Rivellia quadrifasciata(Macquart), the soybean nodule fly (SNF), was reared in the laboratory on detached soybean nodules and in the greenhouse on intact, nodulated root systems of hydroponically grown soybean plants. In greenhouse experiments, significantly more SNF individuals were reared from egg to adult on potted plants of a nodulating soybean near isoline than on its nonnodulating counterpart. Southern pea (Vigna unguiculata) was identified as a new host for larvae by using adult emergence cages. In naturally infested field plots, significantly more adults emerged from southern peas than from soybeans, and none emerged from peanuts or snap beans. Well nodulated soybeans were superior hosts, as compared to poorly nodulated soybeans.