Sycacantha decursiva Feng & Yu, sp. nov.

(Figs. 4, 9)

Diagnosis. Sycacantha decursiva can be separated from other species of the genus by the valva in the male genitalia, which are characterized by a cucullus that is uniformly broad with a basal ventral prominence projecting inward that is about 1/3 times the length of the cucullus.

Types. Holotype: China: ♂, Sun River nature reserve (22º48’N, 100º58’E), Pu’er, Yunnan Province, alt. 1450 m, 13.V.2014, leg. Zhenguo Zhang, genitalia slide no. FWX18114. Paratype: 1♂, same data except alt. 1626 m, 7.VII.2013, leg. Shurong Liu, Yuqi Wang and Kaijian Teng.

Description. Adult (Fig. 4). Head: Frons and vertex pale brown. Antenna brown. Labial palpus pale brown, ascending; median segment not expanded; terminal segment pointed.

Thorax: Collar pale brown; tegula and thorax pale brown dusted with brown; posterior crest indistinct, pale. Hind tibia in male white, expanded slightly relative to other species of the genus, with two pale gray hair pencils basally, the longer with apex white. Forewing length 7.0–8.0 mm; costa arched, apex obtuse, termen straight; costal strigulae cream, striae indistinct; upperside ground color cream mixed with pale brown; markings indistinct, indicated by scattered dark brown scales; an inverted triangular blotch on basal part faintly visible, upper edge on costa between base and strigula five, distal edge extending to base of dorsum, almost straight; faint short lines between a pair of adjacent veins from R 5 to M 1; preterminal fascia a narrow stripe, extending obliquely to termen, indistinct; terminal fascia a small elongate spot; cilia pale ochreous; underside brown, area of hindwing overlap white. Hindwing upperside dark brown except costal area of forewing white, cilia dark brown; underside brown.

Abdomen: Male genitalia (Fig. 9) with tegumen narrow, without shoulders. Socius with inner part larger than outer part, wide triangular; outer part small, a short process. Gnathos a narrow band, slightly broadened laterally. Valva with basal part spindle-shaped, neck very distinct; sacculus with evenly distributed spines, ventral edge arched; cucullus uniform in breadth, with apical part rounded, basal part projecting inward and not expanded, forming an elongate prominence 1/3 times as long as cucullus, densely spined, rounded apically and with a strong apical thorn. Phallus thick, about 1/3 length of valva; cornuti a cluster of short spines.

Female unknown.

Etymology. The specific name is derived from the Latin decursivus (= decurrent), and refers to the character of cucullus.

Note. The specimens were in poor condition and the wings were worn and torn when they were spread. Fortunately, adults had been roughly described before the wings were spread.