Five insecticides were tested againstLaspeyresia pomonella(L.), and their effects onTetranychus urticae(Koch) and its predators were determined. The broadspectrum insecticides permethrin (0.013%), azinphos-methyl (0.05%) and leptophos (0.045%) gave equal control ofL. pomonellaunder a 3-weekly programme of 7 sprays. Poorer control was given by the selective chemicals chlordimeform (0.05%) and diflubenzuron (0.05%). Both chlordimeform and permethrin suppressedT. urticaepopulations. No predators of mites were found on pennethrin treated trees and very few were found on trees sprayed with the organophosphates. Chlordimeform appeared relatively harmless to all stages ofStethorusspp. and diflubenzuron appeared harmless toStethorusadults, but was toxic to the eggs. Small numbers of predatory mites of 3 species were recovered from diflubenzuron treated trees towards the end of the season.