Abstract
The physiological age-structure of populations of the malaria vectorAnopheles darlingiRoot, collected biting man, was determined from collections made from March to June 1979 at the end of the rainy season in the village of Aripuanã, Mato Grosso, Brazil. The number of mosquitoes biting increased during the transition between the wet and dry seasons, but adult survival remained low at all times. Only seven of 1596 females dissected had laid eggs four or more times, and thus the proportion of females that could be potentially infective with malaria sporozoites was 0.4%. The mosquitoes rested in the vicinity of the host for periods of up to 10 min before biting. The results are compared to those obtained during a study onA. darlingion the Manaus-Boa Vista Highway, 1000 km to the north. In this area, peak numbers were collected at the beginning of the rainy season and adult survival was longer than at Aripuanã.