Silencing of Double-Stranded Ribonuclease Improves Oral RNAi Efficacy in Southern Green Stinkbug .

Variability in RNA-interference (RNAi) efficacy among different insect orders poses a big hurdle in the development of RNAi-based pest control strategies. The activity of double-stranded ribonucleases (dsRNases) in the digestive canal of insects can be one of the critical factors affecting oral RNAi efficacy. Here, the involvement of these dsRNases in the southern green stinkbug was investigated. First, the full sequence of the only dsRNase () in the transcriptome of . was obtained, followed by an oral feeding bioassay to evaluate the effect of -silencing on oral RNAi efficacy. The was first silenced in nymphs by -dsRNA injections, followed by exposure to an artificial diet containing a lethal -specific dsRNA. A significantly higher mortality was observed in the silenced nymphs when placed on the ds-containing diet (65%) than in the ds injected and ds fed control (46.67%). Additionally, an ex vivo dsRNA degradation assay showed a higher stability of dsRNA in the saliva and midgut juice of silenced adults. These results provide evidence for the involvement of in the reduction of oral RNAi efficacy in . . This information will be useful in further improving potential RNAi-based strategies to control this pest.