Review of the genus Ressia Sinev, 1988 (Lepidoptera: Cosmopterigidae), with descriptions of four new species from China Author Zhang, Di College of Life Sciences, Nankai University, Tianjin 300071, China Author Li, Houhun College of Life Sciences, Nankai University, Tianjin 300071, China & College of Life and Geographic Sciences, Kashi University, Kashi 844000, China; Xinjiang Key Laboratory of Biological Resources and Ecology of Pamirs Plateau, Kashi 844000, China text Zootaxa 2023 2023-10-30 5360 4 583 592 https://www.mapress.com/zt/article/download/zootaxa.5360.4.7/52135 journal article 10.11646/zootaxa.5360.4.7 1175-5326 10152774 E967718F-F071-49BC-B69D-D4D0E8979530 Ressia disparilis Li , sp. nov. ( Figs 4 , 10 , 16 ) urn:lsid:zoobank.org:act: 65A44BC5-AED7-4E00-9955-3035C7C1CA27 Type material. Holotype ♁. CHINA , Hainan : Tianchi , Jianfengling ( 18.73°N , 108.86°E ), 787 m , 9.III.2016 , leg. QY Wang et al. , slide No. ZD 21076. Paratypes : 5♁ 1♀ , same data as holotype, except dated 5–8.III.2016 , leg. QY Wang et al. , slide No. ZD 21077♁, ZD21577♁, ZD21584 ♀ . Diagnosis. The new species can be distinguished from its congeners by the forewings with markings of bluish-green metallic luster, and having a small silvery white stripe at the tornus; in the male genitalia by the falculate valvae; and the pleural lobes of the male eighth segment with two apical processes greatly different in shape and length. Description. Adult ( Fig. 4 ). Wingspan 9.5–11.0 mm. Head . Vertex dark brown, frons grayish yellow. Antenna dark brown except grayish yellow at apex dorsally, grayish yellow ventrally. Labial palpus with second palpomere yellow, mixed with black scales in distal half; third palpomere dark brown, yellow dorsobasally. Thorax . Dorsum of mesothorax and tegula dark brown. Forewing dark brown; markings silvery white, with bluish-green metallic luster: subbasal fascia almost uniformly wide, straight, extending from basal 1/4 of costal margin to dorsum; wedge-shaped stripe at 1/2 and 3/4 of costal margin as well as near end of fold respectively, tornal stripe smallest and narrowest; fringe concolorous to forewing. Hindwing and fringe dark brown. Fore- and midlegs with coxae and femora dark brown ventrally, yellowish white dorsally, tibiae and tarsi dark brown, tibiae yellowish white at 1/2 and apex dorsally, first tarsomere ringed with yellowish white at base and apex, 4–5 tarsomeres white; hindleg with femur and tibia dark brown except tibia yellowish white at 1/2 and apex on outer surface, yellowish white on inner surface, 1–2 tarsomeres dark brown, first tarsomere ringed with yellowish white at apex, 3–5 tarsomeres white. Male abdomen and genitalia ( Fig. 10 ): Abdomen. Furcate process of eighth tergum indistinctly narrowed to rounded apex. Pleural lobes of eighth segment subrectangular, produced at middle on dorsal margin, obtuse on ventral margin; apex with two processes: dorsal process very small, triangular, ventral process long, slightly broadened medially, distinctly narrowed distally, hooked apically. Male genitalia . Socus with left brachium spatulate, about 2/5 length of right brachium; right brachium slender, curved at distal 1/5, pointed at apex. Valva falculate, slightly broad at base, uniformly slender from near base to cucullus; cucullus narrowed to apex, with dense setae on ventral surface. Left valvella slender, curved at basal 3/4, with sparse setae at apex. Phallus tapered to distal 1/5, narrowly rounded at apex. Female genitalia ( Fig. 16 ). Apophyses posteriores about 1.5 times as long as apophyses anteriores. Sterigma subtrapezoidal, with a sclerotized horn-shaped ventral sac.Antrum short, funnel-shaped. Ductus bursae membranous, as long as apophyses posteriores. Corpus bursae elongate subrectangular, about three times length of ductus bursae; signum absent. FIGURES 9‒14. Structure of 8th abdominal segment and male genitalia of Ressia spp. 9 . R. auriculata , slide No. ZD21583; 10. R. disparilis sp. nov. , holotype, slide No. ZD21076; 11. R. forcipata sp. nov. , holotype, slide No. ZD21568; 12. R. quercidentella , slide No. ZD21160; 13. R. semilunata sp. nov. , holotype, slide No. ZD21571; 14. R. sinevi sp. nov. , holotype, slide No. ZD21576 (9a–14a, furcate process of eighth tergum). Scales = 0.5 mm (9a–14a = 0.2 mm). Distribution. China ( Hainan ). Etymology. The specific epithet is derived from the Latin disparilis , referring to the two differently sized and shaped apical processes of the pleural lobes of the male eighth segment.