Key to known larvae of Onconeura Andersen et Saether

1. AR lower than 1.8; median tooth of mentum as long as adjacent teeth ..................................... O. oncovolsella sp.n.

- AR higher than 1.8; median tooth of mentum usually shorter than adjacent teeth...................................................... 2

2. Ventral head length shorter than 225 µm ............................. Onconeura japi sp. n. and Onconeura similispina sp.n.

- Ventral head length longer than 225 µm ..................................................... Onconeura semifimbriata (Saether, 1981)