Yeldosia, Volynkin, 2023

Volynkin, Anton V., 2023, Yeldosia, a new footman moth genus for a new species from Vietnam (Lepidoptera: Erebidae: Arctiinae: Lithosiini), Ecologica Montenegrina 69, pp. 17-23 : 18-22

Genus Yeldosia gen. n.

https://zoobank.org/ urn:lsid:zoobank.org:act:3C5B05B3-E25A-4ED0-AC11-90A3D02F5A32

Type species: Yeldosia anomala sp. n., by present designation.

Diagnosis. The type species of the new genus ( Figs 1, 2 ) is externally reminiscent of members of the genus Gandhara ( Figs 7, 8 ) but the male is distinguished by the elongate cluster of androconial scales in the proximal section of the cell whereas species of Gandhara have a short cluster distally or lack it. The reliable identification of females requires the examination of the copulatory organs. The male genitalia structure of Yeldosia gen. n. ( Fig. 9 ) is close to the externally dissimilar Danielithosia Dubatolov & Kishida, 2012 ( Fig. 10 , also illustrated by Dubatolov et al. (2012), Dubatolov (2013), and Bayarsaikhan et al. (2017)) due to the massive process of the juxta and the modified configuration of the distal saccular process. However, unlike in Danielithosia , the process of the juxta of the new genus is broadly cylindrical, straight, and has a densely setose distal section whereas it is smooth and having modified shape in Danielithosia . Additionally, in the male genital capsule, Yeldosia gen. n. differs from Danielithosia in the very short and narrow vinculum (it is bilobate or elongated V-shaped in Danielithosia ), the distal saccular process having two dorsally directed lobes along the same axis (the distal saccular process of Danielithosia is bifurcate or unilobate), and the anellus bearing a sclerotised ring which is densely armed with spinules (the anellus of Danielithosia is membranous). The vesica of Yeldosia gen. n. is narrow and has clusters of graniculi whereas it is strongly dilated and bearing short but robust cornuti and clusters of scobination in Danielithosia . Another footman moth genus having a similar strongly elongate and setose process of juxta is the externally dissimilar monotypic Afrotropical Juxtilema Volynkin, 2021 ( Figs 5, 6 , 11 ), which has, unlike in Yeldosia gen. n., a long vinculum, a proximally broad sacculus (in Yeldosia gen. n., it is dilated only medially due to the broad membrane occupying the base of the valva and encircling the base of the juxta), and a thin and unilobate distal saccular process. Compared to the externally similar Gandhara ( Fig. 12 ), besides the aforementioned different juxta structure, the male genitalia of Yeldosia gen. n. have a shorter and weakly sclerotised vinculum, a valva connected with the base of the juxta through a broad membrane, a modified distal saccular process (it is unilobate in Gandhara ), and an anellus bearing a sclerotised ring which is densely armed with spinules, whereas the anellus of Gandhara bears two heavily sclerotised and serrulate plates. The female genitalia configuration of Yeldosia gen. n. ( Fig. 13 ) is dissimilar to Danielithosia ( Fig. 14 , also illustrated by Bayarsaikhan et al. (2017)) and Juxtilema ( Fig. 15 ) due to the different appendix bursae and antrum structures, respectively, and is most reminiscent of Gandhara ( Fig. 16 ), from which the new genus is distinguished by the sclerotised ductus bursae (it is membranous in Gandhara ), and the membranous posterior section of the corpus bursae (it is gelatinous and bears a sclerotised plate in Gandhara ).

Description. Adult male ( Fig. 1 ). Head ochreous yellow. Antenna ciliate. Thorax lead grey, tegula and patagia edged with ochreous yellow. Forewing broad with posteriorly convex costal margin. Costal stripe ochreous yellow, distally tapered. Costal margin edged with black scales in basal third. Forewing ground colour and cilia unicolorous lead grey. Cell with elongate cluster of androconial scales occupying its proximal ¾. Hindwing pale ochreous yellow, with subbasal dark ochreous yellow shade along costal margin. Areas around apex and anal angle suffused with grey. Abdomen grey with admixture of ochreous hair-like scales, genitalia covered with ochreous brown scales. Male genitalia ( Fig. 9 ). Uncus short and narrow, swollen, medially straight and slightly dilated, distally tapered and downcurved, and with tiny claw-like tip dorsally. Tegumen short, with dilated arms fused in posterior two-thirds. Vinculum ca. 1.5 times longer than tegumen, with thin and weakly sclerotised arms. Valva very broad basally and with almost parallel margins medially, its dorsal section distally triangular and apically rounded. Basal section of valva connected to base of juxta through broad membrane. Sacculus thin along this membrane margin, with medial lobe bearing cluster of long hair-like setae, and distal process having triangular dorsal proximal, and trapezoidal distal lobes. Juxta forming massive, broadly cylindrical, straight and long process protruding beyond uncus and having densely setose distal section. Anellus with sclerotised ring densely covered with minute spines. Phallus short and relatively narrow, cylindrical, somewhat downcurved medially, with short and apically rounded coecum. Proximal section of vesica with two short conical diverticula ventrally, of which subbasal one bearing cluster of graniculi. Distal diverticulum of vesica long (almost equal to phallus length), utricular, its distal half downcurved, tapered, and bearing cluster of graniculi. Vesica ejaculatorius originates subbasally-laterally on left side. Adult female ( Fig. 2 ). Antenna filiform. Sexual dimorphism limited: female similar to male but having longer forewing lacking androconial cluster in cell. Female genitalia ( Fig. 13 ). Papilla analis trapezoidal with rounded corners, weakly setose. Apophyses long and thin, apophysis anterioris longer than apophysis posterioris. Antrum short, caliciform, weakly sclerotised. Ductus bursae short, dorso-ventrally flattened and posteriorly weakly sclerotised, anteriorly dilated and obliquely connected to corpus bursae. Posterior section of corpus bursae membranous, tubular and laterally curved. Anterior section of corpus bursae broad and elliptical, weakly granulose and bearing two narrow and serrulate signa medially. Appendix bursae short, conical, membranous, situated postero-ventrally and directed posterolaterally on right side. 7 th abdominal sternite with short anterio-lateral pockets.

Etymology. The generic name is an aggregate of the genus-group name Lithosia and the word ‘yelda’, which is an English transliteration of the Russian word meaning ‘something big, long, cumbersome, and sticking out in plain sight’, and refers to the massive process of the juxta. Gender is feminine.

Figures

Figures 1–8. Lithosiina spp.: adults; 3, 4, 7 and 8 are non-type species of the corresponding genera. Depositories of the specimens: 1, 2, 7 and 8 in MWM/ZSM; 3 and 4 after Bayarsaikhan et al. (2017); 5 and 6 in ANHRT.

Figures 9–12. Lithosiina spp.: male genitalia; 10 and 12 are non-type species of the corresponding genera. Depositories of the specimens dissected: 9 and 12 in MWM/ZSM; 10 after Bayarsaikhan et al. (2017); 11 in ANHRT.

Figures 13–16. Lithosiina spp.: female genitalia; 14 and 16 are non-type species of the corresponding genera. Depositories of the specimens dissected: 13 and 16 in MWM/ZSM; 14 after Bayarsaikhan et al. (2017); 15 in ANHRT.