Genus Discoelius Latreille, 1809

Discoelius Latreille 1809: 140, subgenus of Eumenes Latreille. Type species: Vespa zonalis Panzer, 1801, by monotypy. Senior objective synonym of Tritodiscoelius Dalla Torre, 1904 according to Bequaert & Ruiz 1942: 217. Raised to generic rank by Latreille 1810: 328.

Discoelius: Vecht & Fischer 1972: i–v+199; Carpenter 1986: 6 –8; van der Vecht & Carpenter 1990: 19; Kim 2005: 111 –112; Zhou et al. 2013: 45 –46.

Diagnosis. Mandibles short, obliquely truncate apically, wider at apex than at base, not distinctly cross each other (only tip of mandibles overlap). Clypeus wider than long, with truncate apical margin. Cephalic fovea absent. Vertex not sloping behind ocelli. Anterior face of pronotum without medial pits or foveae. Pronotal carina complete. Epicnemial carina present. Pretegular carina present. Mesoscutum with notauli present (Fig. 28). Tegula much longer than broad, with distinct emargination on its posterior inner margin where it adjoins parategula, posterior end much exceeding end of parategula (Fig. 28). Metanotum oblique, not dentate. Axillary fossa wide. Propodeum without dorsal shelf, sloping posteriorly. Superior carinae absent. Propodeal valvula elongate, not free from submarginal carina posteriorly (Fig. 40). Propodeal orifice wide dorsally (Fig. 39). Metasoma petiolate, T1 less than half as broad as T2, T1 strongly widened in middle then becomes oval (Fig. 70). T 2 in dorsal view bellshaped with apical lamellae. S1 visible along entire petiole length, lateral margins of T1 not approaching each other ventrally and not fused. Mid tibia with two apical spurs (Fig. 44). SMC 2 basally truncate. Prestigma shorter than pterostigma, sometimes almost absent. Male specimens not examined. Body length usually more than 20 mm.

Distribution. Oriental and Palearctic Regions. New report from south India.