The present study was conducted to determine the species composition and seasonal abundance of the prevalent arthropod pests and natural enemies inhabiting canola plantations during 2017 and 2018, growing seasons in Assiut, Upper Egypt. Plant relative susceptibility to cabbage aphid Brevicoryne brassicae L.and effect of the naturally occurring parasitoid species to manage the population trend of this insect pest was evaluated. Data revealed the presence of 14 species belonging to 14 genera, 10 families and 5 orders. Predatory species (Campylomma impicta Wagner and Coccinella undecimpunctata L) were constituted the highest proportion of entomophagous species, while parasitoids were presented by one species only [Diaeretiella rapae (McIntosh)]. The predatory species showed less than 6% dominance and 40% abundance. However, the aphid parasitoid was presented by more than 90% dominance and 60% abundance. Thrips tabaci Lindeman was the highest prevalent phytophagous species, while cabbage aphid B. brassicae ranked the second by less dominance and abundance percentages. Cabbage aphid B. brassicae was found to be active on canola plantations all over both growing seasons. A gradual increase in B. brassicae populations was recorded until the appearance of its peak in March, 5. A gradual decrease in the pest populations was recorded until the end of the season. Bactol cultivar harbored the highest aphid mean numbers (132.47individuals/plant) throughout both seasons of study and classified as susceptible (S) cultivar. Serw 4 and Serw 6 cultivars harbored fewer numbers (98.05 and 85.08 individuals/plant) and classified as low resistant (LR) and moderately resistant (MR) cultivars, respectively. The mean percentage of B. brassicae parasitized by D. rapae during both growing seasons was estimated. Although, the pest populations decreased at mid-March, the parasitism percentages increased until the end of both seasons. The seasonal mean of parasitism percentage recorded 34.76%. Simultaneous decrease of the pest numbers with the increase of its parasitoid confirms the responsibility of D. rapae as a good biological control agent against B. brassicae populations