Description of a new Barsine Walker, 1854 from India and Nepal (Lepidoptera, Erebidae, Arctiinae, Lithosiini)

Abstract A new species, B. kirata Volynkin & N. Singh, sp. nov., similar to B. germana, is described from India and Nepal. The existence of two colour forms in some species of the genus Barsine Walker, 1854 is revealed. A new synonymy is established for Barsine germana (Rothschild, 1913), which includes two forms that were described as three different species: Barsine germana (Rothschild, 1913) (the yellow form) = B. valvalis Kaleka, 2003, syn. nov., and B. thomasi Kaleka, 2003, syn. nov. (the red-spotted forms).

Dissections of numerous specimens of various species of Barsine displayed the existence of two colour forms in some of them: the common form having reddish forewing pattern elements together with black ones, and the yellow form lacking reddish forewing pattern elements. The latter, yellow form is usually very rare and has so far been found only in B. defecta (Figs 19,20), B. orientalis bigamica Černý, 2009 (illustrated by Bayarsaikhan et al. 2018), B. gratissima (de Joannis, 1930), B. obsoleta (Reich, 1937), andB. cacharensis N. Singh &Kirti, 2016. In some species, intraspecific variation is high and expressed not only in the presence or absence of red pattern elements but also in the shade of the ground colour and red spots, the size of the red and black pattern elements, body size, and even forewing shape (Figs 1-10). Such polymorphism is obvious evidence of a polygenic inheritance, and this matter needs extensive molecular study.
The red and yellow forms of some species have been described as distinct species, as in the case of Barsine germana (Rothschild, 1913) (the yellow form; Figs 1-3), and B. valvalis Kaleka, 2003 andB. thomasi Kaleka, 2003 (the red-spotted form;Figs 4-10). In the present paper, we synonymize B. valvalis and B. thomasi with B. germana. In addition, dissections of red-spotted specimens of this group from various regions of Nepal and India revealed the existence of two species very similar externally but clearly different in their genitalia structures. One of them is described below.
The genitalia of specimens deposited in NHMUK, MWM/ZSM, NZCZSI, and ZFMK collections were dissected, stained with eosin B and mounted in Euparal on glass slides using standard methods of preparation (Lafontaine and Mikkola 1987;Fibiger 2007). Photographs of imagos deposited in NHMUK and MWM/ZSM were taken using a Nikon D3100/AF-S camera equipped with a Nikkor 18-55 mm lens. Genital preparations made by A.V. Volynkin were photographed with the same camera attached to a microscope with an LM-scope adapter.
The holotype of B. germana is undissected. However, the senior author has microscopically examined the tips of its valvae, which have the distal saccular process structure identical to those in the holotypes of B. valvalis and B. thomasi. The holotype is also externally similar to specimens from the same region of India, and clearly different from B. kirata, sp. nov. A detailed comparison of B. germana with B. kirata sp. nov. is provided below.
Barsine germana varies considerably in its size: the forewing length is 13-17 mm in males and 16-23 mm in females.

Barsine kirata
Diagnosis. The new species (Figs 11-18) is very similar externally to B. germana (Figs 1-10) and can be distinguished from it by its less wavy antemedial transverse line. The male genital capsule of the new species (Figs 25-28) differs clearly from that of B. germana (Figs 21-24) by the distal ventral process of the valva having a short distal lobe directed dorso-distally and the longer dorsal lobe dorsally directed, while in B. germana the distal lobe is more elongated and distally directed and the dorsal lobe is dorso-distally directed. Additionally, in B. kirata sp. nov. the juxta is broader than that of B. germana, the basal saccular process is stouter and more curved, the distal lobe of valva is larger, and the distal part of the distal ventral process of valva is more robust. The vesica of B. kirata sp. nov. differs from that of B. germana by its slightly narrower 1 st medial diverticulum, the smaller cornuti on the 2 nd medial diverticulum, and the slightly less elongated 3 rd medial diverticulum. The female genitalia of the new species (Figs 31, 32) clearly differ from those of B. germana (29, 30) by the significantly shorter ductus bursae with shorter subostial folds, the wrinkled posterior sclerotised section of corpus bursae, the slightly smaller signum, the presence of the second, bandlike signum in the anterior section of corpus bursae (absent in B. germana), and the slightly smaller lateral membranous protrusion of the corpus bursae.
Description. External morphology of adults (Figs 11-18). Wingspan 14.5-16 mm in males (15 mm in holotype) and 18-20 mm in females. Male antennae ciliate, female antennae filiform, pale ochreous in both sexes. Head crimson with yellow spot on frons. Thorax yellow, with three black dots; collar and tegulae yellow with crimson margins. Forewing broad with slightly elongated and rounded apex. Forewing ground colour yellow, with a pattern of black dots and strokes and various- medial line almost straight, angled inwards at costa, interrupted into a series of variously shaped small spots on veins; postmedial line smoothly curved outwards medially, presented as a series of black thin strokes of different lengths between veins; cilia amber yellow. Hindwing pale pink with yellowish suffusion along veins; cilia amber yellow along outer margin and apex, and pink along anal margin. Yellow form of species lacks all reddish pattern elements. Abdomen pink with admixture of yellow scales. Male genitalia . Tegumen moderately broad, shorter than valva; vinculum short but robust, V-shaped with convex lateral margins. Valva massive, with almost parallel margins; medial costal process broadly trigonal, with convex outer margin and slightly broadened and blunted tip; distal costal process very small, tubercle-shaped; distal lobe of valva large, oblique; sacculus broad, its basal process robust, broad, curved dorsally, apically rounded, reaches the distal costal process; distal ventral process broad, bilobate, its dorsal lobe approximatly two 2 times longer than distal lobe, narrow, apically blunted, directed dorsally; distal lobe short, thornshaped, directed dorso-distally. Uncus narrow, laterally flattened, curved, medially broadened, with claw-like tip; tuba analis broad. Scaphium narrow, weakly sclerotized. Juxta weakly sclerotized, X-shaped, with broader apical lobes. Aedeagus elongated, narrow, slightly curved medially and broadened distally. Vesica membranous, short and broad, with several diverticula: 1 st medial diverticulum elongated, sack-like with rounded tip, its distal half weakly granulated; 2 nd medial diverticulum bilobate, its inner lobe covered with numerous variously sized short but robust cornuti, outer lobe weakly granulated; 3 rd medial diverticulum long, covered with numerous vari-ously sized short but robust trigonal cornuti; 4 th medial diverticulum small, globular, covered with small trigonal cornuti; 5 th medial diverticulum broadly globular, its outer surface with broad cluster of small, trigonal cornuti of various sizes; basal diverticulum absent; distal plate of vesica broad, trigonal with slightly convex outer margin, heavily sclerotized. Female genitalia (Figs 31, 32). Ostium bursae broad. Ductus bursae dorso-ventrally flattened, sclerotized, its lateral margins more weakly sclerotized than medial part; posterior section of ductus bursae slightly broadened, with several narrow longitudinal subostial folds. Corpus bursae broad, sac-like, with posterior section moderately sclerotized with wrinkled posterior margin ventrally, and reniform signum dorsally; border between posterior and anterior sections of corpus bursae weakly sclerotized, with a band of short scobination; anterior section of corpus bursae thick and membranous, with a band-like signum surrounded by a rugose area. Appendix bursae weakly sclerotized and granulated, short, conical, situated postero-laterally, directed posteriorly and curved inwards. Apophyses long and thin, apophyses posteriores thinner and ca 1.8 times longer than apophyses anteriores. Papillae anales broad, trapezoidal, weakly setose.
Distribution. The new species is known from northeastern India (Sikkim, Darjeeling, and Assam) (Kirti and Singh 2016, as B. orientalis bigamica), southeastern India, and Nepal (present study).
Etymology. The Kirata are the people inhabiting the Himalayas and northeastern India.