The present invention relates to the prevention and/or control of infestation by insect pest species. In particular, the invention relates to down-regulation of expression of target genes in insect pests using interfering ribonucleic acid (RNA) molecules. Also described are transgenic plants that (i) express or are capable of expressing interfering RNAs of the invention and (ii) are resistant to infestation by insect pest species. Compositions containing the interfering RNAs of the invention are also provided.