First record of the genus Olepa Watson, 1980 from China (Lepidoptera, Erebidae, Arctiinae, Arctiini)

Abstract Background The tribe Arctiini is a species-rich tribe of the subfamily Arctiinae of the family Erebidae. The genus Olepa Watson, 1980 is distributed in the Oriental and Palearctic Regions and the diversity reaches its peak in south Asia. New information We herein describe the first record of the genus Olepa from China and re-describe Oleparicini (Fabricius, 1775), together with illustrations of its adult and male genitalia. Furthermore, based on an analysis of 658-bp COI barcoding sequences, together with morphological studies, we consider that Olepaschleini Witt et al., 2005 syn. n. is a new synonym of O.ricini.


Introduction
The genus Olepa was originally established by Watson (1980) as a replacement name for the genus Alope Walker, 1855 [preoccupied by Alope White, 1847 (Crustacea)] with Alope ocellifera Walker, 1855 as the type species. Orhant (1986) carried out a taxonomic review of the Olepa ricini Fabricius, 1775 species group, restored the specific status of O. ocellifera Walker and O. clavatus Swinhoe and described four new species from southern India and Sri Lanka. Subsequently, Orhant (2000) added a new species from north-eastern India and divided the genus Olepa into two species groups, based on differences in male genitalia. Subsequent studies revealed three additional species from western Asia, India and Indochina (Witt et al. 2005, Dubatolov 2011, Orhant 2012) and, later, Singh and Singh (2013) revised the internal structure of the genus and described four subgenera (Ricinia, Pseudoolepa, Orhanta and Cornutia). Two

Materials and methods
Morphological study. We photographed the adults using a Sony DSC-RX100 v1.00 camera. To study the wing venation, the wings were removed from the thorax and cleaned with a 1:1 mixture of bleaching liquid. A Nikon D750 camera was used to photograph the venation. Abdomens were removed and macerated in hot 10% sodium hydroxide (NaOH) solution for examination of male genitalia, photographs of which were taken under a Keyence VHX-5000 digital microscope. Terminology of adult and genitalia follows Fang (2000).
Molecular phylogenetic analysis. We selected 19 samples representing the species of Olepa as the ingroup and, for the outgroup, we used Trischalis aureoplagiata and Cyclosiella spiralis (two species of the tribe Lithosiini of the subfamily Arctiinae). We sequenced four specimens from China and the remaining sequences were obtained from GenBank and Bold Systems. DNA was extracted from two or three legs of dried adult specimens using a TIANamp Genomic DNA Kit (Tiangen, Guangzhou, China) following the manufacturer's instructions. We amplified a single mitochondrial gene (a 658-bp fragment of COI) using the general primers 1490-2198 (Folmer et al. 1994). The amplification protocol follows Hou et al. (2021). Sequences were aligned using Clustal W (Thompson 1997) and edited manually using MEGA 7.0 (Kumar et al. 2016). Maximum Likelihood analyses, shown in Fig. 4, were performed using IQ-tree v. 1.6.12 (Trifinopoulos et al. 2016) with the branch support values evaluated by 1000 ultrafast bootstrap (UFBS) replicates (Trifinopoulos et al. 2016) on the web server (http://iqtree.cibiv.univie.ac.at/), the best-fit model used being automatically selected by IQ-TREE (TIM2+F+I chosen according to Bayesian Information Criterion). New sequences have been deposited in GenBank (Table 1).  Figure 1.

Figure 2.
Wing venation of Olepa ricini.   Description Male ( Fig. 1): Length of forewing 20 mm. Antenna, head and thorax brownish-grey; tegula yellow; patagium covered with brownish-grey hair; abdomen scarlet with elongated black spots of various length on the dorsal side. Forewing ground colour dark brown, with six transverse bands comprised of irregular blackish-brown spots. Cilia chequered. Hind-wing ground colour red with black patterns; antemedian band extending from costal zone to dorsum, gradually narrowing; median band obsolete, extending from costa to upper angle of cell; postmedian band thick, running from costa to tornus and interrupted in cell M marginal line serrate, extending from apex to vein CuA . Venation (Fig. 2) Male genitalia (Fig. 3): uncus relatively long and broad and gradually narrowed towards the distal end; tegumen narrow with a semi-oval dorsal plate; juxta shield-like; saccus nearly U-shaped and short; valva moderately broad with its tip curved inwardly; phallus long and slightly S-like curved, carinal plate with a horn-shaped protrusion, vesica broad, with several clusters of small cornuti.

Discussion
The Chinese population of Olepa is morphologically similar to O. schleini and O. ricini. These two species were supposed to be distinguished from each other mainly by the differences in the tip of the valva, i.e. tip rounded in the former and more acute in the latter, together with a great genetic difference in COI sequences (Witt et al. 2005). In addition, another difference was also mentioned in the original description, that is the dark spots on forewing upper side are not surrounded by pale rings in the former, while the pale rings are usually present in the latter. However, based on our examined specimens, we found that the tip of the valva can be quite variable when viewed from different aspects and even flattened, hence we concluded this character cannot be regarded as a stable difference. Moreover, after conducting the BLAST procedure of the COI sequences of O. ricini (GenBank accession numbers AM050280-AM050284) used by Witt et al. (2005) (Fabricius, 1775) and the Chinese Olepa sp. should be also identified as O. ricini.