Ressia semilunata Li, 2023

Zhang, Di & Li, Houhun, 2023, Review of the genus Ressia Sinev, 1988 (Lepidoptera: Cosmopterigidae), with descriptions of four new species from China, Zootaxa 5360 (4), pp. 583-592 : 589

Ressia semilunata Li , sp. nov.

( Figs 7 , 13 , 18 )

urn:lsid:zoobank.org:act:5A37CDAF-6DCB-46F9-9EA8-3FB1D4523D5F

Type material. Holotype ♁. CHINA, Hainan: Tianchi, Jianfengling (18.73°N, 108.86°E), 787 m, 15.I.2016, leg. QY Wang et al., slide No. ZD 21571.

Paratypes: 1♁, Shuiman Town , Wuzhishan City, 650 m, 15.V.2007, leg. ZW Zhang & WC Li, slide No. ZZW08027; 1♁ 1♀ , Wuzhishan , 738 m, 2.XI.2016, leg. X Bai et al., slide Nos. ZD 21562♁, ZD21582 ♀ .

Diagnosis. The new species can be distinguished from its congeners by the forewings with markings encircled by black scales and the white subbasal fascia with anterior 1/4 much narrower and ill-defined; in the male genitalia by having a semilunate cucullus; and in the female genitalia by having a short tubular sterigma.

Description. Adult ( Fig. 7 ). Wingspan 11.0–12.0 mm.

Head. Vertex dark brown, frons grayish yellow. Antenna with scape pale yellow dorsally, dark brown ventrally, ringed with white terminally; flagellum with basal 2/3 dark brown and pale yellow dorsally, pale yellow ventrally, distal 1/3 pale yellow. Labial palpus with second palpomere pale yellow, dark brown at apex; third palpomere dark brown, pale yellow dorsobasally.

Thorax. Dorsum of mesothorax and tegula dark brown. Forewing dark brown; markings white encircled by black scales: subbasal fascia from basal 1/4 of costal margin to dorsum, its anterior 1/4 much narrower and ill-defined, smaller spot at 1/2 and larger spot at 5/6 of costal margin respectively, subtriangular spot at end of fold; fringe concolourous to forewing. Hindwing and fringe dark brown. Legs with coxae and femora yellowish white, tibiae and tarsi dark brown, except tibiae yellowish white at basal 1/6, 1/2 and apex; first tarsomere ringed with yellowish white at base and apex, 4–5 tarsomeres yellowish white.

Male abdomen and genitalia ( Fig. 13 ):

Abdomen. Furcate process of eighth tergum with outer margin produced outward medially, with pointed apex. Pleural lobes of eighth segment oval, with a furcella at base on dorsal margin.

Male genitalia. Socus with left brachium spatulate, about 1/4 length of right brachium; right brachium with basal 1/4 wide, uniformly slender medially, sharply narrowed from distal 1/4 to pointed apex, curved at distal 1/6, hooked apically. Valva with stalk aequilate; cucullus semilunate, with dense setae on ventral surface. Left valvella slender, curved at middle, slightly inflated distally, with dense setae ventrodistally. Phallus with basal 2/3 tubular, distal 1/3 tapered to narrowly rounded apex.

Female genitalia ( Fig. 18 ). Apophyses posteriores 1.5 times as long as apophyses anteriores. Sterigma tubular, with a sclerotized ventral sac. Antrum relatively short, concave at middle on posterior margin. Ductus bursae membranous, twice length of apophyses posteriores. Corpus bursae pyriform, shorter than ductus bursae; signa being five small subcircular plates with small erect lamellar processes.

Distribution. China (Hainan).

Etymology. The specific epithet is derived from the Latin semi- and lunatus, referring to the shape of the cucullus.

Figures

FIGURES 3‒8. Adults (all males) of Ressia spp. 3. R. auriculata; 4. R. disparilis sp. nov., holotype; 5. R. forcipata sp. nov., holotype; 6. R. quercidentella; 7. R. semilunata sp. nov., holotype; 8. R. sinevi sp. nov., holotype. Scales = 2.0 mm.

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).

FIGURES 15‒19. Female genitalia of Ressia spp. 15. R. auriculata, paratype, slide No. ZZW08911; 16. R. disparilis sp. nov., paratype, slide No. ZD21584; 17. R. quercidentella, slide No. ZD21578; 18. R. semilunata sp. nov., paratype, slide No. ZD21582; 19. R. sinevi sp. nov., paratype, slide No. ZD21585. Scales = 0.5 mm.