The objective of this study is to evaluate the importance of plant diversity in insect management in agroecosystems.The conventional management of agroecosystems is based on monoculture, with exploitation of plant genotypes susceptible to pests and diseases, with intense use of agrochemicals and soil mechanization. The impact on agroecosystem biodiversity by intensifying agronomic practices results in losses of important ecological functions: decomposition, nutrient cycling, predation and parasitism. The potential of plant diversity in the sustainability of agroecosystems is recommended through practices such as intercropping, agroforestry systems, management of cover crops, spontaneous herbs and the use of plants attractive to natural enemies and as pest traps. Farm planning should take into account some level of plant diversification to avoid pest insect outbreaks. Thus, it will be possible to reduce pesticides in conventional system, and reduce the number of interventions with alternative substances in farm in agroecological systems.