Spilarctia alisauskasi Dûda, Saldaitis & Volynkin, 2024

Dûda, Juozas, Saldaitis, Aidas & Volynkin, Anton V., 2024, Two new Spilarctia Butler from Southwestern China (Lepidoptera: Erebidae: Arctiinae: Arctiini), Ecologica Montenegrina 75, pp. 67-73 : 68-70

Spilarctia alisauskasi Dûda, Saldaitis & Volynkin , sp. n.

https://zoobank.org/ urn:lsid:zoobank.org:act:B0C7F03F-E5B2-4E25-B46A-9083D4C44B5A

( Figs 1, 2 , 9 , 14 )

Type material. Holotype ( Figs 1 , 9 ): male, “ China, NW of Yunnan, Xiangerila | area, S of Weixi county. 2500m. | 2023.4 [IV.2023]” / “Slide | AV7534 ♂ | A. Volynkin ” ( WIGJ).

Paratypes. 4 males, 8 females, same data as holotype, gen. prep. No.: AV7539 ♀ ( ASV, WIGJ) ; 3 females, same data as holotype, but IV.2024 ( CGM) .

Diagnosis. Spilarctia alisauskasi sp. n. ( Figs 1, 2 ) is externally reminiscent of S. quercii (Oberthür, 1911) ( Figs 3, 4 ) but can easily be distinguished by the somewhat broader forewing with a less elongate apex, the intense pink suffusion on the both wings, the shorter subbasal costal spot, the narrower antemedial and broader postmedial lines, and the well-developed postmedial fascia on the hindwing. The male genital capsule of the new species ( Fig. 9 ) differs clearly from S. quercii ( Fig. 10 ) in the basally broader uncus, the broader vinculum, the broader valva with a subapical costal crest (absent in the congener), the markedly shorter cucullus with a shorter ventral crest, and the broader distal section of the sacculus bearing a considerably broader and shorter postmedial process. The phallus of S. alisauskasi sp. n. is markedly shorter, somewhat narrower and less curved than in S. quercii . Compared to S. quercii , the vesica of the new species is shorter and narrower, has a larger ventral subbasal diverticulum, and a remarkably smaller distal diverticulum. The male genitalia of the new species are also reminiscent of S. gianellii and S. dzyta sp. n. but differ in the broader uncus, the distally broader valva with a larger subapical costal crest, the less upcurved cucullus with a smaller ventral crest, the longer and broader postmedial process of the sacculus, and the vesica configuration and ornamentation.

Description. Adults ( Figs 1, 2 ). Antenna black, shortly bipectinate in male and serrulate in female. Head and thorax pale pinkish-beige. Forewing length 19.0–22.0 mm in males and 24.5–26.0 mm in females. Sexual dimorphism moderate: compared to male, female with somewhat broader forewing, paler ground colour of both wings, reduced forewing markings, and broader postmedial line and larger discal spot of hindwing. Forewing ground colour pale pinkish-beige, pattern black. Subbasal costal and medial posterior spots elongate, dash-like. Antemedial line connecting these spots and consisting of two irregular spots (in female, posterior one short making line interrupted). Postmedial costal spot dash-like. Medial line represented by one or two spots in cell distally. Postmedial line continuous, consisting of irregular spots separated by pinkish suffusion on veins, nearly parallel with outer margin, stretching from distal end of medial posterior spot to subapical part of costa. Submarginal spots irregular, situated medially and at tornus. Forewing cilia concolorous with ground colour. Hindwing somewhat paler than forewing, area along anal margin intensely suffused with pink, markings blackish-grey. Discal spot more or less elliptical, considerably larger in female. Postmedial fascia with irregular margins, interrupted anteriorly and posteriorly, with sub-posterior part extended inwards. Hindwing cilia concolorous with ground colour. Abdomen pale scarlet with broad black rings dilated dorsally. Male genitalia ( Fig. 9 ). Uncus broadly triangular, swollen but dorso-ventrally flattened, with rectangular tip. Arms of tegumen moderately sclerotised, ribbon-like. Tuba analis broad and membranous. Vinculum somewhat shorter than tegumen, U-shaped. Valva proximally dilated, with parallel margins medially, and tapered distally. Costa thin with dilated distal section forming convex subapical dorsal crest. Cucullus narrow, apically rounded with short and rounded ventral lobe on its inner surface. Sacculus proximally broad, medially thin and distally gradually dilated with a short and rounded lobe-like postmedial process of its inner surface; distal sclerotisation of sacculus reaching cucullus. Juxta heavily sclerotised, broad, trapezoidal with V-shaped medial dorsal depression. Phallus cylindrical, slightly downcurved subanteriorly and upcurved posteriorly, more or less equal in length to annulus (in its dorso-ventral measurement), with short and rounded coecum and dilated distal section; dorsal carina protruding into basal diverticulum, serrulate with larger distal denticles. Vesica sack-like with several subbasal and medial diverticula laterally and ventrally, and clusters of graniculi. Distal diverticulum airship-shaped, granulose.

Female genitalia ( Fig. 14 ). Papilla analis broad, rectangular with rounded corners, weakly setose. Gonapophyses rod-like, well-sclerotised, apophysis posterioris ca. 4 times as long as apophysis anterioris. Glandula strongly elongate and branched. Ostium bursae broad. Antrum trapezoidal, heavily sclerotised. Ductus bursae short, dorso-ventrally flattened, heavily sclerotised. Anterior section of corpus bursae globular, membranous, bearing two small rounded signa medio-dorsally and medioventrally. Posterior section of corpus bursae narrow, weakly sclerotised dorsally with heavily sclerotised lateral protrusion on left side. Appendix bursae as long as corpus bursae and originating from posterior section of corpus bursae ventrally, weakly sclerotised proximally, and membranous medially and distally. Proximal section of appendix bursae moderately broad, twisted and directed laterally on right side, medial section tubular, distal section pyriform.

Distribution. Currently known only from its type locality in north-western Yunnan Province (Southwestern China).

Etymology. The species is dedicated to Mr Gediminas Ališauskas (Striukai, Lithuania), custodian and nurturer of the historical heritage of Striukai Village, and founder of Striukai Plant and Stone Park.

Figures

Figures 1–8. Spilarctia spp.: adults. Depositories of the specimens: 1, 2 and 5 in WIGJ; 3, 4, 6 and 7 in ASV; 8 in NHMUK (©The Trustees of NHMUK

Figures 9–12. Spilarctia spp.: male genitalia. Depositories of the specimens dissected: 9 and 11 in WIGJ; 10 and 12 in ASV.

Figures 13–14. Spilarctia spp.: male (13) and female (14) genitalia. Depositories of the specimens dissected: 13 in ASV; 14 in WIGJ.