Key to Japanese species of Stenoscelis

1 Upper margin of scrobe directed to middle of eye (Figs 2, 4, 6, 18, 20, 22 & 24)................................... 2

- Upper margin of scrobe directed to lower margin of eye (Figs 41, 43, 45 & 47).................................... 6

2 Epistome with a pair of tufts of long setae basally (Fig. 68); apex of elytra conjointly acuminate (Fig. 78)..... S. acutipennis

- Epistome with six long setae basally (Figs 69–77); apex of elytra conjointly rounded (Figs 79–81 & 83) or separately produced in a small process (Fig. 82).............................................................................. 3

3 Elytral intervals on declivity with setae as long as or shorter than granules and arranged irregularly in two or three rows (Fig. 79).................................................................................... S. brevithoracicus

- Elytral intervals on declivity with setae longer than granules and each arranged behind a granule in a single row (Figs 80–82) ................................................................................................... 4

4 Rostrum dorsally concave in male, convex in female (Figs 18 & 20); striae of elytra on declivity reticulate, without punctures (Fig. 80)................................................................................... S. cavirostris

- Rostrum dorsally convex in both sex (Figs 22 & 24); striae of elytra on declivity not reticulate, with a row of punctures (Figs 81 & 82)............................................................................................ 5

5 Apex of elytra conjointly rounded (Fig. 81), obtusely angulated in lateral view (Fig. 22); aedeagal body approximately 1.4 times as long as wide, 1.0 times as long as apodeme (Figs 30 & 31); spermatheca with collum developed and ramus not developed (Fig. 34)................................................................................. S. longisetosus

- Apex of elytra separately produced in a small process (Fig. 82), acutely angulated in lateral view (Fig. 24); aedeagal body approximately 1.7 times as long as wide, 1.4 times as long as apodeme (Figs 35 & 36); spermatheca with collum and ramus developed (Fig. 39)............................................................................... S. aceri

6 The subapical sclerotized structure of endophallus with a large spatulate projection on dorsal side. (Figs 48 & 49)...................................................................................................... S. matobai

- The subapical sclerotized structure of endophallus with a pair of projections on dorsal side (Figs 53, 54, 58, 59, 63 & 64)... 7

7 The subapical sclerotized structure of endophallus reniform (Fig. 53)................................... S. reniformis

- The subapical sclerotized structure of endophallus ovate (Figs 58 & 63).......................................... 8

8 The subapical sclerotized structure of endophallus without separated part basally; the pair of projection on dorsal side short (Figs 58 & 59)............................................................................ S. gracilitarsis

The subapical sclerotized structure of endophallus with a separated part basally; the pair of projection on dorsal side long (Figs 63 & 64)............................................................................... S. ogasawarensis