Daily survival rate is a major determinant of the vectorial capacity of mosquitoes, but current methods are difficult or lack the accuracy needed for epidemiologic models. We used daily growth bands on the thoracic apodemes to estimate age and survival of Culex pipiens s.l. from Memphis, Tennessee. Coded specimens of known age were used to evaluate the procedure's accuracy. Field-collected specimens of unknown age were also examined. We were unable to consistently determine the age of the coded, cage-reared specimens. Growth bands in cage-reared specimens were less well-defined than those in field-collected material. In its present form, the method is impractical for ecological or epidemiologic studies.