Olethreutes subtilana (Falkovitsh, 1959)

(Figs 3, 6)

Argyroploce subtilana Falkovitsh, 1959, Entomologicheskoe Obozrenie, 38: 460. TL: Vaganovo vill., N Salair Ridge, Kemerovo Region, Russia.

Olethreutes subtilana Falkovitsh: Kawabe, 1982, Moths of Japan I: 105, II: 170, pl. 24: 5, 284: 7, 291: 11.

Olethreutes subtilanus Falkovitsh: Razowski, 1999, Shilap. Revista de lepidopterología, 27 (5): 103.

Diagnosis. This species is similar to O. captiosana (Falkovitsh) in appearance, but it can be distinguished by the conspicuously smaller forewing length and four metallic silver markings on the forewing, while O. captiosana has three metallic silver markings in the ocellus of the forewing. In the male genitalia, this species also differs from O. captiosana by a line of stout spines at basal 1/3 part of cucullus, the sacculus almost as wide as cucullus, and the distal margin of the sacculus is covered by hair-like spines.

Redescription. Male (Fig. 3). Head: Frons covered with ivory scales. Vertex mixed with dark brown scales. Antenna filiform, covered with dark brown scales. Ocellus present. Labial palpus weakly upcurved, covered by ivory scales, apical segment shortly exposed and erect, mixed with dark brown scales.

Thorax: Patagium with orange scales; tegula grayish orange mixed with grayish brown scales. Forewing length 12–15 mm in males. Forewing broad, elongate-subtriangular, costa slightly curved outwards; apex pointed; termen convexly rounded; brownish orange; the basal area with three metallic silver longitudinal streaks, costal streak slightly oblique inwards; the second streak is straight, not joined with costa; subbasal fascia with a straight metallic silver cross line; the median reticulated area with four eye-like metallic silver markings in the center of the dark ovoid plate, consisting of irregular dots and lines; preterminal fascia with two metallic silver bands extending slightly inward, upper band shorter than the lower one and one short metallic silver band near tornus; cilia ivory and dark brown. Hindwing elongate-ovate, apex rather acute; dark brown, darker apical area; cilia ivory and dark brown.

Male genitalia (Fig. 6). Uncus broad, hooked, apex bifurcate and setose. Socius moderate and drooped. Gnathos partly sclerotized. Tuba analis membranous. Tegumen narrow, long-trapezoidal. Valva elongate, not folded at middle. Cucullus shallowly emarginated at basal 2/3, with line of stout spines at basal 1/3. Sacculus almost as wide as cucullus; a small patch of fine, hair-like spines is present near the distal margin of the sacculus. Phallus narrow apically, partly membranous, without cornuti.

Female genitalia. not examined.

Material examined. 2 ♂, Mt. Hambaek, Taebaek-shi, 13. VI. 1999 (Bae et al.), Genitalia slide Nos. INU-11287, INU-11290 .

Distribution. Korea (Park, 1983), Japan (Nasu et al., 2013), China (Hua, 2005), Russia (St. Petersburg, Siberia) (Falkovitsh, 1959), Germany (Segerer, 2010).

Hostplants. Fallen leaves in Japan (Nasu et al., 2013).