(Figs 1b, 3b, 5b, 7b, 9b, 11b, 13b, 15b, 17c)

Diagnosis. Face swollen, 0.75x as high as wide; scutellum flat, without lateral carina; metapleuron with posterior 0.4 of submetapleural carina present; mid and hind tibiae with extensive areas of densely packed, stout bristles; ovipositor tip lower valve with apical vertical and basal oblique ridges, enclosing tip of upper valve; ovipositor sheath 0.45x hind tibia.

Description (Holotype female). Body length 10.0 mm, fore wing 9.0 mm, ovipositor sheath 1.0 mm. Head. First antennal flagellomere 1.6x length of second; diameter of lateral ocellus equal to ocellar-ocular distance; frons polished; face swollen, distinctly protruding anterior to level of compound eyes, 0.75x as high as wide, with moderate-sized punctures, densely pubescent; clypeus 0.45x as high as wide, apical margin thin, emarginate; malar space about 0.35x basal width of mandible.

Mesosoma. Epomia short; lower anterior corner of pronotum rounded at about 95°; mesoscutum weakly convex, with moderately dense, short hairs anteriorly; notaulus short, shallowly present anteriorly; scutellum flat, pubescent, without lateral carina; mesopleuron with sparse, fine punctures, pubescent, subtegular ridge narrow; epicnemial carina present on lower half, postpectal carina medially forming wide, low flange; metapleuron polished, posterior 0.4 of submetapleural carina weakly present; propodeum without carinae, except pleural carina and posterior 0.2 of lateral longitudinal carina; propodeal spiracle elongate, located at centre of pleural area. Hind leg with femur 2.3x as long as wide, 0.7x length of tibia, hind basitarsus 0.3x length of tarsus, 2.15x second tarsomere, third tarsomere as long as wide; mid and hind tibiae with extensive patch of densely packed, stout bristles covering apical 0.7; largest bristles on mid and hind tarsal claws widened. Fore wing with vein 2 rs-m about 0.77x vein 3 rsm; cu-a opposite Rs+M; hind wing with first abscissa of vein Cu 1 about 0.2x length of vein cu-a.

Metasoma. First tergite 1.05x as long as apical width; dorsolateral carina present from base to spiracle, median longitudinal carina shortly present at base; oblique groove absent; tergite 3 impunctate medially; tergites 4–5 with dense, moderate-sized punctures; ovipositor straight, lower valve with apical vertical and subapical oblique ridges enclosing tip of upper valve, ovipositor sheath 0.45x length of hind tibia.

Colour. Lemon yellow; upper face of antenna black, lower face brown to dark brown, outer side of scape and pedicel yellow, three apical flagellomeres reddish brown; black ocellar area extending to frons and narrowly to hind slope of head; mesoscutum with lateral black mark elongate, joined posteriorly to black mark in front of scutellum, median black spot heart-shaped; propodeum with large lateral and small median black spots basally; mid leg with fifth tarsomere blackish; hind trochanter marked with black, hind femur black apically; basal 0.2 of hind tibia and fifth tarsomere black; wings hyaline with infuscate margins, pterostigma and veins dark brown, except costa yellowish; tergite 1 with black band; tergite 2 with two small, tergites 3–5 with medium-sized and tergite 7 with large black spots.

Male. Similar to female, slightly smaller.

Comparision. The new species can be distinguished from the Indian X. xystra Townes & Chiu, previously the only species included in the xystra species group, by the swollen face, flat scutellum and shorter ovipositor sheath (0.45x hind tibia versus 0.70x). Moreover, X. boehmei sp. nov. has the posterior 0.4 of the submetapleural carina present, the lateral black mark on the mesoscutum is joined posteriorly to the black mark in front of the scutellum, and tergite 2 has two black spots.

Etymology. This species is named after Prof. Dr Wolfgang Böhme (Zoological Research Museum Alexander Koenig, Bonn), in recognition of his support for the study of the first author in Germany and his contribution to biodiversity research in Vietnam.

Distribution. Currently known only from Chu Yang Sin NP, Dak Lak Province, Central Highlands of Vietnam (Fig. 19).

Ecological notes. The specimens were collected in evergreen forest.

Material examined. Holotype: ♀ (IEBR), Dak Lak, Chu Yang Sin NP, 28.vii.2008, H. T. Ngo leg.; Paratype: 1♂ (BMNH), same data as holotype.