Effects of sugar availability on the blood-feeding behavior of Anopheles gambiae (Diptera:Culicidae).

Blood-feeding behavior and survivorship of individual Anopheles gambiae Giles females were observed daily in cohorts with either access to sugar (n = 76) or without sugar (n = 80). Individual mosquitoes were allowed to feed daily on an anesthetized mouse. Mosquitoes provided with sugar lived on average almost 3 d longer than females without sugar (19.0 versus 16.2 d). After stratification by age, mosquitoes in the youngest (5-12 d) and middle (13-19 d) age strata showed no differences in blood-feeding patterns relative to sugar availability. However, mosquitoes from the oldest age group and no access to sugar had more total blood feeds than long-lived females ( > or = 20 d) with access to sugar (9.8 versus 6.5). Furthermore, mosquitoes > or = 20 d old and without sugar available had a higher blood-feeding frequency than females that had sugar available (0.36 versus 0.25 blood meals per female per day). The enhanced blood-feeding capability among older sugar-deprived An. gambiae emphasized the close association between sugar-feeding and blood-feeding behavior and the potential consequences for the transmission of malaria parasites and other pathogens.