Survival ofMicroplitis croceipes(Cresson) adults exposed to residues of insecticides applied at recommended rates to cotton was measured in 1989. In unsprayed check treatments, survival was 91.4% after 24 h. The organophosphates profenofos and acephate and the new-generation pyrethroid bifenthrin were highly toxic toM. croceipes. All other compounds tested showed some selectivity, including esfenvalerate, cypermethrin, thiodicarb, oxamyl, dicrotophos, dimethoate, and cyhalothrin in order of decreasing survival. The effectiveness ofM. croceipesas a biocontrol agent of the bollworm and tobacco budworm might be improved through selective use of insecticides to which the parasitoid is tolerant.