Challenges for economic impact assessment of classical biological control in Kenya and Tanzania.

Abstract

AbstractThis chapter presents a case of economic impact assessment of classical biological control and pesticide use in Kenya and Tanzania, targeting the diamondback moth, one of the most destructive pests of cabbage worldwide. The effect of the release of an exotic parasitoid by the International Centre of Insect Physiology and Ecology in 2001 to control the pest in East Africa is analysed, using econometric methods based on data from a large random survey of cabbage producers in Kenya and Tanzania with and without the biological control. It is shown that farmers producing cabbage in areas where the parasitoid is present use significantly fewer pesticides. Methodologically the damage control function method was applied, which shows that use of pesticides or the presence of the parasitoid increases cabbage output. The chapter indicates incompatibility between current pesticide use practices and the requirements of classical biological control.