Abstract/Summary

Integrated pest management (IPM) has gained recognition worldwide as a key tool for sustainable arable farming. Promoting natural pest control, strategic use of insecticides, and farmer participation are three important elements in IPM. However, knowledge gaps exist related to the economic value of natural pest control service, insecticides’ efficacies and side effects, and farmers’ incentives to adopt natural pest control in arable fields. This thesis addresses these gaps using UK and European arable crop systems. With a natural enemy exclusion experiment and economic surplus method, the annual economic value of predators and parasitoids for the summer grain aphid (Sitobion avenae) control in wheat (Triticum spp.) in South East England was estimated to be £0-2.3 Million, depending on the aphid infestation levels. Insecticidal sprays based on action thresholds would enhance the value of this ecosystem service. By conducting a UK online survey among experts on insecticide efficacies and side effects in oilseed rape (Brassica napus) protection, relatively older chemical groups were perceived to have lower efficacies for target arthropod pests than newer ones. Foliar sprays were perceived to have greater negative impacts than seed treatments on users’ health, natural enemies, pollinators, soil and water. Many foliar active ingredients pose potential risks for non-target arthropod species in UK oilseed rape fields. Through an interview of European arable farmers participating in an agri-environmental project, respondents’ willingness to encourage natural (animal) pest control was relatively low. In comparison, using insecticides to control pests was the typical practice. Ordinal logistic regression indicated that farmers’ decision to promote natural pest control was positively associated with the perceived importance of this ecosystem service on crop production, but negatively associated with the perceived number of important pests in the fields. The implications of these findings and avenues for future research to enhance IPM in arable crops are discussed.