Influences of uncultivated corridors on rates of parasitism of the green cloverworm,Plathypena scabra(F.), in soybean agroecosystems were examined. Soybeans were planted in large experimental plots (0.45 ha); three plots contained corridors of successional old-field vegetation, three plots contained corridors planted in grasses, and three plots were left undivided. Treatments were arranged in a completely random design. No significant differences in larval parasitism were observed between treatments, and location (larvae collected near corridors, ≤5 m, compared with larvae collected farther from corridors, 6–11 m) did not have a significant effect on parasitism ofP. scabra larvae. Parasitism ofP. scabralarvae by the total parasitoid complex, byAleiodes nolophanae(Ashmead), and byCampylochaeta plathypenae(Sabrosky) generally increased in all treatments as the season progressed, but parasitism byC. plathypenaedeclined later in the season. Larval parasitism byCotesia marginiventris(Cresson) declined over time. Larval parasitism may have been related to spatial scale.