Culex mosquitoes in temporary urban rain pools: seasonal dynamics and relation to environmental variables

The study was conducted in a park of Buenos Aires City, where a total of 89 rain pools were sampled weekly for mosquito immature stages over a one-year period. The aim of the present paper was to investigate the seasonal dynamics of three Culex species breeding in temporary rain pools and to analyze the relationships of the presence of these species to pool dimensions, pool age, vegetation, and insolation degree. The three species showed differences in their seasonal patterns, Culex dolosus being present during the whole year, Culex pipiens mainly in the summer season, and Culex maxi almost exclusively during the fall. The variable explaining most of the variation among sampling dates in species composition was weekly mean temperature. A significant positive association was detected among mosquito species, as they were recorded together more frequently than expected by chance. The statistical analyses performed revealed significant positive relationships of all three mosquito species to increasing surface area, whereas no relationship to insolation degree was detected in the studied pools. Culex pipiens and Culex dolosus showed positive relationships to increasing vegetation cover, whereas the presence of Culex dolosus was also related to pool age.