ABSTRACT
The expansion of monoculture in California has resulted in the simplification of the landscape. One effect of this simplification is a decrease in the abundance and activity of the natural enemies of agricultural pests due to the disappearance of habitats providing them with critical food resources and overwintering sites (Corbett and Rosenheim, 1996). Many scientists are concerned that, with accelerating rates of habitat removal, the contribution to pest suppression by biocontrol agents using these habitats will decline further (Fry, 1995; Sotherton, 1984). This will increase insecticide use with consequent negative effects on the sustainability of agroecosystems.
