Key to Japanese species of the genus Stilbops

(Males of auster, japonicus and michinokuensis are unknown)

1. Anterior tentorial pit large, its maximum diameter more than 1/3 length of OD. Apical margin of clypeus sometimes notched medially in anterior view (Fig. 2 C, G). Basal portion of mandible convex (Fig. 3 K, M). Face covered with dense and long setae................................................................................................ 2

-. Anterior tentorial pit normal size, its maximum diameter less than 1/3 length of OD. Apical margin of clypeus convex or subtruncate in anterior view (Fig. 2 A, B, D-F, H-J). Basal portion of mandible flat (Fig. 3 L). Setae on lower part of face not remarkably denser and longer than upper area............................................................... 3

2. Apical margin of clypeus with median notch (Fig. 2 C). Lower end of occipital carina effaced (Fig.4 C). Hind femur black (or sometimes blackish-brown) (Fig. 12 D, E)................................................ S. coeloclypeus sp. nov.

-. Apical margin of clypeus without median notch (Fig. 2 G). Lower end of occipital carina complete (Fig. 4 G). Hind femur brown, not black (Fig. 12 K)................................................... S. mandibularis Kasparyan, 1999

3. Lower part of gena with convex profile in anterior view (Fig. 2 B); in lateral view, strongly concave (Fig. 3 B). Lower end of occipital carina reaching base of mandible (Fig. 4 B). Female with tergites red except for base of TI (Fig. 9 B). Hind leg largely yellow including hind coxa (Fig. 12 B, C)............................................ S. cavigena Kasparyan, 1984

-. Lower part of gena with flat profile in anterior view (Fig. 2 A, D-F, H-J); in lateral view, varying from weakly concave to flat (Fig. 3 A, D-F, H-J). Lower end of occipital carina effaced, not reaching mandibular base (Fig. 4 A, D-F, H-J). Hind coxa always largely black, remainder of hind leg black or yellow (Fig. 12 A, F-J, L-O)................................... 4

4. Hind femur and tibia largely black or blackish-brown (Fig. 12 A, F, G, M, N)....................................... 5

-. Hind femur and tibia largely yellow or brown (Fig. 12 C, H-J, O)................................................ 8

5. Tegula yellow (Fig. 6 A). Lower part of gena not concave (Fig. 3 A)................................ S. auster sp. nov.

-. Tegula black (Fig. 6 D, I). Lower part of gena concave (Figs. 3 D, I)............................................. 6

6. Antenna with 16 flagellomeres. OOD 1.4 times as long as OD. Vein Cu-a of fore wing distant from Rs&M by less than 0.5 times length of Cu-a............................................................. S. femoralis Kasparyan, 1999

-. Antenna with 17 or 18 flagellomeres. OOD 1.4–1.8 times as long as OD. Vein Cu-a of fore wing distant from Rs&M by more than 0.6 times length of Cu-a............................................................................ 7

7. Hind tibia 8.7–8.9 times as long as deep in lateral view. TI 1.2–1.3 (in female) or 1.7 (in male) times as long as wide. Metasomal tergite usually almost black......................................................... S. ezoensis sp. nov.

-. Hind tibia 7.8–8.5 times as long as deep in lateral view. TI 1.3–1.4 (in female) or 1.4–1.6 (in male) times as long as wide. Metasomal tergite usually broadly tinged with red............................................ S. montanus sp. nov.

8. Body densely punctate. Punctures on lateral lobes of mesoscutum separated by 0.3 to 0.9 times their diameter. Lower parts of gena not concave in lateral view (Fig. 2 E).................................................. S. japonicus sp. nov.

-. Body moderately punctate. Punctures on lateral lobes of mesoscutum separated by 1.0 to 1.2 times their diameter. Lower parts of gena more or less concave in lateral view (Fig. 2 F, H, J).................................................... 9

9. Body length about 5.0 mm. Area dentipara of propodeum with lateromedian longitudinal carina complete (Fig. 8 H). Tergites completely black (Fig. 9 I). Clypeus partly yellow. Tegula yellow (Figs. 6 H, 7 H).............. S. michinokuensis sp. nov.

-. Body length about 5.5–6.5 mm. Area dentipara of propodeum with lateromedian longitudinal carina sometimes absent (Fig. 8 F). TII and following tergites red (some specimens of kunashiricus black) (Fig. 9 F, G, K). Clypeus completely black. Tegula yellow or black...................................................................................... 10

10. Pronotum nearly entirely punctate (Fig. 5 F). Area superomedia of propodeum incomplete (Fig. 8 F). Propodeum largely covered with punctures (Fig. 8 F). Tegula yellow (Figs. 6 F, 7 F). Tergites sometimes black in female (Fig. 9 G).......................................................................................... S. kunashiricus Kasparyan, 1999

-. Pronotum with large smooth area on lower half (Fig. 5 J). Area superomedia of propodeum complete (Fig. 8 J). Propodeum covered with fine, small punctures (Fig. 8 J). Tegula black (Figs. 6 J, 7 J). Tergites always red in females (Fig. 9 J)......................................................................................... S. orientalis Kasparyan, 1984