Epicephala parasitica, 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 : 102-105

Taxon classification Animalia Lepidoptera Gracillariidae

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

Epicephala sp. ex Phyllanthus lepidocarpus ( Kawakita and Kato 2009; Kawakita et al. 2015); Epicephala sp. 7 ( Phyllanthus ) ( Kawakita et al. 2010).

Diagnosis.

Sexually dimorphic color pattern and fused seventh sternite and tergite are thus far unknown in any species of Epicephala , making this species highly distinctive within the genus. Overall small size, row of thick spines on ventral margin of cucullus, long spine at cucullus base and numerous short spines on inner cucullus add to the uniqueness of this species in the genus.

Description.

Wingspan: 5.7-7.5 mm.

Head: Females with numerous grayish brown scales on dorsal surface; males with numerous white scales. Labial palpus dark brown to black in females, dark brown in males. Antenna dark brown in females, grayish brown in males, about 1.2 × as long as forewing. Trichoid sensilla on female proboscis rudimentary, shorter than width of proboscis, less than 30 per galea.

Thorax: Brown dorsally in females, white in males. Forewing of females dark brown with narrow white band on dorsum from base to 1/4 of entire length, medially with narrow white band extending from costa to dorsum; a pair of narrow white bands beginning at costal and dorsal margin near 2/3 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; distal end fringed with narrow white band and terminating with narrow black band; cilia dark brown. Hindwing of females dark brown, 0.8 × length of forewing; cilia dark brown. Forewing of males brown with narrow white band on dorsum from base to 2/3 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 orange-brown with black dot centrally, franked by short white band near dorsum; distal end fringed with narrow white band and terminating with narrow brown band; cilia grayish brown. Hindwing of males brown, 0.8 × length of forewing; cilia grayish brown.

Male genitalia: Tegumen rounded triangular. Cucullus rectangular oblong; ventral margin medially concave; basal 1/3 of cucullus fringed with long spines on ventral margin; spines longer than width of cucullus; another distinctly long spine occurring at ventral base of cucullus, 1/2 length of cucullus; distal half of cucullus with numerous short spines on inner surface and few hairs. Sacculus broad, 2 × width of cucullus, 0.7 × length of cucullus, distinctly concave at apex; concave portion of apex fringed with setae; inner wall of sacculus abruptly projecting inward and curved toward dorso-caudal direction, pointed apically; ventral edge of projection fringed with setae. Vinculum U-shaped; saccus thin and rod-shaped, 0.6 × length of vinculum. Aedeagus straight; cornutus absent.

Female genitalia: Seventh sternite completely fused to seventh tergite to form a cylindrical segment. Caudal end of seventh sternite with row of parallel latitudinal ridges. Lamella postvaginalis trapezoid, dilated toward apex, small, 0.3 × width and length of seventh sternite, slightly convex and weakly dentate on caudal margin. Antrum smooth, 0.2 × width and 0.5 × length of seventh sternite. Ductus bursae as long as seventh sternite, with short lateral sac at base; surface of sac and franking portion of ductus bursae with numerous teeth on surface. Corpus bursae elongate oval, as long as combined antrum and ductus bursae; signum absent. Apophyses posteriores 1.7 × length of apophyses anteriores. Ovipositor dentate laterally, angular at apex.

Material examined.

46♂, 40♀. Holotype ♀ - JAPAN: Okinawa Prefecture: Yonaguni Island, Sonai (24.468434, 123.002118), 50 m, collected as larvae in fruit of Phyllanthus lepidocarpus and reared to adult, 16.xii.2012 (KYO). Paratypes - same data as holotype, 2♂, 5♀ (KYO). Other specimens - JAPAN: Kagoshima Prefecture: Amami Island, Setsuko, 17.xi.2002, 2♂, 2♀; Okinawa Prefecture: Miyako Island, Mt. Nobaru, 24.ix.2004, 5♂, 3♀; Ishigaki Island, Omoto, 30.ix.2004, 17♂, 11♀; Iriomote Island, Funaura, 5.x.2003, 13♂, 10♀; Iriomote Island, near the mouth of Urauchi River, 29.ix.2004, 6♂, 5♀; Hateruma Island, 17.xii.2012, 1♂, 3♀.

DNA barcodes.

FJ235386.

Known host and adult behavior.

Known only from Phyllanthus lepidocarpus . Pollination behavior absent. Oviposition in immature fruit, through ovary wall (Fig. 8I). Larva feeds on seeds.

Distribution.

Widely distributed in the Ryukyu Archipelago, Japan (Fig. 9F). The host plant Phyllanthus lepidocarpus is a common weed along roadsides and in cultivated land. Although Phyllanthus lepidocarpus also occurs in mainland Japan, Epicephala parasitica has only been found in the Ryukyu Archipelago.

Etymology.

The name parasitica is the female form of the Latin adjective parasiticus (= parasitic), in reference to the parasitic nature of the species.

Remarks.

This and the following species ( Epicephala nudilingua ) belong to a derived clade of Epicephala specialized to herbaceous species of Phyllanthus (Fig. 10). Pollination behavior has not been observed in any of the species in this clade, so they are pure parasites that derived from a pollinating ancestor ( Kawakita and Kato 2009).