Sorolopha plinthograpta (Meyrick, 1931)

(Figs 1, 2, 11, 16)

Argyroploce plinthograpta: Meyrick, 1931: 135 (♂). TL: Taiwan.

Olethreutes plinthograpta: Clarke, 1958: 539, pl. 268, fig. 1 (left wing).

Eudemis plinthograpta: Issiki, 1957: 69, pl. 11, fig. 332.

Sorolopha plinthograpta: Diakonoff, 1973: 84, figs. 131–133 (♂, ♀ genit.); Kawabe, 1982: 93, pl. 22, figs. 15–16; Park & Ahn, 1987: 186, fig. 12; Kuznetsov, 2001: 287, pl. 171, fig. 1 (♂ genit.); Nasu, 2011: 680, pl. 68, figs. 271a–e; Yu & Li, 2009: 10; Nasu, 2013: 202, pl. 24, fig. 4.

Diagnosis. Sorolopha plinthograpta has a mean forewing length of 7.9 mm (6.3–9.0 mm, n = 30), little or no sexual dimorphism. The forewing is sub-rectangular, expanding posteriorly, and brick-red or blackish-brown with dark-brown shades on the center. The male genitalia of S. plinthograpta are similar to those of S. semiculta (Meyrick, 1909) (cf., Diakonoff 1973: 76, fig. 121), but those of S. plinthograpta have slenderer socii, lacking modified hairs at the apex, and an obliquely truncate phallus. The male genitalia of S. plinthograpta are also similar to those of S. autoberylla (Meyrick, 1932) and S. plumboviridis Diakonoff, 1973 (cf., Diakonoff 1973: 73, fig. 115; 83, fig. 135), but S. plinthograpta has fewer spines on the apical edge of the sacculus, and the terminal part of the cucullus is shorter.

Material examined. JAPAN: HONSHU: Wakayama Pref.: Tanago (33°47′03″N, 135°53′24″E, alt. 59 m), 1♂, emerged on 10. VI.2019, reared from leaves of Actinodaphne acuminata collected on 11. V.2019, K. Sakagami leg., genitalia slide KS184♂; Wadagawa (33°46′02″N, 135°48′41″E, alt. 109 m), 1♂, 2♀, emerged on 8–11. VI.2017, reared from leaves of A. acuminata collected on 14. V.2017, K. Sakagami leg., genitalia slide KS 41♀, 81♂, 82♀; Unehata (33°45′23″N, 135°47′52″E, alt. 147 m), 1♂, emerged on 10. VI.2019, reared from leaves of A. acuminata collected on 11. V.2017, K. Sakagami leg.; Hirai (33°38′14″N, 135°41′23″E, alt. 142 m), 7♂, 4♀, emerged on 3–14. VI.2018, reared from leaves of A. acuminata collected on 8. V.2018, K. Sakagami leg., genitalia slide KS115♂, 116♂, 117♀, 118♂, 127♂, 183♀, 185♂, 186♂, 187♀, 189♀, 205♂; Mt. Nachisan, 1♀, collected on 27.VIII.1959, S. Moriuti leg., (OMU). KYUSHU: Fukuoka Pref.: Inunaki-tôge, collected on 24.IV.1960, K. Yano leg., (ELKU). Ôita Pref.: Beppu, collected on 1937, T. Torinaga leg., (ELKU). Kagoshima Pref.: Ôsumi, Mt. Kirishima, 1♂, collected on 13.X.1953, T. Yasuda leg., (OMU); Satamisaki, 1♂, collected on 14.X.1955, T. Kodama leg., (OMU). NANSEI ISLANDS: Nakanoshima Is.: Mt. Nanatsuyama (29°50′N, 129°53′E, alt. 134 m), 1♂, collected on 13.IX.2018 by light traps, K. Takahashi leg. Takarajima Is.: Ôgomori (29°09′20″N, 129°13′00″E, alt. 5 m), 1♂, emerged on 3.X.2018, reared from leaves of Cinnamomum daphnoides collected on 9.IX.2018, K. Sakagami leg.; Ôgomori (29°09′22″N, 129°12′54″E, alt. 6 m), 1♀, emerged on 1. V.2019, reared from leaves of C. yabunikkei collected on 7.IV.2019, 1♀, emerged on 1–2. V.2019, reared from leaves of Machilus thunbergii collected on 7.IV.2019, K. Sakagami leg.; Mt. Megamiyama (29°09′09″N, 129°11′58″E, alt. 55 m), 1♀, emerged on 3.IX.2018, reared from leaves of M. thunbergii collected on 11.IX.2018, K. Sakagami leg.; Mt. Imakiradake (29°08′49″N, 129°12′07″E, alt. 176 m), collected on 10.IX.2018, K. Sakagami. Amami Ôshima Is.: Chinase (28°21′04″N, 129°26′13″E, alt. 40 m), 1♂, 1♀, emerged on 6. V.2019, reared from leaves of A. acuminata collected on 12.IV.2019, K. Sakagami leg., genitalia slide KS 193♀, 195♂. OKINAWA IS.: Yona (26°45′N, 128°12′E), Kunigami, 1♂, 1♀, emerged on 27.IV.2015, reared from leaves of A. acuminata collected on 29.III.2015, F. Komai leg., genitalia slide KS 17♀, 62♂. Ishigakijima Is.: Mt. Omotodake (24°25′N, 125°11′E), 1♀, emerged on 28.III.2015, reared from leaves of Machilus thunbergii collected on 4.II.2015, F. Komai leg., genitalia slide KS 61♀; Takada-rindou (24°24′N, 124°11′E), 1♂, emerged on 25.III.2012, reared from leaves of M. thunbergii collected on 5.II.2012, F. Komai leg., genitalia slide KS18♂, wing slide 19♂; Ban′na-kôen (24°22′N, 124°10′E), 1♂, emerged on 24.III.2015, reared from leaves of M. thunbergii collected on 25.II.2015, F. Komai leg., genitalia slide KS20♂.

Distribution. China, Taiwan, Japan (Honshu, Shikoku, Kyushu, Nansei Islands), Korea, Russia, Thailand, Vietnam, Indonesia (Java).

Host plant. Actinodaphne acuminata, Cinnamomum daphnoides, C. yabunikkei, C. camphora, Litsea coreana, Machilus thunbergii (all Lauraceae), Elaeocarpus japonicus (Elaeocarpaceae) (Kawabe 1982, Nasu 2011, 2013).

Biology. Adults have been taken from June to October in Honshu, Japan (Nasu 2013), and are commonly collected using light traps. Larvae tie together multiple young leaves of host plants and feed on the leaves in the shelters. Larvae of this species are often found with larvae of other Sorolopha species within the leaf shelters of host plants (Fig. 21). Larvae cut and fold back the edge of a single leaf and pupate inside it.

Remarks. Diakonoff (1973) assigned this species to the herbifera group. Adults collected from the Nansei Islands (Okinawa Is. and Ishigakijima Is.) tend to be darker than those from other regions (e.g., Honshu and Kyushu) in Japan. Papers citing Kawabe (1982) indicating Pueraria montana (Fabaceae) is the host plant of S. plinthograpta (e.g., Le et al. 2013) are incorrect. Kawabe (1982) actually identified the host plant as C. camphora (Lauraceae) (Kawabe 1982).