Brachyzapus Gauld and Dubois, 2006: 544.

Type-species: Polysphincta tenuiabdominalis Uchida, original designation.

Diagnosis

Eyes with scattered, minute hairs; mandible twisted about 60–85 ◦, narrow, upper tooth slightly to distinctly longer than lower; clypeus moderately to strongly convex, separated from face by more or less impressed clypeofacial suture; palpi formula 5: 4; pronotum with upper part of epomia strong and subvertical; mesoscutum moderately long, with impressed notauli, posterolateral flange of mesoscutum strongly broadened; mesopleuron with epicnemial carina well developed, its upper end remote from anterior margin of pleuron; mesopleural sulcus angled opposite mesepisternal scrobe; submetapleural carina complete; propodeum with at least posterior part of lateral longitudinal carina present, posterior transverse carina strong when complete, propodeal spiracle round, not touching pleural carina; tarsal claws of female moderately long, with high basal lobe; fore wing with 3 rs-m entirely absent; hind wing with basal abscissa of M + Cu evenly bowed; distal abscissa of Cu 1 present, spectral; metasoma insertion separated from hind coxal cavities by strong sclerotized bridge; first tergite elongate; second tergite usually with weak anterolateral oblique grooves; ovipositor straight or up-curved at tip, slender, awl-like, without basal ventral swelling.

Gauld and Dubois (2006) provided a key to genera of the Polysphincta -group and all Vietnamese species of Brachyzapus will key easily to Brachyzapus.