Zectran®(4-dimethylamino-3,5-xylyl methylcarbamate), was tested in aerosol form against the 5 larval stages ofPhryganidia californicaPackard, the adult of a primary parasite of the oakworm,Itoplectis behrensii(Cresson), and the adult of a hyperparasite,Dibrachys cavus(Walker). The descending order of tolerance at LD50was: 5th-, 4th-, 3rd-, 2nd-, and 1st-stage oakworm,I. behrensii,andD. cavus.