none The susceptibility of adults and cocooned stages of A. plutellae Kurdj. (Hymenoptera, Braconidae) to 4 synthetic pyrethroid insecticides and 5 other chemical insecticides was tested. The chemicals, formulated as emulsifiable concentrates, were decamethrin (0.0014%), permethrin (0.01%), fenvalerate (0.01%), cypermethrin (0.005%), dichlorvos (0.05%), monocrotophos (0.05%), endosulfan (0.05%), phosalone (0.05%) and quinalphos (0.05%). Adults were exposed for 6 h to filter paper impregnated with insecticide solution and were then transferred to untreated vials for observation. Cocoons were sprayed with the chemicals by means of a glass atomizer and held for adult emergence. The pyrethroid formulations and phosalone had little or no harmful effect on the adults and cocooned stages of A. plutellae, but quinalphos were highly toxic to all stages tested. Dichlorvos, monocrotophos and endosulfan were highly toxic to adults but relatively safe for the cocooned stages.