In laboratory trials against oak defoliater, Gazalina chrysolopha Koll.Three antimoultant chemicals-Atabron, Alsystin and Dimilinin 0.04% concentration gave, respectively, 95.90 and 85% larval mortality within 6 days while the insecticides Malathion and Sevin SP killed 100% and Orthene 80% larvae in the same dose within 24 hours. In lower doses of 0.01 and 0.02% antimoultants caused 60 to 75% and insecticides 70 to 80% larval mortality in the same periods. The pest was controlled by spraying Malathion 57% E.C. in 0.17% concentration on the resting caterpillars at the natural enemies of the pest.