The immature stages of
Ochlerotatus albifasciatus
develop in temporary pools. The present study aims at evaluating the seasonal
dynamics of the aquatic stages of this mosquito, also analyzing the relationship
among their presence and breeding success to some relevant climatic and
environmental variables in the ephemeral rain pools of an urban park.
Nineteen cohorts of
O. albifasciatus
that developed synchronously after rain events were recorded in all seasons.
The proportions of mosquito-positive pools were significantly higher during
the fall-winter period than in the spring-summer months (p < 0.001).
The presence of this mosquito species was positively related to the amount
of rain (p < 0.001), whereas negatively correlated to air temperature
(p < 0.05) within a 5.2 to 29.7ºC range. The distribution of
the number of cohorts per pool throughout the year was grouped (variance/mean:
3.96), indicating that these habitats were not equally suitable as breeding
sites. The immature stages of
O. albifasciatus
were detected in pools belonging to all of the categories of surface area,
depth, duration, vegetation cover, and insolation. However, the proportion
of pools where immature mosquitoes were detected was positively and significantly
related to surface, depth, duration, and vegetation cover. On the other
hand, the proportion of mosquito-positive pools was higher at an intermediate
insolation degree. Our results suggest that although preimaginal stages
were present in all seasons, high temperatures may be unfavorable to larval
development, and substrate vegetation may regulate water temperature.
The positive relationship between the proportion of mosquito-positive
pools and pool size and duration might reflect a strategy of
O. albifasciatus
to accomplish immature development.
