Mormogystia is distinguished from all other Cossidae genus by having large silvery areas on the forewing.

Medium sized, brightly coloured moths. Male antennae bipectinate with very short processes; female antennal pecten much reduced. Large silvery areas on the forewing forming fasciae make this the only Cossidae genus to have such a high contrast pattern. Hindwings are uniform.

Male genitalia. Uncus elongate, with tapering or rounded broad apex; arms of gnathos short, fused to form a medium-size gnathos densely covered with small spines; valvae shovel-shaped, with pronounced sacculus and a large triangular costal projection; transtilla projections short, thick and uncinate; juxta saddle-shaped, with long lateral projections directed upwards; saccus massive, semicircular; aedeagus short, straight, thick; vesica opening located dorsoapically, its edges with short, spiny processes; vesica without cornutus.

Female genitalia. Short oviductus; papillae anales wide, elliptic; apophyses posteriores ⅓ longer than apophyses anteriores; ostium broad, covered with falciform postvaginal plate; ductus wide, sclerotised; bursa membranous, sack-shaped, without signa.

This small genus includes four species distributed in north Africa, Levante, Arabian peninsula and Kenya (Yakovlev 2011 ).

Holotype ♂ (Fig. 1), central part of Socotra Island, Diksam loc., 14 January 2010, leg. A. Saldaitis (deposited in MWM/ZSM; slide No. BJ 1524). Paratypes: 77 ♂ and ♀ (Fig. 2), with same labels as holotype; Socotra Archipelago, Samha Island W., N 12°09', E 052°59', 23–24 February 2008, leg. A. Saldaitis; Socotra Archipelago, Abd al Kuri Island, Towanie vill. env., N 12°10', E 052°13', 25–27 February 2008, leg. A. Saldaitis; Socotra Island, Di Hamri loc., 1 March 2008, leg. Saldaitis; Socotra Island, Di Hamri loc., 20–21 November 2008, leg. Saldaitiene & Saldaitis; Socotra Island, hills near Hadibu, 21 March 2009, leg. A. Saldaitis; Socotra Island, Diksam canyon, 23 March 2009, leg. A. Saldaitis; W Socotra, Shuab, coast line, mangroves, 24 March 2009, leg. A. Saldaitis; N Socotra Island, Ayhft valley, 22 November 2008, leg. A. Saldaitis; S Socotra Island, Wadi Difarroha South side, 15 January 2010, leg. A. Saldaitis; N Socotra Island, Ayhft valley, 12 January 2010, leg. A. Saldaitis; N Socotra Island, Wadi Kam, 13 January 2010, leg. A. Saldaitis; N Socotra Island, top of Ayhft valley, 17 January 2010, leg. A. Saldaitis; E Socotra Island, sand dunes near Irisseyl loc., 18 January 2010, leg. A. Saldaitis; NE Socotra Island, Wadi Difarroha, North side, 19 January 2010, leg. A. Saldaitis (coll. ASV; JBW; LLE; MWM/ZSM; NRCV; RYB). Slide No. BJ 1532 (female).

The new species differs from the related species Mormogystia reibellii (Oberthür, 1876) (Fig. 5), Mormogystia proleuca (Hampson in Walsingham et Hampson, 1896) (Figs 3, 4) and Mormogystia equatorialis (Le Cerf 1933) (Fig. 6) in external appearance, genitalia, DNA and distribution. The new species has a larger wingspan than its congeners: Mormogystia brandstetteri sp. n. 33–35 mm, Mormogystia reibellii 27–31 mm, Mormogystia proleuca 25–29 mm, Mormogystia equatorialis 26 mm. All species of the genus Mormogystia have a similar forewing pattern, but the ground colour of the new species is black as opposed to light ochre, light brown and brown, respectively, for Mormogystia reibellii, Mormogystia proleuca and Mormogystia equatorialis. The head, thorax and abdomen of Mormogystia brandstetteri are intense grey compared to light yellow in Mormogystia reibellii andlight yellow and white in Mormogystia proleuca and Mormogystia equatorialis. Unlike the other species Mormogystia brandstetteri has a black costal spot on the ventral hindwing; in Mormogystia reibellii (Figs 23, 24)and Mormogystia proleuca (Fig. 22) uncus apically tapering, strongly sclerotised valvae not widening and not forming a straight angle; in Mormogystia brandstetteri uncus broad, apex of valvae form a straight angle; in Mormogystia reibellii and Mormogystia proleuca saccus rounded, apically without denticle, whereas in the new species saccus pointed, apically with a denticle; Mormogystia proleuca aedeagus at the basal end markedly narrowing, gradually widening towards apex; Mormogystia reibellii aedeagus of the same width from its middle to apex; in Mormogystia brandstetteri aedeagus widening at proximal end, gradually tapering towards apex. In the most closely related species, Mormogystia proleuca, the bursa is apically broader than basally (Fig. 28) unlike in the new species where the corpus bursae is significantly broader.

Mormogystia brandstetteri is endemic to the Socotra Archipelago while Mormogystia reibellii is distributed in North Africa and the northern part of the Arabian peninsula, Mormogystia proleuca is found in the southern part of the peninsula, and Mormogystia equatorialis is widespread in Kenya. Hampson (1903) and Rebel (1907) believed Mormogystia proleuca to be endemic to the Socotra Archipelago and later Hacker (1999) reported Mormogystia reibellii from Socotra, but the new species described herein was probably implied.

While molecular results alone are insufficient to definitively separate Mormogystia brandstetteri from Mormogystia proleuca, they help corroborate the morphological evidence. Evolutionary distances using the Kimura two-parameter model for comparing four specimens of Mormogystia brandstetteri to four Mormogystia proleuca and to three Mormogystia reibellii specimens, was at least 1.55% and 5.65%, respectively.

Male: Forewing costal margin length of holotype 15 mm, wingspan 33 mm; mean forewing length of paratypes 16 mm, wingspan 35 mm; head, thorax, abdomen and tegulae grey; antennae bipectinate, ½ the length of forewing; ground colour of forewing black, with white silvery pattern. Three white silvery patches form the pattern: fascia of even width runs along the entire costal margin, median fascia widening medially reaches the outer margin of forewing; lower silver patch originates at basal edge and extends along dorsal wing margin to middle. This patch enclosed by ground colour; adterminal line white; fringe grey. Dorsal surface of forewing greyish-white; costal, outer and dorsal margins greyish-black. Hindwing uniform, white, with greyish black spot at costal margin. Female (Fig. 2): Forewing length of allotype 23 mm, wingspan 48 mm; antennae filiform; wing pattern as in males. Intraspecific variation. Adterminal line in some specimens missing; contours of silvery spots forming the pattern vary; hindwings grey.

Male genitalia (Fig. 21). Uncus broad, slightly narrower than its length; apex wide, slightly rounded; arms of gnathos long and strong; gnathos very broad, with rounded apex; apex of saccus gradually tapering, with a pointed denticle; valvae symmetrical, with straight margins, gradually widening apically; costal margin with strong and wide sclerotisation; apex flat; arms of transtilla medium sized, strong, denticle-shaped; juxta large, strongly sclerotised, belt-shaped with a small indentation apically and a conspicuous boat-shaped margin at the basal area; aedeagus strong, straight, large, widening at the proximal end; vesica simple, wide, without cornuti.

Female genitalia (Fig. 28). Papilla analis narrow, covered with short, thin setae; apophysis posterioris 1.4 times longer than apophysis anterioris; antevaginal plate belt-shaped, pointed at the ends; ductus bursae sclerotised; corpus bursae shaped like a long narrow sac, not sclerotised; signa absent.

Both males and females of the new species were strongly attracted to light and were distributed in almost all habitats of Socotra Island as well as the smaller islands of the archipelago – Samha and Abd al Kuri. Acacia is a likely food plant for Mormogystia brandstetteri as larvae of the closely allied species Mormogystia proleuca feed on Acacia [Hampson, 1896]. Also, the new species is especially abundant in the central part of the island, in deeper canyons or rich oasis-like valleys where forests haven’t been cut for fuel like elsewhere on the island. Diksam canyon (Fig. 30), a prime locality for Mormogystia brandstetteri, contains the following plants: Acacia pennivenia, Jatropha unicostata, Lycium socotranum, Gnidia socotrana, Buxus hildebrandtii, Croton socotranus, Leucas virgata, Cissus hamaderohensis, Punica protopunica, Ficus vasta, Euphorbia socotrana, Jathropha unicostata, Lycium socotranum, Gnidia socotrana, Buxus hildebrandtii, Trichocalyx sp., Mitolepis intricata, Ballochia spp., Aloe perryi, Adenium obesum, Asparagus africanus, Seddera fastigiata, Aerva lanata, Rhinacanthus scoparius, Levandula nimmoi, Ocimum forskahlei, Cissus hamaderohensis (Miller and Cope 1996). Mormogystia brandstetteri flies with several other Socotra Archipelago endemic moths such as Meharia yakovlevi Saldaitis & Ivinskis, 2010, Aethalopteryx diksami Yakovlev & Saldaitis, 2010, (Cossidae), Pelosia sokotrensis (Hampson, 1900), Siccia butvilai Saldaitis & Ivinskis, 2008, (Arctiidae), Cerocala socotrensis Hampson, 1899, Agrotis brachypecten Hampson, 1899, Leucania diopsis Hampson, 1905 and Mythimna sokotrensis Hreblay, 1996 (Noctuidae).

The new species is dedicated to our good friend Johann Brandstetter, an eminent German painter and entomologist.

Meharia is distinguished from all other Cossidae genus by a number of apomorphous characters: the specific “tineoid appearance”, the reduction of the lateral processes of the juxta, the specific dorsolateral sclerotization of the asymmetric aedeagus and the specific ribbon – like epiphysis.

These are small to medium sized moths, females larger; eyes naked; male and female antennae bipectinate along their length; proboscis reduced; legs long, slender; foretibia bearing a ribbon-like epiphysis; forewing elongate, rounded on the outer margin; forewing pattern has alternate dark and pale spots and bands transversely; hindwing uniform.

Male genitalia. Simple; uncus unpaired, short, beak-shaped; tegumen massive; arms of gnathos short, slightly broadened distally, fused to form small gnathos; valvae short, broad, with no harpe and processes costally; juxta without lateral processes, simple; saccus protruding backwards, small; aedeagus rather long, slightly curved and asymmetical due to dorsoapical sclerotisation.

Female genitalia. Ovipositor lobes short, slightly acute apically, covered with relatively short, thick bristles, in the shape of triangular sclerites, with long and rather wide apophyses posteriores on the lower part, strongly widening oar-like in the cranial fourth and bearing a slender membranous-like border; tergite and sternite of the 8th segment fused to form a complete circle; sternite slightly swollen, membranous caudally; tergite strongly elongate, bearing a pair of apophyses anteriores, widening oar-like cranially, approximately as long as ½ the length of apophyses posteriores; opening of ostium strongly protruding cranially, located on membrane between the 7th and 8th segments; ostium membranous, with poorly sclerotized lateral bands; antrum membranous, tube-shaped, 1½ times longer than the 8th tergite, narrowing sharply, separate form membranous ductus bursae; corpus bursae membranous, saccular, without signa.

Eleven species of Meharia have been reported so far (Yakovlev and Saldaitis 2008), primarily from the deserts and arid mountains of the Western Palearctic and Africa.

Holotype ♀ (Fig. 9), NE Socotra Island, Wadi Difarroha, North side, 19 January 2010. leg. A. Saldaitis (deposited in MWM/ZSM); (slide No PI 2011/1) Paratypes: 3 ♀ (Fig. 10), S Socotra Island, Wadi Difarroha, South side, 15 January 2010. leg. A. Saldaitis; (coll. ASV; MWM/ZSM); (slide No BJ 1523).

The new species differs from the related species Meharia acuta Wiltshire, 1982 (Figs 8, 12) by forewing pattern, DNA and distribution. In Meharia acuta, the basal spot at the costal wing margin is missing. Meharia hackeri has a straight basal fascia at the costal wing margin for ¼ the length of forewing and a narrow white fascia, with a wide interruption antemedially and a narrow interruption tornally, running along the entire inner margin. Meharia acuta has no such fascia, but has a wide subterminal band. DNA barcodes clearly separate Meharia hackeri from Meharia acuta. Three identical sequences of Meharia hackeri were compared to those of a single Meharia acuta specimen resulting in a significant 7.48% variation.

Meharia acuta is distributed in the Arabic peninsula, Meharia hackeri is endemic to Socotra Island.

Female: Forewing costal margin length of holotype 10 mm, wingspan 21 mm; forewing length of paratypes 11 mm, wingspan 22 mm; antennae slightly longer than half the length of forewing; bipectinate, color white, black at base; head and tegular yellowish-white; labial palpi yellowish brown, white at base; ground colour of forewings yellowish-brown with white longitudinal fascia forming wing pattern, basal fascia in the costal area straight, running to ¼ the length of forewing, curved fascia extending medially from inner margin to ⅔ the length of forewing, its extension ends at terminal wing margin, medially the fascia and its interrupted portion in terminal area bordered by dark brown scales with black inserts; narrow white fascia, widely interrupted antemedially and narrowly interrupted tornally, runs along the entire inner margin, cilia yellowish-white, ventral forewing brown; hindwing greyish-yellow, cilia light brown, ventral hindwing brown.

Male genitalia: unknown.

Female genitalia (Figs 13, 14): Papilla analis triangular, covered with short, thin, very long setae; apophysis posterioris about the same length as papilla analis; apophysis anterioris very short, broad, with V-shaped sclerotisation apically; ostium concave; antrum weakly sclerotised basally with a loop forming very narrow ductus bursae; corpus bursae not sclerotised, shaped like a small sac.

Known only from the central part of Socotra Island. Meharia hackeri is likely endemic to Socotra Island. All specimens were collected in mid-January; Meharia hackeri females were attracted to light and appear to have a very local distribution as the species was discovered only in Difarroha Valley (Fig. 31). The new species was collected in the central part of the country in an oasis-type valley dominated by various tree and shrub species such as: Jatropha unicostata, Lycium socotranum, Gnidia socotrana, Buxus hildebrandtii, Croton socotranus, Punica protopunica, Ficus vasta, Euphorbia socotrana, Jathropha unicostata, Mitolepis intricata, Aloe perryi, Adenium obesum (Miller and Cope 1996). It flies with several other Socotra Archipelago endemic moths such as Meharia yakovlevi Saldaitis & Ivinskis, 2010, (Cossidae), Pelosia sokotrensis (Hampson, 1900), (Arctiidae), Cerocala socotrensis Hampson, 1899, Agrotis brachypecten Hampson, 1899, Plecoptera butkevicii Hacker & Saldaitis, 2010, Acantholipes canofusca Hacker & Saldaitis, 2010, Stenosticta wiltshirei Hacker, Saldaitis & Ivinskis, 2010 (Noctuidae).

The new species name is dedicated to Hermann Hacker, a prominent German lepidopterist, who has contributed much to the investigation of macro-moths of the Arabian peninsula and Africa.

Male genitalia (Fig. 11): The authors examined the genital structures of several more male specimens, noting that the valvae are variable in shape being slightly narrower and slightly concave in costal and dorsal areas. The vesica is narrow, long, and almost the same length as aedeagus.

This species was described from a single male. This specimen was collected in Hadibu environs, in the hills covered by dense shrubby vegetation dominated by the following plants: Rhus thyrsiflora, Buxus hildebrandtii, Carphalea obovata, Sterculia africana, Dracaena cinnabari, Rhus thyrsiflora, Carphalea obovata, Tamarindus indica, Commiphora socotrana, Commiphora ornifolia, Commiphora parvifolia, Boswellia ameero, Boswellia elongata, Boswellia bullata, Boswellia dioscorides, Boswellia nana, Punica protopunica, Acacia pennivenia, Cephalocroton socotranus, Indigofera socotrana, Dirachma socotrana, Allophylus rubifolius, Maerua socotrana, Acridocarpus socotranus, Sterculia africana, Zizyphus spina–christi, Ficus vasta, Ficus salicifolia, Arthrocarpum gracile, Ormocarpum caeruleum (Miller and Cope 1996). In January 2010, five more specimens were collected (1 ♂, N Socotra Island, Wadi Kam, 13 January 2010, leg. A. Saldaitis (Fig. 7); 2 ♂ central part of Socotra Island, Diksam loc., 14 January 2010, leg. A. Saldaitis; 2 ♂ S Socotra Island, Wadi Difarroha South side, 15 January 2010, leg. A. Saldaitis). Meharia yakovlevi appears to be a very rare and local species showing a slightly higher abundance in the central part of the country with oasis-like valleys and canyons with relict woody vegetation. These habitats were dominated by the following plants: Jatropha unicostata, Lycium socotranum, Gnidia socotrana, Buxus hildebrandtii, Croton socotranus, Punica protopunica, Ficus vasta, Euphorbia socotrana, Jathropha unicostata, Mitolepis intricata, Aloe perryi, Adenium obesum (Miller and Cope 1996).

Aethalopteryx is distinguished from close Trismelasmos Schoorl, 1990, Acosma Yakovlev, 2011, Strigocossus Houlbert, 1916 and AzygophlepsHampson, 1892 genus by having cup-shaped antennae in both sexes, forewings with slight reticulated patterns and reduced arms in males gnathos and particularly genital structure of the females.

Medium sized moths. Male and female antennae cup-shaped; forewing elongate with slight reticular pattern, often with a spot in the costal area and spots in the postdiscal area; hindwing with indistinct reticular pattern.

Male genitalia. Uncus long, thin, basally considerably narrower than width of tegumen; arms of gnathos reduced; tegumen massive; valvae with slightly uneven margins and with rounded apex; saccus massive, semicircular; juxta broad, with wide leaf-shaped lateral processes; aedeagus slightly bent, vesica with a long belt-shaped sclerite forming the projection of lateral aedeagus wall.

Female genitalia. Form short oviductus; papilla analis elongate, gradually narrowing; apophyses posteriores twice the length of apophyses anteriores which are furcate at basal part; ductus membranous, broad, very short; corpus bursae shaped like a long narrow sac, with a star-shaped signum on the lateral surface; bulla located in basal third of bursa on a long membranous ductus.

Thirty-four species of Aethalopteryx have been reported (Yakovlev 2011), primarily from the east Africa with some distributed elsewhere in Africa or in the Arabian peninsula.

Male genitalia (Fig. 26). The authors examined several more male specimens and found some variation in the genital structures. Valvae of newly examined specimens were significantly wider; apex rounded; costal margin even; vertical juxta processes not tapering, with obtuse apices; vesica simple, long, tapering, almost the same length as aedeagus.

A newly described species, highly local, known only from the central part of Socotra Island from two valleys: the Diksam canyon (Fig. 30) and the Difarroha valley (Fig. 31), which are characterized by the following relict woody vegetation: Dracaena cinnabari, Buxus hildebrandtii, Croton socotranus and numerous other endemic plants (Miller and Cope 1996).

Azygophleps is distinguished from similar genera such as Sansara Yakovlev, 2004, Strigocossus Houlbert, 1916 and Aethalopteryx Schoorl, 1990 by its females’ apically bipectinate antennae, its long forewings rounded at the apex, the abscence of arms in its males’ gnathos, its thick aedeagus, and a short, wide ductus and corpus with a small star-like signum in its females.

Medium sized moths. Male antennae cup-shaped, those of female bipectinate (apically with gradually reducing pectin); forewing long, with rounded apex, with dense reticular pattern formed by transverse lines and spots; hindwing lightly coloured and uniform.

Male genitalia. Uncus medium-sized, apically hooked; arms of gnathos absent; tegumen medium sized, usually wider than basal part of uncus; valvae with almost straight margins and wide rounded apex; juxta medium-sized, with long, narrow, well-sclerotised lateral processes; saccus semicircular, massive; aedeagus thick, with long sclera forming aedeagus wall.

Female genitalia. Forming long ovipositor; papilla analis stretched, slightly tapering towards apex; apophyses posteriores more than twice as long as apophyses anteriores which are forked basally; ductus short, wide, sclerotised at base; corpus sac-shaped, with a small star-like signum; bulla located on the apical part of bursa.

Twenty-eight species of Azygophleps have been reported (Yakovlev 2011), primarily throughout Africa with a few species distributed in the Arabian peninsula and Asia.

Female size and wing pattern similar to the male, however in Socotra specimens the pattern of the forewing is darker and the dorsal margin of hindwing has a reticular pattern. Antennae in females are cup-shaped as in males, but pecten are significantly shorter. Both female specimens from Socotra Island differ from typical Azygophleps larseni from Oman in external appearance. Without opportunity to compare Azygophleps larseni male genitalia we abstained from assigning the Socotra population to a separate taxon. Hampson (1903), Rebel (1907) and Hacker (1999) mistakenly attributed Azygophleps inclusa (Walker, 1856) (Fig. 15) to Socotra Island.

Male genitalia (Fig. 25). Oman’s Azygophleps larseni male paratypus specimen’s genitalia illustrated showing strong aedeagus, apically three times wider than proximally and simple, rounded, short vesica.

Female genitalia (Fig. 29). Papilla analis stretched, rounded apically; apophyses posteriores more than twice longer than apophyses anteriores which are forked at basal part; ductus short, wide, sclerotised basally; corpus sac-shaped, with a small star-like signum; bulla sclerotised, located on the median part of bursa.

This species is distributed in Iraq, Iran, Oman and mainland Yemen. Two specimens were caught in Socotra Island, ♀ (collecting date: Yemen, 500 m, Socotra isl., Ayhft riv. valley, 25 November 2008, Saldaitiene & Saldaitis leg.). Azygophleps larseni in Socotra is a very rare and local species. The Ayhft valley is a unique place in Socotra, with 80% of all vegetation found in Socotra Island. This valley is constantly fed by fresh water from the Haghier Mountains and its slopes are densely covered by tropical-type evergreen trees and shrubs: Dracaena cinnabari, Rhus rhyrsiflora, Euryops arabicus, Buxus pedicillata, Gnidia socotrana, Cocculus balourii and many other plants(Miller and Cope 1996).