dsRNA generated from D. citri trehalase gene is effective in reducing fitness and/or survival of D. citri. Thus genetically altered plants expressing the dsRNA and plants to which dsRNA solutions are applied increase D. citri mortality and reduce D. citri infestation. With reduced D. citri population, the spread of microorganisms for which D. citri is a vector is reduced. Such microorganisms include, but are not limited to, C. Liberibacter species, including: CLas, CLam, and CLaf. Thus, applying of the D. citri trehalase dsRNA to a plant reduces disease and/or microorganism transmission by killing D. citri that feed on the treated plant.