Impact of stressful conditions on the survival of Culex pipiens exposed to Rift Valley fever virus.

Several groups of Rift Valley fever (RVF) virus-exposed and unexposed Culex pipiens were allowed differential access to a carbohydrate food source and their survival monitored. When stressed by deprivation of a carbohydrate source, mean survival times of RVF virus-exposed mosquitoes were consistently higher than those of unexposed mosquitoes in each of the carbohydrate-deficient experiments. These differences were statistically significant when mosquitoes were provided 5% sucrose for 24 hours. Mosquitoes that were provided access to a carbohydrate source for 24 h after a bloodmeal and then were denied access survived significantly longer than did those mosquitoes denied access, regardless of their exposure to RVF virus. When not stressed, RVF virus-exposed individuals had slightly higher daily survival rates than did unexposed individuals.