Pest Management in Sub-Saharan Africa: Mitigating the Challenges of Insecticides Use

Abstract

Intensification of agricultural production practices has led to monocultures of crop varieties over large areas of land. This has elevated many insects to economic pests’ status. In these systems, farmers typically rely on insecticides to mitigate the damaging effects of insect pests. Although all insecticides have negative human and environmental health consequences when applied, the severity of the impact differs depending on the toxicity of their technical compound and on its formulation. Thus, the World Health Organization (WHO) recognizes five insecticide classes: (Ia) extremely hazardous, (Ib) highly hazardous, (II) moderately hazardous, (III) slightly hazardous and (U) unlikely to present an acute hazard. In African agriculture, farmers’ choice of insecticides to mitigate pest damage is based on efficacy and cost. This often leads to the purchase of cheap insecticides, the majority of which are classified as extremely or highly hazardous. This chapter therefore discusses the different systems of pesticide classification, why pesticides are needed in agriculture and assesses the justification for insecticide use in selected major crops. It further examines the effects of insecticides on natural enemies of pest species and on human health. Finally, the chapter discusses sustainable methods to mitigate the negative effects of insecticide use in smallholder crop production systems.