The invention relates to a genetically transformed or transfected bacterial cell of a gut symbiont of an insect belonging to the Order Thysanoptera wherein said cell is transformed to express double-stranded RNA (dsRNA) active against at least one selected insect gene； a vector for transforming or transfecting said bacterial cell； an insect including said transformed bacterial cell and a method of pest control employing the use of said bacterial cell and/or said insect.
