ABSTRACT
The biogeographic region rather than the single homogeneous field may often be the appropriate unit for pest-management research (Levins and Wilson, 1979). According to Rabb (1978), an agroecosystem should be conceived as an area large enough to include those uncultivated landscapes that influence crops through intercommunity interchanges of organisms, materials, and energy. Our single-commodity approach in organizing research on pests often allows us to ignore associations with other crops, host plants, and adjacent plant communities that are of critical importance in the life systems of pests.
