In order to find the suitable concentration for the control of Spodoptera Frugiperda (J.E. Smíth) the most important com platge, the present in investigation work was realice, between may and august of 1 998, in the district of Juan Guerra, in San Martin region, it's located to 06° 35' south latitude and 76º 19' west longitude to 230 m.s.n.m. The installation of the experiment was realice in the zone of the Nacional Programe for the corn investigations in the E.E.”Et Porvenir" INIA. The experimental design - used, was make with blocks complitly to hazard form, with four repetitions and five treatments. In the in investigations, were study four concentrations (T1 = 25 g/ha. de VPN), T2 = 50 g/ha. de VPN. T3 = 75 g./ha. de VPN y T4.= 100 g/ha de VPN), and a witness (T5 = water), added twenty treatments in study was apply Baculovirus (Virons of poliedrose nuclear) in order to control t...