Whitefly Gene Knockdowns and Mortality By Orally-Delivered Dsrnas Silence Gut- and ‘Whole Body'-Encoded Genes

Management of the whitefly Bemisia tabaci (Genn.) pest and plant virus vector relies primarily on traditional insecticides. RNA-interference (RNAi) is a homology-dependent innate immune response that occurs naturally in eukaryotes, including insects and results in gene silencing when a transcript is targeted for degradation by a double-stranded RNA (dsRNA) with which it shares identical sequence homology. Selected whitefly gene targets identified bioinformatically from in silico-annotated ‘B biotype’ whitefly transcriptome libraries constructed from whole adult whiteflies or from the ‘gut’ of the whitefly B. tabaci B biotype. Orally delivered dsRNAs that shared 100% sequence homology with the respective genes were tested for knock-down using B. tabaci adults. Gene knock-down was quantified by qPCR and whitefly mortality was tabulated. Results indicate non-transgenic dsRNAs offer a useful approach for characterizing whitefly gene function, and for identifying prospective biopesticide targets for whitefly management.