Eretmocera impactella (Walker, 1864)

(Figs 5, 23–25)

Gelechia impactella Walker, 1864: 637. Type locality: India. TD: BMNH.

Eretmocera impactella (Walker): Moore, 1887: 514; Walsingham, 1889: 34; Fletcher, 1920: 122; Moriuti & Yasuda, 1983: 431; Bengtsson, 2002: 106; Passerin d’Entrèves & Roggero, 2007: 9; Zhang & Li, 2011: 415; Lou et al., 2018: 356.

Material examined. 1 ♂, 1 ♀, Gaoligong Mountain Forest Park (24.83°N, 98.77°E), Baoshan City, Yunnan, China, 2157 m, 24.vii.2015, leg. Kaijian Teng and Xia Bai, slide Nos. LK 17075 ♂, LK17204 ♀.

Diagnosis. Eretmocera impactella (Walker, 1864) is similar to Eretmocera octopunctata Li, sp. nov., under which the diagnostic differences are provided above.

Redescription. Adult (Fig. 5) wingspan 13.5 mm. Head blackish brown, with metallic hue, smoothly scaled; neck with cream white scales, like a necklace. Labial palpus with basal segment shining white; second and third segments blackish brown on except white on dorsal surface of second segment; third segment almost as long as second segment, acute at apex. Antenna black, with metallic bluish sheen, 3/5 length of forewing; flagellum with basal half thickened by moderately raised scales on posterior margin. Haustellum with whitish yellow scales basally. Collar, thorax, tegula and forewing dark copper brown to blackish brown, with metallic hue; metathorax with a pair of ochreous yellow spots laterally. Forewing narrowly elongate, lanceolate, basal 2/3 uniformly wide, distal 1/3 narrowed to acute apex; with indistinct four light grey to greyish yellow spots: one spot at distal 1/5 of costal margin, one at about middle of cell, largest, crossing fold posteriorly, one at basal 1/3 of dorsum and at end of fold respectively; cilia blackish brown. Hindwing and cilia dark brown, cilia yellow basally. Legs blackish brown except femora as well as fore- and mid tibiae creamy white on dorsal surface.

Male genitalia (Fig. 23): Uncus strongly sclerotized, approximately three times as long as tegumen, separated, slightly narrowed to rounded apex, with dense setae laterally. Gnathos arm broad-banded, H-shaped; distal process with basal 3/4 almost uniformly wide, distal 1/4 abruptly narrowed to pointed apex, curved ventrad. Tegumen short, deeply concave in broad V-shape on anterior margin. Valva straight, slender, clavate, distal 1/5 densely setose and slightly widened, rounded apically, slightly longer than uncus. Vinculum very narrow, Y-shaped, anteriorly extending to before apex of saccus by two straight gradually narrowing folds. Saccus elongate fusiform, 1.2 times length of valva, pointed apically. Phallus less than half-length of valva, slender, narrowed from middle to pointed apex.

Segment VIII (Fig. 24). Tergum tongue-shaped; anterior margin broadly concave, forming two slender lateral lobes with a pointed tip; posterior margin truncate. Sternum with anterior and posterior margins deeply notched to 1/4, both ends bilobed, arched at anterior 2/5 laterally; anterior lobes stout, each lobe protruded outwardly near base, obtuse at apex; posterior lobes slender, slightly narrowed to pointed apex.

Female genitalia (Fig. 25). Papillae anales sub-rectangular. Apophyses posteriores slightly longer than apophyses anteriores. Eighth sternum widely concave on posterior margin, forming two triangular posterolateral processes; eighth tergum concave semicircularly on posterior margin, roundedly produced posterolaterally. Ostium bursae small, longitudinally narrow. Antrum and ductus bursae same length about half of apophyses anteriores, membranous. Corpus bursae large, elliptical, 1.8 times length of apophyses anteriores.

Host plants. Amaranthaceae: Achyranthes aspera L., Alternanthera sessilis (L.), Amaranthus sp., A. viridis L., A. spinosus L.; Chenopodiaceae: Beta vulgaris L., Chenopodium album L.; Compositae: Vernonia cinerea (L.); Papilionaceae: Arachis hypogaea L.; Oxalidaceae: Averrhoa carambola L.; Poaceae: Pennisetum sp., Zea sp., Z. mays L.; Sapindaceae: Nephelium lappaceum L.; Dipterocarpaceae: Shorea robusta Gaertn (Passerin d’Entrèves & Roggero 2007). The heterogeneity of putative host plants reported in the literature may reflect collecting sites of adults more than actual larval hosts.

Distribution. China (Hong Kong, Taiwan, Yunnan), India, Myanmar, Oman, Pakistan, Singapore, Sri Lanka, Thailand, United Arab Emirates.