Summary
As the first attempt on ecological studies on the natural breeding places of black flies in Brazil, this study carried out in the vicinities of the city of Manaus, state of Amazonas, aimed at oetecting the natural predators of the Simulium fulvinotum larvae by means of capillary tube precipitin test (not specific for S. fulvinotum) and agar-gel immunodiffusion test, aided by observations of S. fulvinotum larval remains in the intestines of suspected predators. Larvae of species of the genera Macronema (Hydropsychidae) and Lepidoptera (Nymphulinae, Pyralidae) were incriminated for the first time as predators of black flies. Naiads of Libellulidae (Odonata), Perlidae (Plecoptera) and larvae of Corydalidae (Neuroptera) were also incriminated as predators of the S. fulvinotum larvae in their natural breeding places.