The spontaneous presence of natural enemies in crops represents one of the best allied to the Integrated Pest Management programs. The habitat management includes preventive measures based on close knowledge of the functioning of agroecosystems, performing actions upon pests and their enemies. These actions carried out on the habitats both in crops and in the non-cultivated areas, are aimed to conserve and enhance the populations of natural enemies. These preventive methods preserve the biodiversity of pest natural enemies in agroecosystems, using suitable management practises in agreement with ecological agriculture, and maintaining a high number of species, both predators and parasitoids.