A review of the tiger moth genus Amerila Walker, 1855 from Flores Island, Indonesia, with a description of a new species (Lepidoptera: Erebidae: Arctiinae)

The Flores Island is a part of the East Nusa Tenggara Group belonging to the Lesser Sunda Archipelago. The Lepidoptera fauna of this remote island comprises two species of the genus Amerila Walker, 1855, i.e. Amerila astreus (Drury, 1773) and Amerila rosenfeldae sp. nov . The first species is widespread from India and Southeast Asia to New Guinea, while the latter taxon appears to represent a lineage endemic to Flores.

Conversely, only one species in the genus Amerila Walker, 1855 was recorded from the Flores Island, i.e. the widespread Amerila astreus (Drury, 1773) ). This genus is rich in endemic species described from New Guinea and adjacent islands (e.g. Häuser 1993), and discoveries of additional taxa from the Lesser Sunda Archipelago were expected. It should be noted that the taxonomic knowledge of Amerila representatives from the Oriental Region and Australasia is far from being complete (Holloway 1988;Singh & Singh 2012;Spitsyn & Potapov 2019), whereas the Afrotropical taxa have been reviewed and illustrated in a series of works (Häuser & Boppré 1997;Przybyłowicz et al. 2019).
This work aims to describe one more Amerila species from remote mountain range in the middle part of the Flores Island and to report on further occurrences of Amerila astreus from this area.

Materials and methods
The type series of the new species and samples of Amerila astreus were studied in the Lepidoptera collection of the Russian Museum of Biodiversity Hotspots [RMBH], N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia. The specimens and genitalia processing and photographing followed those described in our earlier works Spitsyn & Bolotov 2020;Spitsyn & Potapov 2020). Diagnosis. This widespread species can be distinguished from other taxa from tropical Asia and Australasia by having a pink dorsal side of the abdomen in both the male and the female. Externally, it resembles A. eugenia (Fabricius, 1794) (type locality India) but can be distinguished from it by having a grey ground color of the wings, a lesser curved ampulla, and larger coremata. This species can be separated from A. rhodopa Walker, 1864 (type locality India) and A. vitrea Plötz, 1880 (type locality West Africa) by having a clear dark, elongated spot between the cell apex and the costa on the forewing, and from A. fumida (Swinhoe, 1901) (type locality Indonesia: Halmaheira Is.; Timor) by having semitransparent wings.
Distribution. India, Sri-Lanka, Nepal, mainland China, Taiwan, the Philippines, Indochina, Indonesia, and New Guinea (Dubatolov 2010). On the Flores Island, this species was recorded from the sea level to 1100 m a.s.l. this study Diagnosis. The novel species is similar to A. astreus but can be distinguished from it by having a larger size, broader wings, a pink edging on the patagium and tegula, and much smaller male coremata. Further, the new species can be separated from A. erythropus (Rothschild, 1917) [endemic to the Umboi Island between New Guinea and New Britain] by having a strait termen and acute apex of the hindwing. The male genitalia structure of the new species is similar to that of A. abdominalis (Rothschild, 1933) (type locality Malaysia) and A. omissa (Rothschild, 1910) (type locality India). However, the new species can be distinguished from these two taxa by having a sclerotized plate in the vesica near large cornuti and by a monochromatic dorsal side of the abdomen.

Description.
Male. Wingspan 53-58 mm, forewing length 28-31 mm (N = 6). Eye olive. Antenna brown, with a pink color proximally. Frons white with a black central spot. Vertex white with a black central spot. Labial palpus short (approximately equal to 1.5 eye's diameter), pink, with black stripes. Thorax whitish gray with six black spots on the dorsal side, two black dots from each side near the base of the forewings, and one black spot laterally. Patagium and tegula white with pink edging and black central spots. Patagium with one more spot anteriorly. Legs pink; inner side of the femur white; outer side of the foreleg and middle leg's tibia pink with a brown stripe. The foreleg coxa large, pink, with a white base and black central dot. Forewing almost transparent, greyish basally and near the anal edge. Forewing apex and distal part of the costal margin (from the middle of the cell) light brown. The cell apex with a large light brown or black spot. Forewing base with two black dots, and a large, pink rectangular spot formed by elongated scales. Hindwings semitransparent, darkened at the apex and along the termen, with sparse pink scales at the base and along the termen. Underside of both wings follows pattern of the upper side, but without two dots and a pink spot at the base of the forewing. The base of the costal vein pink. Abdomen pink ventrally, and white with two rows of black dots dorsally.  Male genitalia. Tegumen large and broad. Uncus small, with acute apex. Saccus small, wide. Valva rounded, densely covered with long hairs. Coremata rather small, rounded. Ampulla is directed to the base of the valva (its direction to the outer margin of the valva on the slide is an artefact of preparation; see Fig. 2A). Juxta broad. Aedeagus short and very broad. Vesica long, equipped with double strong cornuti and a sclerotized plate below the cornuti. Female. Wingspan 62 mm, forewing length 31 mm (N = 1). Externally, similar to the male but differs from it by having narrower and elongated wings. The rectangular pink spot near the base of the forewing, and the pink edging on the patagium and tegula are absent. Female genitalia. Ostium bursae large; ductus bursae broad. Bursa with one spike and double signum having long spines. Apophyses anteriores medium long; apophyses posterioris rather elongated. Papilla analis large, rectangular.
Distribution. This species is known to occur in two mid-altitude localities (altitude 1010-1100 m a.s.l.) south of the town of Bajawa at the foothill of the Inerie Mount on Flores.
Etymology. The novel species is dedicated to Dr. Sonia B. Rozenfeld (Moscow, Russia), a Russian ornithologist.