Key to identify nymphs of Callibaetis subgenera

1. Anterior surface of forefemur near ventral margin without trifid or bifid setae (Fig. 19 A)................. Cunhaporanga

1’. Anterior surface of forefemur near ventral margin with trifid or bifid setae (Fig. 15 B)................................2

2. Posterior surface of hind femur with two rows of curved and pectinated setae (Fig. 19 F in Cruz et al. 2014)...... Callibaetis

2’. Posterior surface of hind femur without rows of curved and pectinated setae (Fig. 15 E in Cruz et al. 2014)...............3

3. First segment of maxillary palp and labial palp without stout setae (Figs 2 E and 2G)........................ Abaetetuba

3’. First segment of maxillary palp and labial palp with stout setae (Figs 10 E)..................................... Aiso