Key to adults of Yangus species in the World

1 Body relatively large. Male and female forewing length more than 2.0 mm and 2.3 mm, respectively................................................................................................... Y. hyalinus (Mathur, 1975)

- Body relatively small. Male and female forewing length less than 1.6 mm and 1.9 mm, respectively.................... 2

2 Antenna relatively long. Antennal length/ head width ratio more than 1.2.......................... Y. pennatae Li, 2011

- Antenna relatively short. Antennal length/ head width ratio less than 0.8.......................................... 3

3 Forewing long oblong oval, almost parallel; pterostigma straight. Paramere curved subapically. On Harrisonia perforata ( Rutaceae).......................................................................... Y. burckhardti sp. nov.

- Forewing oval, slightly narrowing to the apex in apical half; pterostigma curved. Paramere recurved subapically. On Albizia odoratissima ( Fabaceae)........................................................... Y. oblongus (Mathur, 1975)