Abstract: RNA interference (RNAi) is a powerful molecular technique, and has been widely applied to researches on insects. The technique is largely employed to study functional genes and functional genomics, and so far has been applied in 19 species of several insect orders. There are several ways to obtain RNAi in insects, such as injection, soaking, feeding, developing transgenic organisms and virus mediation, of which feeding might be most applicable due to its simplicity in practice. Systemic RNAi has been observed only in some insects, and the RNAi signals were first considered to be transferred by sid-1 gene in insects, but the mechanism has not been fully elucidated. Transgenic plants producing dsRNA have showed a significant protection of plants from pest damaging, suggesting that the RNAi technique can be applied as a new strategy for improving pest management. The study on RNAi in insects is currently in the very beginning phase, and further work needs to be done to address the mechanism of RNAi in insects, especially the mechanism of systemic RNAi. The approaches to RNAi are expected to be improved in favor of application of RNAi technique to the function identification of insect genes and the practical management of insect pests, aiming at boosting the development of entomology.

Key words: Insect, RNAi, functional gene, gene silencing, pest control