The potential for combining two alternative pest management tactics, F-1 sterility and a parasitoid, was examined in the laboratory and in the greenhouse. Studies compared the acceptability and suitability of progeny from irradiated (100 Gy) and nonirradiated beet armyworm, Spodoptera exigua (Hubner), males as hosts for Cotesia marginiventris (Cresson). Results from these studies revealed that progeny of irradiated S. exigua males and nonirradiated S. exigua females are acceptable and suitable hosts for C. marginiventris development. Cotesia marginiventris females showed no oviposition preference for S. exigua progeny from females paired with either irradiated or nonirradiated males. Cotesia marginiventris and F-1 sterility appear to be compatible tactics that potentially could be integrated into a preventative pest management program for S. exigua.