Stephanus bidentatus van Achterberg & Yang, 2004

Hong, Chun-dan, van Achterberg, Cornelis & Xu, Zai-fu, 2011, A revision of the Chinese Stephanidae (Hymenoptera, Stephanoidea), ZooKeys 110, pp. 1-108 : 41-43

Stephanus bidentatus van Achterberg & Yang, 2004 Figs 376386

Stephanus bidentatus van Achterberg and Yang 2004: 104-106.

Type material.

Holotype, ♀ (CAFB), "CHINA: Henan, Longyuwan, Lianchuan, 700m, on trunk of Quercus tree with Cerambycidae larvae, 13.vii.1996, Zhong-qi Yang".

Other material.

1 ♀ (SCAU): CHINA: Henan, Neixiang County, Baotianman, 13-15.vii.1998, Yun Ma, No. 987231.

Diagnosis.

Pronotum without distinct pronotal fold medially (Figs 377, 378); small part of vein M+CU of hind wing pigmented; scutellum densely rugose (Fig. 379); hind femur with 2 large ventral teeth (Fig. 383); first metasomal tergite more slender, about 9 times as long as its maximum width (Figs 384, 385).

Description.

Redescribed after a female from Henan (Baotianman), length of body 17.7 mm, of fore wing 11.9 mm, and of ovipositor sheath 28 mm.

Head. Flagellum with 25 flagellomeres; first flagellomere 3.9 times as long as wide, and 0.7 times as long as second flagellomere; frons (Fig. 382) coarsely reticulate and densely setose; three anterior lobe-shaped coronal teeth of head large, hardly larger than both posterior ones; vertex with four curved, progressively smaller carinae behind level of both posterior coronal lobes, remainder of vertex rather coarsely reticulate-rugose, sculpture becoming finer posteriorly and narrowly reaching occipital carina (Fig. 380); temples smooth except for some small punctures bearing setosity ventrally (Fig. 381), shiny and rather angulate in dorsal view.

Mesosoma. Neck (Fig. 377) comparatively short and robust, anteriorly shallowly emarginate, medio-dorsally smooth and laterally with several coarse and irregular carinae which curved backwards, postero-dorsally at lower level than middle pronotum, with a distinct cavity below pronotal fold; pronotal fold distinctly developed laterally and absent medially; middle pronotum robust, coarsely and irregular rugose, not distinctly differentiated from posterior pronotum (Figs 377, 378); lateral oblique groove of pronotum distinct and rather wide, impression largely carinate and ventral area below it coarsely rugose (Fig. 378); postero-laterally narrowly short setose; posterior part of pronotum dorsally coarsely transversely rugose and somewhat smooth and shiny posteriorly; mesoscutum laterally coarsely rugose-reticulate, medially densely foveolate-rugose, notauli and median groove rather distinct; scutellum completely coarsely reticulate-rugose; axillae densely foveolate (Fig. 379); propleuron coarsely punctate; convex part of mesopleuron reticulate-foveolate and covered with whitish and rather sparse setosity; dorsal part densely rugose and setose; mesosternum with spaced punctures; medially metapleuron strongly convex, coarsely foveolate-reticulate and with short whitish setosity, antero-ventrally weakly crenulate and with dorsal anterior depression rather deep and ventral one less impressed; propodeum (Fig. 379) densely and irregularly rugose-foveolate.

Wings. Fore wing (Fig. 376): vein 1-M 3.6 times as long as vein 1-SR and nearly straight. Hind wing: vein M+CU only partly pigmented and after middle of wing.

Legs. Hind coxa moderately slender, subparallel-sized, largely coarsely rugose, but posterior third striate; hind femur (Fig. 383) slender, largely finely transversely striate, with two acute, large teeth and some denticles in between, laterally with spaced, small punctures and each bearing a whitish seta; basal narrow part of hind tibia 1.3 times long as widened part, parallel-sided and with ventral carina; outer side of widened part of hind tibia coriaceous, with small sparse punctures bearing whitish setae (Fig. 383); inner side flattened, sparsely granulate, apically with densely bristly setose area; hind basitarsus parallel-sided, basally hardly curved, ventral length 8.3 times its width.

Metasoma. First tergite (Figs 384, 385) subcylindrical, 8.9 times as long as its apical width, basally coarsely reticulate-rugose, remainder irregularly and densely rugose (Fig. 384); second tergite basally rugose, remainder mainly smooth; pygidial area not lamelliform posteriorly, pygidial impression reverse V-shaped; length of ovipositor sheath 1.5 times as long as length of body.

Colour. Blackish or dark brown; face brownish; malar space yellowish, distinctly contrasting to dark colour of temple and vertex; fore wing membrane largely pale brownish; tibiae, tarsi brownish, and hind trochantellus pale brownish; ovipositor sheath completely blackish (Fig. 386).

Biology.

A parasitoid of Cerambycidae larvae in Quercus sp., and probably in other deciduous trees ( van Achterberg and Yang 2004).

Distribution.

Palaearctic China (Henan).

Notes.

The name refers to the two ventral teeth of the hind femur. This species is unique in the Stephanidae by the combination of the hind tarsus with five tarsomeres in female and the hind femur with two large ventral teeth ( van Achterberg and Yang 2004).