Nudina Staudinger, 1887

Volynkin, Anton V., Huang, Si-Yao, Spitsyna, Elizaveta A., Bolotov, Ivan N. & Spitsyn, Vitaly M., 2021, Three new species of the genus Nudina Staudinger, 1887 from northern Indochina (Lepidoptera: Erebidae: Arctiinae: Lithosiini), Zootaxa 4970 (3), pp. 547-557 : 548-549

Nudina Staudinger, 1887

Nudina Staudinger, 1887 , Mémoires sur les lépidoptères 3: 187.

Type species: Nudaria nubilosa Staudinger, 1887 , a junior subjective synonym of Miltochrista artaxidia Butler, 1881 (by subsequent designation by Hampson (1900)).

Diagnosis. The genus is closely related to Paranudina (characterized in details by Huang et al. (2019)), from which it differs externally by the bipectinate or serrate antennae of both sexes, whereas in Paranudina ( Figs 20, 21 ), the antennae are filiform. The male genitalia of the two genera are very similar but in Nudina , the juxta lacks robust apical processes which are present in Paranudina ( Fig. 22 ) and considered here as an autapomorphic feature of the latter. The aedeagi of Nudina and Paranudina are similar due to the presence of two robust distal carinal processes, but the distal section of the aedeagus of Nudina is wrinkled and expandable (an autapomorphic feature) whereas it is evenly sclerotized in Paranudina . The male genitalia ground plan of Nudina is also reminiscent of that of the genus Paraheliosia (illustrated by Dubatolov et al. (2014)) due to the short costa and the large distal membranous lobe of the valva. However, in the genital capsule of Nudina , the juxta lacks apico-lateral processes (present in Paraheliosia ), the costa lacks a subbasal process (present in Paraheliosia ), and the clasper bears a process (harpe) which is absent in Paraheliosia . The aedeagus of Nudina differs from that of Paraheliosia by the wrinkled and expandable distal section and the presence of two robust distal carinal processes, whereas in Paraheliosia the distal carinal processes are absent and the distal section of the aedeagus is evenly sclerotized and bears triangular thorns. The vesica of Nudina is relatively short and lacks sclerotized elements while in Paraheliosia it has elongate diverticula bearing clusters of spine-like cornuti. The female genitalia of Nudina are distinguished from those of Paranudina ( Fig. 23 ) by the presence of a postvaginal plate (absent in Paranudina ) and the short and very wide, gelatinous ductus bursae bearing sclerotized plates and clusters of spinules (it is long and lacking spinules in Paranudina . Compared to Paraheliosia , the female genitalia of Nudina are easily distinguishable by the markedly shorter ovipositor, the presence of a postvaginal plate (absent in Paraheliosia ), and the short and very wide, gelatinous ductus bursae (in Paraheliosia , it is long and has an antrum).

The male genitalia of Nudina are characterized by the combination of the following features: (1) the short costa terminating approximately in the basal third or the middle part of the valva; (2) the presence of a clasper fused with the distal end of the costa and the base of the ventro-distal process of valva and bearing a process (harpe) which is very large in certain species; (3) the large distal membranous lobe of the valva; (4) the short and narrow sacculus; (5) the aedeagus having a wrinkled and expendable distal section and two heavily sclerotized distal carinal processes (an autapomorphic feature); and (6) the relatively short membranous vesica lacking cornuti. The female genitalia of Nudina are characterized by (1) the presence of both an antevaginal and postvaginal plates; (2) the very wide but short, gelatinous ductus bursae bearing a sclerotized plate and clusters of spinules (an autapomorphic feature); (3) the relatively small corpus bursae with spinulose scobination; (4) the appendix bursae directed laterally or anteriorly.

Description. External morphology of adults. Forewing length 10–13 mm in both sexes. Sexual dimorphism limited: males have longer lamellae of antennae and somewhat narrower forewing with more elongate apex. Male antenna bipectinate, female antenna shortly bipectinate or serrate. Body and wing colouration yellow. Forewing broadly triangular, pattern represented by wide brown shades; hindwing usually with intense brown suffusion in subterminal and terminal areas. Male genitalia. Uncus moderately long, narrow but stout, pointed apically. Tuba analis membranous. Tegumen short with moderately wide arms. Juxta large, weakly sclerotized, with a deep basal depression medially. Vinculum moderately long, with short saccus. Valva elongate, transtilla weakly or heavily sclerotized (the artaxidia and ankistro species-groups, respectively). Costa short and terminating in medial section of valva. Distal membranous lobe large and elongate. Sacculus short and narrow. Clasper narrow, fused with distal end of costa and base of ventro-distal process of valva, bearing a heavily sclerotized process (harpe). Ventro-distal process of valva robust. Aedeagus tubular, its distal section longitudinally wrinkled and expandable and bearing two robust distal carinal processes. Vesica membranous, curved dorsally, with few short diverticula; distal plate of vesica thin, stick-shaped. Female genitalia. Papillae anales rectangular with rounded corners, weakly setose. Apophyses elongate and thin, apophyses anteriores shorter than apophyses posteriores. Postvaginal plate short but wide, moderately sclerotized. Ostium bursae very broad. Ductus bursae very wide and relatively short, gelatinous, with sclerotized plate and clusters of spinules. Corpus bursae sack-like, weakly spinulose. Appendix bursae elongate and narrow, positioned laterally, directed laterally or anteriorly.

Distribution. The genus is widespread in continental China, Taiwan, Korean Peninsula, south of the Russian Far East, Japan and northern Indochina.

Figures

FIGURES 20–23. Paranudina xizangensis: adults (20, 21), male (22) and female (23) genitalia. The specimens are deposited in SCAU.