Ypsolopha mucronulata sp. nov.

(Figs 22, 73, 122, 169)

Type material. Holotype: ♂, China, Yebadan, Tacheng (46°46′ N, 82°59′ E), Xinjiang Uygur Autonomous Region, 17.vii.1997, genitalia slide No. FXM07023. Paratypes: 1 ♂, same data as for holotype (abdomen missing); 1 ♀, Tacheng (46°46′ N, 82°59′ E), Xinjiang Uygur Autonomous Region, 5.vii.1990, coll. Jinfu Li.

Diagnosis. This species is characterized by the socius with distal 1/6 narrowed sharply to a thorn in the male genitalia (Fig. 122). It is similar to Y. bicostata sp. nov. both externally and internally, but can be distinguished by the forewing having several rows of dark brown scales (Fig. 22), the male saccus slightly shorter than the socius (Fig. 122), and the female signum 3/5 length of the corpus bursae (Fig. 157). In Y. bicostata sp. nov., the forewing lacks rowed dark brown scales (Fig. 23), the male saccus is just 3/5 length of the socius (Fig. 123), and the female signum is 1/2 length of the corpus bursae (Fig. 166).

Description. Adult (Fig. 22): Wing expanse 18.0−20.0 mm. Head white, dark brown around eyes. Antenna grayish brown, ringed with white on each flagellomere. Labial palpus grayish brown except basal segment white; third segment longer than second. Thorax white. Tegula dark brown. Forewing with R4 and R5 almost connate (Fig. 73); grayish brown, tinged with grayish white on distal 1/3, with several longitudinal rows of dark brown scales; costa dark brown on basal 3/4; cell with curved black strip on distal half, with a small black dot at lower angle; yellowish white line extending from end of cell to apex; dorsal band dark brown, with curved yellowish white line along its upper edge, with discontinuous dark brown line above yellowish white line extending to end of fold; apex with a small dark brown speckle; termen dark brown; cilia concolorous with wing except grayish white at apex. Hindwing and cilia grayish brown. Fore- and midlegs grayish brown; hindleg silvery gray.

Male genitalia (Fig. 122): Uncus degenerate. Socius broadened and incurved from base to 5/6, distal 1/6 narrowed sharply to a thorn. Ventral plate of gnathos almost rounded. Valva nearly semicircular. Saccus shorter than socius, parallel-sided to rounded apex. Anellus a quarter length of phallus, densely spinous on distal half. Phallus stout, curved slightly at middle, about 1.5 times length of valva; coecum 1/5 length of phallus; cornuti about 1/2 length of phallus, composed of two broad rows of microspines, each row with several large spines at end.

Female genitalia (Fig. 169): Intersegmental membrane between papilla analis and 8th abdominal segment 1/2 length of abdomen. Apophyses posteriores about 1.6 times length of apophyses anteriores. Lamella postvaginalis V-shaped. Antrum slender, cup-shaped. Ductus bursae longer than corpus bursae, broadened gradually from inception of ductus seminalis to corpus bursae. Corpus bursae sacklike; signum about 3/5 length of corpus bursae, ridged at anterior 1/4 and posterior 1/6 respectively.

Distribution. China (Xinjiang).

Etymology. The specific epithet is derived from the Latin mucronulatus, meaning with sharp end, referring to the male socius with distal 1/6 narrowed sharply to a thorn.