The functional response of O. flavidus Brulle was studied as part of an evaluation of the effectiveness of this species in reducing fall armyworm, S. frugiperda (J. E. Smith), populations. The parasitization rate of O. flavidus increased in a nonlinear manner as host density increased. The handling time (T-h) and the search rate (a) estimated by fitting the random parasite equation to the data were T-h = 14.6 min, a = 1.87 ( apprx 2800 cm-2/day). O. flavidus parasitized 79% of hosts at the lowest densities and 67% of hosts at the highest densities tested. none