Stilbops michinokuensis sp. nov.

(Figs. 2 H, 3 H, 4 H, 5 H, 6 H, 7 H, 8 H, 9 I, 10 H, 12 L, 13)

Diagnosis. Small species, body length 5.0 mm. Anterior tentorial pit small (Fig. 2 H), its margin not concealed by setae; lower part of gena with concavity in lateral view (Fig. 3 H). Upper end of epomia closely located with upper margin of pronotum in lateral view (Fig. 5 H). Apical 0.7 of clypeus yellow; legs except for coxae entirely yellow; metasomal tergites black, its lateral side tinged brown.

Description. Female (n=2). Body length 5.0 mm; length of fore wing 4.3 mm.

Head 0.6 times as long as wide; clypeus 0.6 times as long as wide, narrowly punctate dorsally, its margin convex in anterior view (Fig. 2 H); anterior tentorial pit small (Fig. 2 H), its margin not concealed by setae; face 0.6 times as long as wide, densely punctate, punctures on center part longitudinally or obliquely elongated; frons covered with punctures as face, area above antennal socket transversely striated; OOL 2.0 times as long as OD; POL 1.6 times as long as OD; lower end of occipital carina effaced (Fig. 4 H); GOI 0.6; lower part of gena with concavity in lateral view (Fig. 3 H); malar space 1.0 times as long as basal width of mandible; basal portion of mandible flat. Antenna with 17 flagellomeres; flagellomere I 1.2 times as long as II, and terminal flagellomere 4.0 times as long as preceding one; sensilla placodea present on flagellomere III and following all segments.

Mesosoma (Figs. 5 H, 6 H, 7 H, 8 H): lower margin of pronotum angulate (Fig. 5 H); upper end of epomia closely located with upper margin of pronotum in lateral view (Fig. 5 H); lateral area of pronotum punctate except for smooth area on lower 0.2–0.3, transversely rugulose along lower half of posterior margin (Fig. 5 H); mesoscutum with weak notaulus on anterior 0.3; smooth area around episternal scrobe rather small; upper end of epicnemial carina reaching lower 0.2–0.3 of pronotum; juxtacoxal carina present; all carinae of propodeum present except for lateral part of anterior transverse carina and partly effaced middle section of lateral longitudinal carina, anterior part of lateromedian longitudinal carinae coalescent (Fig. 8 H); all areas of propodeum punctate except for area superomedia largely smooth (Fig. 8 H).

Fore wing: Cu-a distant from Rs&M by 0.6 times length of Cu-a; ICI 0.8. Hind wing: NI 5.0; one basal hamulus, five distal hamuli.

Hind femur 4.8 times as long as deep in lateral view; hind tibia 8.5 times as long as deep in lateral view; hind tarsomere ratio I; II; III; IV; V = 3.0; 1.3; 1.0; 0.5; 0.8.

Metasoma: TI 1.2–1.3 times as long as maximum width, with median dorsal carina on near anterior 0.4, without distal depression, and lateral margin weakly convex basally (Fig. 10 H); TII and TIII with slight round convexities; subgenital plate covered with shallow and fine punctures. Ovipositor straight; ovipositor sheath 0.5 times as long as hind tibia.

Coloration (Figs. 6 H, 7 H, 9 I, 12 L): body black, except for: apical 0.7 of clypeus yellow; yellow mandible except for base and apex; yellow palpi; antenna blackish-brown, its ventral side more or less yellow; yellow tegula; all legs yellow except for coxae brackish-brown to black; wing veins and stigma yellowish-brown; lateral side of metasomal tergites blackish-brown; metasomal sternites blackish-brown except for membranous area yellow; ovipositor yellow to yellowish-brown.

Male. Unknown.

Type series. Holotype: female [Honshu] Yamagata Pref., Mts. Iide, Yachidaira, 19. vi. 1988, K. Konishi leg. (NIAES). Paratype: [Honshu] 1Ƥ, Iwate Pref., Yamada, 29–30. v. 1989, Y. Katayama leg. (NIAES).

Distribution. Japan (Honshu) (Fig. 13).

Etymology. The specific name is from the “Michinoku”, referring to the local name of Tohoku district, north of Japan.

Remarks. This species is the most slender and smallest species of Japanese Stilbops . This species closely resembles kunashiricus in the reduction of propodeal carina and can be distinguished from the latter by the smaller body, the yellow clypeus (completely black in kunashiricus), the black metasomal tergites (usually partly red in kunashiricus) and the lateral margin weakly convex basally (straight in kunashiricus).