RNAi Biopesticides for Root-Feeding Insects

Root-feeding insect pests present a significant challenge to global agriculture, often remaining hidden beneath the soil and causing damage to crop roots before visible signs of damage emerge. Conventional pest control methods, primarily relying on chemical pesticides, have limitations such as non-target toxicity and the development of resistance, necessitating the exploration of alternative approaches. In this context, RNA interference (RNAi) emerges as a natural defense mechanism with potential for the management of various pests, including root-feeding insects. RNAi biopesticides can selectively target-specific genes of root-feeders, hindering their growth, development, and survival, while providing safe and environmental-friendly alternatives adaptable to various delivery methods. This chapter presents a comprehensive review of RNAi studies focused on root-feeding insects for the first time, highlighting the efficacy of RNAi and its impact on different insects. By comparing the effectiveness of representative genes silenced through RNAi and their effects on the growth, development, and survival of root-feeding insects, this chapter enhances the understanding of RNAi as a feasible pest control strategy. Importantly, we explore current and potential RNAi delivery methods, whether through plants, microbes, or the soil, emphasizing the need to address key research gaps, especially the unique challenges for efficient delivery of the RNAi agents to the roots to control the root-feeding insects. Furthermore, we discuss the advantages and disadvantages of different delivery approaches, the possible environmental impact in the long-term, providing insights for future research and the development of RNAi biopesticides for root-feeding pest insects for field application.