Two new species of the genus Meleonoma Meyrick from China (Lepidoptera, Gelechioidea, Xyloryctidae)

Abstract Two new species of Meleonoma Meyrick, 1914a (Gelechioidea, Xyloryctidae) from southeastern China are described: Meleonoma foliiformis Yin, sp. nov. from Guangxi Province and M. projecta Yin, sp. nov. from Fujian Province. Adults and male genitalia are described in detail. A list of the Meleonoma species occurring in China is given. The taxonomic position of Meleonoma has been unstable, and under debate. Nonetheless, it is here tentatively placed in the family Xyloryctidae, following the latest molecular phylogenetic study concerning this genus.


Introduction
The genus Meleonoma Meyrick was established in 1914 in the family Oecophoridae, for three species, with Cryptolechia stomota Meyrick, 1910a as the type species. Prior to this study, 35 valid species had been reported over the world, of which 14 had been discovered in China. The first ever described species of the genus was collected in Heilongjiang Province of China and published by Christoph under the original name of Euteles flavimaculata Christoph, 1882. However, it was not transferred into Meleonoma until very recently (Lvovsky 2015). After that, 14 species with various distributions were described by Mey-rick, successively from 1906 to 1935, of which seven were placed directly in Meleonoma, viz. M. heterota Meyrick, 1914a andM. petrota Meyrick, 1914a, both published along with the generic description; M. psammota Meyrick, 1915;M. implexa Meyrick, 1918;M. nephospora Meyrick, 1930;M. pardalias Meyrick, 1931;M. impulsa Meyrick, 1934. The other seven were originally published in various genera, and transferred into Meleonoma later on, viz. M. capnodyta (Meyrick, 1906) in Borkhausenia Hübner, [1825] 1816; M. crocomitra (Meyrick, 1914b) in Pseudodoxia Durrant, 1895;M. facunda (Meyrick, 1910b) in Leptosaces Meyrick, 1888;M. stomota (Meyrick, 1910a), M. aridula (Meyrick, 1910c), M. malacobyrsa (Meyrick, 1921) and M. torophanes (Meyrick, 1935) in Cryptolechia, Zeller, 1852. Years later, Viette (1955 reported the new species M. diehlella from Madagascar. Wang (2002, 2004) reported five new species from China. Lvovsky (2015) described five new species from Nepal and China and transferred Cryptolechia peditata Wang, 2006b into Meleonoma. Yin and Wang (2016a, b) reported two new species from Taiwan and four new ones and one new record from Thailand. In the same year, Park and Park (2016) described two new species and one new record from Korea.
Meleonoma are mostly small to medium-sized moths, mainly distributed in the Australian, Afrotropical, Palearctic, and Oriental faunal regions; the genus is especially rich in the Oriental faunal region. Meleonoma is characterized by the front of the head usually covered with appressed scales and the vertex with erect and hairlike scales; the labial palpus bearing three segments and recurved upwardly, extending well beyond the vertex, with the third segment shorter than the second one; the scape without pecten; the tibia of all legs clothed with long hairs above; the forewing with ground color usually yellow or black or approaching one of these two colors, forewing patterns diverse, usually with an oblique, wide, yellow or dark brown fascia. The venation of the forewing is as follows: R1 from about middle of cell, R4 and R5 arising from upper angle of cell and stalked at the half of their length, R5 reaching to near apex, M1 and M2 parallel, M2, M3 and CuA1 all arising from near the lower angle of the cell and separated from each other, CuA1 and CuA2 parallel, CuP weakly developed. The venation of hindwings is as follows: Rs, M1 and M2 nearly parallel, M3 and CuA1 stalked at the base or arising from the same point of the cell, CuA2 far from CuA1, arising from about 4/5 of the posterior margin of the cell, and CuP well developed. Tergum II-VII of abdomen with patches of a broad area of directed setae (Figs 3, 4). Meleonoma can also be identified by some key characters, such as the male genitalia with a welldeveloped uncus, a partly sclerotized circular or entirely membranous gnathos, and a well-defined saccus; by the female genitalia with an entirely or partly sclerotized ductus bursae, and one signum, often with spines if present (Wang 2006a;Yin and Wang 2016b;Kim and Lee 2017).
Nothing is known about their host plants.
The taxonomic status of the genus is controversial and the genus has been placed in different families and subfamilies of the Gelechioidea. It was originally described in the family Oecophoridae (Meyrick 1914a). After that, Clarke (1965) placed Meleonoma in the Cosmopterigidae (without any comments). Since then, many researchers followed his treatment (e.g., Nye and Fletcher 1991;Wang 2002, 2004). Lvovsky (2015) transferred the genus into the Lypusidae. The most recent phylogenetic study of Kim et al. (2016) indicated that Meleonoma most likely belongs to the Xyloryctidae. Although the taxon sampling in Kim et al. (2016) was limited for this genus, their work is currently the only one based on molecular phylogenetic evidence. Therefore, we tentatively follow this and place Meleonoma in the Xyloryctidae.
In this study, two new species are described from China: M. foliiformis Yin, sp. nov. from Guangxi Province and M. projecta Yin, sp. nov. from Fujian Province. The species number of this genus is thus increased to 37.

Material and methods
The examined specimens were collected from Guangxi and Fujian Provinces in southeastern China in 2018. The descriptive terminology of the anatomical structures generally follows Wang (2006a), however in descriptions of the male genitalia, the more proper term phallus rather than aedeagus is applied here following Kristensen (2003). Photographs of adults were taken using a Canon EOS 6D Mark II camera plus an EF 100 mm f/2.8L MACRO IS USM lens with the help of EOS Utility 3.10.20 software. Images of genitalia were captured using a Leica DM4 B upright microscope and photomontage was performed with Leica Application Suite X imaging software. All type specimens are deposited in the Morphological Laboratory, Guizhou University of traditional Chinese Medicine, Guiyang 550025, Guizhou, China.  (2015).  (Meyrick, 1910b) in both appearance and genitalia. The differences between M. foliiformis and M. facunda in the male genitalia are as follows: M. foliiformis with the ventral process of the sacculus in a distinct leaf shape and the phallus with the distal 1/4 hooked; M. facunda with the ventral process of sacculus tiny, triangular in shape and the phallus straight.
surface of labial palpus with segment 1 and distal half as well as end of segment 2 densely covered with dark-brown scales, inner surface yellow; segment 3 yellow, about 3/4 length of segment 2; antenna with scape pale yellow; flagellum alternately pale yellow and dark brown on dorsal surface, ventral surface pale yellow; ocelli absent; scales of proboscis pale yellow.
Thorax: Tegula and mesonotum blackish brown anteriorly, yellow posteriorly; legs whitish yellow, tibiae scattered with blackish brown scales and tarsi with blackish brown speckles on outside. Forewing (Fig. 1): Length 6.0-7.0 mm (N = 2), about 3.5 X as long as wide, along costa with blackish brown streak from base to about basal 1/5, distal 1/3 of costa with several blackish brown dots; a dark-brown fascia extending from near middle of costa obliquely to tornus, slightly wider posteriorly; cell with 2 blackish brown dots, one set at middle of cell, the other set at distal 2/5 of fold; apex dark brown, somewhat forming a triangular patch along termen; cilia yellow except dark brown on tornus. Ventral surface yellowish brown. Hindwing (Fig. 1): translucent grayish brown, gradually darkening towards apex; cilia grayish brown.
Biology. The host plant of the larva stage is unknown. The adults were collected using lamp attraction in June.
Distribution. China (Guangxi Province). Etymology. The specific name, the Latin adjective foliiformis, means leaf-like, and refers to the leaf-shaped ventral process of the sacculus. Diagnosis. This new species can be distinguished from its congeners easily by the unique character in the male genitalia. In M. projecta, the distal portion of the sacculus with a heavily sclerotized process. It is also slightly similar to M. malacobyrsa externally. They can be distinguished by the fascia in the forewings: M. projecta with the fascia indistinct, whereas it is clearly outlined in M. malacobyrsa. In M. projecta the valva has no odontoid process on the ventral margin, sacculus with apex produced and phallus with tiny teeth near apex; M. malacobyrsa has the valva with an odontoid process on the ventral margin, sacculus concave and without a tooth on the phallus.

Meleonoma projecta
Description. Head: vertex with grayish brown scales at middle, front yellow; labial palpus long and recurved, extending well beyond vertex, with smooth scales, outer surface of labial palpus with segment 1 and segment 2 dark brown, inner surface yellow, apex of segment 2 with blackish brown dots; segment 3 yellow, scattered with blackish brown dots, about 1/2 of second segment; antenna with scape earthy yellow on ventral surface and blackish brown on dorsal surface, with flagellum ringed, alternately blackish brown and earthy yellow; ocelli absent; scales of proboscis yellow.
Thorax: Tegula and mesonotum blackish brown mixed with yellow; legs light yellow, grayish brown on ventral surface, with grayish brown speckles on outside surface of tibiae and tarsi. Forewing (Fig. 2): Length 7.0-8.0 mm (N = 2), about 3.0 X longer than wide, blackish brown mixed with yellow scales; costa with a large diffused yellow blotch at about distal 1/5. Ventral surface dark brown; an oblique dark brown fascia running from basal 2/3 of costa to tornus; cell with 2 blackish brown markings, set at middle and end of cell respectively; cilia dark brown except yellow basally. Hindwing (Fig. 2): grayish brown; cilia grayish brown. Ventral surface of forewing and hindwing dark brown.
Biology. The host plant of the larva stage is unknown. The adults were collected using lamp attraction in May.
Distribution. China (Fujian Province). Etymology. The specific name, the Latin adjective projectus, refers to the heavily sclerotized process of the sacculus.