Argyresthia is the largest genus within Argyresthiidae, currently including 106 species worldwide (Lewis and Sohn, 2015;Liu et al., 2017;Santa-Rita et al., 2020). Kyrki (1984) defined the Argyresthia group (= Argyresthiidae in Kyrki, 1990) with three autapomorphies: in the male genitalia, the saccus absent; the vinculum anteriorly produced on the sides; and the male sternite VIII V- or Y-shaped. These characteristics can play a role of diagnoses for Argyresthia, as Kyrki’s definition was based on a single genus. The adult moths of Argyresthia are small in body size and narrow-winged with often lustrous forewing patterns. When resting, they lay their head down and raise their end up (Fig. 1). The larvae are mostly endophagous on the buds, fruits, twigs, and leaves of various woody seed plants (Dugdale et al., 1998). The genus includes several pest species, for example, Argyresthia pruniella and A. conjugella damaging apple trees (Alford, 2015).
Studies on the species diversity of Argyresthia in Korea are scanty. Park (1983) included only Argyresthia conjugella Zeller in his checklist of the Korean Microlepidoptera. Sohn (2007) recorded three congeners new to Korea: A. ivella (Haworth), A. laevigatella (Heydenreich) and A. magna Moriuti. Na et al. (2017) added two species of Argyresthia: A. albicomella Moriuti and A. alpha Friese et Moriuti. Given their diversity in the neighboring countries, the Korean fauna of Argyresthia seems to be still underestimated. In the present article, two species of the genus, A. subrimosa Meyrick and A. umbrina Liu, Wang et Li, 2017 are reported for the first time from Korea. Two isolated populations of A. subrimosa from the Island Jejudo and Ulleungdo are compared with each other in the external and genital morphology.
Material and Methods
Specimens examined are deposited in three institutional collections: Natural History Museum, London, United Kingdom (NHMUK); Department of Science Education, Gongju National University of Education, Gongju, Korea (GJUE); and National Institute of Biological Resources, Incheon, Korea (NIBR).
Slide specimens of genitalia were prepared, following Clarke (1941), except that chlorazol black and Euparal resin were used for staining and permanent mounting, respectively. Terms for genitalia followed Moriuti (1977). In the specimen data, the ‘GSN’ in brackets stands for the genitalia slide number.
Taxonomic Accounts
Family Argyresthiidae Bruand, [1850]
ArgyresthiaHübner, [1825]
ArgyresthiaHübner, [1825]: 422. Type species: Phalaena goedartella Linnaeus, 1758.
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= ArgyrosetiaStephens, 1829: 205. Type species: Phalaena goedartella Linnaeus, 1758.
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= BlastotereRatzeburg, 1840: 246. Type species: Phalaena bergiellaRatzeburg, 1840.
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= EderesaCurtis, 1833: 191. Type species: Phalaena pruniella Clerck, 1759.
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= IsmeneStephens, 1834: 247. Type species: Phalaena pruniella Clerck, 1759.
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= OligosTreitschke, 1830: 299. Type species: Phalaena pruniella Clerck, 1759.
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= ParaargyresthiaMoriuti, 1969: 30. Type species: Paraargyresthia japonicaMoriuti, 1969.
Argyresthia subrimosaMeyrick, 1932 큰광택집나방 (Figs. 1-4, 6-7, 9)
Argyresthia subrimosaMeyrick, 1932: 227. Type locality: China, Kwanhsien.
Argyresthia mutuuraiMoriuti, 1964: 20. Type locality: Japan, Hokkaido, Sapporo.
Description. Habitus (Figs. 1-4) - Head: Vertex and frons pale yellowish brown. Labial palpus pale orange, intermixed with dark brown scales laterally. Antenna 5/6 as long as forewing; scape pale orange; flagellum black with white annulations. Thorax: Tegula pale yellowish brown, intermixed with brownish gray scales in distal half; mesonotum pale orange. Forewing length 5.5-6.9 mm, pale orange, densely striolate with dark gray; cilia dark gray on forewing apex, pale orange on apical area, dark fuscous on termen. Hindwing and cilia dark fuscous. Male genitalia (Figs. 6-7) - Subscaphium 2x longer than socius. Socius elliptical, with ca. 18 scale-like setae on ventral surface and two setae on top. Valva lobate, slightly convex at middle of costa, broadly-round along saccular margin; stiff-setose area present on apical area and upper border of sacculus. Vinculum narrowly produced anterolaterally. Phallus nearly straight, 2.5x longer than valva; carina spiniform; spinulate cornutal zone 1/7 as long as phallus. Female genitalia (Fig. 9) - Papillae anales narrowed dorsodistally. Ovipositor as long as ductus bursae. Apophyses posteriores 3x longer than apophyses anteriores. Ductus bursae narrow, slightly dilated near corpus bursae. Corpus bursae ovate, spinulate concentrically around signum; signum 1/2 as long as corpus bursae, scobinate, cruciform, with lateral branches at anterior 1/4.
Materials examined. 4♂2♀, Gyongbuk Prov., Ulleung-gun, Is. Ulleungdo, Buk-myeon, Nari-dong, Mt. Seonginbong (37°31′03.4″N 130°51′51.3″E, alt. 420 m), 12 vii 2018 (JC Sohn), [GSN] SJC-1333 (♂), 1361 (♀), GJUE & NIBR; 3♂, Jeju Prov., Jeju-si, Nohyeong-dong, Cheonwangsa (33°24′ 36.1″N 126°29′43.3″E, alt. 673 m), 4 vii 2016 (JC Sohn), [GSN] SJC-1360; 1♂, ditto, 1 viii 2016 (JC Sohn).
Distribution. Korea (new record), Japan, China.
Host plants. Unknown.
Remarks. The holotype of Argyresthia subrimosa Meyrick from NHMUK was examined (Fig. 4). It is the largest among the Korean congeners. The Korean specimens of this species showed a different shape of valva from Moriuti’s (1964) illustration. My examination of the unmounted genitalia of the specimens suggested that such difference was resulted from how to spread the valvae during slide preparation. Interestingly, the Korean populations of A. subrimosa were found from two remote islands, Ulleungdo and Jejudo (Figs. 3 and 4). They exhibited no significant difference in the genitalia (Figs. 6 and 7).
Argyresthia umbrina Liu, Wang et Li, 2017 황갈광택집나방 (Figs. 5, 8, 10)
Argyresthia umbrina Liu, Wang et Li, 2017: 60. Type locality: China, Shanxi Prov., Jiexiu Co., Mt. Mian.
Description. Habitus (Fig. 5) - Head: Vertex white; frons pale orange. Labial palpus pale reddish brown laterally, pale orange mesally. Antenna 3/4 as long as forewing costa; scape pale orange dorsally, white ventrally; flagellum dark purplish brown, with white annulations. Thorax: Tegula orange; mesonotum lustrous, white, intermixed with orange scales at center. Forewing length 4.1-5.5 mm, pale orange, tinged with white on basal 1/3 of dorsum, reticulate with brownish orange; cilia brownish orange on apical area, fuscous on termen. Hindwing and cilia brownish gray. Male genitalia (Fig. 8) - Subscaphium 2/3 as long as valva. Socius securiform, with 19-21 scale-like setae on ventral surface and two setae on top. Valva linguiform, widest at middle, setose on apical and saccular areas; costa curved at basal 1/3; zone of stiff setae present on upper boarder of sacculus. Vinculum rectangular, emarginated ventromedially. Phallus 2.5x longer than valva, slightly curved at middle, gradually narrowed to apex; spinulate cornutal zone 1/3 as long as phallus. Female genitalia (Fig. 10) - Papillae anales subconical, setose. Ovipositor 2.5x longer than eighth segemt. Apophyses posteriores 2.1x longer than apophyses anteriores. Antrum elongate, funnel-shaped. Ductus bursae narrow, gradually broadened to corpus bursae from middle. Corpus bursae globular, spinulate on posterior half; signum as subtriangular sclerite, with curved long horn-like, scobinate lateral branch at anterior end.
Materials examined. 5♂5♀, Jeonnam Prov., Goheung-gun, Yeongnam-myeon, Mt. Palyongsan, 21 vi 2019 (JC Sohn), [GSN] SJC-1359 (♀); 3♀, Jeonnam Prov., Goheung-gun, Is. Oenarodo, Yenae-ri, near Naro tunnel, 25 vi 2020 (JC Sohn), GJUE & NIBR; 1♂, Jeonnam Prov., Goheung-gun, Is. Dolsando, Mt. Geumosan, Hyangilam, 24 vi 2019 (JC Sohn), [GSN] SJC-1358; 2♀, Jeonnam Prov., Yeosu-si, Is. Geumodo, Nam-myeon, Dupo-ri, 23 vi 2019 (JC Sohn), [GSN] SJC-1383; 1♀, Jeonnam Prov., Yeosu-si, Is. Geumodo, Mt. Kalibong, 23 vi 2019 (JC Sohn).
Distribution. Korea (new record), China.
Host plants. Unknown.
Remarks. The Korean records of this species represent its first occurrence outside of China.