Winter biology of Aedes albifasciatus (Diptera : Culicidae) from Cordoba, Argentina

Host-seeking females of Aedes albifasciatus (Macquart) were collected from April to September 1997, kept under seminatural conditions, and offered sug ar solution and blood. Daily survival of females ranged from 0.91 to 0.96, with blood fed females living longer than sugar fed females. Overall, 43% o f engorged females completed a gonotrophic cycle, and 15% of them refed and completed a second gonotrophic cycle. The life expectancy of females emerg ing at the end of summer was longer than those that emerged during winter. Immature developmental time and the developmental threshold were estimated by regression. Embryo development was recorded during autumn, winter, and s pring, with a duration of 5-9 d. The developmental threshold for eggs was e stimated to be 2.28 degreesC. Egg mortality varied from 0.51 to 0.74. The d evelopment time for larva and pupa was between 16 and 29 d and was signific antly correlated with temperature. The developmental threshold for larvae a nd pupae was estimated to be 4.75 degreesC. A greater proportion of females than males emerged when temperatures averaged less than or equal to 18 deg reesC. Larval and pupal mortality was high at temperatures below the develo pmental threshold. Aedes albifasciatus females remained gonotrophically act ive and immature development continued during winter in Cordoba (10 degrees C isotherm).