Methods and compositions which increase the concentration of an inhibitory RNA specific for a target sequence in a cell are provided. In one embodiment, the methods and compositions employ a first polynucleotide comprising a silencing element for a target pest sequence operably linked to a promoter active in the plant cell; and, a second polynucleotide comprising a suppressor enhancer element comprising the target pest sequence or an active fragment or variant thereof operably linked to a promoter active in the plant cell. The combined expression of the silencing element with the target pest sequence, or an active variant or fragment thereof, leads to the amplification of the inhibitory RNA produced from the silencing element over the achievable with only the expression of the silencing element alone. Thus, the various methods and compositions of the invention provide improved methods for the delivery of inhibitory RNA to a target organism.