Eugoa leucomelaena Bayarsaikhan & Bae, 2019

Bayarsaikhan, Ulziijargal, Ko, Jae ˗ Ho & Bae, Yang ˗ Seop, 2019, A new species of the genus Eugoa Walker, 1858 (Lepidoptera, Erebidae, Arctiinae) from Cambodia, Zootaxa 4543 (3), pp. 414-420 : 415-419

Eugoa leucomelaena Bayarsaikhan & Bae , n. sp.

( Figs. 1 , 5 , 9 )

Type materials. Holotype: 1 ♂, Cambodia, Kampot Prov., Bokor (N10˚37′15″, E104˚05′00″), 14.VII.2012 (YS Bae, YD Ju, BS Park, SM Na, JW Kim), Gen. Slide No. INU˗1594C. Paratypes: Cambodia (1 ♂, 1 ♀) : 1 ♀, Central Cardamom, Koh Kong Prov. (N11˚58′47″, E103˚22′22″), 28. VI.2011 (YS Bae, XV Le, U Bayarsaikhan, BS Park, MS Kim, KW Kim), Gen. Slide No. INU˗1596C ; 1 ♂, Seima, Mondulkiri Prov. (N12˚10′48″, E106˚58′54″), 1.VII.2011 (YS Bae, XV Le, U Bayarsaikhan, BS Park, MS Kim, KW Kim), Gen. Slide No. INU˗1595C .

Diagnosis. The wing pattern and male genitalia structure of the new species resembles to the members of Eugoa aridoides species˗group. Of them, E. arida van Eecke, 1920 , E. aridoides Holloway, 2001 , E. gracilisa Bucsek, 2008 and E. grandipuncta Bucsek, 2008 are closely allied to the new species, that four species with a slender, pointed distal saccular process slightly flexed apically; in female genitalia, ductus bursae weakly sclerotized, tubular; corpus bursae peanut˗shaped, heavily covered with thin spines in cervix of bursae partly and basal part of bursae. However, E. leucomelaena n. sp. differs from those of allied species in the valva straight, double concave lens˗shaped, with heavily setose and several sclerotized spines in the medial area of valva; basal ampulla of valva absent; apex of valva rectangular; distal saccular process shorter than apex of valva, strongly flexed in subapically; aedeagus strongly flexed subapically and vesica with 5˗6 short, slender spines ( Fig. 5 ); in female genitalia, ductus bursae wine glass˗shaped, more or less sclerotized partly; corpus bursae with rounded plate of thin spines in cervix of bursae ( Fig. 9 ). Whereas in E. arida van Eecke , valva elongate, broadly curved inwards, with heavily setose in the medial area of valva; basal ampulla of valva short, finger˗shaped, covered with small spines; apex of valva rounded; distal saccular process rather longer than apex of valva, roundly flexed in subapically; aedeagus almost straight, with row of small spines apically and vesica with a bundle of slender spines ( Fig. 6 ); female genitalia, ductus bursae stout, tubular, weakly sclerotized whole of length; first part of corpus bursae (near cervix of bursae) densely covered with thin spines fully ( Fig. 10 ). In E. aridoides Holloway , valva elongate, weakly curved inwards, with heavily setose in the medial area of valva; basal ampulla of valva short, finger˗shaped, covered with small spines; apex of valva roundly rectangular; distal saccular process almost same length with apex of valva, roundly flexed in subapically; aedeagus almost straight, with row of small spines apically and vesica with three or four robust spines ( Holloway 2001: fig. 388); female genitalia, ductus bursae tubular, become broader toward cervix of bursae, weakly sclerotized whole of length; first part of corpus bursae (near cervix of bursae) with irregularly rounded plate of thin spines ( Holloway 2001: fig. 406). In E. gracilisa Bucsek , valva tapering, broadly curved inwards, with heavily setose in the medial area of valva; basal ampulla of valva rounded, covered with small spines; apex of valva rectangular; distal saccular process rather longer than apex of valva, broudly flexed in medially; aedeagus strongly waved and vesica with a field of large cornuti ( Fig. 7 ); female genitalia, ductus bursae stout, tubular, weakly sclerotized whole of length; corpus bursae densely covered with spines fully ( Fig. 11 ). In E. grandipuncta Bucsek , valva strongly tapering, just curved inwards apically, with heavily setose in the medial area of valva; basal ampulla of valva oval, covered with small spines; apex of valva rectangular, with small denticles; distal saccular process almost same length with apex of valva, slightly flexed in subapically; aedeagus straight and vesica with four large cornuti and a field of small spines ( Fig. 8 ); female genitalia, ductus bursae stout, tubular, weakly sclerotized whole of length; first part of corpus bursae (near cervix of bursae) sparsely covered with thin spines fully ( Fig. 12 ).

Description Adult ( Figs. 1 a–c). Wingspan 17 mm, length of forewing 7˗7.5 mm in male (n=2), 7.5 mm in female (n=1). Head, patagium, tegula and thorax light brown. Forewing ground color light brown, with one dark rounded discoidal spot; antemedial, medial and postmedial lines brown, indistinct; subterminal line brown, almost straight; cilia light brown. Hindwing pale in male, fuscous in female, with dark discoidal spot; cilia pale. Male genitalia ( Fig. 5 ). Uncus tapering, slightly bent, with small apical spine. Tegumen triangular. Valva straight, double concave lens˗shaped, with heavily setose whole of length and several sclerotized, long spines in the medial area of valva; apex of valva rectangular; distal saccular process shorter than apex of valva, strongly flexed in subapically, end of apex sharp. Juxta weakly sclerotized, blunt. Saccus “V’˗shaped. Aedeagus strongly flexed subapically, weakly sclerotized whole of length and vesica with 4˗5 diverse length of slender spines. Female genitalia ( Fig. 9 ). Lamella antevaginalis and lamella postvaginalis weakly sclerotized. Ductus bursae wine glass˗shaped, weakly sclerotized in “head of glass” and narrow, strongly sclerotized in “foot of glass”. Corpus bursae peanut˗shaped, membranous, with rounded plate of thin spines in cervix of bursae and basal part of bursae heavily covered with thin spines.

Distribution. Cambodia (Kampot, Koh Kong, Mondulkiri provinces).

Etymology. The specific epithet is derived from the Greek “ leucom ” meaning “whiteness” and “ melaen ” meaning “blacken”, referring to the adult color.

Taxonomic notes. The aridoides species˗group of the genus Eugoa were classified by Bucsek (2008) comprises 17 described species ( Table 1), E. arida* van Eecke, 1920 , E. aridoides Holloway, 2001 , E. hectogamoides Holloway, 2001 , E. clavata Holloway, 2001 , E. grandipuncta Bucsek, 2008 , E. ellipsis Bucsek, 2008 , E. apexinigra Bucsek, 2008 , E. tridens Bucsek, 2008 , E. bidentata Bucsek, 2008 , E. gracilisa Bucsek, 2008 , E. aliquotpunctata Bucsek, 2008 , E. nata Dubatolov & Bucsek, 2013 , E. tricuspida Bucsek, 2014 , E. signula* van Eecke, 1926 , E. cyclota* Fang, 2000 , E. novaki* Bucsek, 2012 , and E. hampsoni* Holloway, 2001 . All members of the species group have a pale brown ground color forewing with a dark discoidal spot and not clear dark markings; in male genitalia, valva elongate, incurve, densely covered with setae; basal ampullae short, densely covered with short setae; distal saccular process slender, towards the apex of valva, bi˗ or trifurcated apex or pointed; aedeagus straight, with several spine˗shaped cornuti ( Bucsek 2008: 437; Dubatolov & Bucsek 2013: 289; Bucsek 2018 *, pers. com.).

Figures

FIGURES 1–4. Adults of genus Eugoa spp. 1a. Eugoa leucomelaena n. sp., male (holotype, INU˗1594C). 1b. ditto, female (paratype, INU˗1596C). 2a. E. arida, male (syntype, Fort de Kock, Sumatra, RMNH.INS.910453). 2b. ditto, female (syntype, Fort de Kock, Sumatra, RMNH.INS.910454). 3a. E. gracilisa, male (paratype, Malaysia W, SAS.042˗m˗1). 3b. E. gracilisa, female (paratype, Malaysia W, SAS.043˗fm˗1). 4a. E. grandipuncta, male (holotype, Malaysia W, SAS.008˗m˗1). 4b. E. grandipuncta, female (paratype, Malaysia W, SAS.005˗fm˗1).

FIGURES 5–8. Male genitalia of genus Eugoa spp. 5. Eugoa leucomelaena n. sp. (paratype INU˗1595C). 6. E. arida (syntype, RMNH.INS.843440). 7. E. gracilisa (SAS.EU072). 8. E. grandipuncta (SAS. EU002).

FIGURES 9–12. Female genitalia of genus Eugoa spp. 9. Eugoa leucomelaena n. sp. (paratype INU˗1596C). 10. E. arida (syntype, RMNH.INS.910454). 11. E. gracilisa (SAS. EU073). 12. E. grandipuncta (SAS.EU079).