Data on an entomological survey of species of Anopheles in the district of Ariquemes are presented and the occurrence of malaria in this district and in the State of Rondonia is discussed. The results of the. entomological Survey in the urban area of Ariquemes showed the diversity of the species in the different Sections, and it was possible to verify the degree of penetration by anophelines into the town.
Autochthonous cases of malaria and the presence of the principal vector of human malaria in the Amazon, Anopheles darlingi, are correlated. The dynamics of malaria transmission in the urban area are examined and the risks of transmission in each Section are discussed. Vector control strategies, based on the manipulation of the habitat, are presented.
In the rural area, population parameters are being studied, related to (1) biting activity, natural resting sites, site of reproduction and movement to blood sources; and (2) behaviour of the populations with regard to biting activity and host preferences. The results, though preliminary, show variation in the population density and in the species diversity, that appear to be related to seasonal changes.
Variations in the host preferences of the species were also observed, and high antropophily of A. darlingi was detected. Two important parameters in the hematophagous activity of A. darlingi were recorded: it was observed that the anophelines are entering the house near ground level and are not resting on walls sprayed with DDT. In the surrounding vegetation there is a preferences as to the place of resting which may be either high or low.