Halone arcuata Bayarsaikhan & Bae, 2022

Bayarsaikhan, Ulziijargal, Bucsek, Karol, Cha, Yeong-Bin, Le, Xuanvi, Kwon, Hyung Wook & Bae, Yang-Seop, 2022, A new Halone Walker (Lepidoptera, Erebidae, Arctiinae, Lithosiini) from Vietnam with establishing of a new combination, Zootaxa 5093 (3), pp. 385-391 : 386-388

Halone arcuata Bayarsaikhan & Bae , sp. nov.

( Figs. 1 , 5 , 9 )

Type materials. Holotype: ♂, Vietnam, Prov. Ninhbinh, NP. Cucphuong, 1.V.2005 (YS Bae & JM Kim), Gen. Slide No. INU˗10303 V, deposited in PPRI . Paratypes (1 ♂, 2 ♀) VIETNAM : 1 ♂, 2 ♀, same data as for the holotype, Gen. Slide No. INU˗10156 V (female), 10429 V (female), 10431 V (male), deposited in INU .

Diagnosis. Halone arcuata sp. nov. differs from other congeners by its dark brown longitudinal streak (the antemedial and the disco-cellular spots are almost connected) in the discal area of the forewing. The male genitalia of the new species is similar to those of Halone victorai Bucsek, 2014 , H. solitus Bucsek, 2014 and H. hollowayi Bayarsaikhan & Bae, 2019 due to the irregularly projected tegumen, the well-developed saccular process as length as elongated, membranous cucculus. However, H. arcuata sp. nov. differs from the allied species in having a roundly arch-shaped projection of the tegumen and a dentate, strongly arcuate and sclerotized saccular process, with an acuminate apex, while in H. viktorai (illustrated by Bucsek 2014: gen. MalS25; present paper fig. 6), the subapical projection of the tegumen is slender, almost straight and spine-shaped, and the saccular process is slender, weakly tapering, entire, with a rounded apex. In H. solitus (illustrated by Bucsek 2014: gen. MalS26; present paper fig. 7), the apical projection of the tegumen is broad and rectangular, and the slender saccular process is entire, slender and apically rounded. In H. hollowayi (illustrated by Bae & Bayarsaikhan 2019: fig. 5; present paper fig. 8), the apical projection of the tegumen is strongly tapering, curved, the saccular process is more stout than in H. arcuata sp. nov., entire and has an irregularly rectangular apex. In the female genitalia, the following features clearly separate the new species from all the other known females of genus Halone : (1) the postvaginalis plate is sclerotized, “bow tie”-shaped and densely serrulate; (2) the anterior section of the antrum is broadly rounded, sclerotized, with weakly waved edge; (3) the lamella antevaginalis is horizontally elongate, arch-shaped and sclerotized.

Description Adult ( Figs. 1a, 1b ). Length of forewing 6˗7 mm in males (n=2), 7˗7.5 mm in females (n=2). Head, patagium, tegula and thorax sordid white, mixed with brown scales. Forewing ground color sordid white, with pale brown sprinkles; medial discal area with a short, longitudinal dark brown streak (antemedial and discocellular patches almost connected); cilia sordid white. Hindwing pale brown; cilia gray. Abdomen fuscous in both sexes, tinged with pale yellow in females. Male genitalia ( Figs. 5a, 5b ). Uncus stout, acuminate, with a stout and apically rounded ventral process. Tegumen weakly sclerotized, strongly shouldered, with roundly arch-shaped apical projection. Anal tube membranous, scaphium weakly trapezoid, with weakly sclerotized edge. Distal section of valva membranous, sparsely setose, narrow, apically rounded, almost equal in length to tegumen. Saccular process strongly arcuate, sclerotized, with dentate proximal half and with acuminate apex, almost equal in length to valva. Saccus broadly “U”˗shaped. Aedeagus stout, weakly sclerotized; vesical scobinated, with seven slender spines and elongate, sclerotized tube. Female genitalia ( Fig. 9 ). Papillae anales weakly covered with setose. Postvaginal plate sclerotized, “bow tie”˗shaped, densely serrulate.Antrum sclerotized, broadly rounded, with slightly waved posterior margin with a shallow incision medially. Apophysis posterioris slender, about 2 times longer than thiker apophysis anterioris. Lamella antevaginalis strongly sclerotized, horizontally elongated, arch-shaped. Right section of ductus bursae heavily sclerotized and tubular, while left section broad, membranous, with rectangular sclerotized plate. Corpus bursae globular, membranous, with a strongly dentate signum medially.

Distribution. Vietnam (Ninhbinh Prov.).

Etymology. The specific epithet is derived from the Latin “ arcuatus ” meaning “arched”, refers to the arched saccular process and arch˗shaped projection of tegumen in the male genitalia.

Figures

FIGURES 1–4. Adults of new and compared species of Halone. 1a. H.arcuata sp. nov., male, Vietnam, holotype (INU˗10303V). 1b. ditto, female, Vietnam, paratype (INU˗10429V). 2. H. viktorai, male, Malaysia, holotype. 3. H. solitus, male, Malaysia, holotype. 4a. H. hollowayi, male, Cambodia (paratype, INU˗1568C). 4b. ditto, female, Cambodia (holotype, INU˗10033C).

FIGURES 5–8. Male genitalia of new and compared species of Halone. 5a. H. arcuata sp. nov., holotype (INU˗10303V). 5b. ditto, paratype (INU˗10429V). 6. H. viktorai, holotype (MalS25). 7. H. solitus, holotype (MalS26). 8. H. hollowayi, paratype (INU˗1568C) (scale bar for 5a and 5b).

FIGURES 9–10. Female genitalia of new and compared species of Halone. 9. H. arcuata sp. nov., Vietnam, paratype (INU˗10429V). 10. H. hollowayi, Cambodia, holotype (INU˗10033C).