They were evaluated in conditions of laboratory the side effects of Fipronil (30 mg i.a./1), Imidacloprid (150 ml i.a./I), Pymetrozine 300 mg i.a./1), Natural Pyrethrins (80 ml La./1) and Triflumuron (150 mg La./I) on the different stages of development from Hyposoter didymator. The insecticides provided through the diet to larvae of third stage of Spodoptera littoralis parasited by H. didymator. The evaluated parameters were mortality of the larvae of the guest, cocoon formation of the parasitoid, total emergency of adults and beneficial capacity of H. Didymator. Imidacloprid, Fipronil and Triflumuron caused a mortality upper to 80% in the larvae of third stage of S. littoralis, which prevented the cocoon formation on the part of the larvae of the parasitoid. In addition Triflumuron reduced the number of adults emerged being stated malformations from the larva of Hyposoter. Whereas the Natural Pyrethrins affected the longevity of the adults, reducing it near a 50% in relation to the Control. When evaluating the beneficial capacity of the adults of the parasitoid differences between the treatments were not observed. Spodoptera littoralis (Noctuidae) : Host Hyposoter didymator (Ichneumonidae) : Parasite Life cycle and development; Development; Metamorphosis; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Ecology; Population dynamics; Pollution; Chemical pollution; Abiotic factors; Chemical factors Hyposoter didymator; Emergence; Lepidopteran hosts; Insecticides effect on non target parasitoid; Spodoptera littoralis; Mortality; Fertilizer and pesticide pollution; Insecticides; Fertilizers and pesticides Spodoptera littoralis; Hymenopteran parasites; Insecticides effect on non target parasite; Hyposoter didymator none