Three new species of Epicephala Meyrick (Lepidoptera, Gracillariidae) associated with Phyllanthus microcarpus (Benth.) (Phyllanthaceae)

Abstract Three new species of Epicephala Meyrick, 1880 are described based on specimens reared from fruits of Phyllanthus microcarpus (Benth.): Epicephala microcarpa sp. n. and Epicephala laeviclada sp. n. from Guangxi and Hainan, and Epicephala tertiaria sp. n. from Guangdong and Guangxi. Photographs of adults and illustrations of genital structures are provided.


Introduction
The genus Epicephala Meyrick, 1880 of the moth family Gracillariidae has been reported to have close coevolutionary relationships with the genera Glochidion, Phyllanthus and Breynia of the plant family Phyllanthaceae. Epicephala currently consists of 46 described species worldwide, mainly distributed in the Old World (Vári 1961;Kuznetzov 1979;Nielsen et al. 1996;De Prins andDe Prins 2005, 2011;Zhang et al. 2012). In China, nine species have been recorded prior to this study (Zhang et al. 2012).
The present paper describes three new species based on specimens reared from the host-plant, Phyllanthus microcarpus (Benth.) (Figs 1−5) from Guangxi Zhuang Autonomous Region, Hainan and Guangdong provinces, while the authors were study- ing their biology and coevolution with the host-plant (to be reported upon in different papers). Phyllanthus microcarpus was previously a synonym of Phyllanthus reticulatus Poir. until Luo et al. (2011) showed they are two different species, with differences in vegetative and floral characteristics, and different habitats and distribution.

Material and methods
The field study was conducted from 2011 to 2013 in Pingxiang, Guangxi Zhuang Autonomous Region, and from 2009 to 2014 in several nature reserves in Hainan Province, China. Specimens examined in this study were collected or reared from fruits of Phyllanthus microcarpus (Benth.). Genitalia dissection and mounting methods follow Li and Zheng (1996). Photos of the host-plants were taken in the field using a Canon PowerShot G10 digital camera. Photos of adult specimens were taken with a Leica M250A stereo microscope, and illustrations of the genitalia were prepared by using a Leica DM750 microscope, and refined in Photoshop®CS4 software.

Description of new species
Description. Adult (Fig. 6). Forewing expanse 5.0−7.5 mm. Head white to pale yellowish brown, lateral sides with long black scales. Labial palpus black, inner surface of second and distal portion of third segments mixed with white scales. Antenna dark brown, with narrow greyish white rings, more distinct on dorsal surface. Thorax white. Tegula with basal half brown, distal half greyish white. Forewing greyish brown to dark brown, markings dense and compact; three pairs of white striae from both costal and dorsal 2/3, Figures 6-8. Adults of Epicephala spp. 6 E. microcarpa sp. n., paratype ♂ 7 E. laeviclada sp. n., holotype ♂ 8 E. tertiaria sp. n., paratype ♀ (Scale bars = 1.0 mm). 1/2 and 3/4 extending obliquely outward to middle and end of cell as well as outside of cell, dorsal striae broader and clearer than costal striae; basal 1/6 of dorsum with broad white band; a narrow silvery-white fascia with metallic reflection from costal 5/6 to dorsum, arched outward medially; distal 1/6 ochre brown, with a central black dot edged by a short white streak or a dot near costa, with a white band along dorsum; cilia greyish white except black at base and apex, adjacent white from costal margin along termen to tornus, then grey along dorsal margin. Hindwing and cilia greyish brown. Abdomen dark brown.
Host-plant. Phyllanthaceae: Phyllanthus microcarpus (Benth. Diagnosis. This species is similar to Epicephala microcarpa sp. n. in appearance, but can be separated from the latter by the compacted sacculus with bluntly rounded apex that connects with a ridge in the inner surface of the valva, the stout bullet-like phallus with cornuti composed of spinules that are grouped into one bundle in the male; the cone-shaped lamella postvaginalis is conspicuous, and the corpus bursae with only one small signum in the female. In E. microcarpa sp. n., the sacculus is narrower and longer, and its apex is usually sharp and lacks a sclerotized ridge in the inner surface of the valva, and the straight phallus has cornuti composed of spinules that are grouped into two bundles in the male; the broad and very short lamella postvaginalis is unconspicuous, and the corpus bursae has a pair of large signa in the female. Description. Adult (Fig. 7). Forewing expanse 5.0−7.5 mm. Head white to greyish brown, lateral sides with long black scales. Labial palpus black, inner surface greyish white to black, basal 1/3 of second and both ends of third segments greyish white. Antenna dark brown, scape with long and narrow scales, flagellum with narrow greyish rings. Thorax white to greyish brown. Tegula brown, apically greyish white. Forewing brown to dark brown; three white striae from costal 1/4, 1/3 and 2/5 extending obliquely outward to 1/3 width of forewing; dorsum with broad white band along basal 1/3, serrated on upper edge, distally with a stria extending obliquely outward to middle of cell, with a small triangular white spot and an obliquely outward stria at middle and before 5/6, respectively; a narrow silverywhite fascia with metallic reflection from costal 5/6 to dorsum; distal 1/6 ochreous, with a central black spot edged by a white dot near costa and a white band along dorsum; cilia greyish white except black at basal margin and apex. Hindwing and cilia greyish brown. Abdomen dark brown.
Distribution. China (Guangxi and Hainan). Etymology. The specific name is derived from the Latin laevis (smooth) and cladus (branch), in reference to individuals of the host-plant, Phyllanthus microcarpus (Benth.), having glabrous branches.
Remarks. The host-plant, Phyllanthus microcarpus (Benth.), has glabrous and pubescent forms that were formerly identified as the varieties P. reticulatus var. glaber (glabrous) and P. reticulatus var. reticulatus (pubescent). However, P. reticulatus also has such forms, and other characters are needed to separate the two plant species. The larva of Epicephala laeviclada sp. n. has only been found on the glabrous plants. Diagnosis. This species is similar to Epicephala microcarpa sp. n. in both appearance and genitalia, but can be separated from the latter by distal 1/6 of the forewing having a broad white band along costa; the narrower valva as long as the tegumen and rounded at apex, and the narrower and shorter sacculus approximately 2/3 length of the valva in the male; the ovipositor not constricted basally, the lamella postvaginalis digitated, the ductus bursae membranous, and the smaller corpus bursae with very minute signa in the female. In E. microcarpa sp. n., the forewing has a short white streak or a dot near costa in distal 1/6; the valva is broader and longer than the tegumen and its apex is oblique, the sacculus is somewhat broader and approximately 4/5 length of the valva in the male; the ovipositor is constricted at base, the lamella postvaginalis is unconspicuous, basal 2/3 of the ductus bursae is sclerotized and densely covered with longitudinal wide pleats, and the signa are large in the female.
Description. Adult (Fig. 8). Forewing expanse 6.0−8.5 mm. Head cream white, with dark brown laterally. Labial palpus black, inner surface and outer ventral margin of second segment white, inner surface of third segment white to greyish brown. Antenna dark brown, with narrow greyish white rings. Thorax white. Tegula and forewing brown to dark brown; forewing with three pairs of white striae from both costal and dorsal 1/4, 2/3 and 3/4 extending obliquely outward to middle and end of cell as well as outside of cell respectively, costal striae narrow, inconsecutive and usually indistinct, dorsal striae broad and clear, latter two striae inconsecutive; dorsum with a broad white band along basal 1/3; a narrow silverywhite fascia bearing bluish metallic reflection from costal 5/6 to dorsum, arched outward medially; distal 1/6 ochreous, with a central black dot near fascia at 5/6, with broad white band along costa and dorsum; cilia along termen to tornus pale grey except black at base and ochre brown at apex. Hindwing and cilia pale grey. Abdomen greyish brown. Male genitalia (Fig. 11). Tegumen broadly elliptical, lateral sides narrow and sclerotized. Valva narrowed, rectangular, as long as tegumen, slightly narrowed medially, gently curved upward, apex rounded, with long dense setae ventrally. Sacculus narrowed, approximately 2/3 length of valva, tapered to sharp apex. Transtilla slender, curved downward, acute apically. Vinculum broad, nearly U-shaped; saccus slender, shorter than vinculum, apex acute. Phallus broad, straight, approximately 3/4 length of valva; cornuti composed of dense spinules.
Distribution. China (Guangdong and Guangxi). Etymology. The specific name is derived from the Latin tertiarius (third), indicating that this is the third species reared from the host-plant Phyllanthus microcarpus (Benth.).
Remarks. The larvae were reared from glabrous individuals of Phyllanthus microcarpus in Guangzhou, Guangdong Province, and from pubescent individuals of P. microcarpus in Pingxiang, Guangxi Zhuang Autonomous Region. Both glabrous and pubescent forms are now treated as one species (Luo et al. 2011). This interesting phenomenon may have some significance in the coevolution between the Epicephala moths and the Phyllanthaceae plants.