Epicephala nudilingua, Kawakita, Atsushi & Kato, Makoto, 2016

Kawakita, Atsushi & Kato, Makoto, 2016, Revision of the Japanese species of Epicephala Meyrick with descriptions of seven new species (Lepidoptera, Gracillariidae), ZooKeys 568, pp. 87-118 : 105-107

Taxon classification Animalia Lepidoptera Gracillariidae

Epicephala nudilingua sp. n. Figs 1, 2, 3, 4, 5, 6, 7

Epicephala sp. ex Phyllanthus ussuriensis ( Kawakita and Kato 2009; Kawakita et al. 2015).

Diagnosis.

Aside from Epicephala parasitica , this species is smaller than any other known species of Epicephala . Exaggerated cornutus, spiracle on seventh tergite, bilobed lamella postvaginalis and heavily sclerotized and curved antrum, clearly distinguish this species from other known Epicephala .

Description.

Wingspan: 7.0-8.3 mm.

Head: With numerous gray scales on dorsal surface. Labial palpus dark brown. Antenna dark brown, about 1.2 × as long as forewing. Trichoid sensilla on female proboscis absent.

Thorax: Grayish white dorsally. Forewing dark brown with narrow white band on dorsum from base to 1/3 of entire length; three pairs of narrow white bands beginning at costal and dorsal margin near 1/2 to 3/4 length of wing and extending obliquely toward wing apex, terminating before reaching mid-width of wing; a narrow silver band with metallic reflection extending from costa to dorsum at 5/6 length; distal 1/6 brown with black dot centrally, franked by narrow white band near dorsum; distal end fringed with narrow white band and terminating with narrow dark brown band; cilia grayish dark brown. Hindwing dark brown, 0.8 × length of forewing; cilia grayish dark brown.

Male genitalia: Tegumen rounded triangular. Cucullus rectangular oblong, dilated at apex, covered with numerous hairs on inner surface; ventral base with small out ward projection; surface of projection with numerous thin spines. Sacculus elongate triangular, acute at apex, 1.6 × width of cucullus at base, 0.9 × length of cucullus; distal portion of ventral margin slightly concave. Vinculum V-shaped; saccus thin and tapering, as long as vinculum. Aedeagus straight; cornutus large, emerging from 2/3 length of aedeagus and extending beyond apex of aedeagus for 0.3 × length of aedeagus, 0.5 × as thick as aedeagus, with thick spines sparsely on surface.

Female genitalia: Seventh tergite with a pair of spiracle anteriorly. Lamella postvaginalis deeply bilobed, 2 × as broad as ostium bursae, as long as seventh sternite; each lobe finger-shaped, extending straight toward caudal end. Antrum heavily sclerotized, smooth on surface, abruptly curved ventrally and posteriorly to continue to ductus bursae. Ductus bursae curving abruptly anteriorly, gradually tapering to continue to corpus bursae; basal 1/3 with numerous sclerotized teeth on surface. Corpus bursae elongate oval, as long as combined antrum and ductus bursae; signum absent. Apo physes posteriores 1.7 × length of apophyses anteriores. Ovipositor dentate laterally, weakly angular at apex.

Material examined.

19♂, 7♀. Holotype ♀ - JAPAN: Tochigi Prefecture: Fujioka, Watarase-yusuichi (36.226554, 139.671697), 20 m, collected as larva in fruit of Phyllanthus ussuriensis and reared to adult, 22.ix.2012 (KYO). Paratypes - same data as holotype, 13♂, 4♀ (KYO). Other specimens - JAPAN: Tokyo Prefecture: Machida, Minamiotani, 29.x.2004, 6♂, 1♀; Oita Prefecture: Bungo-Takada, Shinei, 8.ix.2015, 1♀ (T. Hirano).

DNA barcodes.

FJ235387.

Known host and adult behavior.

Known only from Phyllanthus ussuriensis . Oviposition behavior has not been observed in the wild. Floral dissection suggests that the egg is laid in young fruit through the ovary wall between the wall and ovule. Larva feeds on seeds.

Distribution.

Known only from three populations in Tochigi, Tokyo and Oita Prefecture, Japan (Fig. 9F). The host plant Phyllanthus ussuriensis is widespread in the temperate regions of Japan and other parts of East Asia, so the species is likely to be found elsewhere. The plant was common at damp habitats in flood plains before 1980s but is now uncommon and locally threatened in Japan.

Etymology.

The name nudilingua (a noun in apposition) derives from the Latin nudus (= naked) and lingua (= tongue) in reference the hairless proboscis of the female, which is a derived condition in Epicephala .