Herpetogramma okamotoi Yamanaka, 1976

(Figs. 1K, 4C, 4D)

Herpetogramma okamotoi Yamanaka, 1976: 2–5, figs 3, 6, 9. TL: Japan, Hyogo Pref., Takasago.

Material examined. 3 males, Andeok, JJ: Jeju, 2020.07.24. (Kim SS).

Diagnosis. Herpetogramma okamotoi can be diagnosed by the blackish forewing with the weakly dentate and medially strongly curved postmedial line, and the large black discal dot, and the blackish hindwing with the black discal dot and medially projected postmedial line. H. okamotoi is externally similar to other species of Herpetogramma in wing color and wing pattern elements but can be distinguished by the shape of the costal part of the postmedial line of the forewing. The male genitalia of Herpetogramma okamotoi are similar to those of other Herpetogramma but can be distinguished by the broad and trapezoidal shape of the saccus and the long sclerotization without spine-like cornutus on the aedeagus.

Description. Wingspan 23–24mm. Antennae filiform; frons broad, top ochreous, middle brownish, bottom grayish; maxillary palpi minute, tip blackish; labial palpi moderate in length, about 2.5 times to eye diameter, 1 st segment whitish, 2 nd segment laterally dark brownish. Body white. Forewing light blackish in ground color; antemedial line blackish, slanted; postmedial line blackish, costally weakly dentate, medially strongly curved inward; central fascia costally broad, tapered from middle to dorsum, a minute black dot close to the antemedial line, discal dot black, long, slanted, almost meets to the middle part of the postmedial line; subtermen dark brownish; termen lined with yellowish white. Hindwing blackish; anteriorly with a black dot; postmedial line blackish, medially strongly projected outward; termen blackish. Male genitalia. Uncus long, slender, basally thick, tapered distally and hairy distally, apex obtuse; vinculum dorsally almost flat, medially weakly convex that continuously extended to the basad of costa of valva; juxta broad; saccus trapezoidal with a pair of sacs of coremata. Valva rugby-ball shaped; costa concave, sclerotized. Aedeagus long, slender, apically expanded, with thin plate-like sclerotization; diverticulum with long sclerotization, but no spine-like cornutus. Female genitalia (based on Okamoto, 1970). Papillae anales flat, thin, plate-like; posterior apophyses thick, almost 1.5 times of 8 th segment; anterior apophyses thick, gradually tapered distally; ostium bursae simple, funnel-shaped; ductus bursae long medially with a sclerotized colliculum, anteriorly expanded; corpus bursae large elliptical, signum a small sclerotized plate-like process.

Distribution. South Korea and Japan

DNA barcoding. One specimen from South Korea (OK501196) was sequenced, and the genetic difference between H. okamotoi and its relative, H. sphingealis Handfield and Handfield was 6.2%.

Remarks. The genus Herpetogramma comprises 100 species worldwide, highly species rich in the Neotropical and Oriental regions (Nuss et al., 2003 –2021). The tribe was the monophyletic supported by the following synapomorphies; the relatively long sensillar setae of basal antennomeres in males, the porrect 3 rd labial palpomere, the conical, non-capitate uncus, and the corpus bursae with a granulose area (Mally et al., 2019). The species of this genus feed various food plants from ferns to angiosperms (Solis, 2008), and H. okamotoi feeds on a fern species, Pteris multifida Poiret (Aspleniaceae) in Japan (Okamoto, 1970).