﻿Revision of the genus Charitoprepes Warren (Lepidoptera, Crambidae), with the description of a new species from China

﻿Abstract The genus Charitoprepes is revised based on morphological characteristics, and Charitoprepesaciculatasp. nov. is described as new from China. Additionally, the female genitalia of C.lubricosa are described for the first time based on new material. The differences among species of this genus are diagnosed, along with images of adults and their genitalia.


Introduction
The genus Charitoprepes was erected by Warren (1896) with Charitoprepes lubricosa Warren, 1896 from India as the type species. Hampson (1896) synonymized Charitoprepes with Heterocnephes Lederer, 1863, which was followed by other authors for more than 100 years. Charitoprepes was treated as valid genus by Kim et al. (2014), with C. lubricosa as the only species. Mally et al. (2019) transferred Heterocnephes apicipicta to Charitoprepes based on morphological characteristics and, until now, this genus only contained two known species (Nuss et al. 2023). The genus is distributed in China, India, Japan, and South Korea (Inoue 1963;Wang et al. 2003;Choi 2010;Kim et al. 2014).
Charitoprepes species are easily distinguished from those of other genera in having an elongated elliptical black patch at the apex of the greyish brown forewings. Species in this genus are externally very similar, but they can be distinguished by their genitalia. In this study, the morphological characteristics of this genus are revised, and one new species is described from China.

Materials and methods
The specimens were collected using a light trap and killed with ethyl acetate or ammonium hydroxide. The specimens, including the type material of the new species, are deposited in the College of Plant Protection, Southwest University, Chongqing, China (SWU). The corresponding author examined the type specimen of Charitoprepes lubricosa deposited in Natural History Museum, London, United Kingdom (NHMUK). Genitalia preparation mainly follows Li and Zheng (1996). Images of the adults were photographed using a digital camera (Nikon P7700), and images of the genitalia were captured with a digital camera (Leica DFC 450) attached to a digital microscope (Leica M205 A). The terminology mainly follows Maes (1995) and Mally et al. (2019).
Diagnosis. This genus is distinguished by the greyish-brown body and wings; the forewing with an elongated, elliptical, black patch at the apex. This genus can be distinguished from Heterocnephes by its labial palpi bent and upturned normally, the corpus bursae with two thin, band-like signa present or absent. In Heterocnephes, however, the second segment of labial palpi is inflated and nearly oblong, along with its third segment protruded forward (Wang 1980), the corpus bursae has two round signa, and the valva is broader than that of Charitoprepes. Generic characteristics. Adult. Body and wings greyish brown. Frons rounded. Antenna filiform, with sparse cilia ventrally. Labial palpi bent and upturned. Maxillary palpi filiform. Forewing with orbicular and discoidal stigma present, an elongated, elliptical, black patch along costa at apex; length of cell approximately half of wing; discocellulars arcuately incurved; R S1 very close to R S2+S3 ; R S2 anastomosed with R S3 approximately three-fifths beyond cell; M 2 , M 3 and CuA 1 originating from posterior angle of the cell and uniformly spaced at base. Hindwing with length of cell half of wing; discocellulars strongly, arcuately incurved; Rs anastomosed with Sc+R at long distance; M 1 and Rs shortly stalked at base beyond cell; M 2 , M 3 and CuA 1 originating from posterior angle of cell (Fig. 1A, B). Legs shiny white. Middle tibia with distal inner spur approximately twice length of outer spur; hind tibia with inner proximal spur approximately triple length of outer proximal spur, and inner distal spur approximately twice length of outer distal spur. Tympanal organs with fornix tympani surface projecting from the tympanic frame. Praecinctorium strongly bifid (Fig. 1C).
Male genitalia. Uncus long and thin, with the distal part swollen and covered with minute setae. Valva broad. Fibula spine-like and downcurved. Sacculus sclerotized, with an apical triangular process overlapping with the fibula. Saccus broad and rounded, tapered terminally. Cornutus present and diverse.
Female genitalia. Apophyses anteriores as long as apophyses posteriores, or longer. Ductus bursae varies from short and broad to long and thin. Corpus bursae elliptical or oval. A pair of thin, band-like signa present or absent.
Remarks. According to Kim et al. (2014), this genus can be identified by an elongated, elliptical, black patch at apex of forewing and dark brown, discoidal stigma on the hindwing. In C. aciculata sp. nov., however, the discoidal stigma on the hindwing is absent. Therefore, the morphological characteristics of Charitoprepes have been revised in this study, with supplementary wing venation and genitalia characteristics.   apex. Patagium, tegula and pale greyish brown. Fore and hind wings with terminal area pearly grey. Forewing greyish brown along veins, orbicular stigma and discoidal stigma conspicuous and dark brown; middle third of costa pearly grey. Hindwing with dark brown, discoidal stigma. Veins towards margin finely dark on fore and hind wings. Cilia brown, with a white basal line. Legs shiny white, epiphysis orange-yellow. Abdomen pale greyish brown, pale grey ventrally.
Remarks. The female genitalia of this species are described for the first time.
Charitoprepes apicipicta (Inoue, 1963   Diagnosis. This species is very similar to C. lubricosa in appearance, but its greyish brown wings and body are darker than those of C. lubricosa. It also can be distinguished by the stout phallus, which has two fusiform cornuti decorated with numerous minute spines, and the ductus bursae, which is elongated and far more slender than that of C. lubricosa. Description. Male genitalia (Fig. 4C). Valva square, with sparse setae. Saccus broad. Phallus stout, two fusiform cornuti decorated with numerous minute spines (Inoue 1963).
Remarks. There are occasionally some spines scattered in the ductus bursae of female specimens, which suggests that the cornuti in the male genitalia are deciduous (Fig. 4D). Diagnosis. This species is similar to C. lubricosa and C. apicipicta in appearance, but it can be differentiated by its darker body and wings, as well as the absence of the discoidal stigma on the hindwing, which is conspicuous in C. lubricosa and C. apicipicta. The wing venation of this species is somewhat different from that of C. lubricosa. The forewing of the latter has the R S4 slightly curved and close to R S2+S3 at the base, while the R S4 is straight and distant from R S2+S3 in this new species (Fig. 1A, B). Furthermore, the stalk length of M 1 and Rs of the hindwing in this new species is longer than that of C. lubricosa. It also can be distinguished by the slender and extremely elongated phallus accompanied by an elongated, bent, needle-like cornutus; the elongated ductus bursae has a sclerotized longitudinal line approximately four-fifths of its length, and the corpus bursae is much shorter than the ductus bursae and has no signa. In C. lubricosa and C. apicipicta, the phallus is stout, and the former has a spicate cornutus and the latter has two fusiform cornuti; the ductus bursae has no longitudinal line, and the corpus bursae bears a pair of thin, band-like signa in these two species. The corpus bursae is much longer than the ductus bursae in C. lubricosa, and is almost as long as the ductus bursae in C. apicipicta.

Charitoprepes aciculata
Description. Adult (Fig. 3D). Body and wings dark brown, greyish. Forewing length 11.0-13.0 mm, wingspan 21.0-26.0 mm. Frons greyish brown, white laterally; vertex brown. Antenna brown, scape white ventrally. Labial palpi with first segment white, second and third segments dark brown. Maxillary palpi white, dark brown near apex. Patagium, tegula, and thorax dark brown. Fore and hind wings with terminal area pale grey. Forewing with orbicular and discoidal stigma black, sometimes indistinct; an elongated elliptical black patch at apex; a black line along terminal margin, discontinuous. Hindwing with a black line along terminal margin, discoidal stigma absent. Cilia brown, with a white basal line. Legs shiny white, epiphysis orange-yellow. Abdomen dark brown, pale grey ventrally.
Male genitalia (Fig. 4E). Uncus long and thin, with the distal swollen and covered with minute setae, apex obtuse rounded and slightly concaved at middle. Valva oval, with sparse setae. Fibula thick, hooked apically. Saccus broad, strongly sclerotized. Phallus slender and extremely elongated, bent, with an elongated needle-like cornutus of nearly same length.
Etymology. The specific name is derived from the Latin aciculatus for needle, in reference to the needle-like cornutus.
Distribution. China (Hainan, Yunnan). Kim et al. (2014) considered Charitoprepes lubricosa as a possible pest, but there has been no host reported for either of the two known species of the genus. The long, narrow, longitudinal signa are unusual in Spilomelinae. Besides C. lubricosa and C. apicipicta, the genus Maruca Walker, 1859 also have such signa, as well as a similar uncus. In Agrioglypta Meyrick, 1932, some species also have similar signa, but they are shorter and wider, and the other species have two rounded signa. Whether these special signa in Charitoprepes indicate a relationship to Maruca can only be made clear after a thorough phylogenetic study of the tribe Margaroniini, subfamily Spilomelinae.

Discussion
History Museum, London, United Kingdom (NHMUK) for providing access to the corresponding author for examining type specimens of Charitoprepes. We also give our thanks to Dr Nathalie Yonow for reviewing the language of our manuscript, and to three reviewers for their revisions and helpful suggestions for our article. This study was funded by the National Natural Sciences Foundation of China (No. 31772500) and the Natural Sciences Foundation Project of Chongqing (No. CSTB2022NSCQ-MSX1164).