RNA interference (RNAi) describes the ability of double-stranded RNA (dsRNA) to inhibit homologous gene expression at the RNA level. The specificity is sequence-based and depends on the sequence of one strand of the dsRNA corresponding to part or all of a specific gene transcript. In general, RNAi is a post-transcriptional control mechanism involving degradation of a target mRNA by dicers, mediated through the production of small interfering RNAs or short interfering RNAs (siRNAs). No effective

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... Bt toxins are known against sap-sucking homopteran pests such as aphids, leafhoppers etc. With this view in mind, in the current study, RNAi has been applied to block different proteins biosynthesis by sucking insect pests. To achieve the objectives, clones were selected and transcribed to dsRNA. The transcribed dsRNAs were digested with RNase III to prepare siRNAs. Fifty micro liter volumes of test samples containing either control reagent or siRNA in varying quantities were mixed with the insect diet (1ml and 1g for sucking and chewing pests). Five different concentrations, 40, 20, 10, 5, 1 µg/ml of siRNA from a gene were applied to find out the concentration required to kill 50% of insects. The current investigation has explored the utility of RNAi as a tool for specific and strong silencing of various genes in adult sucking pest and larval chewing pest to examine their potential as candidates target genes for pest management. This report says observations of gene knockdown in sucking pests using siRNAs synthesized from different genes through RNAi technology for the first time. The same siRNA treatment resulted in specific gene silencing (not significant) and consequently brought very less mortality percentage. The present results suggest that feeding of siRNAs through an artificial diet can be exploited for the screening of siRNAs for insect pests control and functional genomic studies in both sucking and chewing insect pests.