Ypsolopha varidentella Wang et Li, sp. nov.

(Figs 43, 92, 143, 188)

Type material. Holotype: ♂, China, Mt. Xinglong (35°50′ N, 104°07′ E), 2130 m, 31.vii −4.viii.1993, coll. Houhun Li. Paratypes: 9 ♂♂, 3 ♀♀, same data as for holotype except 2120−2230 m, 31.vii −4.viii.1993, 9 ♂♂, 2 ♀♀, 2178 m, 19−20.viii.2007, coll. Feng Yang & Hanguang Gao, Yuzhong County, Gansu Province; 1 ♂, Dangchuan (34°32′ N, 105°53′ E), Tianshui, Gansu, 1331 m, 29.vii.2006, coll. Xinpu Wang & Xiangfeng Chi; 4 ♂♂, Jingyuan County (35°29′ N, 106°19′ E), Ningxia Hui Autonomous Region, 30.vii.1983; 1 ♂, Qiuqianjia (35°33′ N, 106°25′ E), Mt. Liupan, Jinyuan County, Ningxia, 1700 m, 2.vii.2008, coll. Shulian Hao & Zhiwei Zhang.

Diagnosis. This new species is characterized by the forewing having a slender white line that runs along below the fold and obliquely crosses the fold at 2/3, and then reaches end of the cell at middle. It is similar to Y. dentella (Fabricius), but can be separated by the vertex, the thorax and the dorsal band gray or grayish brown, the broad triangular uncus and the phallus slightly longer than the valva in the male genitalia, and the V-shaped lamella postvaginalis in the female genitalia. In Y. dentella (Fabricius), the head, the thorax and the dorsal band are yellowish white (Fig. 41), the uncus is arched and the phallus is about 1.4 times length of the valva in the male genitalia (Fig. 141), and the lamella postvaginalis is composed of two sclerotized parallel bands in the female genitalia (Fig. 186).

Description. Adult (Fig. 43): Wing expanse 19.0−20.0 mm. Head with vertex pale grayish brown, blackish brown around eyes, frons white. Antenna white, mixed with pale greyish brown scales on scape, ringed with brown on each flagellomere. Labial palpus white, second segment brown on outer surface, tuft triangular, 1.5 times as long as labial palpus, third segment about 1/2 length of second, with distal half gray on ventral surface. Thorax gray, paler laterally; tegula brown. Forewing with CuA1 and CuA2 very short stalked (Fig. 92); apex relatively widen, slightly hooked; brown except dark gray on apex; dark brown stripe extending from base to basal 2/3 of fold, its ventral margin edged with a fine white line obliquely upward across end of stripe, then reaching end of cell at middle; grayish brown band between white line and dorsum running from base to tornus; cilia yellowish brown except dark brown on apex and grayish brown below apex. Hindwing pale gray, brown on apical area; cilia with basal 1/3 brown, distal 2/3 yellowish brown. Abdomen grayish brown dorsally, yellowish white ventrally. Fore- and midlegs gray, paler on femara and inner side; hindleg grayish white, white ventrally, tarsus pale.

Male genitalia (Fig. 143): Uncus broad triangular. Socius slender, pointed at apex. Ventral plate of gnathos rectangular, almost truncate apically, dense spinous. Valva ovate, slightly arched dors-ventrally, rounded apically; ventral margin shallowly concave near base, with sparse setae on basal 1/3. Saccus about 2/3 length of socius, basal 1/3 shrunk, slightly pointed at apex. Anellus about a quarter length of phallus, sparsely spinous on distal half. Phallus slightly longer than valve, curved medially; coecum 1/5 length of phallus; cornuti about 2/5 length of phallus, composed of two rows of microspinses, distal spines larger and denser, somewhat forming a hair brush.

Female genitalia (Fig. 188): Intersegmental membrane between papilla analis and 8th abdominal segment 2/5 length of abdomen. Apophyses posteriores about twice length of apophyses anteriores. Lamella postvaginalis Vshaped. Antrum parallel-sided. Ductus bursae about 1.3 times length of corpus bursae, paralle sided laterally. Corpus bursae broad oval; signum about 2/5 length of corpus bursae, dentate along margins, ridged at anterior 1/3, narrowed posteriorly to base of corpus bursae.

Distribution. China (Gansu, Ningxia).

Etymology. The specific epithet is derived from the Latin prefix vari-, meaning variable, and a specific name dentella, referring to the similarity of the two species.