Four new species of Epicephala Meyrick, 1880 (Lepidoptera, Gracillariidae) associated with two species of Glochidion (Phyllanthaceae) from Hainan Island in China

Abstract Four new Epicephala species that feed on the seeds of Glochidion sphaerogynum (Phyllanthaceae) from Yinggeling Mountain Nature Reserves in Hainan Province of China are described: Epicephala domina sp. n., Epicephala impolliniferens sp. n., Epicephala angustisaccula sp. n. and Epicephala camurella sp. n. The latter two species are also associated with Glochidion wrightii. Photographs of adults and genital structures are provided.


Introduction
The genus Epicephala Meyrick, 1880 consists of 49 described species worldwide, mainly distributed in the Old World, with 15 species occurring in the Australian Region, 28 in the Oriental Region, one in the Palaearctic Region, and six in the Afrotropical Region (Vári 1961;Kuznetzov 1979;Nielsen et al. 1996;De Prins andDe Prins 2005, 2014;Zhang et al. 2012b;Li and Yang 2015). In China, thirteen species have been recorded prior to this study (Meyrick 1935;Kendrick 2005;Hu et al. 2011a, b;Zhang et al. 2012b;Li and Yang 2015;Wang and Li 2015;Yang and Li 2015). But there are still a large number of undescribed species of Epicephala, especially in tropical areas (Kawakita et al. 2004;Kawakita andKato 2006, 2009;Hembry et al. 2012Hembry et al. , 2013. In the course of studying the coevolutionary relationships between Epicephala moths and Glochidion plants in Yinggeling Mountain Nature Reserves of Hainan Province, we identified four new Epicephala species. Epicephala domina sp. n. and E. impolliniferens sp. n. are associated with G. sphaerogynum (Müll. Arg.) Kurz; E. angustisaccula sp. n. and E. camurella sp. n. are associated with both G. sphaerogynum (Figs  1-4) and G. wrightii Benth.
Larvae of Epicephala species feed on seeds in the fruit of their host-plants in the family Phyllanthaceae (Euphorbiaceae sensu lato). Some Epicephala species have been known to be highly species-specific with their host-plants within Phyllanthaceae (Kawakita 2010, Hu et al. 2011b, Zhang et al. 2012c, and have presumably coevolved with their hosts. In most cases, within pollinating Epicephala and their hosts, a single species of Epicephala and a single species of Phyllanthaceae are uniquely associated at a single site, producing so-called "one-to-one" patterns of interaction (Kawakita and Kato 2006;Zhang et al. 2012b). However, in some cases, more complex patterns of specialization, such as one-to-two (Kawakita and Kato 2006;Zhang et al. 2012a), one-to-three  and two-to-two (Zhang et al. 2012c) patterns, have occurred. We find one-to-four and one-to-two relationships, which will be described further in a separate paper. The present paper just aims at describing the four new Epicephala species associated with the two Glochidion species from Hainan Island in China.

Material and methods
Specimens examined in this study were mainly reared from fruits of host-plants, which were gained during a field study from 2009 to 2014 in Yinggeling Mountain Nature Reserves (18°59'30"−19°04'20"N, 109°28'00"−109°35'30"E) in midwestern Hainan Province, China (Fig. 1), and only some were collected on flowers or leaves of two Glochidion plants in the late evening. Genitalia dissection and mounting methods follow Li and Zheng (1996). Photos of the host-plant G. sphaerogynum were taken in the field using a Canon Power Shot G10 digital camera. Photos of adult specimens were taken with a Leica M250A stereo microscope. Illustrations of the genitalia were prepared by using Leica DM750 microscope, and refined in Photoshop® CS4 software.
The type specimens and vouchers of host plants are deposited in the Insect Collection, College of Life Sciences, Nankai University (NKUM), Tianjin, China and some paratypes are deposited in the Department of Life Sciences, Division of Terrestrial Invertebrates, Natural History Museum, London, UK (BMNH).

Taxonomic account
Epicephala domina Li, sp. n. http://zoobank.org/0161B207-D186-47ED- 9,11,15 Description. Adult (Fig. 5). Forewing expanse 7.5−11.0 mm. Head creamy white tinged with pale yellow, lateral sides with long brown scales. Labial palpus white or grayish white, distal half of second and third palpomeres dark brown on outer surface, inner surface of third palpomere white to gray. Antenna grayish brown. Thorax white. Tegula yellowish brown. Forewing grayish brown to deep brown; three pairs white striae from both costal and dorsal margins at 2/5, 3/5 and 4/5 extending obliquely outward to middle as well as to end and outside of cell, third dorsal striae broader and more distinct; dorsal margin with a broad white band extending from base to tornal area; a narrow silvery-white fascia with metallic reflection from costal 6/7 to dorsal margin; distal 1/7 yellowish brown, with a central black dot, with a triangular white dot near costa and a white streak along dorsal margin; cilia basally black, medially grayish white, distally black from distal 1/7 of costal margin along termen to tornus, gray along dorsal margin. Hindwing grayish brown; cilia brown along costal margin and grayish or yellowish brown along dorsal margin.
Male genitalia (Fig. 11). Tegumen broadly triangular, narrowed and sclerotized laterally. Tuba analis elongate, gradually narrowed toward apex, exceeding caudal margin of tegumen apically. Costa sub-rectangular, longer than tegumen, distal 1/3 more or less broadened, apex obliquely rounded; dorsal margin straight; ventral margin with basal 3/4 slightly arched inward, with a rounded process at 3/4, with dense long setae on distal half. Sacculus elongate oval, about 4/5 length of costa, acute-angled apically, dorsal margin more arched, distal part of dorsal and ventral margins heavily sclerotized. Transtilla broad at base, long triangular. Vinculum broad V-shaped, rounded on posterior margin; saccus club-shaped, shorter than vinculum, acute at apex. Phallus thin and straight, as long as valva; cornutus in a shape of a rolled plate, with minute spines.
Female genitalia (Fig. 15). Ovipositor small, bilobed apically, dentate laterally. Apophysis posterioris slightly longer than apophysis anterioris. Lamella postvaginalis large, as long as 8th abdominal segment, heavily sclerotized, deeply concave at middle on caudal margin to half length, forming two triangles with acute apex. Antrum cylindrical, strongly sclerotized, as long as ductus bursae. Ductus bursae about half length of apophysis anterioris, membranous, with broad longitudinal sclerotized parallel folds, extending from base to corpus bursae; ductus seminalis membranous, arising anterior of antrum. Corpus bursae oval, as long as ductus bursae, with reticulate patches medially; signum a stout tooth, placed at middle.
Diagnosis. This new species is similar to the majority of Epicephala species in forewing pattern by having a white dorsal margin, but can be separated from other species by its genitalia. The new species is more similar to E. ancylopa Meyrick, 1918, but can be distinguished from the latter in the male genitalia by the ventral margin of the n., female paratype 6 E. impolliniferens sp. n., female paratype 7 E. camurella sp. n., male paratype 8 E. angustisaccula sp. n., male paratype 9-10 Morphology of female proboscis: 9 E. domina sp. n., female paratype, head slide No. WZB14297 (genitalia slide No. WZB14295 for determination) 10 E. impolliniferens sp. n., female paratype, head slide No. WZB14298 (genitalia slide No. WZB14160 for determination). Scale bar: 2.0 mm (5-6); 0.5 mm (9, 10). costa with a rounded process at 3/4, the sacculus about 4/5 length of the costa and the acute apex; and in the female genitalia by the lamella postvaginalis as long as the 8th abdominal segment and the presence of signum. In E. ancylopa (Lectotype ♂, BMNH, examined; Syntypes: ♂, BMNH, examined, genitalia slide No. 32324, ♀, BMNH, examined, genitalia slide No. 32330, both dissected by Houhun Li), in the male geni-talia the ventral margin of the costa has a rounded process at 2/3, the sacculus is about 3/4 length of the costa and bluntly rounded at apex; in the female genitalia the lamella postvaginalis is shorter than the 8th abdominal segment and the signum is absent. Description. Adult (Fig. 6). Forewing expanse 7.0−10.5 mm. Head white to yellowish white mixed with brown scales. Labial palpus white, inner surface with scattered grayish brown scales; distal 1/2 to 2/3 of second palpomere brown to dark brown on outer surface, third palpomere dark brown on outer surface except tip. Antenna grayish brown to dark brown, each flagellomere paler at base. Thorax white. Tegula dark brown. Forewing brown to dark brown; three pairs white striae from both costal and dorsal margins at 2/5, 2/3 and 3/4 extending obliquely outward to middle as well as to end and outside of cell, second dorsal stria longest and third costal stria shortest; dorsal margin with a broad white band extending from base to tornus; a silvery-white fascia with metallic reflection from costal 6/7 to dorsal margin, gently arched outward; distal 1/7 yellowish brown, with a central black dot, with an indistinct white dot at costa and a white streak along dorsal margin; cilia basally black, medially white, distally black from distal part of costal margin to apex, white from termen to tornus, gray along dorsal margin. Hindwing yellowish white (especially at base) to brown; cilia gray.
Male genitalia (Fig. 12). Tegumen broadly oval, sclerotized laterally. Costa as long as tegumen, slightly broadened at base, rounded at apex, with long dense setae ventrally, distal 4/5 nearly parallel dorso-ventrally; dorsal margin straight; ventral margin with lobed process obliquely outward. Sacculus elongate oval, about 3/4 length of costa, acute distally. Transtilla broad at base, narrowed triangularly, curved ventrad distally, acute apically. Vinculum V-shaped, rounded on posterior margin; saccus broad digitiform, as long as vinculum, slightly narrowed at base, rounded at apex. Phallus thick and straight, slightly longer than valva, gently thinned from base to apex; cornuti consisting of four to six spines, usually one or two large, compactly grouped into a bundle.
Diagnosis. This species is similar to E. domina sp. n. in appearance, but can be separated from the latter by the female proboscis without tip-dilated sensory setae (Fig. 10); in the male genitalia by the apex-rounded costa with a lobed process on ventral margin medially, the sacculus with apex elongate-acute, the phallus with four to six cornuti compactly grouped into a bundle; in the female genitalia by the apically acute ovipositor, the small rounded lamella postvaginalis, the antrum as long as the lamella postvaginalis, the ductus bursae about same length of apophysis anterioris. In E. domina sp. n., the female proboscis possesses a large number of tip-dilated sensory setae as most species in the genus (Fig. 9), which can hold numerous pollen grains for pollination; in the male genitalia the costa has an obliquely rounded apex and a rounded protuberance at 3/4 on ventral margin, the sacculus is shortly acute at apex, the cornutus is a rolled plate; in the female genitalia the ovipositor is bilobed at apex, the lamella postvaginalis consists of two triangles with acute apex; the antrum is as long as the ductus bursae, and the ductus bursae is about half length of the apophysis anterioris.
Remarks. Epicephala impolliniferens sp. n. is the first species of non-pollinating Epicephala associated with Glochidion, and the second named species within the genus (following E. relictella Kuznetzov, 1979) in which the female proboscis lacks the tip-dilated sensory setae on its surface for carrying pollens. Species of the genus Epicephala are noteworthy for their obligate pollination habits, which involve mutualistic relationship with trees of Phyllanthaceae. However, both E. impolliniferens sp. n. and E. relictella Kuznetzov are not associated with pollination in biology referring to the morphology of the female proboscis. Epicephala relictella feeds on the seeds of Flueggea suffruticosa (Pall.) Baill. (Hu et al. 2011b). Kawakita and Kato (2009)  Etymology. The specific name is derived from the Latin im-(= not), pollinicus (= pollen) and ferre (= to carry, to bear), in reference to the non-pollinating habit. Description. Adult (Fig. 7). Forewing expanse 7.0−10.0 mm. Head white, mixed with brown scales. Labial palpus white, second and third palpomeres dark brown on outer surface, second palpomere scattered with grayish brown scales on inner surface. Antenna grayish brown to dark brown. Thorax white. Tegula brown, with a few grayish white or brown mottled white scales distally. Forewing grayish brown to brown, sometimes tinged with ochreous scales; three pairs white striae from both costal and dorsal margins at 1/3, 3/5 and 4/5 extending obliquely outward to middle and end of cell as well as to outside of cell, second dorsal stria longest and extending to 6/7; dorsal margin with a broad white band from base to tornus; a silvery-white fascia with metallic reflection from costal 6/7 to dorsal margin, nearly straight; distal 1/7 ochreous, with a central black dot, with a white dot at costa and a broad white streak along dorsal margin; cilia white from distal part of costal margin along termen to tornus except black at base and apex, grayish white to gray along dorsal margin. Hindwing gray; cilia grayish white to gray.
Diagnosis. This new species is similar to E. frenata Meyrick, 1908, but differs from the latter in the shape of sacculus and phallus in male genitalia as well as in the shape of sterigmatic sclerotizations in female genitalia. In the male genitalia of the new species, the apex of the sacculus is truncate obliquely and the phallus is gently curved at distal 1/3; in the female genitalia, the caudal margin of the lamella postvaginalis is deeply concave medially and the lamella antevaginalis is a pair of sclerotized and curved carinae. In the male genitalia of E. frenata (Syntype♂, BMNH, examined, genitalia slide No. 32303, dissected by Houhun Li;syntype♀, BMNH, examined, genitalia slide No. 32304, dissected by Houhun Li), the apex of the sacculus is broadly rounded and the phallus is straight; in the female genitalia, the caudal margin of the lamella postvaginalis is slightly concave and the lamella antevaginalis is absent. Distribution. China (Hainan). Biology. Glochidion wrightii is the primary host-plant and G. sphaerogynum (Phyllanthaceae) is secondary. Larvae feed on seeds in the fruit.
Etymology. The specific name is derived from the Latin camur (curved) and postfix -ella, in reference to the lamella antevaginalis being a pair of sclerotized and curved carinae in the female genitalia.
Epicephala angustisaccula Li, sp. n. http://zoobank.org/C083610A-8261-4A76- 8E1F-D1F7012B2620 Figs 8, 14, 18 Description. Adult (Fig. 8). Forewing expanse 7.0−8.5 mm. Head grayish white to white, laterally mixed with brown scales. Labial palpus grayish white, grayish brown on outer surface of second palpomere, basal 2/3 of third palpomere brown. Antenna grayish brown. Thorax dirty white to snowy white; tegula grayish white to brown. Forewing grayish brown to deep brown; costal margin with three parallel white striae obliquely extending outward from basal 1/3, 1/2 and 3/4 respectively, first and third striae broad and short, reaching 1/3 of wing width, second stria narrow and long, reaching midwing; a broad creamy white band extending from base to tornus along dorsal margin, its upper margin extended to a broad, ill-defined white stria at 2/5, reaching below fold dorsally, second white stria from 2/3 obliquely outward to meet second costal stria at midwing, third stria from beyond second one and parallel with it to midwing, sometimes meeting third costal stria; a silvery fascia with metallic reflection from costal 5/6 to dorsal margin, slightly arched outward medially; distal 1/6 yellowish brown, with a central black dot, with a small white dot at costa and a white   (15a, 16a). streak along dorsal margin; cilia white from distal part of costal margin along termen to tornus except black at base and apex, gray along dorsal margin. Hindwing gray to deep gray, sometimes basal 1/3 densely covered with rough black scales; cilia gray.
Female genitalia (Fig. 18). Ovipositor small and short, triangular, dentate laterally, acute apically. Apophysis posterioris 1.6 times longer than apophysis anterioris. Lamella postvaginalis well developed, heavily sclerotized, composed of two narrow, widely spaced rectangular plates derived from caudal margin of ostium bursae, about half length of 8th abdominal segment, caudal margin serrated. Ostium bursae sclerotized, broad. Antrum heavily sclerotized, broad, as long as 8th abdominal segment, with large rounded appendix protruding near ductus bursae on right side. Ductus bursae slightly longer than antrum, sclerotized, expanded, broader than corpus bursae; ductus seminalis arising from base of ductus bursae. Corpus bursae elongate oval, as long as ductus bursae; signum triangular, small, placed at posterior 1/3. Diagnosis. This species is similar to E. domina sp. n. in appearance and genitalia, but can be separated from the latter in the male genitalia by the subtriangular sacculus and the dilated basally phallus; in the female genitalia by the apically acute ovipositor and the lamella postvaginalis being shorter than 8th abdominal segment. In E. domina sp. n., in the male genitalia the sacculus is broad-oval and the phallus is not dilated basally; in the female genitalia the ovipositor is bilobed apically and the lamella postvaginalis is as long as 8th abdominal segment. Etymology. The specific name is derived from the Latin angustus (narrow) and sacculus, in reference to the distally narrowed sacculus in the male genitalia.  (17a, 18a).