Notes on Glaucocharis (Lepidoptera, Crambidae) from China, with descriptions of two new species

Abstract Two new species belonging to the genus Glaucocharis Meyrick, 1938 are described from southwest China: Glaucocharissperlingisp. n. and G.nussisp. n. The female of G.castaneus Song & Chen, 2002 is described for the first time. The geographical distribution of the genus in China is analysed. The precipitation of the warmest quarter is revealed to be the strongest predictor affecting the present distribution pattern of the genus. A map showing the distribution of the known Chinese localities of Glaucocharis is provided.


Introduction
The genus Glaucocharis, one of the most species-rich genera of the subfamily Crambinae (Lepidoptera, Crambidae), was established by Meyrick (1938) with Glaucocharis stella Meyrick, 1938 as the type species. To date, the genus has 153 described species worldwide (Nuss et al. 2018). The main taxonomic contributions concerned the faunas of the Palaearctic and Oriental Regions (Bleszynski 1965;Gaskin 1974b;Wang and Song 1983;Ganev 1987;Wang et al. 1988;Song 1993;Chen et al. 2001Chen et al. , 2002Chen et al. , 2003Sasaki 2007;Li and Li 2012;Park et al. 2018), followed by the Australian Region (Gaskin 1971(Gaskin , 1974a(Gaskin , 1974b(Gaskin , 1985 and the Ethiopian Region (Bleszynski 1966(Bleszynski , 1970Bassi and Mey in Mey 2011). In China, the first specimen of Glaucocharis was recorded as early as 1932 from Tianmushan, Zhejiang Province (Bleszynski 1965), and a total of sixty species have been recorded in the country prior to this study (Li and Li 2012).
Among them, forty-nine species have China as the type locality (Suppl. material 1: Table S1). To date, all known localities of Chinese Glaucocharis clearly indicate a mostly eastern distribution, but this geographical pattern was never previously mentioned.
Morphologically, the members of the genus can be recognized by characters of the forewing: the apex usually with an apical mark, the termen below the apex with an indentation reaching the tip of M 1, and well-developed marginal spots. In the wing pattern, Glaucocharis is similar to Roxita Bleszynski, but can be distinguished by the forewing with a well-developed M 1 and the valva without a ventral fold in the male genitalia; in Roxita, M 1 in the forewing is absent and the ventral fold of the valva is often present (Li and Li 2012). Several species groups have been proposed based on external characters and genitalic structures within Glaucocharis by Gaskin (1985) and Wang et al. (1988). However, it is relatively difficult to assign some ambiguous members to any proposed group on morphological characters alone. There is a need for a more insightful classification of species groups in this large genus based on an integrative approach using molecular data and morphological characters.
In the present paper, two species of Glaucocharis are described from the Mabian Dafengding National Nature Reserve, southwest of China. The geographical pattern of distribution presented by the genus in China is also commented upon.

Material and methods
All specimens were collected at night with a mercury-vapour lamp. The specimens were hand-collected alive and killed by ammonium hydroxide just prior to mounting and spreading as shown in Landry and Landry (1994). The terminology for morphological structures follows Bleszynski (1965) and Gaskin (1985). Photographs of adults were taken with a Zeiss AxioCam Icc 5 digital camera attached to a Zeiss SteREO Discovery V12 microscope. Illustrations of the genitalia were prepared with a DV320 OPTPro2010-Chs digital camera attached to an Optec BK-DM320 microscope. All specimens examined are deposited in the Insect Museum, Jiangxi Agricultural University, Nanchang, China (JXAUM).
The distribution of Glaucocharis was analysed using MaxEnt (Phillips et al. 2006) and was based on distributional data extracted from previous studies (Bleszynski 1965;Wang and Song 1983;Wang et al. 1988;Song 1993;Chen et al. 2001Chen et al. , 2002Chen et al. , 2003Li and Li 2012), the specimens examined in this study (Suppl. material 1: Table S1), and twenty environmental variables (Suppl. material 1: Table S2). Geographic coordinates were taken from Wu et al. (1997) and converted into decimal coordinates (Suppl. material 1: Table S1). MaxEnt was set with 10 000 as the maximum number of background points. The model's goodness-of-fit and the relative importance of each of the variables were evaluated by area under the receiving operator curve and the jackknife procedure, respectively. Climatic data were retrieved from the WorldClim database (http://www.worldclim.org) at a resolution of 10 arc-min (Hijmans et al. 2004). The cartographic illustration was created using dismo R package (Hijmans and Elith 2017). Diagnosis. This new species is similar to Glaucocharis electra (Bleszynski) by having slender uncus and gnathos, and thin and long valva in the male genitalia. It can be distinguished by the basal process of the costa of the valva with two projections, the juxta ending with three spine-like projections, and the phallus with a line of tiny spinelike cornuti in the male genitalia (Fig. 7). In G. electra, the costa of the valva only has a single projection, the juxta is concave distally, and the phallus has only one cornutus (Bleszynski 1965: pl. 32 fig. 4).

Glaucocharis sperlingi
Description. Male adult (Figs 1, 2): Forewing length 5.5-6.0 mm. Frons and vertex pale brown. Labial palpus pale yellow on outer side except for brown base and tip, white ventrally. Maxillary palpus pale brown, white distally. Antenna pale brown and yellowish white in alternance on dorsal surface, pale yellow ventrally. Tegula and thorax white mixed with pale brown. Forewing white, sparsely covered with pale brown scales; antemedian line pale brown, straight except curved inward near costa; reniform stigma pale brown, small and ovate; postmedian line pale brown, arched outward; apex pale yellow, with white apical stripe; termen pale brown, with two black marginal spots; fringe pale brown mixed with white. Hindwing white, covered with pale brown scales along apex; fringe concolourous with forewing. Abdomen brown and white in alternance on dorsal surface. Legs white.
Male genitalia (Fig. 7): Uncus slightly concave at two-thirds, tapering to pointed apex. Gnathos curved upward slightly, apex with triangular projection and small spine on dorsal and ventral margin, respectively. Tegumen approximately as long as gnathos. Valva broad basally, narrowed towards blunt apex; ventral margin indented at about three-fourths; costa with adjacent triangular and spine-like projections at base. Saccus well-developed, gently narrowed towards distal tip. Juxta anteriorly convex, slightly broadened in basal one-third, then narrowed towards tip, ending with three spine-like projections. Phallus slightly shorter than valva; tiny cornuti spine-like, placed in one line.
Female unknown. Distribution. China (Sichuan). Natural history. Unknown except that the moths are in flight in early August and come to light. The habitat in which this species has been collected is located at 1100 m altitude, at the foot of the mountain. Most parts of the mountain are covered with trees belonging to families Lauraceae and Fagaceae (Fig. 10).  Diagnosis. This species can be distinguished from its congeners by the unique characters in the male genitalia. The costal projection is absent and the phallus has a single strong spine-like cornutus (Fig. 8).
Description. Male adult (Figs 3, 4): Forewing length 5.5-6.0 mm. Frons and vertex pale brown mixed with yellowish white. Labial palpus basal half and distal one-fourth blackish brown on outer side, otherwise yellowish white. Maxillary palpus pale brown, yellowish white distally. Antenna yellowish white. Tegula and thorax pale brown. Forewing covered with pale brown scales; costa and dorsum with blackish spot near middle; antemedian line unrecognized; reniform stigma blackish brown, small and round; postmedian line brown, arched outward; apex orange, with white apical stripe; termen orange mixed with pale brown, with four black marginal spots; fringe pale brown. Hindwing pale brown; fringe white mixed with grey. Abdomen blackish brown and white in alternance on dorsal surface. Legs pale brown.
Female unknown. Distribution. China (Sichuan). Natural history. See above under this heading for Glaucocharis sperlingi sp. nov. Etymology. In honour of Dr Matthias Nuss, who contributed profoundly to systematic research on pyraloid moths, and who maintains and expands the most important tool for taxonomic information on the world pyraloid species: GlobIZ (www.pyraloidea.org).
Remarks. The generic assignment of G. nussi is primarily based on the external characters. However, its male genitalia are atypical for Glaucocharis. Characters of both sexes and molecular data would have to be analysed phylogenetically to provide a more insightful hypothesis concerning its classification. Maxillary palpus pale brown to blackish brown, pale yellow distally. Antenna blackish brown and pale yellow in alternance on dorsal surface, pale yellow ventrally. Tegula and thorax blackish brown. Forewing densely covered with blackish brown scales; antemedian line black, dorsal two-thirds inconspicuous; reniform stigma unrecognized; postmedian line blackish brown, arched outward; apex orange, with white apical stripe; termen orange mixed with pale brown, with two black marginal spots; fringe blackish brown. Hindwing blackish brown; fringe pale brown except blackish brown subbasally. Abdomen blackish brown on dorsal surface. Legs pale brown.

Glaucocharis castaneus Song & Chen, 2002
Female genitalia (Fig. 9): Papillae anales ovate, about one-third length of posterior apophyses. Tergite eight about two-thirds as long as anterior apophyses. Lamella postvaginalis roughly U-shaped. Antrum swollen and densely covered with small spines. Remarks. The female of G. castaneus is described for the first time herein. The male of this species was described and figured adequately by Chen et al. (2002).

The geographical distribution of Glaucocharis in China
The geographical distribution of Chinese Glaucocharis was analysed using MaxEnt based on the known localities (Suppl. material 1: Table S1) and twenty environmental variables (Suppl. material 1: Table S2). The results clearly indicate that the precipitation of the warmest quarter (Bio18) was the strongest predictor of the geographical distribution of the genus in China, and the mean diurnal range (Bio2, mean of monthly maximum and minimum temperatures) and the minimum temperature of the coldest month (Bio6) were revealed to be the second and third most important factors respectively in the environmental variables (Suppl. material 1: Table S2).
At present, all Glaucocharis species in China occur in humid-semi-humid areas (pale blue to green), which can be separated from arid-semi-arid areas (dark blue) in western China by using the climate data Bio18 (Fig. 11). Furthermore, based on all Glaucocharis species catalogued in China (Suppl. material 1: Table S1), most members of the genus occur south of 32°N (southern China) where the minimum temperature of the coldest month is above 0 °C. The precipitation and temperature have higher explanatory power for the occurrence of the genus in China in accordance with the analysis of MaxEnt. The available data suggest that precipitation limits the dispersal of known species. Meanwhile, temperature could have a significant influence on the exceptionally high species diversity of the genus in southern China. However, the species diversity pattern of Glaucocharis detected here does not precisely reflect the latitudinal gradient inasmuch as the unique species diversity between 25°N and 32°N is much higher than in the other areas, and many distribution gaps are found between the known localities (Fig. 11). In further research, it would be essential to explore more precisely the biotic and abiotic requirements for individual Glaucocharis species as well as to describe the largely unstudied diversity of the genus in eastern China.
improve the manuscript throughout. Special thanks are given to the two anonymous reviewers for their insightful comments and suggestions on the manuscript. This project was supported by the National Natural Science Foundation of China (No. 31601885).