Estimates of Survival, Population Size, and Emergence of Culex tarsalis at an Isolated Site1,2

Abstract

Mark-release-recapture studies were made of an isolated population of Culex tarsalis Coquillett in Kern Co., Calif. The population is a target for future genetic control trials. Adult mosquitoes were marked with fluorescent dusts and released one morning each month from Apr. through Sept., 1976. Recovery collections were usually made 10 consecutive nights and mornings after a release and recaptured 52 marked males and 867 marked females. CO²/light traps provided 90% of 132,719 C. tarsalis collected. About 88% of those in the traps were females. Daily survival rates ranged from 64–77%, based on regressions of the numbers of marked females trapped on successive nights after release. The mean population estimates ranged from 154,892 in June to 52,836 in Sept. Daily estimates of emergence of females ranged from 51,992 in June to 12,115 in Sept. Monthly estimates of population size were plotted with relative base-line measurements of the female population so that the latter could be used by extrapolation to indicate population size.