1	Metasomal sternum II basally strongly swollen, in lateral view bulging anteriorly (Fig. 21)	2
–	Metasomal sternum II gradually swollen posteriorly, in lateral view with ventral margin weakly and smoothly curved (Fig. 8)	3
2	Clypeus in lateral view only weakly convex anteriorly (Fig. 22). Disc of scutellum nearly flat, in lateral view smoothly passing from dorsal margin of mesoscutum (Fig. 24). Male clypeus as wide as high	Polistes dawnae Dover & Rao
–	Clypeus in lateral view distincly convex (Fig. 23). Disc of scutellum convex (Fig. 25). Male clypeus about 1.1 times as wide as high	Polistes mandarinus de Saussure
3	Medium-sized wasps; fore wing length 10.5−14.5 mm. Jugal lobe of fore wing much reduced. Marginal cell of fore wing with dark spot at apex	Polistes delhiensis Das & Goupta
−	Large-sized wasps; fore wing length 15.5−18 mm. Jugal lobe of fore wing large, rounded. Marginal cell of fore wing without dark spot	4
4	Pronotum with strong striation (Figs 26, 27) Female metasomal sterna without longitudinal ridges	5
–	Pronotum with weak striation weak or absent. Female metasomal sternum IV medially with paired longitudinal ridges (Fig. 9)	6
5	Pronotal striation somewhat irregular (Fig. 26), spaces between striae densely and distincly punctured. Dorsal surface of pronotum smoothly curved down to the lateral surface. Male metasomal sternum VII without tubercle. Clypeus, mesoscutum, metasomal segments III−VI entirely black	Polistes sagittarius de Saussure
–	Pronotal striation regular and very strong (Fig. 27). Border between dorsal and lateral surfaces of pronotum distinctly angled. Male metasomal sternum VII with weak tubercle (Fig. 28). Clypeus, mesoscutum, metasomal segments II−VI etirtely brown	Polistes strigosus Bequaert
6	Pronotum with dense, coarse punctures, their edges forming reticulation (Fig. 6). Disc of scutellum convex. Metasomal sternum II in lateral view convex ventrally in anterior half. Anterior margin of male clypeus nearly straight (Fig. 10). Metasomal terga brown, with some black marks. Wings hyaline	Polistes brunetus Nguyen & Kojima, sp. n.
–	Pronotum with sparse, small punctures. Disc of scutellum hardly convex. Metasomal sternum II in lateral view weakly convex ventrally in the anterior two thirds. Anterior margin of male clypeus rounded. Metasomal terga yellow with dark brown and/or black bands. Wings infuscate	Polistes japonicus de Saussure