The aim of this study was to investigate the efficiency of four pesticides thiamethoxam, emamectin benzoate, lambadacyalothrin and methomyl (Lannate) against brassica plant pests Bemiciatabaci, Pries rapae and their side effects on the associated natural enemies infesting brassica plants under field condition during the two growing seasons, 2021 and 2022 in Sharkia governorate in Egypt.
           The obtained results showed that the thiamethoxam compound recorded the highest reduction percentage against Bemiciatabaci after 1, 7 and 10 days of spray. Also,emamectin benzoate and lambadacyalothrin compounds recorded the highest reduction percentage against Pierisrapae pests after 1, 7 and 10 days from treatment. The side effect was a significantly effectual reduction inpopulation predators, where's methomyl gave efficacy against Chrysoperlacarnea, also emamectin benzoate gave efficacy on Cocconellaseptumpunctata, while other compounds showed a lowereffect in population predators.