Nokona vietnamica O. Gorbunov et Arita, 2020

Gorbunov, O. G. & Arita, Yu., 2020, Two new species of the genus Nokona Matsumura, 1931 (Lepidoptera: Sessiidae) from Vietnam, Far Eastern Entomologist 412, pp. 1-12 : 2-6

Nokona vietnamica O. Gorbunov et Arita , sp. n.

http://zoobank.org/NomenclaturalActs/ EE2864DA-F64F-44F6-AE1D-D5820DA0A282

Figs 1–6

MATERIAL. Holotype – ♂ with labels: “ Vietnam / Ninh Binh Prov., / Gia

Vien, / Cuc Phuong, 370 m / 26.IV.2015 / Y. Arita leg.”; “ SESIIDAE / Pictures No

/ 0169-0170–2018 / Photo by O. Gorbunov”; “Genitalia examined / by O. Gorbunov /

Preparation No / OG–029-2018”; “ HOLOTYPUS ♂ / Nokona vietnamica / O.

Gorbunov et Arita, 2020 / O. Gorbunov des., 2018” ( NSMT).

DESCRIPTION. Male (holotype) ( Figs 1, 2 ). Alar expanse 22.8 mm; body length

13.6 mm; forewing 10.0 mm; antenna 6.1 mm.

Head with antenna and scapus dark brown to black with dark blue-violet sheen;

frons dark gray with bronze-purple sheen and a white stripe laterally; basal joint of pictures No 0163-0164–2018), alar expanse 22.8 mm; 2 – ditto, underside.

labial palpus dark brown to black with greenish sheen, remain joints palpus dark brown to black with greenish sheen exterior-dorsally and yellow to pale yellow interior-ventrally; vertex black with bright greenish-anthracite sheen; pericephalic hairs yellow dorsally and white laterally.

Thorax with patagia dark brown to black with violet sheen; tegula dark brown to black with bronze-violet sheen and a small yellow spot anteriorly; mesothorax dark brown to black with bronze-violet sheen and a small yellow spot posterior-laterally;

besides this, tegula and mesothorax covered with sparse, short, white hairs; metathorax dark brown to black with greenish sheen; thorax laterally dark brown to black with blue-violet sheen and with three small yellow spots: anteriorly, medially and at base of forewing; posteriorly both metepimeron and metameron dark brown to black with violet sheen and with long white hairs.

Legs with neck plate mixed with white, dark gray and yellow scales; fore coxa,

femur and tibia dark brown to black with greenish-violet sheen, beside this, femur and tibia with a row of long hair-like scales posteriorly; fore tarsus dark gray dorsally and gray ventrally; mid coxa dark gray with greenish-bronze sheen and a few white scales; mid femur and tibia dark brown to black with greenish-violet sheen;

spurs dark gray-brown with a few gray scales internally; mid tarsus dark gray-brown with bronze sheen exterior-dorsally and gray interior-ventrally; hind coxa dark gray with greenish-bronze sheen and a few white scales; hind femur dark brown to black with greenish-violet sheen and with long white hairs posteriorly; hind tibia dark brown to black with greenish-violet sheen and a few white scales at base of mid spurs; spurs dark gray-brown with a few gray scales internally; hind tarsus dark brown to black with bronze sheen and a few white scales distally on two basal tarsomeres.

Forewing dorsally black with a few yellow scales with golden sheen at base; all opaque parts dark brown to black with dark blue sheen; transparent areas poorly developed; external transparent area undeveloped; anterior and posterior transparent areas small covered with translucent with electric-blue lustre and a few dark brown scales; ventrally opaque parts dark brown to black with dark blue-violet sheen and a few brick-red scales at cross-vein; cilia dark brown with bronze sheen.

Hindwing transparent; veins, discal spot and outer margin dark brown to black with dark violet sheen; discal spot broad with parallel margins, reaching to vein M 3;

outer margin broad, about twice as broad as cilia; cilia dark brown with bronze sheen.

Abdomen dorsally dark brown to black with greenish-violet sheen; tergite 2

with a narrow yellow stripe distally; ventrally dark brown to black with dark violet sheen; sternite 1+2 with a few yellow scales anteriorly; anal tuft well-developed,

clipped spear-shaped, dark brown to black with greenish-violet sheen and narrowly white laterally.

MALE GENITALIA (holotype, genital preparation No OG –029-2018) ( Figs 3–6 ) .

Uncus narrow, slightly broadened medially, slightly broadened and rounded distally,

covered with a lot short setae and scales in dorso-distal two thirds; tegumen small;

gnathos somewhat broader than tegumen, with a short tooth medially; tuba analis with subscaphium broadly sclerotized ( Fig. 3 ); valva ( Fig. 4 ) triangular-oval, covered with multifurcate hand-shaped setae in dorsal two thirds, short simple setae at dorsal margin, and a row of pointed elongated setae subventrally; medial row of handshaped setae narrow; crista sacculi low, densely covered with strong pointed setae;

saccus ( Fig. 5 ) slightly longer than vinculum, straight, slightly broadened and rounded basally; aedeagus ( Fig. 6 ) rather thick, broadened basally, about 1.5 times shorter than valva; vesica with numerous minute flat cornuti.

paration No OG –029- 2018): 3 – tegumen-uncus complex; 4 – valva; 5 – saccus; 6 – aedeagus.

Scale bar: 0.5 mm.

FEMALE. Unknown.

DIFFERENTIAL DIAGNOSIS. By the structure of the male genitalia this new species seems to belong to the N. bicincta species-group and superficially resembles to some dark forms of N. pilamicola (Strand, 1916) (type locality: Taiwan: Taitung

Hsien, Taitung) and N. powondrae (Dalla Torre, 1925) (type locality: Taiwan: Tainan

Hsien, Kuantyling).

From dark forms of the first species compered, N. vietnamica sp. n. can be distinguished by the colouration of the tegula (entirely dark brown to black with bronze-violet sheen in N. pilamicola , vs. dark brown to black with bronze-violet sheen and a small yellow spot anteriorly in new species), mesothorax (brown to dark brown with an admixture of a few yellow scales distally in the species compared, vs. dark brown to black with a small yellow spot posterior-laterally in N. vietnamica sp. n.;

vs. Fig. 1 with figs 1–3 in Arita et al., 2016: 250) and abdomen dorsally (at least tergites 2 and 4 each with a narrow dark ohreous or yellow stripe distally in N. pilamicola , vs. tergite 2 with a narrow yellow stripe distally in N. vietnamica sp. n.;

compare Fig. 1 with figs 35 and 36 in Arita & Gorbunov, 2001: 148 or figs 9 and 10

in Kallies et al., 2014: 191, or with figs 1–3 in Arita et al., 2016: 250). In addition,

these two species differ from each other by some details in the male genitalia (compare Figs 3–6 with figs 58a–d in Arita & Gorbunov, 2001: 175).

New species is separable from the dark forms of N. powondrae (figs 27–29 in

Arita & Gorbunov, 2001: 147) by the scapus (yellow-orange ventrally in N. powondrae , vs. entirely dark brown to black with dark blue-violet sheen in N. vietnamica

sp. n.), labial palpus (basal joint dark brown to black with purple sheen, mid and apical joints dorsally white, externally dark brown to black with purple-green sheen, internally yellow-orange, ventrally yellow-orange distally and black dorsally in the species compared, vs. dark brown to black with greenish sheen, remain joints palpus dark brown to black with greenish sheen exterior-dorsally and yellow to pale yellow interior-ventrally in the new species) and abdomen dorsally (at least tergites

2 and 4 each with a narrow yellow-orange stripe distally in N. powondrae , vs. dark brown to black with greenish-violet sheen; tergite 2 with a narrow yellow stripe distally in N. vietnamica sp. n.; compare Fig. 1 with figs 23–29 in Arita & Gorbunov,

2001: 147).

From some other species of the N. bicincta species-group, namely N. bicincta

(Walker, 1865 [“1864”]) (type locality: “ North China ” [= China: Shanghai or Beijing]) ,

N. iridina (Bryk, 1947) ( China: Jiangsu, Shanghai (?)), N. pernix (Leech, 1889)

(type locality: Japan: Honshu, Oiwake) and N. rubra Arita et Toševski, 1992 (type locality: Japan: Ryukyus, Amami-Ohshima, Akatsushiyama), N. vietnamica sp. n. is distinguished by a combination of the colour signs of various parts of the body.

BIONOMICS. The larval host plant is unknown, but highly likely it could be a species of Paederia , for example P. foetida L. ( Rubiaceae ). The holotype was collected at the end of April.

HABITAT. The male was collected on the edge of the rainforest.

DISTRIBUTION. The new species is known only from the type locality in the

Cuc Phuong National Park in North Vietnam (Ninh Binh Province).

ETHYMOLOGY. This new species is named after the country of Vietnam.

Figures

Figs 1–2. Nokona vietnamica O. Gorbunov et Arita, sp. n.: 1 – holotype ♂ (Sesiidae

Figs 3–6. Male genitalia of Nokona vietnamica O. Gorbunov et Arita, sp. n. (genital pre-