Ecological considerations of the introduction of Cotesia flavipes Cameron Hymenoptera: Braconidae for biological control of Chilo partellus Swinhoe Lepidoptera: Pyralidae in Africa.

Abstract

The exotic parasitoid, Cotesia flavipes, was released in 1993 in Kenya for biological control of the introduced stemborer, Chilo partellus. The release has been criticised in some quarters as being potentially ecologically disruptive. This review of the programme explains why this is unlikely to be the case. Pre-release studies indicated that 2 indigenous stemborers, Chilo orichalcociliellus and Sesamia calamistis, occur sympatrically with C. partellus in native and agricultural habitats in the area of introduction. Investigations on the host selection behaviour of Cotesia flavipes demonstrated that the 2 indigenous stemborers were suitable hosts for C. flavipes in the laboratory. A third indigenous species that occurs outside of the release area, Busseola fusca, was not a suitable host. It is anticipated that C. flavipes will only become established in areas where the dominant stemborer species are suitable for its development. The ecological implications of the introduction and establishment of C. flavipes in East Africa are discussed.