Habitat diversity at the field and landscape level: Conservation biological control research in California viticulture

Abstract

The intensification of viticulture in California has led to the creation of grape monocultures characterized by an absence of non-crop plant diversity in and around vineyards. The continued expansion of vineyards into California native plant communities has also led to an aggregate reduction of non-crop habitats at the landscape scale (Heaton and Merenlender 2000). Such increased concentration of plant host resources and the reduction of non-crop habitats supporting natural enemies have been shown to increase pest densities, with associated crop losses and reduce overall crop productivity (Root 1973; Russell 1989; Corbett and Rosenheim 1996a; Altieri and Nicholls 2004). To manage recurring pest problems, California grape growers rely principally on the use of synthetic pesticides, including organophosphate and carbamate insecticides, known to pose a range of environmental quality and human health risks (Bentley 2009; CDPR 2009; UC IPM 2010b; Eskenazi et al. 2010).