Optimization of dsRNA Length and Target Position for Enhanced RNA Interference Efficiency Targeting the Chitinase Gene MsChi2 in Mythimna separata

Abstract

Simple Summary Mythimna separata is a destructive pest of major cereal crops, including maize, wheat and rice, causing severe yield losses worldwide. Current management relies heavily on chemical insecticides, which pose risks to the environment and lead to resistance. RNA interference is a biological approach that uses double-stranded RNA molecules to switch off essential genes in insects. In this study, we investigated how the length of these RNA molecules and target site selection within the gene affect their ability to control this pest. Our results revealed that a 200 bp RNA fragment was most effective, resulting in high mortality and significantly reducing larval growth. We also found that targeting specific regions of the gene produced greater gene-silencing efficacy than targeting other regions. These findings provide practical guidance for designing more effective RNA-based insecticides, supporting the development of environmentally friendly pest management strategies for sustainable agriculture.