1. Oncopsis sulphurea Anufriev, 1967

Figs. 1–5, 59–63

Description. Cuticle very smooth, shiny. Males from Southern Maritime Territory yellow with dark pattern on face, pro- and mesonotum (Figs. 1, 4–5); forewings strongly infumose with yellowish scutellar margins and transparent areas on costal margins. Males from Kurile Islands brownish yellow, dark pattern is almost absent (Fig. 2). Females from mainland and island populations bright yellow without dark pattern (Fig. 3).

Penis rather narrow in caudal view (Fig. 59), with ventral margin convex in side view (Figs. 60–61). Lower appendage of dorsal connective slightly bent ventrally, with forked apical part C-shaped, upper branch somewhat longer and wider than lower one (Figs. 61–62). Style parallel-margined, with acute tip (Fig. 63).

Body length (including tegmina): ♂, 5.0– 5.6 mm; ♀, 5.5–5.8 mm.

Differs from most other Russian species in coloration. In external appearance, dark colour form somewhat similar to O. nitobei (Matsumura, 1912), O. furva Anufriev, 1977, and O. sepulcralis Anufriev, 1967 (Figs. 6–7, 10–12, and 16–17). Differs from all Russian species by the shape of the lower appendage of dorsal connective.

Host. Betula sp. in Russia, B. ermanii in Japan (Hayashi et al., 2005).

Distribution. Russia: Southern Maritime Territory (Southern Sikhote-Alin’ Mtn. Ridge), Kurile Islands (Shikotan, Kunashir); Japan: Hokkaido, Honshu (Hayashi et al., 2005).