Survival of adult Aedes aegypti (L.) was studied in Thailand (1995) and Pue
rto Rico (1996) during periods of high and low dengue virus transmission. R
esting males and females were collected inside houses by aspiration. Female
s were separated into different cages by their degree of engorgement and ov
arian development. Teneral adults were obtained from pupae collected from n
atural breeding sites. All mosquitoes were given access to water, held at a
mbient temperature in the shade, and their survival monitored daily. We cal
culated median survival for each stage to estimate when mosquitoes had to f
eed again or die. No differences in survival between seasons were observed
in Thailand. In Puerto Rico, except for wild males, survival was longer in
the cool/dry season than in the hot/rainy season, indicating that mosquitoe
s may need to feed more frequently during the high than low dengue transmis
sion season. During both study periods and at both sites, blood-engorged fe
males survived as long or longer than mosquitoes in other gonotrophic or de
velopmental stages. Except in Puerto Rico during the cool season, when fema
les had a relatively high probability of surviving 3-4 d without feeding, f
emales needed to feed approximately every other day to avoid death caused b
y starvation. Our results indicate that in some regions, there are seasonal
differences in the length of time female Ae. aegypti can survive without f
eeding, females with a blood meal can survive for a longer time than those
without blood, and teneral males can live longer without food than teneral
females.