Aedes albifasciatus is a flood water mosquito occurring in the
southern countries of South America. It is a competent vector
of the Western Equine Encephalitis (WEE) and causes important
losses on milk and beef production in central Argentina. Field
work was carried out from December 1990 to March 1993, on a
monthly basis during the dry season and biweekly during the
rainy season. Larvae were collected using the 'dipping'
technique and females with CDC traps baited with CO2. Field
collected larvae were used to build laboratory cohorts, from
which basic population parameters were estimated. Eggs
survived up to six months on dry soil, although there was a
linear decrease of viability with time. At 23 C, larval
development time was around nine days, and all adults emerged
within one week. The estimation of larval development in the
laboratory seems to be very near the development on the field,
as larvae have been collected on average eight days after a
rainfall. Egg to adult survival was 83%, with the highest
mortality on fourth larval instar (6%). In the laboratory
studies, sex proportion among the adults was 1:1, females
lived longer than males (median 13 and five days,
respectively), and adult survival pattern showed a constant
number of individuals dying per unit time. Field collected
females layed an average of 84 eggs per batch, and completing
up to five gonotrophic cycles, suggesting an estimated
survival of up to 35-50 days.
