Ypsolopha yasudai Moriuti, 1964

(Figs 45, 94, 145, 189)

Ypsolophus yasudai Moriuti, 1964: 204 .

Ypsolopha yasudai Moriuti: Moriuti, 1977: 98; Zinchenko & Ponomarenko, 2008: 53; Sohn et al., 2010: 33. Type locality: Japan (Honshu).

Adult (Fig. 45): Wing expanse 18.0−19.0 mm. Forewing with CuA1 and CuA2 separated (Fig. 94).

Material examined. 1 ♀, Laoshan, Maoershan (45°16′ N, 127°30′ E), Heilongjiang Province, 15.vii.2009, coll. Weichun Li & Jiayu Liu; 1 ♀, Maoershan (45°16′ N, 127°30′ E), Heilongjiang Province, 18−19.vii.2009, coll. Weichun Li & Jiayu Liu; 1 ♂, 2 ♀♀, Erdao (43°21′ N, 125°39′ E), Jilin Province, 1010 m, 4.viii.2004, coll. Aihuan Zhang; 4 ♀♀, Laotudingzi, Huanren County (41°15′ N, 125°21′ E), Liaoning Province, 7−9.viii.2009, coll.

Weichun Li & Jiayu Liu; 7 ♂♂, 1 ♀, Buerjin County (47°41′ N, 86°59′ E), Xinjiang Uygur Autonomous Region, 1114−1407m, 24−25.vii.2007, coll. Xinpu Wang et al.; 1 ♂, 2 ♀♀, Habahe County (48°02′ N, 86°26′ E), Xinjiang Uygur Autonomous Region, 1264 m, 27.vii.2007, coll. Xinpu Wang et al.

Distribution. China (Heilongjiang, Jilin, Liaoning, Xinjiang), Japan, Korea, Russia.

Diagnosis. This species is similar to Y. varidentella sp. nov. and Y. falcella (Denis et Schiffermüller) externally, but differs from Y. varidentella sp. nov. in the forewing having a small black dot below middle of the fold (Fig. 45), which is absent in the latter species; differs from Y. falcella by the absence of the short white line at end of the cell, which is present in the latter species. Ypsolopha yasudai is related to Y. nigrofasciata Yang in the male genitalia, but can be separated by the subulate uncus (Fig. 145), which is triangular in the latter species (Fig. 137). Ypsolopha yasudai is similar to Y. nemorella (Linnaeus) in the female genitalia, but can be separated by the relatively long signum that is about 1/2 length of the corpus bursae (Fig. 189), which is 1/3 length of the corpus bursae in the latter species (Fig. 195).

Remarks. This species is somewhat variable in appearance, viz., the ground colour varying from yellow to pale grayish brown, the area between the fold and the dorsum varying from yellowish white to grayish brown. In spite of these differences, the black dot below middle of the fold, the wing venation, and the genital characters are stable.