Key to adult male Oxyagrion lacking blue spots and with dorsum of abdominal segment ten without horns

1. Dorsum of abdominal segments 8–9 black .................................................................. 4

1’. Dorsum of abdominal segments 8–9 red ...................................................................... 5

2. Dorsum of abdominal segments 7–9 black; cerci, in lateral view equal in length to paraprocts (Fig. 7, 9) ...................................................................................... O. zielmae

2’. Dorsum of abdominal segment 7 red, segments 8–10 black; cerci, in lateral view, shorter than paraproct (Fig. 8, 10) ............................................................... O. miniopsis

3. Paraprocts shorter than 1/2 length of cerci (Fig. 11); apical segment of genital ligula with long lobes on segment III ..................................................................... O. rubidum

3’. Paraprocts longer than 1/2 length of cerci (Fig. 12); apical segment of genital ligula with short lobes on segment III .................................................................... O. pavidum