Two field experiments were conducted to study the population dynamics of whitefly, Bemisia tabaci (Genn.) and the cotton mealybug, Phenacoccus solenopsis Tinsley .The efficacy of some insecticides against these insect pests infesting eggplant plants were evaluated at Sharkia Governorate during the two successive seasons of 2016 and 2017. The obtained results revealed that B. tabaci recorded four peaks of abundance and the highest peak was the fourth one during 2016 and 2017 seasons, respectively. Moreover, P. solenopsis recorded two peaks in the first season 2016 and the highest peak was the second one, while in the second season 2017, it had three peaks and the highest peak was the third one. The infestation of these insect pests was more abundant in the second season than in the first one, which may be due to the influence of the studied climatic factors. Moreover, results showed that Lambada-cyhalothrine+thiamehoxam and imidacloprid were the most efficient insecticides against B. tabaci followed by pyriproxyfen, abamectin+thiamethoxam, buprofezin and spiromesifen, which classified as moderately toxic against the tested insect during the two seasons, respectively. And also, results indicated that thiamethoxam and abamectin were the most toxic insecticides against P. solenopsis followed by imidacloprid, emamectin benzoate, pyrethrins and chlorpyrifos in both seasons, respectively. This study might leads to understand the ecology of these pests, which will help in designing the integrated pest management programs for their control. On the other hand, it shows the role of systemic insecticides, which are less harmful to natural enemies.