INFLUENCE OF SUCCESSIONAL AND GRASSY CORRIDORS ON PARASITISM OF PLATHYPENA-SCABRA (F) (LEPIDOPTERA, NOCTUIDAE) LARVAE IN SOYBEAN AGROECOSYSTEMS

Influences of uncultivated corridors on rates of parasitism of the gre en 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 w ere left undivided. Treatments were arranged in a completely random de sign. No significant differences in larval parasitism were observed be tween treatments, and location (larvae collected near corridors, less- than-or-equal-to 5 m, compared with larvae collected farther from corr idors, 6-11 m) did not have a significant effect on parasitism of P. s cabra larvae. Parasitism of P.'scabra larvae by the total parasitoid c omplex, by Aleiodes nolophanae (Ashmead), and by Campylochaeta plathyp enae (Sabrosky) generally increased in all treatments as the season pr ogressed, but parasitism by C. plathypenae declined later in the seaso n. Larval parasitism by Cotesia marginiventris (Cresson) declined over time. Larval parasitism may have been related to spatial scale.