In laboratory tests, exposure of Toxorhynchites rutilus rutilus to resmethrin at the established LD-90 dose for Aedes aegypti did not reduce the daily adult survival or egg hatch. Average fecundity was reduced from 5.6 to 2.3 eggs/female/day during the first three or four days of oviposition. The potential reduction in fecundity of released predators that subsequently become exposed to routine applications of insecticides in an integrated control program would be minimized by adulticiding prior to predator release.