Susceptibility of six cultivars belonging to three Solanaceous plant species; Pepper (California wonder and Hyb Morad), Eggplant (Hyb Snow f1 and Black Shanta f1) and Potato (Santana and Hermis) was evaluated to infestation with common aphids, whiteflies, leafhoppers and thrips species and their associated predators throughout two early summer seasons, 2012 and 2013. Results showed significant differences between different plant species/cultivars and population density of these insects and also with their associated predators. Photosynthetic pigments (Chlorophyll a, Chlorophyll b and Carotenoids) analysis showed negative relationship with sap sucking insects infestation. Also different leaf biochemical components such as total phenol, total soluble sugars and total free amino acids revealed negative relationship with sap sucking insects infestation, while total flavonoids analysis showed insignificant differences. These results could be concluded the importance of cultivar selection in any integrated pest management program as well as the effective role of different plant biochemical components on plant resistance against insect pests