Key to species of Heteropodagrion and Mesagrion

1. RP 3 arising before subnodus (Fig. 2d), with supplementary sectors between IR1and RP 2, IR2 and RP 2, and IR2 and RP 3–4; females without excisions on prothoracic anterior margin......................................................2

1´RP 3 (at least in Fw) arising at or little beyond subnodus, without supplementary sectors between IR2 and RP 2 (Fig. 3 a, b); females with excisions on prothoracic anterior margin (Fig. 3 c).............................. Mesagrion leucorrhinum

2. Paraproct less than 0.25 length of cercus; apical segment of genital ligula armed with a long flagellum with screw-like tip (Fig. 3 f); female with basal and distal dark rings on all abdominal segments; distribution: Panamá and western Cordillera (Colombia), Ecuador ................................................. Heteropodagrion superbum / sanguinipes complex

2´Paraproct longer than cercus (Fig. 2f, g); apical segment of genital ligula bilobulate, trumpet-shaped, and with laterally expanding distal lobes surpassing middle region of ligula in lateral view (Fig. 2i, h); female with basal pale rings on all abdominal segments; distribution: Putumayo Dept., Colombia and possibly Ecuador ................. Heteropodagrion croizati