Taxonomy of the genus Antiochtha Meyrick (Lepidoptera, Lecithoceridae) in China, with descriptions of three new species

. Antiochtha is a genus of the family Lecithoceridae characterized by the forewing with veins M 2 and M 3 coincident, the hindwing with vein M 2 absent, and the male genitalia with the valva narrowed from base to apex. The genus comprises 23 species and is mainly distributed in the Oriental Region. In this paper, we describe three new species: Antiochtha erromera sp. nov., A. hainanensis sp. nov. and A. miniscula sp. nov., and propose a new synonym, A. rotunda Zhu & Li, 2009 syn. nov., of A. jianfengensis Zhu & Li, 2009. Antiochtha semialis Park, 2002 is newly recorded in China and its female is described for the first time. Torodorinae, new species, new record.


Introduction
The family Lecithoceridae Le Marchand, 1947 is one of the most diverse lepidopteran family, yet the family has received little attention due to the absence of specialists and lack of economic significance. Autapomorphies of the family distinguishing it from other Gelechioid-moths include: 1) the antenna as long as or longer than the forewing; and 2) the male genitalia with a median process of gnathos always downturned, except in the subfamily Crocanthinae. The family is now divided into four subfamilies: 1) Lecithocerinae Le Marchand, 1947, based on the genus Lecithocera Herrich-Schäffer, 1853; 2) Torodorinae Gozmány, 1978, based on the genus Torodora Meyrick, 1894; 3) Ceuthomadarinae Gozmány, 1978, based on the genus Ceuthomadarus Mann, 1864; and 4) Crocanthinae Park, 2015, based on the genus Crocanthes Meyrick, 1886. More than 1400 species of the family are reported worldwide (Park et al. 2021), which are widely distributed in Oriental, Ethiopian, Australian and Palearctic regions. The biology of the group is poorly studied, but there is still some information available, such as its larvae feeding on non-living material and organisms, the adults having mostly nocturnal activity periods (Gozmány 1978;Common 1990;Komai et al. 2011;Park & Mey 2016).
Antiochtha Meyrick, 1905 is a genus of the subfamily Torodorinae, which was erected by Meyrick (1905) with A. balbidota Meyrick, 1905 from Sri Lanka as the type species. The genus Antiochtha was regarded as a synonym of Gasmara Walker, 1864 (Meyrick 1925;Clarke 1965), but the latter was a preoccupied name by Gasmara Walker, [1863] in Geometridae. Hence, Antiochtha was assigned as the subjective replacement name for Gasmara Walker, 1864(Sattler 1973Gozmány 1978). Members of the genus are characterized by the forewing with M 2 and M 3 coincident, the hindwing with M 2 absent, and the male genitalia with the valva narrowed from base to apex. Antiochtha is similar to Halolaguna Gozmány, 1978 in the male genitalia, but can be distinguished by the absence of M 2 in the hindwing, whereas it is present in the latter genus.
The aim of the present paper is to describe three new species, to propose a new synonym, and to describe the female of A. semialis Park, 2002 for the first time.

Material and methods
Specimens were collected in China using light traps. Wingspan was measured from the tip of the left forewing to the tip of the right forewing. Genitalia slides were prepared following the methods introduced by Li (2002). Images of adults and genitalia were taken using Leica M205A and Leica DM750 microscopes, respectively, coupled with the Leica Application Suite 4.2 software. Terminology follows Gozmány (1978). Abbreviations used in this paper include:

Diagnosis
The new species is similar to A. hainanensis sp. nov. in appearance and wing venation. It can be distinguished in the male genitalia by the valva extending outward distally, the juxta with an imbricated median process shorter than the uncus on the posterior margin, and the absence of the lamella antevaginalis in the female genitalia; in A. hainanensis, the valva is strongly upturned distally, the juxta has an elongate median process on the posterior margin approximately as long as the uncus, and the female genitalia has a banded lamella antevaginalis.

Description
Adult (Figs 1A, 2A). Wingspan 11.0-13.0 mm. Head orange white, mixed with yellowish brown on occiput. Antenna orange white. Second palpomere of labial palpus orange white mixed with dark brown on inner surface, dark brown except orange white at apex on outer surface, roughly scaled ventrally; third palpomere orange white. Thorax orange white; tegula dark brown. Forewing with costal margin nearly straight, apex roundly produced, termen shallowly concave; ground colour dark brown, mixed with orange-white scales, orange white mixed with brown ventrobasally; antemedian fascia orange white, curved in S shape from about basal 2/₅ of costal margin to basal 2/₅ of dorsum, edged with black scales on its inner margin; discocellular stigma small, elliptical, black, encircled by orange white; costal spot small, wedge-shaped, orange white, from distal 1/₅ extending to M 1 ; dorsal spot smaller, orange white, from distal 1/ ₅ extending to M 2+3 ; fringe greyish black, basal line orange white; M 1 stalked with R 3+4+5 , M 2+3 and CuA 1+2 stalked, CuA 1 and CuA 2 coincident. Hindwing and fringe brown; fringe with orange-white basal and median lines. Legs orange white, mixed with dark-brown scales.
MAle genitAliA (Fig. 3A). Uncus wide at base, narrowed to beyond middle, thereafter slightly widened to rounded apex, sparsely setose laterodistally. Gnathos with basal plate produced to a digitate process posteriorly; median process wide at base, narrowed to about basal ¼, thereafter uniform to distal ⅓, distal ⅓ slender, hooked, pointed at apex. Valva extending outward, wide at base, narrowed to narrowly rounded apex, densely setose in distal ¼; costa shallowly concave; sacculus banded, shorter than half length of valva, slightly concave inward ventrally. Vinculum produced anteriorly, forming a triangular saccus. Juxta narrowed medially, broadly rounded on anterior margin; posterior margin with an imbricate process at middle bearing apical spine; posterolateral lobe triangular; lateral lobe digitate, setose distally, arising from below posterolateral lobe, nearly as long as posterolateral lobe. Aedeagus stout, shorter than valva, straight, with semiovate preapical lobe ventrally, with dense granules in vesica; cornuti consisting of two small plates, placed distally.
FeMAle genitAliA (Fig. 4A). Eighth abdominal sternite represented by two lateral plates bearing sparse, strong setae. Apophyses posteriores about 1.5 times as long as apophyses anteriores. Ostium bursae large, rounded. Antrum membranous. Ductus bursae approximately three times as long as corpus bursae; ductus seminalis arising from between antrum and ductus bursae, nearly as wide as ductus bursae, helical. Corpus bursae small, elliptical; signum situated at middle, elliptical, serrate along margins, with narrow, horizontal central groove.

Diagnosis
The new species is similar to A. erromera sp. nov. superficially, and the differences between them are stated in the diagnosis of the latter species.

Etymology
The specific epithet is derived from the type locality.

Description
Adult (Figs 1B, 2B). Wingspan 10.0-11.5 mm. Head and antenna orange white. Second palpomere of labial palpus orange white mixed with dark brown on inner surface, dark brown on outer surface, roughly scaled ventrally; third palpomere orange white. Thorax orange white; tegula dark brown. Forewing with costal margin slightly arched, apex roundly produced, termen shallowly concave; ground colour dark brown, mixed with orange-white scales, orange white mixed with brown ventrobasally, blackish brown from base to antemedian fascia along costal margin; antemedian fascia orange white, curved in S shape from beyond basal 2/ ₅ of costal margin to basal 2/₅ of dorsum, edged with black scales on inner margin; discocellular stigma elliptical, black, encircled by orange white; costal spot small, orange white, at distal ¼; dorsal spot smaller, orange white, at distal ¼; subterminal line orange white, running from below costal spot sinuate to dorsal spot, discontinuous; fringe greyish black, basal line orange white; M 1 stalked with R 3+4+5 , M 2+3 and CuA 1+2 short-stalked, CuA 1 and CuA 2 coincident. Hindwing brown; fringe greyish brown, with an orange-white basal and median lines. Legs orange white mixed with dark-brown scales except foreleg dark brown ventrally.

Diagnosis
This species is similar to A. purpurata Zhu & Liu, 2009 in both appearance and male genitalia. It can be distinguished in the male genitalia by the posterolateral lobes of the juxta subacute at the apex, the lateral lobes shorter than the juxta (Fig. 3C-D); and in the female genitalia by the eighth abdominal sternite without a process on the anterior margin (Fig. 4C). In A. purpurata, the posterolateral lobes are straight at the apex, the lateral lobes are as long as the juxta (Zhu & Li 2009: 23, fig. 2c), and the eighth abdominal sternite has a process at middle on the anterior margin (Zhu & Li 2009: 24, fig. 3b).

Remarks
Antiochtha rotunda Zhu & Li, 2009 is synonymized with A. jianfengensis Zhu & Li, 2009. Antiochtha rotunda is identical to A. jianfengensis in appearance, venation, as well as in the female genitalia, and differs only by the sacculus more produced distally in the male genitalia (Fig. 3D), hence it should be treated as an individual variation.

Diagnosis
The new species can be distinguished from its congeners by the smaller size (9.5-10.0 mm), and the distally narrowed forewing with costal margin concave beyond middle.

Etymology
The specific epithet is derived from the Latin ̒ minisculus̕ , referring to the small size of the adult.

Description
Adult (Figs 1e, 2C). Wingspan 9.5-10.0 mm. Head and antenna orange white. Labial palpus orange white except dark brown on outer surface of second palpomere. Thorax orange white; tegula dark brown. Forewing narrowed distally, costal margin gently concave beyond middle, apex roundly produced, termen shallowly concave; ground colour dark brown except pale orange from basal 2/₅ to apex along costal margin, mixed with orange-white scales in distal 3/₅; dorsum with an orangewhite spot at base; antemedian fascia orange white, from basal 2/₅ of costal margin oblique outward to before middle of dorsum; discocellular stigma small, rounded, black; costal spot orange white, at distal 1/₅; dorsal spot smaller, orange white, at distal 1/₅; fringe greyish brown, basal band orange white; M 1 stalked with R 3+4+5 , M 2+3 and CuA 1+2 almost arising from same point, CuA 1 and CuA 2 stalked for about half length of CuA 2 . Hindwing and fringe pale greyish brown; fringe with orangewhite basal line and weak median line. Legs pale yellow except fore and mid femora and fore tibia dark brown ventrally.

Diagnosis
This species is similar to A. hemitatos Park, 2017 superficially. It can be distinguished in the male genitalia by the uncus narrowed distally, the gnathos with a stout median process, and the juxta with a large median process (Fig. 3F); in A. hemitatos, the uncus is widened distally, the median process of the gnathos is narrowly elongate, and the juxta lacks a median process (Park & Bae 2017: 287, figs 5-6).

Remarks
This species was originally described from Thailand based on three male specimens. In this paper, we newly record this species in China and describe its female for the first time.

Discussion
The vein M 2 in the hindwing is a key character, sometimes the only character, to distinguish a genus from its allies in Lecithoceridae, such as Sarisophora Meyrick, 1904from Lecithocera Herrich-Schaffer, 1853, Deltoplastis Meyrick, 1925from Torodora Meyrick, 1894, and Antiochtha Meyrick, 1905from Halolaguna Gozmány, 1978(Gozmány 1978Wu 1997;Park 2012). Park & Bae (2017) described a new species from Laos, Antiochtha hemitatos, possessing the hindwing with the vein M 2 present. In the study, they redefined the generic characters of Antiochtha with the vein M 2 in the hindwing absent or present, which confused the relationship between Antiochtha and Halolaguna. Thereby, we herein recommend that the absence of the vein M 2 in the hindwing should be treated as one of the generic characters of Antiochtha until a detailed molecular analysis of the related genera is conducted.