Key to Japanese Gibberifera species

1 Cucullus oval (Fig. 11); vesica with 15–19 deciduous cornuti and two or three non-deciduous ones (Fig. 12); papilla analis broad (Fig. 15); sclerite plate of signa in female genitalia small (Fig. 15)................. G. hepaticana Kawabe & Nasu

- Cucullus oblong (Figs 7, 9); vesica with 10–12 deciduous cornuti and without non-deciduous ones (Figs 8, 10); papilla analis narrow and long (Figs 13, 14); sclerite plate of signa in female genitalia broad (Figs 13, 14).......................... 2

2 Vertex white (Fig. 5); hindwings light grayish brown (Fig. 5); uncus deeply bifurcated and Y-shaped (Fig. 9); sterigma laterally elongated plate, with posterior edge not convex (Fig. 14); colliculum small and ring shaped (Fig. 14); ductus bursae not wrinkled (Fig. 14); corpus bursae globular (Fig. 14)........................... G. simplana (Fischer von Röslerstamm)

- Vertex grayish brown (Fig. 4); hindwings grayish brown (Figs 1–3); uncus shallowly bifurcated, with two short arms (Fig. 7); sterigma small oblong plate, with posterior edge rather convex (Fig. 13); colliculum as long as 2/5 of ductus bursae (Fig. 13); apical 2/5 of ductus bursae wrinkled and slightly constricted anteriorly (Fig. 13); corpus bursae inverse pear-shaped (Fig. 13)................................................................................... G. xylosmae sp. nov.