Trends in insecticide resistance in Sub-Saharan Africa

Arthropod plant pests and vectors of tropical diseases pose a major threat to food security and human/animal health, respectively (Clarkson et al., 2018). Insecticides serve as the leading management approach for plant pests and disease vectors, hence necessitating the need for effective chemical insecticides for sustainable pest control (Nauen et al., 2019). Increased misuse and heavy reliance on insecticides have consequently resulted in prevalent resistance development not only in Sub-Saharan Africa (SSA) but globally (Sparks & Nauen, 2015). Aside from insecticide resistance development, excessive insecticide use poses hazardous effects on the environment, human and animal health, as well as impeding integrated pest management approaches that are in place (Siddiqui et al., 2023). The Insecticide Resistance Action Committee (IRAC) defines resistance as ‘a heritable change in sensitivity of a pest population reflected in the repeated failure of a product to achieve the expected level of control when used according to the label recommendation for the pest species’ (IRAC, 2024). The mode of action classification (MoA) scheme established by IRAC serves as a tool to categorize and group insecticides and acaricides for purposes of guided information to relevant stakeholders (Sparks & Nauen, 2015). Based on the MoA scheme, insecticides are classified into specific grouped chemistries assigned based on their target sites (Nauen et al., 2019). Major registered insecticide chemical classes used in arthropod pest control include: pyrethroids, carbamates, organophosphates, diamides, spinosyns, avermectins, neonicotinoids, benzoylureas, organochlorines among many others (IRAC International MoA Working group, 2024).