The discovery of RNA interference (RNAi) at the end of the previous century immediately attracted a lot of interest because of its obvious potential for applications in medicine and agriculture. From this viewpoint, the prospective for its utilization in insect/arthropod pest control was initially less clear, and it may seem as a curious development that RNAi-based insecticides against notorious insect pests now enter commercialization. However, this realization occurred in parallel with the increasing evidence of the role that RNA molecules play in the communication among cells in the organism and among organisms within the ecosystem. This review provides a flashback of how RNAi was discovered in insects and how the technology gradually developed from a tool for gene silencing to an insecticide with a new mode of action (class 35 named RNA interference target suppressors) in the classification by the Insecticide Resistance Action Committee ( https://irac-online.org ). At present, RNAi adds to the toolset for integrated pest management (IPM) and may have a future in stacked formulations to fight insecticide resistance (IRM).