Aproctella alessandroi n. sp., parasitic in various Passeriformes in Colombia and Guadeloupe, and A. golvani n. sp., a similar species with smaller microfilariae parasitic in sparrows in Guadeloupe, are described. The life cycle of A. alessandroi was studied in Aedes togoi (development in 13 days in the flight muscles; first-stage larva cylindrical; third-stage larva 1 330-1 600 microns long; oesophago-intestinal junction distinct). The larval biology of Aproctella is very similar to that of Cardiofilaria, confirming the close relationship of these two genera. The biology differs from that of two other genera of Splendidofilariinae of birds, Splendidofilaria and Chandlerella (vectors: Culicoides and Simuliids; development in flight muscles and haemocoel; first stage larva almond-shaped; third stage larva 400-600 microns de long; oesophago-intestinal junction indistinct). In these latter genera, the larval biology is remarkably similar to that of Lemdaninae of reptiles and birds (Saurositus, Eufilaria). It seems there is not a distinct separation between the Splendidofilariinae and the Lemdaninae.