Field experiments were undertaken to evaluate the influence of eggplant, tomato and pepper, as a host plants, on the efficacy of the growth regulator Applaud and the parasitoid Diaeretiella rapae (Mcintosh) against the green peach aphid Myzus persicae Sulz. Results indicated that both the growth regulator and the parasitoid were more effective when used on eggplant than on tomato or pepper plants. Aphid insects disappeared from the plants after four weeks of treatment when the parasitoid and the growth regulator were used together. However, the general means were 30.2 and 33.6 insect/plant for Applaud and applaud with the parasitoid treatments respectively .The general mean of the parasitoid treatment alone was 50.4 insect/ plant while it was 114.7 insects/ plant in the control treatment. Result also indicated that the parasitoid was more effective on pepper plants than on eggplant and tomato. Mean of insects was 46.5 insects/ plant while it was 37.8/ plant for applaud and the parasitoid treatment. Results have also indicated that parasitoid emerged from aphid treated with applaud were less effective against aphid than the normal individuals. Percent parasitism was 81.5 and 48.0% for normal and Applaud treated parasitoid. Therefore the application of the growth regulator should be considered with minimum dosage in order to help in conserving the parasitoid and may be other natural enemies which will contribute in achieving an effective and safe integrated control practice against this pest in the field.