow. This plant genus encompasses many widespread and endemic species occurring from Central Asia to the Mediterranean, which is suggests the discovery of further records and species of Zarcinia spp. in this area, e.g., in Turkey and even in Greece.
provided the map, and to J. Dunlop (MfN, Berlin), who corrected the English text. The reviewers O. Karsholt and D. Shovkoon, the subject editor L. Kaila, and editor of Nota Lepidopterologica are thanked for their constructive criticism and suggestions.