Insecticidal proteins and RNAi in the control of insects

RNA interference (RNAi) is a gene-silencing mechanism conserved across Eukaryota widely used as a research tool to study gene function and, since 2007, investigated for managing insect pests. Interest in this technology for controlling insect pests derives from its highly sequence-specific mechanism of action and low environmental persistence. RNAi can be used to engineer crops for insect resistance traits (referred to as Host Induced Gene Silencing; HIGS) or as a sprayable bioinsecticide (Spray Induced Gene Silencing; SIGS) for use in integrated pest management programs. Both HIGS and SIGS applications can contribute to global food security and sustainable agriculture by reducing the application of environmentally toxic pesticides. Oral RNAi is also being explored to control mosquitoes transmitting various medically important pathogens. This chapter provides an overview of the current understanding of RNAi in insects and its development into commercial products. Specifically, it includes the most current knowledge regarding the mode of action, uses of RNAi for pest management, ecological and human safety and regulation, and stakeholders' perception and engagement. The chapter concludes with questions and challenges that must be addressed to enable RNAi-based bioinsecticides to reach their full potential.