Beneficial insects play a vital role in the cotton ecosystem and are a realistic management tool in Integrated Pest Management (IPM). Protecting and enhancing natural predators and parasitoids can greatly reduce pest levels. Secondary pest outbreaks can also be reduced when selective insecticides are used in conjunction with natural enemies in cotton. Additionally, time between spraying can be extended therefore reducing insecticide resistance. Numerous laboratory and field studies have shown that adult Trichogramma wasps are highly susceptible to most broad-spectrum insecticides, in particular synthetic pyrethroids. Trials assessing the influence of insecticides on immature stages of Trichogramma spp developing within the host egg have shown that the egg protects the parasitoid from toxic compounds. However Suh et al. (2000) noted that the first wasp to emerge from an egg has an increased chance of being killed by the insecticide residue on the egg surface as it chews through the chorion. Therefore wasps that emerge from the egg once the exit hole has been made, may avoid insecticide ingestion, thereby increasing their survival rate. The aim of this study is to evaluate the toxicity of insecticides on adult and developing Trichogramma pretiosum.