Taxonomy of the facialis species-group of the genus Meleonoma Meyrick, 1914 (Lepidoptera: Autostichidae) from China, with descriptions of nineteen new species Author Zhu, Xiaoju College of Life Sciences, Nankai University, Tianjin 300071, China. & College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong 271018, China. Author Wang, Shuxia College of Life Sciences, Nankai University, Tianjin 300071, China. text Zootaxa 2025 2025-05-20 5637 1 99 125 https://doi.org/10.11646/zootaxa.5637.1.4 journal article 310131 10.11646/zootaxa.5637.1.4 ea2c27d6-f3d4-446a-8d72-a2d50cc4e498 1175-5326 15562113 9DDDC67B-5DAB-4045-996D-F2B3C4308896 Meleonoma microda sp. nov. ( Figs 13 , 35 ) Type material. CHINA , Xizang : Holotype ♂ , Beibeng Town ( 29.24°N , 95.17°E ), Motuo County , 987 m , 12.VIII.2017 , leg. MJ Qi & XF Yang , slide No. ZXJ19373 . Paratypes , Xizang : 2♂ , same data as holotype; 4♂ , same data as holotype, except 13–15.VIII.2017 . Diagnosis. The new species is similar to M. ventrospinosa Wang & Zhu, 2020 in features of the male genitalia. It can be distinguished by the costal part of the valva widened from base to middle and without an apical spine on the ventral margin, and the sacculus lacking an apical process. In M. ventrospinosa , the costal part of the valva is uniformly wide from base to 3/5 its length and has a spine at the apex on the ventral margin, and the apex of the sacculus has a process (Wang & Zhu 2020: 342 , fig. 27). Description. Adult ( Fig. 13 ). Forewing length 4.5–5.0 mm. Head with pale yellow scales. Labial palpus pale yellow; second segment black at apex; third segment slightly shorter than second segment.Antenna pale yellow; flagellum alternated with brown on dorsal surface except several basal tarsomeres pale yellow. Thorax pale yellow; tegula pale yellow, mixed with black scales basally. Legs pale yellow, with exceptions on ventral surface: coxa of foreleg with sparse black scales, tibia black, tibiae of mid- and hindlegs black distally, tarsus of foreleg black at middle of basal tarsomere and at apical three tarsomeres, tarsus of midleg with basal four tarsomeres black except yellow at apices, tarsus of hindleg with sparse black scales on basal tarsomere, all femora with scattered black scales. Forewing with costal margin arched, apex narrowly rounded; ground colour pale yellow, with scattered black scales; costal margin black along basal 1/3, forming a stripe, unequal in width; costal spot large, inverted triangular; apical patch black, semicircular, running from distal part of costal margin along termen to before tornus; tornal spot black; plical spot black, indistinct, at middle of fold; fringe dark brown, interrupted by yellowish brown. Hindwing and fringe dark grey. Abdomen. Male genitalia ( Fig. 35 ). Uncus clubbed, wide at base, slightly narrowed to 2/5 its length, distal 3/5 uniformly narrow except slightly dilated apex. Tegumen arched in broad U shape, sclerotized on outer margin. Costal part of valva narrow at base, slightly widened to middle, thereafter turned upward and narrowed to rounded apex, setose; ventral margin heavily sclerotized, with a row of tiny spines ranging from near base to before middle, obtusely angled at middle; costa broadly and shallowly concave medially, costal band with sparse short setae; transtilla heavily sclerotized, curved upward distally. Sacculus sub-triangular, wide at base, gradually narrowed to rounded apex, with a carina extending from middle of ventral margin to before preapex of dorsal margin. Saccus approximately 1.5 times length of uncus, wide at base, gradually narrowed to rounded apex. Juxta slender. Phallus longer than twice length of costal part of valva, tubular in basal 2/5, narrowed from middle to apex, forming a dorsal bar; irregular belt from below dorsal bar curved upward distally, reaching beyond apex of phallus, with spine basolaterally. Female unknown. Distribution. China ( Xizang ). Etymology. The specific epithet is derived from the Greek mikros (small) and the Latin dens (tooth), referring to the row of tiny spines on the ventral margin of the costal part of the valva.