Eumetriochroa araliella Kobayashi, Huang & Hirowatari, sp. nov.

Eumetriochroa araliella Kobayashi, Huang & Hirowatari sp. nov.

Figs. 2 E–H, 5, 9, 10, 17.

Diagnosis. All Eumetriochroa species possess a forewing with vein R1 (Fig. 5 A). The forewing pattern of this species is easily distingished from other species by the three dark greyish-brown oblique streaks (Fig. 2 E–H). The genital structure of this species is similar to E. hederae Kumata and E. miyatai Kumata, but it is distinguished from them by the bowl-shaped vinculum with saccus long virgulate in the male genitalia (Fig. 5 D, E) and very small signum in the female genitalia (Fig. 5 G).

Adult. (Fig. 2 E–H). Wing expanse 6.0 mm in holotype, 5.0– 8.1 mm (6.9 mm in average of eleven paratype specimens) in paratypes. Vertex and frons lustrous white; vertex with lustrous white scales appressed on occiput. Labial palpus whitish, porrect, slightly upcurved, with pale blackish brown scales in the base. Maxillary palpus absent. Antennae as long as forewing, lustrous white annulated with whitish brown. Thorax white to pale brown. Abdomen dark grey. Anal tuft grey. Forewing. White with dark greyish-brown oblique streaks; first triangular patch from base to 1/5, second broad, at costal 1/3, third linear at costal 1/2, obscure and narrow from middle to dorsum, apical patches at 9/10 of wing. Cilia white and dark grey at costal area with one apical dark grey transverse strigula; sometimes a blackish apical spot at apex; terminal cilia white with fuscous fringe line near termen. Hindwing whitish grey or grey; cilia white. Wing venation (Fig. 5 A, B).

Male genitalia (Fig. 5 C–F). Tegumen as long as valva. Vinculum bowl-shaped, with saccus long virgulate. Valva slender, acute at apex, with plumose setae occuring on interior part of apex. Aedeagus tubular, as long as valva; vesica without spines.

Female genitalia (Fig. 5 G). Apophysis anterioris and apophysis posterioris slender. Ostium bursae membranous; ductus bursae long, tubular. Corpus bursae small, with very small signum on central part.

Pupa. (Fig. 17). Pale yellow to ochreous, 2.8–3.0 mm in length, 0.3–0.4 mm in diameter. Vertex with a short, triangular frontal process (Fig. 17 B, C, E). Clypeus with a pair of short setae (Fig. 17 A, B, F). Dorsum of A2–A10 with a concentration of small spines in anterior portion (Fig. 17 G, H). A10 furcated with a pair of beak-shaped processes from caudal apex, rolled dorsally (Fig. 17 I, J–L).

Host plant. Dendropanax trifidus (Thunb.) Makino ex Hara, Evodiopanax innovans (Siebold & Zucc.) Nakai, Eleutherococcus sciadophylloides (Franch. & Sav.) H. Ohashi and Fatsia japonica (Thunb.) Decne. & Planch. (Araliaceae).

Distribution. Japan (Mie, Nara, Fukuoka, Kagoshima (Amami Is.) Prefectures).

Specimens examined

Type material. 15 (53 4Ƥ 6 exs).

Adults: Holotype 3, Japan: Kumawata, Soni, Uda, Nara, 12.x.2011 em., S. Kobayashi, Host: Evodiopanax innovans, 9.x.2011 (ex pupa) (genitalia slide no. OPU-SK366) in OPU. Paratypes 233Ƥ5exs. Same host plants as holotype, [Nishi–rokuban–cho, Yuri–gaoka, Nabari, Mie]: 1Ƥ, 23.xi.2009 em., S. Kobayashi & S. Teramura, 8.xi.2009 (ex larva); 13 1Ƥ 1 ex, 23.x.2010 em., S. Kobayashi, 16.x.2010 (ex larva). [Hikosan, Fukuoka, H. Kuroko leg.]: 2 exs, 10 & 14.xi.1954; 13 1Ƥ, 4 & 22.x.1955. 1 ex, 11.ix.1959, Host: Eleutherococcus sciadophylloides. 1 ex, 3.v. 1957 in OPU. [Kuninao, Yamato, Amami, Kagoshima, S. Kobayashi leg., 6.iii.2012 (ex pupa)]: 13 1Ƥ 1ex, 9–14.iii.2012 em., Host: Dendropanax trifidus,; 13, 20–22.iii.2012 em., Host: Fatsia japonica Pupae: 5 exs.

[Host: Evodiopanax innovans, S. Kobayashi leg.]: [Nishi–rokuban–cho, Yuri–gaoka, Nabari]: 1 ex, 23.x.2010, 16.x.2010 (larva); 4 exs, 12 & 26.ix.2011, 10.ix.2011 (ex larva).

Etymology. The specific epithet, araliella, is derived from the family name of the host plant, Araliaceae.

Biology. This species has 2–3 generations per year. The larvae emerged from July to November in Nara and Mie Prefectures. We observed larvae on Evodiopanax innovans forming a narrow, long serpentine mine; about 30~ cm in length, clear and colorless. The mines (Fig. 9 A–D) were only found on the abaxial epidermis of leaves, usually 1–3 mines per leaf. The late instar larva is 3.0–4.0 mm long and pale greenish yellow in coloration (Fig. 9 E–G). A pupal cocoon fold (white to creamy white, 4.5–5.0 mm in length, 0.8–1.0 mm in width) situated at the end of the mine, usually found along leaf margins (Fig. 9 H). We also observed the mined leaf of Fatsia japonica to be a narrow, long linear mine (whitish, about 20~ cm in length; 0.6–5 mm in width; brownish frass line: ~1.0 mm in width) (Fig. 10 C, E, F). A pupal cocoon fold (white, 9.0 mm in length, 2.0 mm in width) situated along leaf margins.

Biotope. The Kumawata valley (type locality of E. araliella) is part of Tokai Nature Trail connecting Soni Vilage and Uda City (Murō Vil.), Nara Prefecture with a planted forest of Japanese cedar and cypress mixed with fagaceous trees and with few host plants (Fig. 1 E).