Wingspan 29-31 mm in male (n = 6), 28-29 mm in female (n = 8).
Head - Proboscis fully developed; 2nd labial palpal segment fringed with long scales extending anteriorly, 3rd segment porrect; frons round frontally; eye large; male antennae contorted at approximately 1/3 at base.
Thorax – Clothed with black and orcheous long scales on three segments, paired crests on mesothorax black. Male legs with mid-and hind-femurs fringed with long black scales on innerside; mid-tibia and 1st tarsi covered with long scales on innerside; mid 2nd tarsi and two spurs of hind tibia fringed with erected long scales. Forewing ground colour black; short scales arising from Cu1 humeral plate; termen produced and acute at vein M3; tornus with short scale-tuft at approximately 2/3 part at base; antemedial line, orbicular stigma indistinguishable; reniform stigma with white margin and an internal oblique stripe; medial spot white, ovate, laying on distal margin of reniform stigma; postmedial line indistinguishable, but with glommy grey scaling at distal margin; submarginal stripes and marginal line ubdistinguishable. Hindwing orcheous.
Pregenital abdomen – Ground coloration orcheous with light-coloured intersegmental stripes; crests brown and black, present at 1st to 4th segments; male with specialized scale tufts arising latero-ventrally from 2nd sternite; male 7th sternite scelotized at approximately 1/4 part at end with posterior-lateral extension, 8th sternite and its paired lateral rods fringed with long scales; posterior margin of 8th sternite ladder-shaped and incised antero-medially, pair lateral rods expanded and incised forewards; female 7th sternite membranous without modification.
Male genitalia - Uncus down-curved with apex expanded and densely setose, base of uncus slightly projected bilaterally and fused with apex of tegumen; scaphium consisting of two slender sclerites laying almost parallely; subscaphium having two bend-like sclerites attaching firmly with tuba analis; tegumen ridged at anterior margin, membranous part broadened medially with long filiform scale tufts arising postero-ventrally; tegumeno-ventral sclerites fused with tegumen; transtillae fused with lower end of tegument; apex of anellus bifurcate downwards as foreceps; manica enclosing phallobase with and covered with minute spinulose scobination on both lateral sides; juxta fused with sacculus laterally and connected with transtillae ventral-laterally; vinculum short and protruded apical-laterally; saccus dorm-shaped ventrally with a slender bifid apex at posterior-ventral extension; valvae with sacculus broader and more sclerotized than membranous costal region, but without clasper and harpe complex; subzone I of sacculus hooked, subzone II truncate, subzone III with proximal part ridge-wrinkled postero-dorsally and with squamiform scales upon it, distal part papillate pointing latero-ventrally and with gathered long scale tufts at apex and short hair tufts antero-ventrally. Aedeagus heavily sclerotized, phallobase protruded anteriorly and palmate with 2 lateral and 4 pairs of symmetrical stout spines arising posteriorly, vesica two lateral parts, left part membranous, right part heavily wrinkled with single laterally.
Female genitalia - Papillae anales slightly sclerotized at anterior margin and truncate from lateral view; 8th sternite absent; apophysis posterioris extending anteriorly to anterior margin of 8th tergite; apophysis anterioris slender, extending anteriorly to medial part of 7th tergite; ductus bursae short, narrow and membranous near antrum, braodened at posterior part; corpus bursae membranous and 1.5 times longer than 7th sternite, signum absent, additional internal sclerite pyriform attaching on corpus bursae postero-ventrally, appendix bursae membranous but multi-rolled; wrinkled ductus seminalis arising from apex of corpus bursae.
Bryophila nigrescens Wileman, 1915: 161 (Type locality: Taiwan, [Chia-yi], Rantaizan, female. Type in NHM)
TAIWAN. Hsinchu County: 3♀♀, Kuanwu (= Guanwu), 14-V-1991, Y. B. Fan leg. (TFRI); Nantou County: 1♂2♀, Heliouping, 22-VIII-1991. Y. B. Fan leg. (TFRI); 2♂1♀, Meifeng, 1-8-VI-1980, D. R. Davis leg. (NMNH); holotype, 1♀, Rantaizan, 15-II-1909, A. E. Wileman leg. (NHM); 1♀, Tayuling, 1 to 9-VI-1980, D. R. Davis leg. (NMNH); Kaohsiung County: 1♀, Shanping, 25-II-1988, Y. B. Fan leg. (TFRI); 1♂, Duo-na, 16. IX. 2005, S. Wu leg. (NHM); 1♀, same locality, 10-XII-2005, S. Wu leg.; 1♂, same locality, 12-X-2006, S. Wu leg. (NTUIM)
Endemic in Taiwan.
Distribution in Taiwan
Medium elevation primary broad-leaved forests of the main island.