Plusiodonta nicobarensis, Singh & Ahmad & Raha, 2022

Singh, Navneet, Ahmad, Jalil & Raha, Angshuman, 2022, Contribution to the Erebidae fauna of the Great Nicobar Island, India with description of two new species (Lepidoptera: Noctuoidea), Zootaxa 5165 (1), pp. 79-94 : 85-86

Plusiodonta nicobarensis sp. nov.

( Figs 6–7 , 20–21)

Holotype: ♂, India, Andaman and Nicobar Islands, Great Nicobar Island , 4 km South of Vijay Nagar, 12.xi.2018 (NZCZSI, 9274/H10), K. C. Gopi & Party leg.

Paratype: India, Andaman and Nicobar Islands, Great Nicobar Island, Galathea , 1 ♂, 07.xi.2018 (NZCZSI, 9275/H10), K. C. Gopi & Party leg.

Diagnosis: Morphologically, Plusiodonta nicobarensis sp. nov. is most closely similar to P. auripicta , but is distinct in having smaller wingspan, forewing with less acute apex, less pronounced bulge at the middle of termen, irrorations more bluish-grey rather than purplish-grey in P. auripicta , brown-smudged golden patches and spots, thus, appearing duller than in P. auripicta , brighter submarginal metallic golden spot adjacent to the postmedial line just above vein Cu2 and the apex is without any small, triangular grey spot. In male genitalia, P. nicobarensis sp. nov. is distinct from P. auripicta by the longer uncus, single long acute harpe instead of two triangular projections of the sacculus in P. auripicta , the presence of four small thorn-like spines on the distal sclerotized bar of sacculus rather than a small, blunt, irregular, sclerotized ridge in P. auripicta and somewhat oval-shaped juxta formed of two distally blunt lobes (juxta triangular in P. auripicta ) ( Singh 2014). In P. nicobarensis sp. nov., aedeagus is longer, straight with vesica bearing an apical spinose thumb-like sclerotized cornutus, whereas in P. auripicta , aedeagus is shorter, slightly curved, vesica without any cornutus ( Singh 2014).

Description. Male: Head: covered with fulvous scales, frons paler; antennae ciliate, brown, base white interspersed with fulvous; palpi upturned, fulvous, outer sides brown; collar covered with white-tipped fulvous scales interspersed with brown.

Thorax: pale brown, suffused with fuscous; patagia reddish brown, bordered with white; tegulae pale brown; ventrally pale ochreous brown; fore and mid leg dark brown on outer side, inner side pale, hind leg pale golden brown, tarsi of all legs with white segmental bands.

Wings: Forewing length: ♂ 14–15 mm. Forewing apex acute, slightly extended; termen more or less straight till vein M2, then slightly produced outward till vein Cu2, and again sharply and inwardly angled to tornus; ground colour rufous with bluish-grey irrorations concentrated in the basal and middle areas of forewing; a roughly quadrate golden patch smudged with brown at sub-basal part of costa which is enclosed by another dark rufous quadrate patch, proximal and distal borders of it is defined by bluish-grey lines extended to sub-median vein, proximal line is prominent than distal line; beyond this patch, a double, oblique, sinuous, dark brown antemedial line distinct from costa to vein 3A+2A then obsolete to inner margin, line densely irrorated with bluish-grey scales; reniform distinct, pale bluish-grey, defined by dark brown border and dusted with bluish-grey scales outside, particularly towards costa; postmedial line double, sinuous, running obliquely outward from costa to vein R5, then sharply angled beyond reniform and running obliquely inward to inner margin, lower part of this line below vein Cu2 marked with dense bluish-grey, rest of line blackish-brown; submarginal area with a subapical brown-smudged golden, lunular, black bordered, wavy band, disappearing at vein M2 which again reappears just above Cu2 and meets inner margin just before tornus; a prominent metallic golden spot in submarginal area adjacent to postmedial line just above vein Cu2; a short marginal, lunular, purplish-grey streak on veins M2 and M3; a marginal thin, lunular, purplish-grey line; cilia dark brown. Hindwing bronze-brown suffused with fuscous, suffusion is more towards outer margin; cilia fuscous brown. Underside of both wings pale yellowish-brown, forewing darker than hindwing.

Abdomen: Dorsally pale brown with fuscous suffusion, ventrally pale yellowish-brown.

Genitalia: uncus long, curved, hook-like and setosed; tegumen 1.4 times longer than vinculum; valva broad, distally expanded with sharp costal angle, apex with a prominent extension on costal side; sacculus broad with a prominent, sclerotized, acute harpe and distal sclerotized bar having four small thorn-like spines, extended above valva apex, terminally bifurcated into small acute spines near apical costal extension; juxta small formed of two slightly sclerotized distally blunt lobes; vinculum well sclerotized; saccus triangular, v-shaped. Aedeagus long, straight; vesica with an apical, spinose thumb-like sclerotized cornutus.

Female: Unknown.

Etymology: The new species is named after its collection locality, the Great Nicobar Island.

Remarks: With this, the total species count under Plusiodonta is updated to 42 from the world with 3 species from India. Moreover, this is the first ever report of the genus from any Indian island. The specimens were collected from the lowland dipterocarp forests having altitude below 150 m.

Figures

FIGURES 1–10. Adults of new species and new records of Erebidae from the Great Nicobar Island. 1, Anoba rigida, male, dorsal side; 2, Garudinia shompen sp. nov., male (Holotype), dorsal side; 3, Nishada sambara, male, dorsal side; 4, Teulisna chiloides, male, dorsal side; 5, ditto, female, dorsal side; 6, Plusiodonta nicobarensis sp. nov., male (Holotype), dorsal side; 7, ditto, ventral side; 8, Tamba cosmoloma, male, dorsal side; 9, T. occidinawa, male, dorsal side; 10, Anereuthina renosa, female, dorsal side.