Key to species of genus Neopius Gahan

1. Face yellow; notauli nearly complete, basal half crenulate and gradually reduced posteriorly; vein m-cu of fore wing shorter than vein 2-CU1; occiput rather straight in dorsal view.......................................... N. citrinus sp. n.

- Face largely dark brown; notauli complete, extended to medio-posterior depression; vein m-cu of fore wing about 1.5× vein 2-CU1; occiput concave in dorsal view................................................. N. rudis Wesmael, 1835