Irepacma denticulata Wang, sp. nov.

(Figs 3, 11, 18)

Type material. Holotype ♁, Yunnan: Yexianggu (22.17°N, 100.87°E), 762 m, 11.VII.2015, leg. KJ Teng & X Bai, slide No. XZX20537.

Paratypes: Yunnan: 6♀, same data as holotype except dated 8, 11–12.VII.2015, slide Nos. TZL21047, TZL21048; 28 ♁ 5♀,Yexianggu, Xishuangbanna, 762 m, 17–20.VII.2014, leg. KJ Teng et al., slide Nos.LiSR17015♁, TZL20631♁, XZX20538 ♀.

Diagnosis. The new species can be distinguished from its congeners in the male genitalia by the costa of the valva bearing a conspicuous horn-shaped process at basal 1/3, the sacculus bifurcated from its half, and the distally dilated aedeagus with a denticle near apex.

Description. Adult (Fig. 3). Wingspan 9.5 – 14.5 mm.

Head pale yellow. Labial palpus pale yellow. Antenna yellow, with yellowish brown rings.

Thorax. Mesonotum and tegula pale yellow. Forewing pale yellow; discal, discocellular and plical stigmata small, brown; fringe pale yellow. Hindwing and fringe pale yellow. Foreleg yellow, except on dorsal surface femur with scattered blackish brown scales, tibia and tarsus blackish brown; mid- and hindlegs pale yellow.

Male genitalia (Fig.11).Uncus wide at base,narrower medially,slightly dilated distally,sclerotized mediolaterally, apex rounded. Gnathos with basal arm narrowed to ventral plate; ventral plate transversely subovate, with dense fine spines along apical margin. Valva subrectangular, triangularly produced at basal 3/5 of costal margin, apex rounded; ventral margin almost straight, with fine setae distally; costa reaching 1/3 length of costal margin, with triangular process near base and horn-shaped process at its end. Sacculus with basal half broad, bifurcate from its half, forming two distal processes: dorsal process slender, sclerotized, dilated distally, with denticles on apical margin; ventral process narrowed from base to pointed apex, with a line of spines along ventral margin distally. Saccus shorter than uncus, slightly narrowed to rounded apex. Juxta short, trapezoidal. Aedeagus longer than valva, rod-shaped in basal 1/3, abruptly widened at basal 1/3, thereafter narrowed to basal 3/5, slender from 3/5 to 5/6, dilated distally, with a denticle near apex.

Female genitalia (Fig. 18). Papilla analis bell-shaped. Eighth sternal plate setose, obtusely rounded on posterior margin, with two eyebrow-like processes near posterior margin medially, with triangular sclerite posterolaterally; anterior margin shallowly concave, medially with bifurcate process from distal 3/5. Antrum expanded posteriorly, concave at middle on posterior margin, produced posterolaterally and forming small narrowing process. Ductus bursae sclerotized except membranous anteriorly. Corpus bursae ovate; signum subround, with denticles.

Distribution. China (Yunnan).

Etymology. The specific epithet is derived from the Latin denticulatus, referring to the denticle near the apex of the aedeagus.