Resistance of Busseola fusca to Cry1Ab Bt maize plants in South Africa and challenges to insect resistance management in Africa.

Abstract

The evolution of resistance to Bacillus thuringiensis (Bt) maize by the African stem borer, Busseola fusca, in South Africa highlighted the importance of the development of appropriate integrated resistance management (IRM) strategies for stem borers in Africa. Landscape heterogeneity is characteristic of African agroecosystems. This heterogeneity, in addition to between field and within-field spatial mosaics resulting from variable gene expression in Bt maize, will provide challenges to managing resistance evolution of the lepidopteran stem borers that attack maize. Adding to this landscape heterogeneity is the cultivation of open-pollinated maize varieties (OPVs) and bimodal rainfall patterns that allow two maize cropping seasons each year in many subtropical and tropical areas. The role that these factors, as well as aspects such as low-dose expression events, refuge compliance, the genetic bases of resistance, pest behaviour, host plant range and farming practices, may play in the evolution of stem borers to Bt maize in Africa are addressed in this chapter.

Taxonomy of Non-sporulating Bacteria Tested in Biological Control Against Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae)

“…The development of resistance also was observed in Sesamia nonagroides (Lepidoptera: Noctuidae), Ostrinia nubilalis (Lepidoptera: Pyralidae) and in genetically modified maize fields in Spain (Kranthi et al, 2006). In South Africa, a specific case of resistance by Busseola fusca (Lepidoptera: Noctuidae) over GM Cry2Ab maize crops was well studied and the resistance was effect of the evolution and inheritance of a recessive autosomal gene by the pest, conferring the tolerance trait (Berg & Campagne, 2015;Campagne et al, 2017).…”