SUMMARY
The frequency and distribution of darlingi species of epidemiological interest in the reservoir of the Tucuruí Hydrelectric dam (State of Para) were detected. Collections were made during the periods of July to September of 1980 and during two periods in 1981, February/March and October/November. The collecting sites were localized along the Transamazon Highway (BR-230) between Marabá and Villa Repartimento, the Highways, BR-422, PA-263, the Tocantins river; Caraipé river basin, the city of Tucurui and the construction site of the. Tucuruí dam. A total of 9,918 anophelines were identified for a total of 12 species of the subgenera Nyssorhynchus, Arribalzagia and Anopheles, of which the former was most abundant. Anopheles darlingi, the principal vector of human malaria, was detected in various parts of the study area, both as adults and as larva. It is questioned whether the species A. nuñez-tovari, A; triannulatus and A. oswaldoi are secondary vectores of malaria in this region, as A. darlingi was recorded in all the sites where autochtonous cases of malaria occurred. As these three species, as well as A. noroestensis and A. albitarsis, are amply distributed with high populations in the area, they should be included in any control program. The hypothesis that focuses of A. darlingi as well as A. nuñez-tovari, A. triannulatus, A. oswaldoi and A. albltarsis will probably become established at various points within the reservoir when completed. As it is shown that A. darlingi is found near the permanent and temporary residencial nuclei it is suggested that the forest around such setlements be gradually reduced to form a belt of less dense vegetation of sufficient dimensions such that the residential nuclei be isolated from the forest-dwelling populations of A. darlingi.