The species of biological control agents which affect soybean pests in the Tidewater area were investigated, and their relative values were determined. Two pentatomids, <u>Podisus Macu1iventris</u> Say and <u>Stiretrus anchorago</u> F., were the only significant bio-contro1 agents which attacked the Mexican bean beetle, <u>Epi1achna varivestis</u> Mulsant. Thesepredators were not able to hold the pest population in check. A parasitic fly, <u>Trichopoda pennipes</u> F. was the only important biological control agent which attacked the green stinkbug, <u>Acrosternum hilare</u> (Say). Host and habitdt preferences of the fly suggested the presence of two strains in Virginia. Distribution of the fly was very uneven. Fungal disease was found to be an important control agent of many (larval) Lepidoptera. It was the most important control agent of <u>Plachypena scabra</u> (F.). P. <u>scabra</u> was also controlled by predation and parasitism. Nine parasites attacked the larvae and pupae. No effective biological controls were found for the corn earworm, <u>Heliothis zea</u> (Boddie). The only significant control agent, fungal disease, acted too slowly to prevent economic damage by this insect. / Master of Science