Metriochroa fraxinella Kumata, 1998

Kobayashi, Shigeki, Huang, Guo-Hua, Nakamura, Akihiro & Hirowatari, Toshiya, 2013, Four new species of Gracillariidae (Lepidoptera) from China and Japan, and description of the pupal morphology of the genera Corythoxestis, Eumetriochroa, Guttigera, and Metriochroa, Zootaxa 3619 (2), pp. 101-129 : 110

Metriochroa fraxinella Kumata, 1998

Fig. 15 .

Metriochroa fraxinella Kumata, 1998: 100 –103, figs 8, 13(A, B), 15(A), 26(A, B). Type locality: Japan (Nagano).

Pupa. ( Fig. 15 ). Yellow, 3.4–4.1 mm in length, 0.5–0.6 mm in diameter. Vertex with a small triangular frontal process ( Fig. 15 B, E, H). Dorsum of A2–A10 with a pair of short setae ( Fig. 15 F, I). A10 furcated with a pair of short stick-shaped processes from caudal apex, rolled dorsal side ( Fig. 15 M); second pair of anteriorly curved, small conical, caudal processes from dorsal side ( Fig. 15 N–O); third pair of laterally curved, short, stout caudal processes ventrally ( Fig. 15 K).

Host plant. Fraxinus spp., Fraxinus sieboldiana Blume , Ligustrum japonicum Thunb. , L. micranthum Zucc. in Japan, Oleaceae ( Kumata 1998) .

Distribution. Japan (Honshu, Kyushu, Ogasawara Is.) ( Kumata 1998).

Specimens examined. 2 exs.

Adults: [Host: L. japonicum ]: 1 ex, Owada, Saitama, 24.iii.2012 em., R. Osada, 11.iii.2012 (ex pupa); 1 ex, Mikata, Mitsushima, Tsushima Is., Nagasaki, 20.iv.2012 em., S. Kobayashi, 27.iii.2012 (ex larva).

Pupae: 3 exs.

1 ex, Owada, Saitama, 24.iii.2012, R. Osada, 11.iii.2012 (ex pupa); 2 exs, Mikata, Mitsushima, Tsushima Is., Nagasaki, S. Kobayashi, 27.iii.2012 (ex larva).

Biology. Kumata (1998) recorded the biology of this species. In the present study, we newly recorded the length and/or width of mines, larvae, and cocoon folds. We observed larvae on Ligustrum japonicum forming a serpentine mine on the adaxial epidermis; whitish, 0.4–2.0 mm in width; frass line: ~0.5–1.0 mm in width; usually 1–2 mines per leaf. The late instar larva is 5.5 mm long and yellow in coloration. A pupal cocoon fold (yellow to brown, 8.0–10.0 mm in length, 1.9–2.6 mm in width) is situated at the end of the mine, usually along a leaf margin.

Figures

FIGURE 15. Pupa of Metriochroa fraxinella Kumata, 1998. A. Head, ventral view. B. Cocoon cutter, ventral view. C. Frons. D. Head, lateral view. E. Cocoon cutter, lateral view. F. Spines on 7 th abdominal tergum, lateral view. G. Head, dorsal view. H. Cocoon cutter, dorsal view. I. Spines on 7 th abdominal tergum. J. A 7 – A 10, ventral view. K. Cremaster, ventral view. L. Anus. M. A 8 – A 10, lateral view. N. Dorsal view. O. Caudal processes on A 10, dorsal view. ds: dorsal seta; sds: subdorsal seta; ls: lateral seta; vp: ventral process of cremaster.