Xanthene dye treatment caused mortality in every developmental stage of the house fly,Musca domestica. Treated adults exhibited decreased fecundity and reduced egg viability. Treated eggs allowed to develop in untreated media and untreated eggs allowed to develop in treated media resulted in greater than 90% mortality prior to adult emergence. Early fourth instar larvae placed in dye treated media at 2.0 g/kg exhibited reductions of up to 81% in adult emergence.