Unilepidotricha ulleungensis Lee & Roh, 2025

Unilepidotricha ulleungensis Lee & Roh , sp. nov.

( Figs. 1 View FIGURE 1 , 2 View FIGURE 2 )

Type material. Holotype. [ KOREA] ♂, Taeha-ri, Seo-myeon, Ulleung-gun , Gyeongsangbuk-do, 19.vii.2022, 37°30´31.14˝N; 130°49´19.58˝E, leg. D.J. Lee, J.W. Kim & H. Lee, Genbank accession no. PQ650779, voucher no. ECHNIBR3026 GoogleMaps . Paratypes. 5♂, same locality as holotype; Genbank accession no. PQ650780-PQ650782, voucher no. ECHNIBR3027-3031 GoogleMaps .

Diagnosis. This species is very similar to Xeringinia altilis Meyrick, 1893 , but can be distinguished by a trapezoidal patch on the third sternum. The male genitalia are very similar to Unilepidotricha gracilicurva Xiao & Li , but the basal part of uncus is fused together (separated each other in U. gracilicurva ).

Description. Adult ( Fig. 1A–E View FIGURE 1 ). Wingspan 12.0–14.0 mm. Head with creamy-white, hair-like scales on vertex and frons. Antenna filiform; reached 4/5 of forewing; scape covered with creamy-white scales; each segment yellowish-white; Mouthpart reduced or absent; galae vestigial; maxillary palpi short, covered with yellowish-white scales; labial palpi three segmented, covered with creamy-white scales and dark brown scales laterally; Thorax creamy-white, with dark brown scales on tegula anteriorly. Forewing with all veins present and free; ground color creamy-white, with ocher to dark brown pattern of streaks and patches; two oblique streaks at basal and 1/3 from costa to dorsum; a V-shape streak at 1/2 from costa to dorsum; scattered patches apical half; dark brown scales on margin of tornus; approximately 2.7–2.8 times as long as width including fringe (about 3.7–3.8 times as long as width excluding fringe). Hindwing with all veins present and free; Sc+R 1 displaced anteriorly; M 1 and M 2 stem stalked; M stem branched in medial cell; with single bristled frenulum; ground color grayish-brown, without any pattern; approximately twice times as long as width including fringe (about 3.1–3.3 times as long as width excluding fringe). Male abdomen with setae that form a trapezoidal patch on the membrane between the third and fourth sternum.

Male genitalia ( Fig. 2A–C View FIGURE 2 ). Uncus with bifid, sclerotized, bristled socii. Gnathos U-shaped; a pair of gnathos arms sclerotized, pointed, and fused basally. Tegumen broad, somewhat longer than basal breadth. Vinculum narrow ring shaped, slightly articulated to tegumen. Saccus long narrower to apex, about 0.4 times as long as valva. Valva moderately elongated, sub-trapezoid, narrower to basally; costal margin nearly straight; ventral margins at 4/5 narrower to rounded apex; inner side of valva with numerous setae, except slightly sclerotized ventral margin. Aedeagus long cylindrical about 2.5 times as long as length of saccus.

Female genitalia. Unknown.

Etymology. The species name is derived from the type locality (Ulleungdo island) in Korea. Ulleungdo island is a volcanic island located in the East Sea and is about 130km away from the nearest land. It is an island that has never been connected to the mainland and has a unique ecosystem. The island is known to have 1,177 species of insects, including 4 species endemic to Korea ( Lim et al. 2013).

Distribution. Korea (Ulleungdo island).

DNA barcodes. DNA barcode sequences were obtained from four specimens of Unilepidotricha ulleungensis . The DNA barcode (COI) were compared to those of 46 specimens in 19 species, 40 sequence downloaded from NCBI. Genetic divergence of COI, using uncorrected p-distance amongst the Meessiidae species, ranged from 6.3% to 32.7%, while intraspecific divergence ranged from 0% to 2.3% ( Table 2 View TABLE 2 ). The molecular analyses (p-distance and NJ) revealed that Homostinea curviliniella , Hybroma servulella , Isocorypha mediostriatella , and Diachorisia velatella were closely related to Unilepidotricha ulleungensis sp. nov. ( Table 2 View TABLE 2 , Fig 3 View FIGURE 3 ), The maximum difference amongst populations with Homostinea curviliniella was 0.2%, Hybroma servulella 0.2%, Isocorypha mediostriatella 0.3%, and Diachorisia velatella 1.1% ( Table 2 View TABLE 2 ). Genetic divergence between Unilepidotricha ulleungensis sp. nov. and its molecularly related species Homostinea curviliniella , Hybroma servulella , Isocorypha mediostriatella , and Diachorisia velatella are 22.6%, 19.4%, 19.7%, and 20.1%, respectively and that strongly supported the separation of meessiid moths ( Table 2 View TABLE 2 ).