The history of source reduction for the control of salt-marsh mosquitoes on the Atlantic seaboard is reviewed in the light of its effectiveness, cost and impact on the tideland environment. Those parts of the salt marsh needing ditching or impounding are characterized on the basis of vegetation and of elevation with respect to tides. Source reduction limited to these parts is very effective, and amortization of costs over only a few years makes it more economical than repetitive chemical treatments. New technologies in source reduction will in time convince environmentalists of the merit of these methods of marsh management. Three published papers are singled out for special criticism because of their damaging effects on the achievement of good salt-marsh mosquito control.