Key to known males of Onconeura Andersen et Saether
1. Antenna with 10 or less flagellomeres.......................................................................................................................... 2
- Antenna with more than 10 flagellomeres.................................................................................................................... 4
2. Superior volsella wide with a concave posterior margin. (Figs 1 B, 4B) ...................................................................... 3
- Superior volsella narrow, posterior margin almost straight (Fig. 2 B) ......................................... Onconeura japi sp.n.
3. Inferior volsella small; median margin of gonocoxite ventrally with two protuberances bearing setae, in addition to superior and inferior volsella (Fig. 1 B)............................................................................. Onconeura cascatinha sp.n.
- Inferior volsella large; median margin of gonocoxite straight and without protuberances (Fig. 4 B) ............................ ........................................................................................................................................ Onconeura oncovolsella sp.n.
4. AR 0.6 – 0.7; wing longer than 0.9 mm; antenna with 11 flagellomeres; tergites III and IV with more than 9 setae .. 5
- AR lower and wing length shorter than above; antenna with 12 flagellomeres; tergites III and IV with less than 9 setae.............................................................................................................................................................................. 6
5. Phallapodeme strongly curved posteriorly (Andersen & Saether 2005, fig. 1H)............................................................ ....................................................................................................... Onconeura undecimata Andersen et Saether, 2005
- Phallapodeme slightly bent posteriorly (Paggi 1985, fig. 9) ................................ Onconeura desertica (Paggi, 1985)
6. One seta on laterosternite IX; anal lobe absent on wing (Figs 6 A, B) ............................ Onconeura similispina sp.n.
- Two or three setae on laterosternite IX; anal lobe present .......................... Onconeura semifimbriata (Saether, 1981)